The Dénar®Mark II System

TECHNIQUE MANUAL

The Dénar®Mark II System

TECHNIQUE MANUAL

Published byWhip Mix Corporation - West

1730 East Prospect Rd., Suite 101Fort Collins, CO 80525

Toll-Free: 1-800-201-7286Fax: 1-970-472-1793www.whipmix.com

ACKNOWLEDGEMENTS

The Mark II System was developed to fill a need that existed primarily in dentalschools, but also among practicing dentists and laboratory technicians. The Schoolsof Dentistry expressed a desire for an effective teaching system that was competi-tively priced. Practicing dentists and technicians expressed a need for a simple Arconarticulator that was anatomically accurate which could be used for simple restorativeprocedures and to mount diagnostic casts when illustrating occluso-condylar rela-tions to patients for case presentations. There was also a need for an instrument sys-tem offering an intermediary step to the incorporation of the principles of occlusionas well as one offering upward potential to more advanced systems.

We set these needs as our objectives and proceeded to accomplish the task with thehelp of many professionals who provided us with both direction and assistance forwhich we are most grateful.

Doctors Rex Ingraham, Patrick M. Walker, Donald C. Curntte, Albert Solnit, HowardM. Landesman, Glen D. Richardson, all at the University of Southern California, gaveus extremely valuable inputs with respect to the needs of the undergraduate stu-dents. We are indebted to them particularly for their constructive criticism, eventhough painful at the time.

A special word of appreciation is expressed to Doctors Sumiya Hobo and Frank V.Celenza for their contributions in the early design phases of the instrumentation system.

In planning the preparation of the Mark II Technique Manual, it was our intent that itencompass more than just mechanical instruction in the use of the Denar® Mark IISystem. We wanted to offer more by also providing related instruction in the theoryof occlusion as it directly pertains to the use of the instrument. Special credit must goto Dr. Niles F. Guichet for his contributions and the time he spent working with us,particularly in view of the demands of his teaching schedule.

We wish to acknowledge the direction and wisdom that we received from Doctors L.D. Pankey, Loren Miller, Henry Tanner, James Zuccarella, Mel Steinberg, and Mr. JackSnyder, of the Pankey Institute, with respect to how the system can be used by prac-titioners wishing to render quality dentistry through the incorporation of the principlesof occlusion. A great deal of encouragement in this area was also received from Dr.Peter E. Dawson to whom we are equally grateful.

To insure the System’s compliance with the purest theories of gnathology we aremost indebted to Dr. Peter K. Thomas. He made what seems like “impossibledemands” to arrive at perfection. Fortunately, his toughness was matched with agreat deal of patience.

Through the development phases many different opinions were expressed, but therewas at all times one common goal: to provide dentistry with a quality occlusal instru-mentation system. We believe we accomplished this goal. This feat took the efforts,contributions, dedication and assistance of many more people not mentioned, and toall of them as well: we are very grateful.

CONTENTS

I. IntroductionWho Should Use The Mark II System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5Why Should The Mark II System Be Used . . . . . . . . . . . . . . . . . . . . . . . . . 6

II. The Denar® Mark II Articulator (Semi-adjustable)Articulator Manipulations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7Articulator Adjustments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8Hand Grasps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-11

III. Relating Condylar Movements to Occlusal Anatomy . . . . . . . . . 12-16

IV. The Immediate and Progressive Side ShiftAdjustments (Bennett Shift) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

V. The Denar® Mark II Facebow/Earbow (Model D31AB)Locating Three Reference Points on Patient’s Face . . . . . . . . . . . . . . . . . 19Making the Facebow/Earbow Registration . . . . . . . . . . . . . . . . . . . . . . . . 21Transferring the Facebow/Earbow to the Articulator. . . . . . . . . . . . . . . . . 24

VI. Mounting the Casts in the ArticulatorThe Maxillary Cast . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27The Mandibular Cast . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

VII. Setting the Articulator to Checkbite RecordsSimulating the Orbiting Condylar Paths . . . . . . . . . . . . . . . . . . . . . . . . . . 30Simulating the Protrusive Condylar Paths. . . . . . . . . . . . . . . . . . . . . . . . . 31

VIII. Incisal Table AdjustmentsCustom Incisal Table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32Adjustable Incisal Table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

IX. Treatment ProceduresFixed and Removable Partial Denture Restorations . . . . . . . . . . . . . . . . . 35Complete Dentures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

APPENDICES

A. Checkbite Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36B. Denar® System Protocol for Dentist-Laboratory Relations . . . . . . . 42C. Calibration Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45D. Occlusal Plane Analyzer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51E. Selecting Instruments for Occlusal Treatment. . . . . . . . . . . . . . . . . 55F. Accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58G. Care and Maintenance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60H. Parts List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61

IMPORTANT

Your Denar® Mark II Articulator and Facebow/Earbow are precision instruments man-ufactured to precise tolerances and designed to give you years of troublefree service.Like all precision instruments they must be handled carefully to avoid damage. Athorough study of the information contained in this instruction manual will insure youof the benefits which these instruments offer.

DO NOT ADJUST the factory adjustment screws illustrated in figure 2A. They are forfactory use only. Adjustment of these screws in the field can alter the instrument’soperation and may require factory repair.

Also the microadjustable adjustment lockscrews illustrated in figure 2B are used tocalibrate the centric relation position of your Mark II articulator to tolerances of plusor minus one thousandths of an inch from the factory reference position. Adjustmentof these screws can alter the precise factory alignment of your articulator. Do notmodify the setting of these adjustment screws until after you have read this instruc-tion manual and thoroughly understand the function of these adjustment screws asexplained in Appendix D. These microadjustment screws should only be used in con-junction with a Denar® Field Inspection Gage to calibrate your articulator.

fig. 2A fig. 2B

Factory Adjustments

Microadjustment Screws

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I. INTRODUCTION

WHO SHOULD USE THE DÉNAR® MARK II SYSTEM

DOCTORS WHO WANT:• To mount casts quickly and easily on a semi-adjustable instrument thatmechanically and accurately reproduces mandibular movements.

• To produce restorations by means of checkbite records and/or the func-tionally generated path (FGP) techniques.

• A useful tool for diagnosis and for the fabrication of restorations when notutilizing a pantograph and fully adjustable articulator.

• A semi-adjustable articulator with the immediate side shift adjustmentcapability.

• Casts mounted on a very rigid articulator in the position of maximum inter-cuspation.

• To incorporate the benefits of the Denar® Two Instrument System.

TECHNICIANS WHO WANT:• A practical, rigid and easy to use articulator.• To efficiently produce restorations that require fewer remakes than restora-tions constructed on articulators of lesser adjustment capability.

• To receive mounted casts.• To service dentists using the Denar® Two-Instrument System.

EDUCATORS WHO WANT:• An economically priced articulator and facebow for student issue withoutviolating sound anatomical principles.

• Occlusal instruments that fulfill the needs of all restorative departments.• To avoid the need for the student having a separate articlulator for eachrestoration under construction.

STUDENTS WHO WANT:• To study Occlusion and the movement of the temporomandibular joint.A means of progressing to a fully adjustable articulator and pantograph.

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WHY SHOULD THEMARK II SYSTEM BE USED

Simple and Practical to UseThe Denar® Mark II Articulator andFacebow System enables the user toquickly and easily mount casts of apatient’s teeth on an instrument that isboth an equivalent of their natural rela-tionship and which also can be mechan-ically programmed to simulate themandibular movements of the patient.To accomplish this mechanical equiva-lence, the Mark II articulator has adjust-ment capability to duplicate the moreclinically significant movements of themandible. Those condylar paths ofmovement of lesser clinical significancehave not been ignored, but instead, areconstructed to average anatomicdimensions.

Accurate Diagnostic andTreatment SystemThe Mark II System is a particularly use-ful tool for the diagnosis and for the fab-rication of restorations when not utilizinga pantograph and fully adjustable artic-ulator. The simplicity and accuracy withwhich the system may be used enablesthe user to produce precision occlusalrestorations that require significantlyless in the mouth modifications thanrestorations constructed on articulatorsof lesser adjustment capability.

Excellent Learning ToolThe Mark II System is built aroundsound principles of human anatomy andis consequently ideal for study of TMJcharacteristics and theories of occlu-sion. Understanding this system facili-tates progress to a fully adjustable artic-ulator as the movements and adjust-ments are the same.

Constructed with ClinicallyNeeded FeaturesThe Mark II System is easy to use. Thearticulator is rigid with a very positivecentric lock. It is of the Arcon construc-tion with the back designed for maxi-mum lingual visibility to the casts. Theupper and lower bows come apart andlock together in the open and closedpositions (no rubber bands needed).The articulator can be placed level in theupside down position for mounting thecasts without the need of a plasteringstand. The facebow sidearms are inde-pendently adjustable and can be locat-ed to either the hinge axis or the exter-nal auditory meatus (opening) of theears.

EconomicalThe Mark II Articulator which is compet-itively priced is also two instruments inone. Not only is it a semiadjustablearticulator with the features describedabove, but also because of the microm-eter adjustments in the condylar areas,the condyles can be adjusted threedimensionally with the Denar® FieldInspection Gage to tolerances of plus orminus .001 inches (.025 mm) whichallows transfer of the mounted casts toother Denar® articulators. This featurereduces the need for a separate articu-lator for every restoration under con-struction.

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In order to be proficient in the use of thearticulator to diagnose condylar paths ofmovement and to fabricate occlusalrestorations, the operator must haveknowledge of:

• The articulator condylar controlsand how to adjust them.

• The proper hand grasps for manip-ulating the articulator through itsexcursive movements.

In this section of this manual we will firstdiscuss the simple procedure of how toopen and close the articulator properlyand how to operate the centric latch.Secondly we will discuss the location ofthe articulator condylar controls andhow to adjust them. Lastly we will coverthe proper hand grasps for manipulatingthe articulator through its excursivemovements. How to adjust the articula-tor to checkbite records is discussed inanother section of this manual.

ARTICULATOR MANIPULATIONSTo assemble the articulator hold theupper bow approximately parallel to thelower bow and simply place it on thelower bow.

Centric Latch OperationWhen the articulator is closed it can belocked in the centric position by pushingthe centric latch to the down position.The centric latch is opened by placingthe index finger on the trigger locatedunderneath the center of the crossbar ofthe lower bow and by placing the thumbon top of the upper bow (fig. 3). Nextapply pressure with the index finger; itmust be released by the trigger. Whenthe centric latch is open the upper bowcan be removed from the lower bow bylifting it vertically while maintaining theupper bow parallel to the lower bow.

To Open the ArticulatorApply downward pressure to the top ofthe upper bow over the centric latch andfossa assemblies with the heel of thepalm of the left hand and simply openthe articulator. The opening movementof the articulator automatically engagesthe centric latch and locks it (fig. 4).

II. THE DÉNAR® MARK II ARTICULATOR

fig. 3

fig. 4

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To Lock in the Open PositionWhen the articulator is opened, theupper bow can be moved downwardtoward the lower bow so that thecondyles move forward in their fossae toengage the lock open position (fig. 5).

To Close the ArticulatorTo close the articulator move the upperbow up and forward to disengage thelock-open position and close the articu-lator (fig. 6).

ARTICULATOR ADJUSTMENTSThe articulator is a mechanical equiva-lent of the lower half of the head __ amechanical jaw so to speak. In order todiscuss the adjustments of the articula-tor or specifically the fossa controls, itwould be helpful to discuss the condylarpaths of movement of the humanmandible. In a lateral mandibular move-ment the condyle on the side towardwhich the mandible moves is termed therotating condyle (fig. 7). The condyle onthe side opposite the side towardswhich the mandible moves is termed theorbiting condyle.

In a lateral mandibular movement theorbiting condyle moves inward, down-ward and forward and orbits about the

rotating condyle which is simultaneous-ly rotating and moving outward duringthe mandibular side shift.

orbiting path - the path of move-ment of the orbiting condyle.rotating path - the path of move-ment of the rotating condyle.protrusive path - the path ofmovement of the condyle in astraight protrusive movement.

fig. 5

fig. 6

fig. 7

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Protrusive AdjustmentsThe inclination of the protrusive condy-lar path can be adjusted by looseningthe protrusive adjustment lockscrew.The protrusive condylar path inclinationscale is below the protrusive adjustmentlockscrew and is calibrated in incre-ments of 5 degrees (fig. 8).

Immediate Side Shift AdjustmentThe medial fossa wall can be displacedstraight medially by means of the imme-diate side shift adjustment. The scale forthe immediate side shift adjustment islateral to the adjustment lock screw ontop of the fossa (fig. 9). The scale is aVernier scale calibrated in .2 millimeterincrements. The scale reads medialwardfrom its lateral extremity.The index in fig.10 indicates an immediate side shift set-ting which is more than 0 but less than 1full millimeter. By reading the Vernierscale on the lower portion of the scalemedialward from the index it can bedetermined that the immediate side shiftis .6 of a millimeter since it is the thirdgraduation that lines up with a millimetergraduation on the upper portion of thescale.

Progressive Side Shift AdjustmentThe angle of inclination of the medialfossa wall to the sagittal plane beadjusted by loosening the progressiveside shift adjustment lockscrew andmoving the insert from 5 to 15 degrees.The scale for the progressive side shiftadjustment is anterior to the adjustmentlockscrew and is calibrated in 5 degreeincrements. (fig. 11).

fig. 8

fig. 9

fig. 10

Scale

Lockscrew

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Rear Wall InclinationThe posterior fossa wall of the Mark IIArticulator is nonadjustable but is con-structed to average anatomic dimen-sions. It is inclined posteriorly 25degrees to allow for a backward move-ment of the rotating condyle as it movesoutward (fig. 12).

HAND GRASPSTo use the articulator properly the oper-ator must master the proper handgrasps. A right handed operator curlsthe fingers of the left hand under themandibular crossbar and places his leftthumb on top of the upper bow (fig. 13).To effect both left and right lateral excur-sive movements the left thumb guidesthe back of the upper bow while theforefinger and thumb of the right handholds the incisal pin moving it in thedesired direction. These hand graspscan be best described as the underhandpush __ pull grasps and the underhandprotrusive grasps. In order to executelateral movements the centric latchmust be open.

Underhand Push GraspsTo effect a right lateral mandibularmovement be sure the latch is open andmove the upper bow to the left. (The leftside of the articulator is the left side ofthe instrument as it is viewed from therear.) Pressure is applied with the leftthumb to insure the left orbiting condylemaintains contact with its superior andmedial fossa walls and the right rotatingcondyle maintains contact with its supe-rior and rear fossa walls (fig. 13).

fig. 11

fig. 12

fig. 13

RearWall

11

Underhand Pull GraspsTo effect a left lateral mandibular move-ment the upper bow is moved to theright and pressure is applied with theleft thumb to insure that the right orbit-ing condyle maintains contact with itssuperior and medial fossa walls and theleft rotating condyle maintains contactwith its superior and rear fossa walls(fig. 14).

Underhand Protrusive Grasps(Protrusive Push Grasp)To effect a straight protrusive movementthe upper bow is moved straight poste-riorly with the right hand and the leftthumb is used to apply downward pres-sure on the back of the upper bow sothat the condyles maintain contact withtheir superior fossa walls.

The overhand grasps as contrastedfrom the underhand grasps are alsouseful in manipulating the articulatorand are required to efficiently set a fullyadjustable articulator to a pantographicrecord. Figure 15 illustrates theOverhand Push Grasp; fig. 16 theOverhand Pull Grasp, and fig. 17 theOverhand Protrusive Grasp. Whenemploying the overhand grasps tomanipulate the articulator be sure toapply pressure to the back of the articu-lator to insure that the condyles main-tain contact with their respective fossabearing surfaces.

fig. 14

fig. 15

fig. 16

fig. 17

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The Dénar® Mark II Articulator is of theArcon construction; i.e., the condylesare attached to mandibular bow and thefossa assemblies are fixed to the maxil-lary bow. This construction which is afacsimile of the anatomical structures,enables the articulator to more accu-rately simulate condylar paths of move-ment. In addition this constructionmakes it easy to understand the relationof condylar paths of movement toocclusal anatomy.

An understanding of the relationshipswhich exist between condylar paths ofmovement and occlusal anatomy is aninvaluable aid in the use of an articulatorfor diagnosis and treatment. The follow-ing exercises which utilize the articulatoras a teaching method are helpful toenable you to quickly understand theserelationships.

Set the left immediate side shift adjust-ment to 1 millimeter and left progressiveside shift adjustment to 15 degrees. Byobserving the articulator movementsfrom the back of the articulator it is easyto understand why the immediate andprogressive side shifts are so named(fig. 18). Hold the articulator in centricrelation. Since the left medial fossa wallis set to permit a one millimeter immedi-ate side shift, centric relation is achievedwhen the right condyle touches itsmedial fossa wall.

Move the articulator in a right lateralmandibular movement until the leftorbiting condyle contacts its medialfossa wall and note that the rotatingcondyle and mandible move immediate-ly to the right. As you continue the rightlateral mandibular movement the orbit-ing condyle move downward, forwardand inward. Note that during this move-ment of the orbiting condyle the rotating

condyle and mandible move progres-sively more to the right as the orbitingcondyle advances. Repeat this articula-tor movement and note that the rotatingcondyle moves immediately to the rightand then progressively more to the rightas the orbiting condyle advances.

mandibular side shift (Bennett Shift):the bodily side shift of the mandiblewhich occurs during a lateral jawmovement.immediate side shift: a mandibularside shift in which the orbiting condylemoves essentially straight medially asit leaves centric relation.progressive side shift: a mandibularside shift which occurs at a rate oramount which is directly proportionalto the forward movement of the orbit-ing condyle.

By observing a right lateral mandibularmovement from the front of the articula-tor you can see that the path of move-ment of the orbiting condyle (orbitingpath) as it moves inward, downward andforward is guided by the superior, rearand medial fossa walls (fig 19). Thiscondylar path of movement is associat-ed with and has its principal effect onthe balancing inclines of cusps on theorbiting side (fig. 20B).

III. RELATING CONDYLAR MOVEMENTSTO OCCLUSAL ANATOMY

fig. 18

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of the marginal ridge, fossa, or centralgroove of the tooth (fig.21).

An increase of the progressive side shiftmovement of the articulator has an effectof flattening the balancing inclines ofcusps on the orbiting side mediolaterally(fig. 22).

The closer a cuspal incline is to a condylarpath of movement the greater is the influ-ence that condylar control has on occlusalanatomy. Consequently due to the factthat the orbiting condyle is moving down-ward so rapidly as it moves forward, weobserve that as we move more distally inthe dental arches the lingual cusps ofmaxillary molars project increasinglydownward and the buccal cusps ofmandibular molars project increasinglyupward to harmonize the occlusion tocondylar paths of movements (fig 23).

Again by observing a right lateral condylarmovement from the front of the articulatoryou can see that the path of movement ofthe rotating condyle (rotating path) as itmoves outward is guided by the rear andtop fossa walls (fig.24). This path of move-ment is most closely associated with andhas its principle effect on the workinginclines of cusps on the working side (fig.20A).

The rotating condylar path may be inclinedupward or downward as the rotatingcondyle moves outward. This upward anddownward inclination of the rotatingcondylar path in the coronal plane has itsprinciple influence on the height of theworking inclines of posterior cusps on therotating side (fig. 25). If the rotating condy-lar path is inclined upward the cusps mustbe flatter (fig. 25A). If the rotating condylarpath is inclined downward the cusps maybe steeper (fig. 25C). The Mark II Articu-lator cannot be adjusted to upward ordownward movements of the rotatingcondyle.

fig. 19

fig. 20

fig. 21 fig.22

Three articulator adjustments establish thecharacter of the orbiting path on the artic-ulator: the immediate side shift adjustment,the progressive side shift adjustment andthe protrusive inclination of the superiorfossa wall.

An increase of the immediate side shiftmovement of the articulator has an effectof increasing the bucco-lingual dimension

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The rotating condylar pathmay be inclinedforward or backward as the rotatingcondyle moves outward. This forward andbackward inclination of the rotatingcondylar path in the horizontal plane hasits principle effect on the intermeshing ofthe working inclines of cusps on the work-ing side (ridge and groove direction).

The Dénar® Mark II Semi-adjustableArticulator has the rotating condylar pathreset to the average anatomic inclination(out and backward 25 degrees).

Figure 26A illustrates a frontal view ofmolar tooth relations in a right lateralmandibular movement. Although the rotat-ing condyle moves straight outward thefunctioning tooth inclines on the rotatingside have a slight downward inclinationdue to the fact that the path of movementof the orbiting condyle is inclined remark-able downward.

fig. 24

fig. 25

fig. 23

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The closer the functioning tooth incline isto the condylar path of movement themore the tooth incline simulates thatcondylar path of movement.The interrelat-ing tooth inclines on the orbiting side infigure 26A have steep inclines to comple-ment the path of movement of the orbitingcondyle.

Figure 26B illustrates a left lateral move-ment. Due to the fact that the left rotatingcondyle is moving straight outward the leftmaxillary buccal cusps must be kept shortto allow the left mandibular buccal cuspsto escape. It is this influence of the rotat-ing and orbiting condylar paths onocclusal anatomy that establishes the

Curve of Wilson. The more posteriorly weprogress in the dental arches themandibular teeth take on a greater lingualinclination and the maxillary teeth take ona greater buccal inclination to harmonizeocclusal anatomy to condylar paths ofmovement (fig. 27). The condyle tracks apath in its fossa just as a buccal cusp of alower molar tracks a path in its fossa onthe occlusal surface of an upper molar. Forall practical purposes in the use of articu-lators to establish dental articulation, thetemporo-mandibular joint can just bethought of as another tooth, the fourthmolar__ another anatomic control of jawmovement (figs. 26C and 27).

fig. 26 fig. 27

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To facilitate a clear understanding of therelation of the orbiting condylar path toocclusal anatomy study fig. 28.Illustrated are the cuspal inclines of theleft bicuspids and molars which areassociated with the orbiting condylarpath. It is the distal aspects of the max-illary lingual cusps’ buccal inclines(shaded) which interrelate with themandibular buccal cusps’ lingualinclines, mesial aspects. In your mind’seye it is helpful to dissect out these cus-pal inclines (fig. 28A) and visualize whatinfluence a change in the character ofthe orbiting path on the articulatorwould have on these aspects of the

cusps. Three articulator controls estab-lish the character of the orbiting path onthe articulator __ the immediate sideshift adjustment and the inclination ofthe medial and superior fossa walls. In-creasing the immediate side shift adjust-ment on the articulator increases theclearance between these cuspal inclines(fig. 28B). Increasing the progressiveside shift movement of the articulator(increasing the inclination of the medialfossa wall) flattens the cuspal inclinesmediolaterally (fig. 28C). A decrease ofthe inclination of the superior fossa wallflattens the cuspal inclines anterio-pos-teriorly (fig. 28D).

fig. 28

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It should be noted that unlike mostsemi-adjustable articulators the Denar®

Mark II Semi-adjustable Articulator hasthe capability of more accurately simu-lating the mandibular side shift (BennettShift) by more accurately simulating thecomponent condylar movements: theimmediate side shift and the progressiveshift. The immediate side shift isexpressed in units of tenths of a millime-ter (fig. 29A). The progressive side shiftis expressed in degrees (fig. 29B).

The immediate side shift of the mandiblehas primary influence on the width ofthe central groove of posterior teeth.Theprogressive side shift has its principalinfluence on the balancing inclines ofposterior cusps on the orbiting side andon the direction of the ridges andgrooves of posterior teeth, primarily onthe orbiting side.

Figure 30 illustrates the protrusive, orbit-ing and rotating path records of the rightand left temporomandibular joints of 50patients (100 TMJ records). 1 The X andY axes are calibrated in increments of 1millimeter. You will note that the orbitingpath is divided essentially into two com-ponents: immediate side shift and pro-gressive side shift. Furthermore with fewexceptions once the immediate sideshift has occurred the progressive sideshift records are approximately parallelto each other and are inclined approxi-mately five to seven degrees to thesagittal plane. The biggest variable isthe immediate side shift component ofthe orbiting path.

Points A, B and C on one orbiting pathrepresent three different condylar posi-tions at which lateral checkbite position-al records may be taken on one patient.It should be noted that if an articulatorpossessing a progressive side shift andnot an immediate side shift adjustmentwere set to each of the three condylarpositions A, B and C as shown in fig. 30.It would produce three different progres-sive side shift inclinations correspon-ding to the three dotted lines in figure 30__ all of which inclinations would bewrong. On the other hand, if an articula-tor possessing a progressive as well asan immediate side shift adjustment

IV. THE IMMEDIATE AND PROGRESSIVE SIDESHIFT ADJUSTMENT (Bennett Shift)

fig. 29

1. Lundeen, Harry C. and Wirth, Carl G.: Condylar Movement Patterns Engraved in Plastic Blocks,J. Prothet. Dent. December 1973.

Pages 870-875.

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(Dénar® Mark II) were adjusted so thatthe progressive side shift was pre-set tothe average anatomic dimension of sixdegrees, one immediate side shiftadjustment setting would intersect withall three condylar position checkbiterecords (A, B, and C) which remarkablyreduce the amount of irritation that oth-erwise might be introduced in the occlu-sion. Therefore when adjusting the MarkII Articulator to lateral checkbite records,always set the progressive side shiftadjustment to the 6˚ average anatomicdimension for this diagnostic procedure.

fig. 30

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The Dénar® Mark II Facebow/Earbow isused to register the correct position forthe patient’s maxillary cast to be mount-ed in the articulator. In other words, thefacebow/earbow records the relation ofthe patient’s maxillary dental structuresto the horizontal reference plane andtransfers this relationship to the articula-tor.

The use of the Denar® Facebow/ Earbowinvolves three overall procedures:

A. Locating three reference pointson the patient’s face

B. Assembling the face-bow/earbow on the patient

C. Transferring the face-bow/earbow to the articulator

The detailed steps of each of thesethree procedures is as follows.

LOCATING THREE REFERENCEPOINTS ON THE PATIENT’S FACEThe components of the facebow kitneeded are: the reference plane locatorand reference plane marker. These twoitems are used to locate three anatomi-cal reference points on the patient’sface. Of these three points, two are pos-terior and one is anterior.

There are two means of locating theposterior points. The first is by preciselocation of the terminal hinge axis with a

hinge axis locator.1 The second means isby locating the points by averageanatomical measurement, which is sim-pler and faster, and is the proceduredescribed in this section of this manual.

V. THE DÉNAR® MARK IIFACEBOW/EARBOW (Model D31AB)

1. Other reference material must be consulted for detailed instructions on how to precisely locatethe terminal hinge axis position (i.e., the “Denar® Procedures Manual __Procedures for OcclusalTreatment” or the “Denar® Office Tutor” ).´

´

fig. 31

fig. 32

´

REFERENCE ROD INDEX

MILLIMETER SCALE 43mm

NOTCH

POSTERIOR REFERENCE POINT HOLE

20

Average measurement may be used tolocate the posterior reference pointswhenever you do not vary the verticaldimension of the casts on the articula-tor, or, in other words, when themandibular cast is to be transferred tothe articulator by means of an interoc-clusal record taken at the correct verti-cal dimension and the vertical dimen-sion is not going to be changed on thearticulator.

Place the “reference plane locator”along the right side of your patient’sface. It should extend from the middle ofthe upper border of the external audito-ry meatus to the “outer canthus” of theeye. In other words, the reference planelocator should extend from the middleof the upper border of the ear-hole tothe outer corner of the eye (fig. 33).

There is a small hole in the upper poste-rior area of the locator. Once the locatoris in position on the patient’s face, useyour felt-tipped pen to gently markthrough the hole onto the face (fig. 34).

Make the mark on both sides of thepatient’s face.

The position of the “anterior referencepoint” is measured up 43 millimeters

from the “incisal edges” of the central orlateral incisor, toward the inner corner ofthe eye. The notched out area of the“reference plane locator” is used tomake this measurement. The notch is 43millimeters in length.

Simply rest the lower edge of the notchon the incisal edge of the right central orlateral incisor. On an edentulous patientmeasure up from the low lip line. The“low lip line” is the lower border of theupper lip when it is in repose. In eithercase, mark the anterior reference pointbelow the inner canthus of the right eyewhere the top point of the locator touch-es the patient’s face (fig. 35).

fig. 33 fig. 34

fig. 35

21

Measure the distance between the ante-rior reference point and the inner can-thus of the eye (fig. 36). Record thismeasurement in the patient’s file forfuture reference. In this way, if the ante-rior teeth are removed or modified thesame anterior reference point can belocated by measuring downward fromthe fixed immovable inner canthus ofthe eye.

The final step is to mark the “horizontalreference plane” on the right side of thepatient’s face. Just line the ruler upbetween the anterior and posterior ref-erence points. Hold the ruler so that it isjust out of contact with the patient'sskin, so that it will not displace the skin,and then draw a short line on the side ofthe face. This line represents the “hori-zontal reference plane” (fig. 37).

You will therefore notice that the hori-zontal reference plane is identified onthe face of the patient by two posteriorreference points in the area of the termi-nal hinge axis and one anterior referencepoint located 43 millimeters above theincisal edges of the maxillary anteriorteeth or low lip line of the patient.

MAKING THE FACEBOW/EARBOW REGISTRATION(Assembling the Facebow/Earbowon the patient)

The components of the kit needed are:the bitefork, anterior crossbar, referencerod, reference rod clamp, and the rightand left facebow side arms with nylonearplugs at the ends of the posterior ref-erence slides (fig. 31).

Attach the bite fork to the crossbar sothe reference rod clamp is to thepatient’s right, and the u-shaped part inthe bite fork is above the crossbar (fig.38). Then load the upper surface of thebite fork with two thicknesses of base-plate wax (fig. 39). Soften the wax to adead soft consistency in warm water oran open flame, and then put the loadedbite fork in the patient’s mouth to get alight indexing impression of the maxil-lary teeth. When the bite fork is firstplaced in the mouth, be certain to lineup the crossbar so that it is parallel tothe coronal and horizontal planes of thepatient. Also be sure to be careful not todepress or displace any mobile teeth __

all you really need is a slight impressionof the tips of the cusps (fig. 40).

Remove the bite fork from the patient’smouth, and place the maxillary cast, ifavailable, in the bite fork to confirmaccurate seating. If the maxillary castseats accurately in the bite fork, you cannow begin assembly of the facebowrecord.

Put the bite fork assembly back in thepatient’s mouth, indexing it to the maxil-lary teeth. Have the patient hold the bite

fig. 36

fig. 37

22

fork in place (fig. 41). This can be donemost conveniently by having the patientbite on the index and middle fingers ofthe left hand. Alternatively position cot-ton rolls on the occlusal surface of thelower posterior teeth and instruct the

patient to maintain the bite fork in placewith gentle biting pressure.

Adjust the reference rod clamp so it isparallel to the reference plane markedon the patient’s face (fig. 42).

fig. 38 fig. 40

fig. 39 fig. 41

23

At this point you will be ready to attachthe facebow side arms. Note that theyare marked right and left and refer to thepatient’s right and left. Make sure thatthe scales on the posterior referenceslides are adjusted to their zero posi-tions.

A. Facebow ApplicationRemove the nylon earpieces on boththe posterior reference slides andbegin the attaching of the side arms(fig. 43). First you will need to locatethe right side arm on the crossbar sothat the lockscrew on the crossbarclamp faces upward and the posteri-or reference pin at the end of theposterior reference slide lightlytouches the posterior referencepoint. Secure the side arm clamp tothe anterior crossbar. Then attachthe left side arm similarly.

B. Earbow ApplicationMake sure the nylon earpieces areon both posterior reference slides.Position the right arm on the cross-bar so that the lockscrew on thecrossbar clamp faces upward andthe nylon earpiece fits snugly in theexternal auditory meatus. Secure theside arm clamp tightly and attach theleft side arm similarly.

At this point the facebow/earbowrecords the relationship of the maxillary

dental structure to the posterior refer-ence points. The only thing remaining tobe done is to relate the maxillary dentalstructures to the anterior referencepoint.

Insert the reference rod into its clampbringing it up from underneath theclamp, with the step in the rod facingtoward the patient’s right (fig. 44). Holdthe reference plane locator between thethumb and index finger of your left handso that you can read the instructions onthe back. The semilunar notch on thelocator’s inferior surface should beplaced over the bridge of the nose. Notethe small hole in the center of the loca-tor. Turn the locator down flat so that theinstruction side faces downward andindex the hole on the locator over thesmall dowel-like projection on the upperextremity of the reference rod. Positionyour eye approximately six inches infront of the locator. By line of sightadjust the locator by inclining it anterio-posteriorly and medio-laterally until aprojection of its broad surfaces passthrough both posterior reference pointsas indicated by the posterior referenceslides (fig. 45). At this time the anteriorreference point marked on the patient’sface may be above or below the refer-ence plane locator.

Adjust the height of the reference rod sothat a projection of the locator’s broad

fig. 42 fig. 43

Clamp

24

surfaces passes through the anteriorreference point as well as the posteriorreference points (fig. 45). Then with yourleft hand pull the locator to the side sothat the reference rod is wedged in itsclamp. With the wrench in your righthand tighten the clamp to secure thereference rod in its support.

OPTIONAL The Anterior ReferencePointer, Part No. D145, shown on page58, is an optional accessory to the face-bow which may be used in lieu of the ref-erence plane locator (ruler) to adjust thereference rod to the anterior referencepoint marked on the patient’s face.

Now slightly retract the posterior refer-ence slides so that they will not scratchthe patient’s face or hurt the ears as youremove the facebow/earbow assemblyfrom the patient’s face. Once removedrepostion the slides to their original zeropositions. The facebow can now beused to accurately locate the maxillarycast on the articulator.

TRANSFERRING THE FACEBOW/EARBOW TO THE ARTICULATORTo prepare the articulator to accept thefacebow, set the immediate side shiftadjustments to zero, the progressiveside shifts to 5 degrees and protrusivecondylar paths to 30 degrees. The verti-cal dimension of the incisal pin shouldalso be set to zero (fig. 46).

Next secure a mounting plate to theupper bow of the articulator and a max-illary cast support to the lower bow (fig.47). The maxillary cast support fits ontothe lower bow of the articulator in lieu ofa mounting plate. It will help support theweight of the cast and prevent deflec-tion of the facebow.

When attaching a mounting plate to thebow of an articulator always turn themounting plate in the same direction thelockscrew is turned as the mounting plateis secured to the articulator bow. (fig. 48).

fig. 44 fig. 45

fig. 47

fig. 46

Progressive Side Shift 5˚Protrusive Adjustment 30˚Incisal Pin & Table 0˚All Other Settings 0˚

25

A. Facebow TransferIf the facebow/earbow is used as a face-bow (the posterior reference points areoriented to the posterior referencepoints marked on the side of thepatient’s face in the area of the terminalhinge axis) the facebow will be attachedto the articulator by indexing the poste-rior reference pins into the facebowindexes on the lateral aspects of thecondyles (fig. 50).

A. Earbow TransferIf the facebow/earbow is used as anearbow the nylon earplugs are removedfor attachment of the bow to the articu-lator and the posterior reference pinsare indexed into the earbow index holeson the lateral aspects of the fossae (fig.50).

If the facebow was oriented to thepatient to posterior reference pointslocated precisely with a hinge axis loca-tor, marked readjustment of the posteri-or reference slides of the facebow toaccommodate it to the articulator couldintroduce a slight mounting error. Inorder to minimize this error, mountingstuds are inserted into the lateralaspects of the condylar elements tominimize the amount of adjustment ofthe posterior reference slides (fig. 51).

Attach the facebow (or earbow) assem-bly to the articulator by equally adjustingboth posterior reference slides so thatboth scales give the same reading whenthe posterior reference pins are firmly

fig. 48

fig. 50

fig. 51

FacebowIndexEarbowIndex

26

seated in their respective condylar orearbow index holes. This can be donemost conveniently by indexing bothposterior reference pins in their respec-tive holes. Observe the setting to whichthe slides are adjusted. The sum ofthese settings divided by 2 is the settingto which the posterior reference slidesare adjusted for proper transfer of thefacebow to the articulator. (For example,the sum of +30 and -10+=20 divided by2=+10.)

The maxillary cast support is adjustedso that the support crossbar firmly con-tacts the undersurface of the biteforkwithout lifting the reference rod from itsbearing surface (fig. 52).

fig. 52

27

The procedures for constructing castsare not discussed in this manual. Onceyou have obtained impressions of theupper and lower arches for purposes ofconstructing the casts, you will in addi-tion require four interocclusal checkbiterecords in order to mount the mandibu-lar cast in the articulator and to adjustthe fossa controls of the articulator: acentric relation record, one right andone left lateral checkbite record and aprotrusive record. The selection of themethod and material used for obtainingthese records is left to the preference ofthe operator. One recommended check-bite procedure is presented in AppendixA of this manual.

THE MAXILLARY CASTFirst secure the maxillary cast to the bitefork with sticky wax or with a light elas-tic band (fig. 53).

With the mounting plate secured in theupper bow of the articulator, fill themounting plate with stone and alsoapply stone to the top of the cast. Besure the mounting stone completely fillsthe recesses of the mounting plate. Thecast is secured to the mounting platewith a “one mix” or “two mix” proce-dure.

“One Mix” Procedure Use one mixof fast set mounting stone to securethe maxillary cast to the mountingplate. With a little experience a neatmounting can be achieved with thistechnique.

“Two Mix” Procedure Use one mixof fast set stone to completely fill therecesses of the mounting plate andto tack the cast to the mountingplate. After the stone is set, removethe mounted cast from the articula-tor and use a second mix of fast set

stone to complete the mounting. The“two mix” procedure is recommend-ed to easily obtain a neat mounting.

Bring the upper bow down on top of thecast, so the stone bonds the twotogether. Now engage the centric latch.Throughout this procedure be sure thatthe condyles maintain centric relationand the incisal pin touches the incisalplatform (fig. 54). Once the stone hasset, remove the maxillary cast supportfrom the articulator.

VI. MOUNTING THE CASTS IN THE ARTICULATOR

fig. 53

fig. 54

28

With the facebow application (not theearbow) it is usually easier to fill themounting plate with stone and stock apile of mounting stone on the maxillarycast if the maxillary bow is removed andinverted on the working surface besidethe facebow-mandibular bow assembly(fig. 55).

THE MANDIBULAR CASTWith the maxillary cast in the articulator,separate the upper bow from the lowerbow and turn the upper bow upsidedown. Orient the mandibular cast to themaxillary cast by accurately seating andluting the centric relation recordbetween the two casts. Secure thecasts assembly with sticky wax or a lightrubber band (fig. 56).

If the centric relation record was takenat an increased vertical dimension, esti-mate the distance the vertical dimensionwas increased by the centric relationrecord and adjust the vertical dimensionof the incisal pin to this dimension.

Fill the lower bow mounting plate withfast set stone and put an appropriateamount of stone on the base of themandibular cast (fig. 57). Then invert thelower bow and seat it on top of theupper bow. Make sure the condyles areseated in their fossae (fig. 58). Makesure that the incisal table is on theincisal pin. Lock the centric latch to itsmost closed portion. Complete the

mounting of the mandibular cast withthe “one mix” or “two mix” procedurepreviously described.

An alternate method of mounting themandibular cast is to first load themounting plate with fast set stone andthen put an appropriate amount of stoneon the base of the mandibular cast.Next grasp the maxillary bow and sup-port the centrically related casts with thethumb, index and middle fingers as illus-trated in fig. 59. Invert the maxillarybow-casts assembly over the mandibu-lar bow and firmly seat the condyles intheir fossae. Close the articulator untilthe incisal pin contacts the incisal table.While maintaining this hand grasp havean assistant move the centric latch to itsmost closed position. After the initial setof the mounting stone has occurred to

fig. 55

fig. 56

fig. 57

29

support the mandibular cast, the fingersare removed from the assembly. Sub-sequently the mounted mandibular castis removed and the mounting is com-pleted with the “two mix” method.

A recommended procedure is to initiallyobtain three centric relation check-biterecords to verify the accuracy of thecentric relation mounting as detailed inAppendix B of this manual.

fig. 58 fig. 59

30

To set the articulator to checkbiterecords you will need the articulator towhich have been mounted both themaxillary and mandibular casts. You willalso need right and left lateral checkbiterecords and a protrusive record.(Alternate techniques require fewercheckbite records and use averageanatomical dimensions for those condy-lar path dimensions not recorded andmeasured.)

In this section we will first diagnose andrecord the characteristics of thepatient’s orbiting paths of movementfrom the two lateral checkbite records,and then diagnose and record the incli-nations of the protrusive condylar pathswith protrusive checkbite record.

SIMULATING THE ORBITINGCONDYLAR PATHFirst remove the maxillary bow from thearticulator and confirm that both pro-gressive side shift adjustments are setto the 6˚ settings. The reason for thissetting was explained in the previoussection on the Immediate andProgressive Side Shift Adjustments.

Next loosen the protrusive and immedi-ate side shift adjustment lockscrews on

both sides of the articulator (a total offour screws). Set the protrusive condylarpaths to 0˚ and move the medial fossawalls medially to the limit of their rangeof movement. Do not tighten thelockscrews.

Seat the right lateral checkbite recordon the mandibular casts. Firmly seat themaxillary cast in the checkbite record bygrasping the maxillary cast as illustratedin fig. 60 or by applying pressure to thetop of the upper bow to immobilize themaxillary cast (due to the fact that theMark II Articulator has the rotatingcondylar paths built to average anatom-ic dimensions, impingement of the rotat-ing condyle against its rear and superiorfossa walls may sometimes preventcomplete seating of the maxillary cast inthe checkbite record). At this time theleft condyle is positioned inward, down-ward, and forward from its centric relat-ed position (fig. 61). Increase the inclina-tion of the left protrusive condylar pathuntil the superior wall of the fossa con-tacts the top of the condyle (fig. 62).Secure the protrusive condylar path inthis position by tightening thelockscrew.

Move the left medial fossa wall laterallyuntil it contacts the condylar element.

VII. SETTING THE ARTICULATORTO CHECKBITE RECORDS

fig. 60 fig. 61

31

Lock the immediate side shift adjust-ment lockscrew.

Note: These three articulator adjust-ments, the immediate side shift, the pro-gressive side shift and the protrusiveinclination of the superior fossa wallestablish the character of the orbitingpath on the left side of the articulator.

Use the left lateral checkbite record andfollow the same procedure to adjust thesettings of the right articulator fossa anddiagnosis the character of the orbitingpath of the right condyle.

Record the articulator settings on thepatient’s record.

Note: It is the adjustment of the rightmedial fossa wall medialward thatallows for a mandibular side shift tothe left as the right condyle movesmedially to bear and move againstits medial fossa wall. Therefore,when the operator writes on thepatient’s record “right immediateside shift .6mm” the reference is tothe articulator adjustment on theright side of the articulator and notto the side to which the mandiblemoves. The right articulator adjust-ment will allow for a mandibularside shift to the left. The articulator’sright side is the right side of the

articulator. A medialward adjust-ment of the right medial fossa wall(right immediate side shift adjust-ment of the articulator) allows for amandibular side shift to the left.Repeat. It is important to note thatthe right immediate side shiftadjustment refers to the articulatorsetting on the right side of the artic-ulator which allows for a mandibularside shift to the left and not to theright.

SIMULATING THE PROTRUSIVECONDYLAR PATHSThe inclinations of the protrusive condy-lar paths are diagnosed in the followingmanner.

Again loosen the lockscrews of the pro-trusive adjustment on both sides of thearticulator. Set the protrusive condylarpath inclinations to zero degrees. Do nottighten the lockscrews. Seat the protru-sive checkbite record on the mandibularcast and seat the maxillary cast in thecheckbite record. Apply downwardpressure to the maxillary cast or upperbow to stabilize the maxillary cast in therecord. Note that the condyles do notcontact their superior fossa walls.Increase the inclination of the protrusivecondylar path on both fossae until thesuperior fossa wall contact their respec-tive condyles. Lock the protrusiveadjustments lockscrews. The inclina-tions of the patient’s protrusive condylarpath have now been diagnosed. Recordthe protrusive condylar path settings onthe patient’s record.

A recommended manner for utilizing thediagnostic data obtained by adjustingthe articulator to protrusive and lateralcheckbite records for fixed and remov-able prosthodontics is presented in the“Treatment Procedures” section of thismanual on page 35.

fig. 62

32

CUSTOM INCISAL TABLEThere are two different custom incisaltables that fit Dénar® Articulators. Theyare shown in fig 63. Part No. D41 is usedwith articulators with the long centricadjustment on the foot of the incisal pin.Part No. D4 1 AB is used with articula-tors having the rounded foot on theincisal pin.

To use either of the custom incisaltables first attach a small mount of coldcure acrylic to the posterior portion ofthe incisal table. Part No. D41 has amachined precision stop on its anteriorportion to maintain the correct verticaldimension and care should be taken toensure that no acrylic is positioned onthe top of the stop. Also the long centric

adjustment at the foot of that incisal pinshould be turned so that the roundedend will more efficiently mold the acrylic.This is done by adjusting the foot so thatits anterior extremity is flush with theanterior surface of its dovetail support.

When the acrylic has reached a ratherfirm consistency, the articulator ismoved in right lateral, left lateral, andprotrusive excursions allowing the ante-rior teeth which are kept in contact toguide these excursive movementsthereby functionally generating a cus-tom incisal guide. This recording istransferred to the incisal table and smallfleur-de-lis is generated in the cold cureacrylic (fig. 64). This is later perfectedwith a vulcanite burr.

The custom incisal table can be used tobest advantage in adjusting to the verti-cal and horizontal overlap relation of theanterior teeth.This is particularly true inadjusting the incisal guidance of thearticulator to natural teeth which exhibitvarying amounts of horizontal overlap ofthe teeth which bear the horizontal loadin the protrusive, right lateral, and leftlateral excursive movements.

ADJUSTABLE INCISAL TABLELong Centric Adjustment.The Long Centric Adjustment is locatedon the foot of the incisal pin. When thereis a horizontal overlap of the anteriorteeth, or a “long centric”, the foot of theincisal pin is adjusted to complementthis tooth relationship in the followingmanner. Set the protrusive inclination ofthe incisal table to its maximum angle.Loosen the foot of the incisal pin andslide it forward (fig. 65). Move the upperbow posteriorly until the lower anteriorteeth contact the lingual surface of theupper anterior teeth (fig. 66).

VIII. INCISAL TABLE ADJUSTMENTS

fig. 64

fig. 63

33

With the right index finger, push the footof the incisal pin back until it just con-tacts the inclined platform of the incisaltable, and tighten the incisal pin footlockscrew in that position (fig. 67). Byallowing the incisal pin to come forwardinto the centric related position again, aspace will be noticeable between thefoot of the pin and the incisal table__

this space is equal to the horizontaloverlap of the anterior teeth. (fig. 68).

Protrusive AdjustmentTo adjust the incisal table for the inclina-tion of the lingual bearing surfaces ofthe anterior teeth, first loosen the incisalplatform and set it back to zero. Do nottighten the lockscrew. Then, move theupper bow posteriorly until the incisaledges of the lower anterior teeth con-

tact the lingual surface of the upperanterior teeth just lingual to their incisaledges. Note that the incisal pin does nottouch the incisal table now (fig. 69).Increase the angle of the table until ittouches the foot and lock the table inthat position (fig. 70).

Lateral Wing Adjustment

The lateral wings of the incisal table areadjusted to complement the lateral rela-tionships of the anterior teeth __ mostfrequently the vertical and horizontaloverlap relationships of the cuspidteeth. To make this adjustment, firstremove the incisal table and loosen thelateral wing lockscrews (fig. 71). Thenreplace the incisal table on the articula-tor to observe visually the angle to whichthe lateral wings must be adjusted to

fig. 67fig. 65

fig. 68fig. 66

34

complement the anterior tooth relation-ships in the following manner. Hold thearticulator in a right lateral mandibularposition so that the right cuspids are infunction. (The upper bow is pushed tothe left. ) Note that the incisal pin doesnot contact the incisal table. With theright index finger, reach behind the tilt-ing platform, and elevate the left wing of

the table until it touches the foot of theincisal pin (fig. 72). Visually take a read-ing on the front scale to note its angularsetting. Do this same procedure on theother side wing. Now remove the incisaltable from the articulator and tighten thelockscrew wings at those settings. Thenattach the table to the articulator again.

fig. 69 fig. 71

fig. 70 fig. 72

Scale

35

The rationale for utilizing the diagnosticdata obtained from protrusive and later-al checkbite records is as follows.

When the protrusive inclination of thesuperior fossa wall is adjusted to the lat-eral checkbite record, a characteristic ofthe orbiting condylar path is diagnosed.This characteristic is associated with thebalancing inclines of posterior teeth onthe orbiting side__the mandibular buc-cal cusps’ lingual inclines’ mesialaspects and the maxillary lingual cusps’buccal inclines distal aspects.

When the protrusive inclination of thesuperior fossa wall is adjusted to theprotrusive checkbite record, the inclina-tion of the patient’s protrusive condylarpath is diagnosed. This inclination of thesuperior fossa wall is associated withthe protrusive contacts of posteriorteeth__the mesial aspects of mandibularcusps and the distal aspects of maxil-lary cusps.

The orbiting path inclination of the supe-rior fossa wall adjusted to lateral check-bite records is always equal to or greaterthan the protrusive path inclination ofthe superior fossa wall adjusted to theprotrusive checkbite record.

FIXED RESTORATION ANDREMOVABLE PARTIAL DENTURERESTORATIONSAdjusting the protrusive inclination ofthe superior fossa to an angle which isslightly less than the patient’s protrusivecondylar path (5 to 10 degrees less)when the restoration is fabricated willprevent the fabrication of protrusivecontacts, or balancing contacts on theorbiting side of posterior teeth in thelaboratory. This is due to the fact thatwhen the restoration is seated in thepatient’s mouth and the patient’s

condyle tracks a steeper protrusive andorbiting condylar path, the posteriorteeth will separate in both the protrusiveexcursion and in the lateral excursion onthe orbiting side.

COMPLETE DENTURESMethod 1. Adjusting the articulator to

the patient’s protrusive condylarpath inclinations for both the pro-trusive and lateral excursive move-ments allows the fabrication of pro-trusive balance in the laboratory,When the restoration is seated inthe patient’s mouth and the patientexecutes a lateral mandibularmovement with the teeth in contact,the patient will feel the primaryoccluding pressures on the workingside. If the patient’s orbiting path isslightly steeper than the articulatorsetting when the restoration wasfabricated, the patient would per-ceive minimal occluding pressureson the balancing side. Howeverorbiting side occlusal contactwould prevent loss of peripheralseal.

Method 2. Adjusting the inclinations ofthe superior fossa wall to thepatient’s orbiting path inclinationsallow the fabrication of bilateral bal-anced occlusion in lateral excursivemovements in the laboratory.Subsequent adjustment of thearticulator to the patient’s protru-sive condylar path inclinations per-mit adjustment of the occlusion toprotrusive balance. This methodpermits development of full archbalanced occlusion. (Note: Ob-taining accurate eccentric check-bite records on extensive tissueborne restorations, although theo-retically attainable, is a difficultaccomplishment).

IX. TREATMENT PROCEDURES

36

CHECKBITE PROCEDURE

The mandibular cast is transferred tothe articulator by:1. occluding it with the maxillary cast2. checkbite procedure3. a combination of the above

In the transfer of the mandibular cast tothe articulator, if the mandibular castcan be occluded accurately in thedesired most intercusped position, themost accurate way to transfer themandibular cast to the articulator is byoccluding it with the maxillary cast.However, if deflective contacts exist inthe patient’s mouth, they must either beremoved by grinding prior to the timeimpressions are taken so the cast canbe accurately oriented in the desiredmost intercusped position or the centricrelation record must be taken at anincreased vertical dimension by check-bite procedure.

There are many satisfactory recordingagents such as waxes, bite registrationpastes, etc., and many techniques withwhich these agents can be employed toadvantage in checkbite registration pro-cedures. However, there is no universalmethod which proves optimum for allsituations. Therefore, the dentist mustbe knowledgeable of the anatomy of therelated structures, neuromuscle physiol-ogy, mandible manipulation techniquesand in the physical properties of thedental materials employed which deter-mine checkbite accuracy. This willenable him to effect a method of choiceas varying situations present them-selves.

It is not within the scope of this text topresent an exhaustive discourse oncheckbite procedure. However, one rec-ommended procedure which effectsbasic principles of checkbite techniquesis presented. Variations of this technique

can be employed as circumstances dic-tate.

The following basic principles shouldalways be employed in any checkbitetechnique.1. The checkbite record should be

obtained as close to the verticaldimension at which the restorationis to be constructed as possible.

2. The dentist should always manipu-late the patient’s mandible inobtaining the checkbite. Thepatient must not be instructed orallowed to bite or close down insuch a manner as to cause flexionof the mandible or movement ofteeth in obtaining the record.

3. The recording media interposedbetween the teeth should be of adead soft consistency as themandible is brought to the desiredposition. This prevents deflectionof the mandible and/or mobileteeth, or the programming of mus-cle function.

TECHNIQUE FORWORKING CASTSThe following technique can be used toregister the mandiblular position at thecorrect vertical dimension or at anincreased vertical dimension. It can beused to register centric or eccentricposition. Described will be the registra-tion of the centric relation position of themandible at the minimal increase of ver-tical dimension which will result in lackof posterior tooth contact.

Fabricate an occlusal programmer bysoftening a small piece of base platewax in a water bath to a soft consisten-cy and adapt it over several teeth in theanterior segment of the mouth as illus-trated in fig. 73. Manipulate the mandible

APPENDIX A

37

into anterior centric relation and gentlyguide the patient repeatingly in terminalhinge closure to lightly tap the soft waxto establish simultaneous contact ofseveral mandibular teeth on the wax.The wax is removed from the mouth andchilled in tap water. The number ofthicknesses of wax used should be theminimum number to effect posterior dis-clusion.

A small amount of denture adhesivecream is applied to the wax occlusalprogrammer in the area that adapts tothe lingual surfaces of the maxillaryanterior teeth (fig. 74) The occlusal pro-grammer is repositioned in the mouth byreindexing it to the maxillary teeth. Theocclusal programmer thus establishes apredetermined stop to vertical closurewith the condyles in centric relation.There is an absence of contactingdeflective inclines posteriorly as a resultof group functioning of teeth in the ante-rior segment of the mouth where theoccluding pressures are the least. Theocclusal programmer reprograms mus-cle function so as to eliminate resistanceto terminal hinge closure previously pro-grammed by deflective contacts.Thedentist can now more easily manipulatethe mandible in terminal hinge closure toobtain the centric relation checkbiterecord.

Similar occlusal programmers can befabricated in eccentric positions to facil-itate obtaining of eccentric checkbiterecords.

Suitable checkbite recording mediasuch as Bosworth’s Superbite ( a rapidand hard setting zinc oxide and eugenolbase material) is placed on themandibular posterior teeth and themandible is guided in terminal hinge clo-sure until the anterior teeth make lightcontact with the occlusal programmer.Since it is undesirable to register deepfissures, grooves and undercuts onteeth and cavity preparations with the

checkbite record media, these areas areblocked out by wiping Vaseline or softwax over the teeth with the index fingerbefore the zinc oxide and eugenol pastematerial is used for checkbite registra-tion. The checkbite record media isallowed to harden without the patientexecuting a biting pressure. Figure 75illustrates an occlusal programmer andcheckbite records accomplished with ahard fast setting zinc oxide and eugenol(ZOE) base material.

If the patient brings the mandible mov-ing muscles into function during the set-ting of the record media, as may occurduring swallowing or bruxing, flexion ofthe mandible or displacement of teethmay occur which would result in aninaccurate record. To insure that thepatient does not bring the muscles into

fig. 73

fig. 74

38

function during the securing of the cen-tric relation checkbite record, the dentistshould periodically gently arc themandible in small terminal hinge rotarymovements preceding the set of therecord media and immediately followingthe set. Resistance to this movementimmediately prior to or after the set indi-cates functions of the patient’s mandiblemoving muscles and the checkbiterecord should be discarded and a newone taken. If resistance to this move-ment is not encountered, the dentist canbe reasonable sure the patient did noteffect muscle function. This technique istermed “dynamic technique” and therecord termed “dynamic checkbite”because of the small movements of thepatients mandible executed by the den-tist during the securing of the record.

The record media selected for this tech-nique should allow an adequate, consis-

tent and not extended working time. Itshould have a flash set to a hard con-sistence that will fracture without warp-ing so the parts can be accuratelyreassembled if fractured. The materialshould be of a dead soft consistencywhen mixed but it must also have suffi-cient body to resist flow so that it willstay in place when positioned on theteeth.

To facilitate the placement of the recordmedia on the occlusal surfaces of themandibular teeth construct small papercones from sheets of paper approxi-mately 4 x 6 inches in dimension. Twistthe papter around the index finger asillustrated in fig. 76 to fashion a conethat has an opening at its large endapproximately 1-1/4 inches in diameter(fig. 77A). The margin of the paper issealed with Scotch Tape so the paperwill not unwrap. The small end of the

fig. 75

fig. 76

fig. 77

39

cone is cut with a scissors to producean opening at the apex approximately1/8 inch in diameter (fig. 77B).

Mix record media and gather it into onemass on the end of the cement spatula.Load the media into the bottom of apaper cone (fig. 77C). Squeeze thepaper cone behind the record media tocapture the media near the apex of thecone and to clean the spatula as it iswithdrawn (fig. 77D). After the spatula isremoved the cone is squeezed with theindex finger and thumb of both hands topush all the media to the apex of thecone and then the cone is folded backon itself to prevent movement of themedia toward the large end of the conewhen it is compressed (fig. 77E).

The cone is squeezed to dispense themedia into the central groove of themandibular teeth (fig. 78). As soon as acone is loaded the operator can pro-ceed to apply the media to the teeth asthe assistant immediately begins to mixanother batch of material for securingadditional centric relation records.

An inexpensive file jacket is used as amixing pad and provides for convenientdisposal of the record media after use. Itis good procedure to obtain three cen-tric relation records. One is used tomount the mandibular cast and theremaining two are used to double checkthe mounting for accuracy with theDenar® Vericheck technique presentedin Appendix B of this manual.

The setting times of zinc oxide eugenolrecord medias vary with temperature,humidity, spatulation time and batchnumber. Under certain conditions thematerial will set very rapidly and theoperator must work quickly to get thematerial to place before the set occurs.Alternately the material may set slowly.Since it is difficult for the operator tomaintain the patient’s mandible in cen-tric relation for extended periods of

time,

time, the operator using a slow settingrecord media should wait for a period oftime after the media is placed on themandibular teeth until the set is about tooccur before manipulating the patient’smandible to centric relation. Therefore,the operator should dispense recordmedia for four batches of material onthe mixing pad (fig. 79). The first batch isuse to time the set of the media and isdiscarded. The remaining three batchesare used to obtain the centric relationrecords.

To time the set, mix the first batch ofmaterial according to the manufacturersrecommendations. Load the cone andapply the first batch of record media tothe mandibular teeth. Do not bring themandible to centric relation. The opera-tor should then start to count slowlyuntil the set occurs. Once the set has

fig. 78

fig. 79

40

been timed the operator knows howlong to pause after the media has beenplaced on the lower teeth before bring-ing the mandible to centric relation. It isdesirable to bring the mandible to cen-tric relation just before the set occurs.For best results it is important that theoperator and assistant work with consis-tent technique throughout this procedure.

TECHNIQUE FORDIAGNOSTIC CASTSCheckbite records made of hard baseplate wax can be used to advantagewhen mounting diagnostic casts. Thewax used should be of a hard, brittleconsistency and fracture without bend-ing at room temperature. For obtainingcentric relation records develop waxwafers composed of two thicknesses ofwax to the dimension illustrated in fig.80. It is best not to include the anteriorteeth in the centric relation record if suf-ficient posterior teeth are present to sta-bilize the casts in the record.

To develop the wax wafers soften asheet of base plate wax in a water bathor open flame. Flame one surface of thewax and fold the wax over on itself onthe flamed surface to bond the wax intoa wafer consisting of two thicknesses ofwax. With a warm spatula trim the waxslightly oversize of the desired dimen-sion. With the wax slightly softened sothe wafer is pliable, position the waferon the maxillary teeth and using theindex fingers adapt the wax to the teethto obtain very light indexing impressionsof the cusps tips and to contour thewafer to the plane of occlusion. Do notimpress the mandibular teeth into thewax at this time. Chill the wax with air sothat it will maintain the shape of theplane of occlusion and remove the waferfrom the mouth. With a warm scalpeltrim the wafer to the desired dimensions.Check the wafer in the mouth or on amaxillary cast to confirm that the wafer iscontoured to the plane of occlusion andis stable on the maxillary teeth.

Soften the lateral edges of the wax in anopen flame until it is dead soft. Quicklytemper the wax in a water bath andposition the wafer on the dry maxillaryteeth to obtain light impressions of thetips of the cusps as previouslydescribed. Guide the mandible in cen-tric relation closure to obtain lightimpressions of the mandibular cusp tipsin the record. It is important that theoperator guides the mandible to thedesired position.The patient should notbe instructed to bite down or close. Assoon as the impressions are obtained,chill the wax with air and remove it fromthe mouth. The record is chilled in coolwater and returned to the mouth andchecked for accuracy. The wafer isplaced on the maxillary teeth and themandible is arced in centric relation clo-sure to occlusal contact. The mandibu-lar cusp tips should come into simulta-neous even contact with their impres-sions in the record. When the mandibu-lar teeth are brought into extemely lightocclusal contact with the record thepatient should preceive no prematurecontact or uneven pressure on ques-tioning.

Lateral Checkbite RecordsA technique for fabricating a right lateralcheckbite record is described. The leftlateral record is obtained in a similarmanner.

Train the patient to allow you to arc themandible in hinge retation with thepatient’s rotating condyle in its most

fig. 80Figure 80 courtesyDr. P. Dawson and C.V. Mosby Co.

41

retruded position and the orbitingcondyle advanced approximately sevenmillimeter. This can be done with the“thumb on chin” method with the thumbon the anterio-inferior border of themandible in the area of the left cuspid.

Construct a wax wafer composed oftwo thicknesses of hard base plate waxto the dimensions illustrated in fig. 81.This is done by fabricating an oversizedwafer as previously described andadapting it to the maxillary teeth with theindex fingers to conform the wafer to theplane of occlusion and to obtain lightimprints of the cusp tips. Chill the waferwith air and remove it from the mouth.Use a warm scalpel to trim the wafer tothe desired dimensions. Return thewafer to the mouth, and position it onthe maxillary teeth to confirm that it isstable on the maxillary teeth and con-forms to the plane of occlusion. Guidethe mandible in right lateral closure tocontact the wax and determine the

number of additional strips of wax whichmust be added to the lateral extremitiesof the mandibular side of the wafer toestablish even contact with themandibular teeth. Lute additional thick-nesses of wax to the mandibular sideand then heat the lateral extremities ofthe wafer in an open flame to soften thewax. Quickly temper the wax in a waferbath and position the wafer on the drymaxillary teeth. Guide the mandible inright lateral closure to obtain lightimprints of the cusp tips in the wax. Chillthe wax with air and remove the waferfrom the mouth and place it in coolwater. The wafer can be returned to themouth and checked for accuracy.

fig. 81

42

The following protocol was developedby a panel of experts in occlusal treat-ment on the philosophy that a dentistseeking good laboratory support willgive the technician complete specifica-tions for fabrication of the occlusalaspects of the restoration.

Recognizing that the position of maxi-mum intercuspation is of paramountimportance, it is the responsibility of thedentist who takes the centric relation orcentric occlusion interocclusal record tomount the mandibular cast. Completespecifications furnished by the dentistto his laboratory for fabrication of theocclusal aspects of restorations include:

1. Full arch master casts mounted inan instrument with trimmed dies ordies with margins that are easilyidentifiable.

2. Instructions for adjusting articula-tor condylar controls (if adjustable)when the restoration is fabricatedplus records for adjustment of theincisal table.

3.Specifications as to which teethare to bear the load in eccentricbruxing movements.

4.Specifications for the class ofocclusal anatomy desired and thecharacter of the position of maxi-mum intercuspation as describedbelow.

DISCUSSION

Mounted Casts with Trimmed DiesTo specify that it is the responsibility ofthe dentist to mount the mandibularcast does not mean that he cannot del-egate this procedure to a dental auxil-iary. For example, in limited restorativeprocedures in which there are sufficientunprepared teeth to accurately index full

arch casts in the position of maximumintercuspation, the mounting procedurecould certainly be delegated to a dentalauxiliary. However, as the restorationbecomes more extensive, if the dentistdelegates the mounting of the casts to adental auxiliary and an error is intro-duced, the dentist should still assumefull responsibility for the mounting error.

Instructions for Adjustment ofCondylar ControlsTo specify that the dentist should pro-vide instructions for adjusting condylarcontrols does not mean that the restora-tion is to be constructed on a fullyadjustable articulator. An example ofinstructions for adjustment of thecondylar controls could be: “Lock theinstrument in centric relation throughoutthe laboratory procedure”. It is theresponsibility of the dentist to specify tohis technician if he wants considerationgiven to eccentric factors of occlusionin the laboratory, and if so, to whatextent.

Dentist__Laboratory RelationsCurrently, most dentists send unmount-ed casts to the laboratory for fabricationof prosthetic restorations. Restorationsare returned to the dentist on unmount-ed casts. If the occlusion is found to bein error when the restoration is insertedin the patient’s mouth, who made theerror__dentist or technician? This condi-tion can result in strained dentist-labo-ratory relations.

It is the responsibility of the dentist whotakes the centric relation record tomount the mandibular cast. When therestoration is returned to the dentist onfull arch mounted casts the dentist has abasis for accurate communication withhis laboratory. If the laboratory services

APPENDIX BDÉNAR SYSTEM PROTOCOL FOR DENTIST-LABORATORY RELATIONS

43

are found to be satisfactory andocclusal discrepancies are identified inthe mouth, the dentist is confident thatthe error was not introduced in the labo-ratory. He can then re-evaluate his pro-cedure to determine the source of error.In other words, if the restoration fits themounted casts but not the mouth, thetechnician cannot be expected to par-ticipate in the additional cost of remakesnot attributed to laboratory procedures.

CLASSIFICATIONS OF OCCLUSALCARVINGSThe following classification of occlusalcarvings as illustrated in figure 82enables the dentist to specify to the lab-oratory the relative amount of time andeffort he desires the laboratory toexpend (and consequently the laborato-ry fee) to fabricate the prescribed occlu-sion.

Alloy Restorations

Class A__Refined Occlusal CarvingThe restoration is fabricated in the man-ner the technician might employ whenusing a simple crown and bridge hingemechanism. When the occlusion issemi-developed, the technician simplybruxes the instrument to burnish awayeccentric interferences and refines theanatomy of the remaining wax.Eccentric irritations are removed fromthe occlusion in the laboratory. This isthe application of principles of occlusionin its simplest form and consequently isa minimum fee laboratory service.

Class AA__Modified Drop WaxBasically, this is a Class A carving withmore refinement. The technician carvesin supplemental grooves and thenaccentuates triangular, cuspal and mar-ginal ridges with the drop wax tech-nique. The ultimate appearance will besimilar to a Class AAA carving. A ClassAA carving requires more laboratorytime than a Class A carving and so the

laboratory fee should reflect 10% to30% increase in the labor factor of theClass A carving.

Class AAA__Complete Drop WaxThe drop wax technique is employed torestore the total occlusal surface and allrestored axial surfaces to obtain themaximum esthetic cusp height, opti-mum cusp distribution, and to harmo-nize the occlusal anatomy with condylarpaths of movement. This type ofocclusal fabrication requires more timeand skill than a Class A or Class AAcarving and consequently the laboratoryfee reflects a 50% to 100% increase inthe labor factor of a Class A carving.However, this can only be done on arestoration involving extensive toothreduction. For example, if the restora-tions are MOD inlays or onlays with min-imum tooth reduction, the cusp distribu-tion has already been accomplished andthe laboratory only needs to do the fill-in-procedures of the drop wax tech-nique. Consequently, a Class AA or AA+carving would suffice.

Centric ContactsThe character of the centric contactsmust produce axial loading of the teeth.This can be accomplished by:

1.Point Contact (•). There is anabsence of contacting inclines.

fig. 82

44

Centric stops are on high spots orlow spots of cusps.

2. Tripod Contacts (...). Centric cuspsdo not hit on their tips but are sup-ported by three or sometimes onlytwo centric contacts on theperimeter of cusp tips.

Developing tripodized centric contacts(...) requires more laboratory time thanpoint contacts (•). Consequently, anadditional laboratory fee is required.When the dentist’s prescription speci-fies a Class AA (...) occlusion, it meanshe desires a Class AA carving withtripodized centric stops and he antici-pates a laboratory fee which will allowthe technician adequate time to performthis service.

PORCELAIN RESTORATIONSAn extension of the above classificationfor alloy restorations is used for specifi-cations of porcelain restorations.

Class A porcelain restorations arecarved to look like Class A alloy restora-tions. Class AA porcelain restorationsare carved with more detail to accentu-ate supplemental grooves and cuspheight to look like a Class AA or AAAalloy restoration. A plus symbol (+)denotes additional staining and charac-terization.Thus a Class AA (•)+ porcelainrestoration is carved to be similar to aClass AA alloy, has point contact centricstops with an absence of contactinginclines and has special staining charac-terization.

DISCUSSION

Laboratory Fees and Instruments forOcclusal TreatmentThe laboratory fee is for the time andskill which the technician employs inharmonizing the occlusion to condylarpaths of movement and is not deter-mined by the instrument used. A fullyadjustable or semi-adjustable articulatorcan be bruxed as easily as a simplecrown and bridge hinge mechanism thathas springs for condylar posts.

The above classification of occlusalcarvings is not an attempt to establishlaboratory fees. It is offered as a meansof establishing more accurate communi-cations between dentist and laboratory.

SUMMARYThe protocol which requires the dentistto mount the mandibular cast gives thedentist “laboratory-control”. This controlof services usually results in better labo-ratory work. The laboratory on the otherhand receives “dentist control” and lessreduced fee remake discussions.

The dentist who mounts his mandibularcast and provides the technician withcomplete specifications for fabricationof the occlusal aspects of the restora-tion enjoys the benefits of improvedcommunications with his laboratory,laboratory control, better laboratorywork, and improved dentist __ laborato-ry relations.

45

The Dénar® Field Inspection Gage is anoptical inspection gage used to cali-brate Dénar® Articulators and laboratoryRelators to tolerances which allow thetransfer of mounted casts between cali-brated articulators and Lab Relators.

NOTE: This manual details the use ofthe Dénar® Field Inspection Gage to cal-ibrate the Dénar® Mark II Semi-adjustable Articulator. It does not detailthe calibration procedure for the Dénar®

D5A Fully Adjustable Articulator and D6Centric Lab Relator; nor does it describethe recommended applications of theDénar® Two-Instrument System. Forcomplete information on these subjectsthe reader is referred to the Dénar®

Office Tutor (Cat. #D1269) and theDénar® Field Inspection GageInstruction Manual (Cat. #D166).

The gage consists of an upper membercalled the “scope” and a lower membercalled the “stage.” The gage is suppliedwith two inter-bow gage pins. Inter-BowGage Pin #1 and Inter-Bow Gage Pin #2(fig. 83).

CARE OF DÉNAR® FIELDINSPECTION GAGEThe Dénar® Field Inspection Gage is aprecision instrument capable of makingmeasurements in three directions to anaccuracy of one ten thousandths of aninch (.0001”). To insure its continuedaccuracy, the components should behandled carefully and not be allowed tocome to rest on a hard surface with aforce which would cause a nick ordeformation of the bearing surface.When a component is not in use, itshould be kept in its protective case. Itis advisable to have a piece of cork, rub-ber, cardboard or other soft, lint-freesurface to rest the gage components onwhen they are not mounted in their caseor on a Dénar® instrument.

IMPORTANT There are several socketset screws on the scope member of theField Inspection Gage. Do not attemptto turn these screws with a wrench.These screws are for use of factoryauthorized personnel only. Manipulationof these screws can affect the accuracyof the instrument.

For accuracy, it is important that thebearing surfaces of the Field InspectionGage components, Articulator, LabRelator, as well as the mounting plates,be wiped clean of foreign material priorto their use.

VERTICAL ALIGNMENTPrior to using the Field Inspection Gageto align a Dénar® Articulator or LabRelator the distance between the maxil-lary and mandibular bows (inter-bowdistance) of the articulator or LabRelator must be precisely establishedby means of the inter-bow gage pin #1,as illustrated in fig. 84.

APPENDIX CCALIBRATION PROCEDURE

fig. 83

46

To use this pin the adjustable incisal pinand the incisal table are removed andthe inter-bow gage pin #1 is secured inposition as shown.

Carefully and without forcing, mount thegage components flush to the articula-tor bows. Make sure to turn the gagecomponent relative to the articulatorbow in the same direction to which thelockscrew is turned as the gage issecured to the bow of the articulator (fig.85).

It is important that the operator use aconsistent amount of torque when tight-ening lockscrews to secure mountingplates or a Field Inspection Gage to thebows of an articulator or Lab Relator.

Tighten the lockscrew without forcing.

When placing a gage component ontothe bow of an articulator the index holeson the surface of the gage that faces thearticulator bow should be carefully andvisually located over their respectiveindex pin on the bow of the articulator toprevent damage of the bearing surfaceof the gage. DO NOT SLIDE THE GAGElaterally over the index pins in anattempt to locate the index pins in thegage by feel. This can cause damage ifdone with too much force.

Figure 86 illustrates the Field InspectionGage and inter-bow gage pin 1 mount-ed in the articulator. At this time you willnote that a space of approximately 1/4to 1/2 millimeter exists between thescope and the stage.

Optional: If you wish to confirm that yourgage is accurate proceed in the follow-ing manner. On the back of the stageyou will find a calibration record as illus-trated in fig. 87. The two large circlesrepresent the faces of the dial indicatorson the right and left sides of the gage asviewed from the rear. On each circle is ascribed calibration mark which is usual-ly found between the +10 and +20 grad-uations. Each graduation represents onehalf-thousandth of an inch (.0005”).These readings are the values which thedial indicators on the respective sides ofthe instruments should read when thescope is allowed to rest on the stage

fig. 84

fig. 85

fig. 86

Space

47

by loosening the maxillary lockscrewwhile the Field Inspection Gage ismounted in an articulator or Lab Relator.

To confirm that your field gage is accu-rate, simply loosen the maxillarylockscrew which secures the scope tothe maxillary bow and firmly press onthe lockscrew as illustrated in fig. 88 toinsure that the scope rests on the stage.

If the dial indicators do not register thecalibration values scribed on the cali-bration record on back of the stage,simply loosen the lockscrew on the faceof the dial indicator (fig. 88) and rotatethe face of the indicator until the indica-tor reads the desired value and thenlock the face in position. The field gageis now calibrated. Resecure the scopeto the face of the maxillary bow, remem-bering to make sure that you rotate theface of the indicator until the indicatorreads the desired value and then lockthe face in position. The field gage isnow calibrated. Resecure the scope to

the face of the maxillary bow, remem-bering to make sure that you rotate thescope in the same direction that youturn the lockscrew as you secure thescope to the face of the articulator. Atthis time the dial indicators will register“O” if both condylar elements of thearticulator are at the correct height.

If the height of the condylar elementsare out of specification proceed in thefollowing manner. On the posterioraspects of the horizontal crossbar arevertical adjustments (A) and verticaladjustment lockscrews (B) as illustratedin fig. 89. Loosen the vertical adjustmentlockscrews on both sides of the articu-lator. While applying downward pres-sure on the maxillary bow above thecondyles, manipulate both verticaladjustments until both dial indicatorsread +5 to +10. A plus reading indicatesthat the condyles are below the desiredheight. Note that when you change theheight of one condyle it affects the read-ing on both dial indicators. Snug thevertical adjustment lockscrews to firmlyseat the pins supporting the condylarelements in their housings but do nottighten all the way. At this time bothcondylar elements are just below thedesired height. Alternately tighten thevertical adjustment screws in smallincrements on the right and left sides ofthe instrument until both dial indicatorsread “O”. Tighten the vertical

fig. 87

fig. 88

48

adjustment lockscrews to secure thecondylar elements in this position.

HORIZONTAL ALIGNMENTThe articulator must be in specificationin the vertical dimension before horizon-tal alignment is made.

On the scope member of the FieldInspection Gage are two forty power(40x) monocular scopes. You are to lookthrough these scopes one at a time. Ineach scope is a reticle graduate in onethousandths of an inch (.001”) incre-ments in four directions off of a centricdot as illustrated in figure 90A. On thelateral wings of the stage are crosshairtargets as illustrated in figure 90B. If anarticulator is in perfect specificationanterior-posteriorly and medio-laterally,the intersection of the target crosshairswill touch the centric dot of the reticle asin figure 90C when viewed through thescope. If the articulator is out of specifi-cation as illustrated in figure 91, theamount it is out of specification can bemeasured with the graduated reticle. Forexample, figure 91 illustrates the viewthrough the scope of an articulator outof specification ten thousandths of aninch (.010”) medio-laterally and eightthousandths of an inch (.008”) anterio-posteriorly.

To align an articulator in the horizontalplane, proceed in the following manner.

On the back of the stage is a calibrationrecord as illustrated in figure 87. Thetwo small circles on the lower portion ofthe record are the calibration records forthe scope’s on the respective sides ofthe articulator. Each graduation off ofthe centric dot represents one thou-sandths of an inch (.001”). the totaldiameter of each small circle representsa little over four thousandths of an inch(.004”), or about the thickness of normalwriting paper. In each of the small circlesyou find a scribed cross mark. This markrepresents the true centric position. Inother words, when you look through themonocular scopes, the true centricposition in some gages is that positionindicated by the scribed cross markedon the calibration record.

fig. 89

fig. 90

fig. 91

AB

49

This calibration system is used becausein manufacture, slight creepage of thecentric dot of the reticle can occur. Thiscalibration system allows for correctionsof this error and maximum accuracy.

In the following instructions to adjust thehorizontal alignment of the articulator, itis assumed that the scribed crossesmarked on the calibration record coin-cides with the centric dots of the reticle.

Loosen the horizontal adjustmentlockscrews illustrated in figure 92 onboth sides of the articulator the mini-mum amount necessary to allow hori-zontal crossbar. Engage the centriclatch of the articulator. While maintain-ing slight downward pressure on thehorizontal crossbar of the lower memberof the articulator to keep the horizontalcrossbar seated flush on the crossbarsupports, slide the horizontal crossbarand maxillary bow assembly in the hori-zontal plane until the centric dots are onthe junction of the crossbar targets asviewed through both scopes. Then whilecarefully maintaining this crossbar posi-tion incrementally tighten in a crisscrosssequence the four horizontal adjustmentlockscrews.

The articulator in now calibrated in thecentric position.

RUN-OUT INSPECTIONPROCEDUREThe articulator was aligned by means ofthe Field Inspection Gage with the pro-trusive condylar path inclinations set to30 degrees. Readjust the right protru-sive condylar path to 10 degrees andtighten the lockscrew. Record the read-ing on the right dial indicator. The tworeadings indicate the amount of run-outof the articulator adjustment. Factoryspecifications require that all articulatorshave a run-out of less than plus orminus five thousandths of an inch(+.005”).

REINSERTION OF THEADJUSTABLE INCISAL PINAfter an articulator is properly aligned bymeans of a Field Inspection Gage, themost convenient way to set theadjustable incisal pin to an accuratezero position is to remove the incisal pin#1 and reinsert the incisal table andadjustable incisal pin set to zero. If thedial indicators do not read zero theheight of the adjustable incisal pin canbe minutely adjusted until the dial indi-cators read zero.

INTER-BOW GAGE PIN #2Inter-bow gage pin #2 is used to pre-cisely adjust incisal pins to the zerodimension in articulators and LabRelators known to be in specification.The incisal pin is raised and the inter-bow distance is established by meansof the inter-bow gage pin #2, as illustrat-ed in figure 93.

The adjustable incisal pin is then adjust-ed and secured to maintain the inter-bow distance established by the inter-bow gage pin #2. It is important to applydownward pressure on the top of theadjustable incisal pin as the lockscrew istightened to prevent upward creepageof the incisal pin when tightening thelockscrews as illustrated in figure 94.

fig. 92

HorizontalAdjustment Screws

50

Use of the inter-bow gage pin #2 requiresa little care and skill. Therefore, after thisadjustment is made be sure to checkcarefully to confirm that the inter-bowdimension of the gage pin was in facttransferred to the adjustable incisal pin.

fig. 93 fig. 94

51

The Broadrick Occlusal Plane Analyzeris used for analyzing the Curve of Speeand developing an acceptable curve ofocclusion, and is recommended for lab-oratory procedures employing theFunctionally Generated Path Technique.

Note: This text describes themechanical function of the BroadrickOcclusal Plane Analyzer. The readeris urged to refer to other textualmaterial as well as classes devotedto the clinical application of this pro-cedure in occlusal correction.

A Broadrick Occlusal Plane Analyzer, fig.95, consists of (1) Card Index #300061,(1) Bow Compass #300087 withgraphite leads of varying hardness,1 (1)extra center points #300088, (`1)Scribing Knife #3017, (1) Needle Point#300089, and (2) Plastic Record Cards#300066.

To use the Occlusal Plane Analyzer thecasts are mounted in the articulator andthe articulator condyles and incisal con-trols are adjusted in the conventionalmanner. The Occlusal Plane Analyzer isattached to the upper bow of the articu-lator as illustrated in fig. 96 by securingit beneath the screws which hold themaxillary mounting plate and incisal pinassembly in place.

It is pointed out that during the ensuingprocedure, the maxillary cast must beremoved from the articulator during thesurvey.

Secure a plastic record card on the rightside of the flag. The plastic record cardsare matte finished on both sides andreadily accept pencil or ink markings.

The relatively small divergence betweenarcs of 3 3/4”, 4”, and 5” radii over thefunctional occlusal surfaces on thelower posterior teeth is shown in fig. 97.An average of 4” radius may be used inthe majority of surveyed cases.Variationis only necessary when a pronouncedCurve of Spee may require a selection ofup to a 5” radius.

APPENDIX DOCCLUSAL PLANE ANALYZER

1. Graphite leads of preferred hardness may be obtained locally from drafting supply houses.

fig. 95

fig. 96

52

A view through both lower secondmolars, fig. 98, illustrates the smalldivergence between arcs of the samethree radii at the functional occlusal sur-faces on the Curve of Wilson.

Insert a piece of graphite lead into thebow compass, tighten thumbscrew, andsharpen to a suitable point. Adjust thebow compass to the radius selected (inthis instance 4”) (fig. 99).

Remove the upper cast, fig. 100, andposition the center point of the bowcompass, set at the 4” radius, on theanterior survey point (A.S.P.) which isusually the disto-incisal angle of thecuspid. If the cuspid is worn flat, theA.S.P. may be at the incisal edge. In anyevent, this point must be selected as themost desirable to “beam” the line andplane of occlusion posteriorally. Onceselected, it is marked on the cuspid andNOT CHANGED. With the center pointof the bow compass positioned on theA.S.P., apply a long arc with the graphitelead (about 3”) on the plastic recordcard. The occlusal plane survey center

(O.P.S.C.) will ultimately be located onsome point on this arc.

Select the posterior survey point (P.S.P.)at the disto-buccal cusp tip of the lastlower molar (fig. 101). Should nonmolars exist, replace the upper cast andplace soft modeling compound over thelower ridge and close the articulatoruntil the incisal in contacts the incisalguide in centric relation. Chill the com-pound and carve away any excess,leaving only the compound contactingthe upper fossae (simulating the lowerbuccal cusp). Remove the upper castand select a P.S.P. on the modelingcompound in the same manner as theP.S.P. was selected on the last molar asdescribed above.

Position the center point of the bowcompass on the P.S.P. and apply an arcwith the graphite lead to intersect thearc from the A.S.P.

Alternate to the molar P.S.P. is a positionon the condylar element of the articulat-

fig. 97

fig. 98

fig. 99

53

or at the middle of the anterior margin ofthe hole on the lateral aspect of thecondyle (fig. 102). Position the centerpoint of the bow compass on thecondylar posterior survey point(C.P.S.P.) and apply an arc with thegraphite lead to intersect the arc formedfrom the A.S.P.

Continue with fig. 101 or 102 and sub-stitute the needle point for the graphitelead. Place the center point of the bowcompass adjusted to the 4” radius at theintersection of arcs on the plastic recordcard (initial occlusal plane survey cen-ter). Sweep the needle point over theocclusal surfaces of the lower posteriorteeth to see how the arc conforms to theexisting occlusal plane. Shift thisocclusal plane survey center (O.P.S.C.)on the long arc on plastic record card(A.S.P. line) until the most acceptableline and plane of occlusion is found. Toraise the line and plane of occlusion atthe distal end, move the point anterior tothe arc intersection.

To lower the line and plane of occlusion,move the point posterior of the intersec-tion. By trial and retrial, the ideal survey

center forming the most acceptable lineand plane of occlusion will be located.

Upon thorough and considered study,locate the best possible line and planeof occlusion for the lower posterior teethto harmonize with all other factors. Thecenter point of the bow compass is nowpierced into this ideal O.P.S.C. on theplastic record card and circled with pen-cil or ink for subsequent relocation. Itmay be advantageous to mark “R”(right) in the upper corner of the plasticindex card for identification (fig. 103).

fig. 100 fig.101

fig.102

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A plastic record card is now secured tothe left side of the flag and marked “L.”Repeat the procedure commencing withfigure 99 for the left survey.

The scribing knife, as furnished, is forplacement into the bow compass forscribing or cutting plaster, compound, orwax during the occlusal plane correc-tion. The edge of the scribing knife maybe sharpened to individual requirementsas the edge supplied may not meet yourpreference.fig.103

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Articulators and other occlusal instru-mentation exists to facilitate both thediagnostic and treatment procedures forthe fabrication of restorations from thesingle tooth to the complete dentition.The question often arises regarding theselection of the instrument of choice fortreating a particular prosthondonticproblem. To answer this question it is ofvalue to first briefly review the progressthat has taken place with the develop-ment of instruments for occlusal treat-ment and its impact on prosthodontictechniques. This will also shed light onwhy there are so many different instru-ments being used.

The earliest articulators, which were ofthe hinge type, were developed primari-ly for full denture construction; i.e., to fillthe need for a mechanical device torelate casts in an anatomically correctposition for the arrangement of artificialteeth.

The next breakthrough resulted from thedesire to duplicate nature’s scheme andprovide patients with improved appear-ance and speech. This led to improveddenture teeth of anatomical form. Also,understanding the anatomy and func-tions of the temporomandibular jointsand their relation to the occlusal schemebrought about the development of artic-ulators of anatomical dimensions withsome adjustment capability to simulatethe more pronounced condylar move-ments of a given patient. These articula-tors were adjusted primarily to interoc-clusal records.

Since the articulators were still not com-pletely adequate, the mouth was foundto be the best articulator to fabricatewax patterns and casting that would beattached to the natural teeth and becompatible with the excursive move-

ments of the jaw. These early articula-tors and occlusal schemes, that wereused to construct dentures resting onmobile tissues, had to be supplementedwith more “in the mouth” procedures toproduce satisfactory results for fixedrestorations.

A great advance came in the late 1940sand early fifties with the popularizationof the “indirect technique” i.e., the useof impressions, casts and dies to dupli-cate the dentition so that most of thework could be done in the laboratory ata bench rather than “in the mouth.” Theintroduction of improved dental materi-als to conveniently develop accurateimpressions and full arch working castscoupled with the advent of high speedcutting tools in dentistry popularizedrestorative procedures for the generalpublic which heralded in a new era inthe development of instruments forocclusal diagnosis and treatment.

Dentists sought more practical means toaccuratelly record and simulate themovements of the jaw in order to deliverbetter restorations in less time throughboth improved laboratory work andoperating efficiency. The goal was toproduce better dentistry faster. It wasthis effort and series of events thatresulted in the development of theDénar® Pantograph and Fully AdjustableArticulator and subsequently theDénar® Mark II System and the Dénar®

Two Instrument System.

Questions often asked are: “Should apantograph and fully adjustable articula-tor be used to fabricate a single goldcrown?” and “How extensive must therestoration be before the use of a panto-graph is indicated?” The simplestresponse to these questions is as fol-lows. If after tooth preparation, there

APPENDIX ESELECTING INSTRUMENTS FOR OCCLUSAL TREATMENT

56

are sufficient unprepared teeth to pro-vide positive stops and guidelines towhich to construct the restoration, therestoration can be constructed in har-mony with the existing occlusion andthe use of a pantograph is not neces-sarily indicated. On the other hand, ifafter tooth preparation, there are insuffi-cient guidelines in the remaining occlu-sion to which to construct the restora-tion, the restoration should be con-structed in harmony with the patient’stemporomandibular joint characteris-tics. These characteristics can be diag-nosed most efficiently with a panto-graph and fully adjustable articulatoralthough other treatment methods areavailable.

In order to better understand the criteriafor selecting the instrument of choice forocclusal treatment a discussion of theexamples on the chart below is helpful.In this discussion reference is made pri-marily to the pantograph and fullyadjustable articulator; however the MarkII System utilizing checkbites and sup-plemented with occlusal equilibrationand the functional generated path tech-

nique, when indicated, can be used toproduce excellent results.

To keep the discussion pertinent, it isassumed that none of the patients in thefollowing examples have temporo-mandibular joint disease.

PATIENT A is a finished orthodonticpatient who has a full complement ofteeth in good alignment. The patient hasa slight occlusal prematurity which hastriggered facial pain. The patient has apathologic occlusion and occlusal treat-ment is indicated. The treatment is pri-marily occlusal equilibration. An articu-lator can be used in diagnostic proce-dures although it is not always neededin treatment.

PATIENT Z on the other hand exhibitsmany missing teeth. The remaining teethare badly broken down. There is exten-sive drifting of teeth and the occlusion istotally disorganized. This patientrequires a complete mouth reconstruc-tion. This restoration could be fabricatedmost efficiently by employing a panto-graph and fully adjustable articulator.

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At what point between the two extremesrepresented by Patient’s A and Z is theuse of a pantograph and fully adjustablearticulator indicated? The answer to thisquestion is presented in the followingdiscussion of Patient’s B through E whoexhibit increasingly complex occlusalproblems.

PATIENT B has a missing right secondbicuspid and a minor centric prematuri-ty. There are no symptoms which can berelated to the occlusal condition. Thepatient has a physiologic occlusion. Therecommended treatment is a three unitbridge. To perform this laboratory pro-cedure the cast can be accurately relat-ed at the correct vertical dimension in anonrigid cast relating device such as aJohnson Olgesby Articulator (which hassprings for condylar posts so that thecasts can be gnashed together) and thebridge fabricated in harmony within theanatomical guides provided by the pre-vailing physiologic occlusion. This pro-cedure could be used successfully if therestoration were one, two or threecrowns on one, two or three of the teethinvolved in the bridge. Alternately amethod preferred by many operators isthe use of the functional generated pathtechnique (FGP) to fabricate this pros-thesis.

PATIENT C has the same mouth condi-tions and occlusal scheme as Patient Bwith the exception that the occlusalscheme has triggered bruxism and thesequelae of bruxism (occlusal disease).This patient first requires occlusal treat-ment and in addition, a three unit bridge.The recommended procedure is to firstequilibrate the natural occlusion to estab-

lish a physiologic occlusion and subse-quently fabricate the three unit bridge (orinlays) as outlined for Patient B.

PATIENT D has the right second bicus-pid missing and in addition the rightsecond molar has indications for fullcoverage. Slight occlusal discrepanciesexist. Whether this patient has relatedsymptoms or not, the procedure manydentists would recommend when thismany teeth are involved in the prosthe-sis is to fabricate the restoration in cen-tric relation. Since after tooth prepara-tions there are no more anatomical con-trols in the occlusion on the right side ofthe mouth to use as anatomical guidesto which to fabricate the restoration,then the next most posterior anatomicalcontrol, the temporomandibular joint, isused as a control for the fabrication ofthe prosthesis (see figures 26C and 27and related discussion). This could beaccomplished most efficiently by utiliz-ing a pantograph and fully adjustablearticulator.

PATIENT E. If Patient B had in additionto the missing right second bicuspid theright second molar missing, the recom-mended treatment would be the sameas for Patient D.

Restorations more involved than thosepreviously listed could all be operatedmore efficiently by employing a panto-graph and fully adjustable articulator oralternately by means of the Mark IISystem supplemented with the func-tional generated path technique and/orocclusal equilibration as describedabove.

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APPENDIX F

Dénar® SemiadjustableArticulator

Mark II Articulator(includes #300197 pin andD41AB platform)

Mark II-P2T2 Articulator(includes #110093 pin andD41 platform)

Mark II-P2T3 Articulator(includes #110093 pin andD46 adjustable incisal table)

P1 (#300197)-round incisal pinfunctions with the D41AB incisalPlatform which has a detent inits superior surface.

P4 (#300270) round shortIncisal Pin functions with theD49 Incisal Platform which has aflat surface

P2 (#11093) Adjustable Incisal Pinfunctions with the D46 AdjustableIncisal Table and the D41 customIncisal Platform

Earbow/Facebow D31AB Bite Fork - StandardDentulous

Bite Fork - Edentulous

Anterior Reference Pointer

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Maxillary Cast Support Remount Record Jig

Mounting Plates Magnetic Mounting System

Dawson Fossa-Guide Pin Pantograph Mounting Fixture

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Your Whip Mix® Articulator is a precisioninstrument and requires care and main-tenance. Periodic cleaning and lubricat-ing as described below will assure pro-longed life and dependable service fromthe instrument. Failure to follow theseinstructions will void your warranty.

CLEANINGUse a mild soap and water solution withthe aid of a brush to dissolve accumula-tions of wax and to wash away car-borundum grit. Then air dry and lubri-cate. DO NOT use strong detergents,alkalines, gasoline or naptha as cleaningagents.

LUBRICATIONLubricate the working and bearing com-ponents with thin film of sewingmachine or high speed handpiece typeoil. Wipe off excess oil to prevent accu-mulations of dust or grit.

A thin coating of petroleum jelly must beapplied to all articulator surfaces thatwill be contacted by the gypsum mount-ing material

STORAGEStore the articulator in a clean, dryatmosphere free of plaster and car-borundum dust; away from acids, alka-lies or corrosive medicaments. Wait afull day after mounting casts beforestoring the articulator in a carryingcase or corrugated carton. Moisturedissipation from the stone in anenclosed area causes alkalinity of thestone mixture which can damage thearticulator surface.

WARRANTYWhip Mix Corporation warrants thearticulator system to be free fromdefects in material and/or workmanshipfor a period of one year. In the event ofa defect, please notify the factory inwriting of the defect prior to returningthe instrument. Whip Mix will, at itsoption, either repair, replace or issuecredit for such defects.

Because Whip Mix Corporation is con-tinually advancing the design of itsproducts and manufacturing methods, itreserves the right to improve, modify ordiscontinue products at any time, or tochange specifications or prices withoutnotice and without incurring obligations.

APPENDIX G

ARTICULATOR

CARE AND MAINTENANCE

FN 80471-F AE R1008

Whip Mix Corporation - West1730 East Prospect Rd., Suite 101

Fort Collins, CO 80525Toll-Free: 1-800-201-7286

Fax: 1-970-472-1793www.whipmix.com

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©2008 Whip Mix Corporation

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The

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TECHNIQUEMANUAL