Tip edge technique

Contents Introduction Tip edge concept Tip edge brackets Tip edge auxiliaries Differential Straight Arch Technique Stages of treatment Final Finishing Conclusion References

Introduction

Since the 1900 Angle introduced various appliances :

Angle’s E-arch Pin and Tube appliance(1910) Ribbon arch appliance (1915) Edgewise appliance(1925)

Edgewise appliance

Labially facing horizontal slot 3-dimensional control over tooth Very high forces were used Anchorage depends on extra oral forces No provision for closure of posterior spaces Arch wire slot restricts the anteroposterior

correction of dental arches

During the early 1930s, P.R Begg reverted to the use of ribbon arch brackets-

Permitted free tipping followed by controlled uprighting Use of round wires Use of differential forces(2 oz) Demands on anchorage units was reduced However the vertically facing slot had the following

limitations: Hindrance in manipulation Reduced mesio-distal control

Begg appliance

Straight wire appliance

1970s Dr Lawrence Andrews introduced the Straight Wire “bracket system”

Concept of Preadjusted appliance-

Tip, torque, in-out compensations for each tooth was available.

Limitations of conventional Straight Wire bracket Moving teeth apex first generates maximum

anchorage resistance Torque control - unwanted reciprocal torque reaction in

adjacent teeth Full expression of torque not achieved- “torque slop”

due to play between bracket and arch wire

Tip edge concept

Peter C Kesling decided to combine both the techniques

Modified a straight wire bracket ,to create Tip Edge bracket

Technique was first introduced at the Kesling-Rocke Orthodontic Centre,Westville,Indiana,USA in 1986.

Differential force technique: initial crown tipping followed by controlled root uprighting with straight arch wires (differential tooth movement with straight arch wires). Therefore it is known as the “Differential straight arch technique”

Arch wire slot permits initial crown tipping mesially or distally and faces horizontally, the slot and bracket are termed “Tip Edge”

Features of tip edge appliance Labially facing arch wire slots –improved

manipulation with elastomeric ties Light forces(2 oz) Reduced strain on anchorage With a rectangular slot ,a 3-D control was afforded Slots open and close during treatment for maximum

ease of arch wire change and minimal discomfort Facilitated intrusion of teeth.

Tip edge brackets

Kesling determined that : It is necessary for each tooth to tip

either mesially or distally –not both directions

All teeth tip distally except those distal to the extraction sites-which tip mesially

Anchor molars should remain upright throughout Rx.

Diagonally opposite corner were removed Permits desired distal crown

tipping Preadjusted in 3 dimensions-

tip,torque,in & out built in Slot size-0.022”x0.028”

Central ridge

Uprighting surface

Lateral extensions

Profile view Occlusal view

Tipping surface

Design features Slot size: 0.022”X0.028” Vertical slot: 0.020”x0.020”- to accept rotating or

up righting springs, power pins ,jigs etc. Both the gingival and incisal ends are chamfered to facilitate the insertion of auxiliaries from either direction.

Lateral extensions- for rotational control hidden behind the arch wire –which is esthetic.

In and out compensation-eliminates the need for lateral, bicuspid or molar offset

Torque built in base Tip built in face

Slot permits initial M-D tipping ,this prevents bowing of arch wire during retraction/space closure and automatically enhances anchorage.

Uprighting surfaces of the slot determine the final tip angulations reached with an uprighting spring. These surfaces can also control torque if an edgewise arch wire is used.

Types of bracket

Narrow metal tip edge bracket

Twin metal tip edge bracket

Narrow ceramic tip edge bracket

Twin version of bracket - 018” or 022” slot size

Known as “Freedom brackets” Disadvantages :

Unaesthetic

Extra bulk-occlusal interferences and accidental

debonds

Mechanical disadvantage when Side Winder springs

are added

Tip edge brackets for first premolar extraction cases

Tip edge brackets for second premolar extraction cases

Tip edge brackets for non extraction or first molar extraction cases

Preadjusted in 3 dimensions-

tip,torque,in & out built in

Tip and torque values for maxillary brackets

Tip and torque values for mandibular brackets

Placement of tip edge attachments Positioning jigs used for bracket placement

Positioning jigs used for bracket placement

Mid crown position is recommended (Parkhouse)

Bracket should be aligned with it’s vertical axis parallel with the long axis of the tooth

Mesio-distally at the midpoint

Height of the bracket should be at vertical midpoint of the fully erupted clinical crown

Jigs can be modified by cutting off the horizontal section leaving only straight vertical markers

Rationale behind a mid crown bonding

Prescribed torque value in the bracket base is effectively expressed

Initial tipping will be more by the incisal placement of the bracket but it also requires an increased amount of root uprighting

Side Winder springs are placed at greater mechanical disadvantage if the distance between the point of rotation and the root apex is increased—resulting in loss of eficiency

Also mid-crown position reduces occlusal interference therefore decreases the number of accidental debonds

Molar tubes Parallel to occlusal surfaces Upper molar tubes placed at the same level as

the bicuspid

Universal premolar tip edge brackets

Similar tip and torque for 1st and 2nd premolars

So, possible to have just 2 upper and 2 lower bicuspid brackets.

Can be switched from R to L side to provide clockwise or counterclockwise crown tipping.

Identification of brackets Arrow - direction of tipping Premolar jigs are modified

by the addition of a 90° angle at the tip of the jig which indicates the direction of tipping

Origin from Queen’s University ,Belfast –called as “Irish jigs”

Auxiliaries used in Tip Edge Technique1.Molar tubes Keep molars upright and permit free sliding of arch wire.

Three types: Single round tube with torquing flap Combination edgewise(0.022”X0.028”) and round

tubes(0.036”) Combination edgewise and flat oval tube for increased

bucco-lingual control

Single round tube with torquing flap Combination of rectangular and round tube

Combination of rectangular and oval tube

Rectangular slot is at the same level as premolar brackets.

Permits the placement of straight arch wire Round tube dimensions:

0.036”inside diameter,0.250”length

Rectangular tubes are of Easy-Out R TP design with the posterior inner lumen slightly flared towards the occlusal. Facilitates archwire removal when a cinchback has been used

2.Tip edge rings Elastomeric rings designed

to function with tip-edge brackets

Designed to retain archwire and prevent mesial and distal tipping during Stage III

Lingually facing lug on either end of the crossbar wedge between the archwire and the bracket to control mesiodistal inclination of the tooth

Straight Shooter (ligature gun)

Advantages

Less time consuming

Places less pressure on the tooth ,more comfortable for the patient

3.Rotating Springs For correction of

rotation Preformed from 0.014”

ss wire Inserted from gingival

aspect

4.Mesiodistal uprighting springs

Optimal means to upright teeth mesiodistally

Standard and Side-winder designs

Provides localised tip control of individual teeth without archwire modification

Fabricated from 0.014” ss archwire

Side-winder springs Coils rest on the labial

surface of the bracket Improves:

Esthetics Hygiene Choice to insert from

gingival or occlusal aspect Mechanical advantages as

centre of the coil is concentric with the centre of the bracket

Invisible Side Winder springs

Wire of spring lies on archwire and bracket

Advantages: Retained in position by the

elastomeric module, in addition to it’s own spring pressure

Enables modules to be changed if necessary, during the root uprighting process without removing springs

Because bulky hook has been eliminated, spring arm has a wide range of activation

Direction of insertion Occlusal and not gingival Masticatory forces coming occlusally are deflected

harmlessly off the coils of a correctly inserted spring, keeping these in close proximity to the bracket face.

If inserted from gingival, occlusal forces might distort them labially away from the bracket –spoils the action of the spring as well as causes discomfort

Identification of spring Spring arm points in the

direction towards which the occlusal tip will rotate

5.Bilevel pins Used to capture auxiliaries

behind tie wings of the bracket

Heads of pins function to retain the auxiliaries and to tie ligature

When used with open coil spring; eliminates the need to use vertical loops or to remove main wire to remove coil

6.Power pins Ideal auxiliaries to engage

elastic or elastomeric Can be inserted from

occlusal or gingival Low profile head with 15°

inclination reducing the need for right and left pins

Can be inserted or removed while both ligature and archwires are in place

7.E-links Elastomeric links

stamped from thermoset material

Less hydrophilic than thermoplastic material

Available in graded lengths

E1to E4 smaller size with no tabs

E4 to larger sizes with tabs

8.Archwires U/L 0.016” round ,hard,resillient wires Vertical loops may be bent into the initial wire Small segment of co-axial wire 0.014” or 0.016” NiTi as auxiliary wires for alignment Advantages:

Rapid anterior bite opening and improve molar control Reduces the number of archwires required to treat a

specific case

0.022” SS used during space closure and final uprighting or torquing

Rectangular archwires retained in brackets with tip-edge rings offer the final expression of tip and torque predetermined in the bracket slot

0.0215”X0.028” SS archwire are preferred for final finishing

Concept & Function

Bite opening Tip-edge slots facilitate intrusion of teeth along the path

of least resistance without creating lateral root movements—open deep bites without the need for extra oral forces

Intrusive forces from: Properly bent 0.016” high-tensile SS wires,

Use of Light inter maxillary elastics(2oz).

Retraction and Space closure without loss of vertical control

Binding between slot and archwire In the canine area incisal deflection of

wire

No binding or incisal deflection of wire in tip edge slot

Dynamic arch wire slot

Tip edge slots become larger as the teeth tip. The vertical dimension within the slot continuously increases with each degree of distal tipping.

Inter bracket distance The tip edge bracket

provides automatic mesiodistal tip control

The tip edge bracket with its propeller shaped archwire slot can provide 100% interbracket distance in both planes.

As the crown is tipped distally, slot size increases, this permits passive engagement of full size SS wire with zero flexing.

Advantages No binding or archwire deflection during retraction Ease of stepping up of archwire size No inadvertent mesial or distal root movement Ease of placing rectangular archwires when third

order discrepancies exist between archwire and slot. No need to use NiTi archwires to avoid discomfort

and accidental debonding

“The Hammock Effect”When a ligature (especially

steel) is used to retain the archwire a “hammock effect” is created that tends to parallel the archwire with the gingival and occlusal edges of the tie wing tips.

This could influence mesial /distal inclinations

Steel ligature when tied loosely minimizes the hammock effect.

Anchorage consideration Extra oral anchorage is not required with Differential

Straight Arch Technique Forces are so light that adequate anchorage can easily

be formed within the mouth. Binding (as in edgewise slots) is nonexistent during

retraction. In DSAT,archwires move distally with anterior teeth

retraction and premolars are not bracketed during Stage I. Therefore no sliding friction occurs---no additional strain on anchorage.

Only friction is in molar tubes which is minimal because tubes are long with large diameter.

Axial inclination control

Controlled root movement which is Selective Physiologic Predetermined

Selectivity Selective axial tooth control w.r.t time and location Tip or torque is achieved by addition of Side-

Winder springs to the teeth requiring correction Rest of the teeth are left undisturbed Application of force is selective and adjacent teeth

are not “round tripped” Promotes stability and patient comfort

Limitation Design of the bracket automatically limits the

degree of M-D uprighting Uprighting continues until the control surfaces

within the slot strike the upper and lower surfaces of the archwire.

Torquing is also limited and ceases even though the spring remains active-determined by the torque built in the bracket

Physiologic Light and continuous forces are transmitted

through the auxiliaries Design of tip edge bracket prevents delivery of

high third order torque forces from flexed rectangular wire

Advantages of Tip Edge brackets

Over conventional edgewise brackets Eliminates undesired force couples to promote rapid

bite opening and prevent midline discrepancies Anchorage problems are eliminated as space can be

closed with light forces and minimum wire deflection. This results in diminished anchorage demands and increased vertical control.

Permits free crown tipping followed by controlled uprighting

Can reposition teeth and jaws with light forces and still maintain total control over their final positions.

Over Begg brackets Horizontally facing archwire slots facilitate initial archwire

engagement especially on rotated teeth. Elastomeric ties provide a cushion or flexibility that enhances patient comfort and reduces the chances for bond failure

In –out compensation eliminate the need for molar (or other) offsets.

Slot designs causes automotive shift from tipping to bodily movement at the predetermined angle and increase anterior anchorage to encourage mesial movement of posteriors –

“Programmed Differential Mechanics” Labio-lingual root torque from rectangular wires possible.

Three stage of Treatment

Stage I Objectives

Open (or close) the anterior bite Eliminate anterior crowding Close the anterior spaces Overcorrect the rotated cuspids and bicuspids Correct posterior cross bites Correct any mesiodistal malrelationships of the

buccal segment as necessary

Stage I archwires 0.016 S-S wire Preformed wires

Fabricated from 0.016” Bow flex archwires

These are size graded according to the distance in mm between the cuspid circles

Intermaxillary circles Bent in a vertical plane or inclined slightly labial located 1mm mesial to canine bracket Anterior portion of the circle is labial to the archwire to facilitate

engagement of distally directed ties or elastics

Advantages of cuspid circles: Easier to bend Can be rolled mesio-distally Less chance of breakageDisadvantage: Less retention of elastic if bent too small or tightly

Cuspid ties Prevents canine from

sliding distally along the wire

Not to be used when aligning crowded anterior teeth with co-axial or NiTi sectional wire

Bite opening mechanics Anchor bends placed 2 mm mesial to molars If reduced overbite or an open bite is present at

the start of the treatment, reduced degree of anchor bends are placed.

Also depends upon the angulation of molars-if molars are tipped mesially, reduced angulation required.

Intermaxillary elastics Use of light Class II elastics (1 to 2 oz)

Worn full time from upper cuspid circles to the distal ends of lower arch wire or from molar hooks

Overbite reduction is more effective with a more distal application of elastic to the molar which better resists distal crown tip and encourages fuller expression of the anchor bends to the anterior segment

Outrigger applianceTo encourage elastic wear

Auxiliary is threaded over an archwire formed with appropriate bite opening bends or sweeps but no intermaxillary circles

Has two elastic hooks that extend labially when elastics are not engaged

Hooks act as a painful reminder

Stage II Objectives:1.Close any posterior spaces

2.Maintain all corrections obtained during stage IEdge to edge relationship of anterior teeth

Anterior space closure

Over rotated cuspids and or bicuspids

Corrected mesiodistal molar relationship

Stage II archwires 0.020” or 0.022” hard round S-S wire Reduced anchor bends Molar offset (vertical) to compensate for the more

gingivally placed round tube Heavier archwires function as retainers to maintain

arch form and bite opening achieved during stage I Heavier wires can better withstand the forces of

occlusion-less likely to get distorted

Remove anchor bends, place sweep in the archwire

Upper- increased Curve of Spee

Lower- Reverse Curve of Spee

Insert wire into rectangular tube (Parkhouse)

Derotation of molar 1mm Molar offset and 10°toe-in for final visit of

stage II Initial stages no need to place these bends as it

increases friction

Levelling of molar Tipped back molars should

be leveled to allow the placement of rectangular archwires

Antitip bend of 10° opposite premolar-molar contact point

Ensures seating of the distal cusp of tipped molars

Can be combined with offset and toe-in

Space closure By E-links form buccal

hook on the first molar to cuspid circle

Available in graded lengths

Usually E-6 or E-5 is selected

Putting on the brakes:

Available space can be closed by protraction of the posterior teeth mesially :

a. Application of passive uprighting spring on the canine,

b.Tipping surface of the tip edge arch wire slots striking the archwire

c. Use of rectangular wire

Automatic canine rotational control during retraction Forces are not applied labial to the surface of

canines. Instead pressure is applied at their contact point

with the lateral incisor

Stage II checks Intervals 6-8 weeks Observe space closure Cut distal ends Check molar widths Labial segment position and inclination excessive Check midlines Check interarch-relationship Avoid overcompression

Pre Stage III To align the premolars Rotate anchor molars Level the occlusal plane Original 0.016 round archwire is used Increased flexibility helps to level occlusal plane

and elevate premolars Light lingual elastomerics to derotate molars Duration-- 6-8 weeks

Stage III Objectives:

Maintain all corrections achieved during stage I and stage II

Achieve desired axial inclination of all teethM-D inclinations are corrected by use of uprighting springsLingual or labial root torque is achieved through torquing auxiliary Tip edge rings maintain and/or influence teeth in final tip angulations

Stage III archwires 0.020” or 0.022” hard round S-S

wires- to counteract the reciprocal forces generated by auxiliaries

Heavy wire functions as retainer Separation of root moving forces

from the archwire permits the precise application of torque and uprighting pressures

Maxillary archwire slight constriction is placed in

the archwire (except in RME and class III malocclusion)

No anchor bends but a gentle curve of spee is given to deliver a gingival force

Maxillary archwire

Mandibular archwire Slightly expanded Slight anchor bends or

Reverse curve of spee Vertical offsets to

compensate for the level of molar tube

In class III Rx –widen the maxillary arch and narrow the mandibular

Cuspid ties are normally not used to allow uprighting of teeth to take place.

Mandibular archwire

Stage III Auxiliaries Torquing auxiliary

Conventional torquing auxiliary

Torque bars

Curved ribbon sections of 0.022 X0.028” Ni Ti formed with 20° of torque.

Individual root torquing auxiliary

Nickel titanium torque bar

Individual Root Torquing auxiliary

Deep Groove brackets For use with torque bars On the maxillary central

incisors Conventional preadjusted

edgewise slot cast into the bottom of tip edge slots.

During stage I and II ,cap fills the groove

In stage III,cap is removed and the torque bar is ligated tightly into the Deep groove under the round archwire.

Uprighting with Side Winder springs

Third order movement by second order force from a Side Winder spring in the presence of a rectangular archwire

Indications for rectangular archwires First proposed by Richard Parkhouse Simplifies treatment and increases stability during

all uprighting and torquing procedures To establish molar root torque

Preparation for rectangular Stage III After completing stage I, 0.016” wire is modified with

vertical curvatures instead of anchor bends ,to avoid the use of vertical offset

Wire is inserted into the rectangular tube instead of round tubes. This elevates premolar brackets to the level of rectangular tube

If premolars are too gingival –initially place the wire into round tube, then into rectangular tube.

Once premolars are aligned ,shift to 0.020” or 0.022” round wire

Rectangular stage III wire 0.0215”X0.028”

rectangular archwire with similar curvature as in round wire

Crimpable hooks are placed midway between canine and lateral incisor brackets facing gingivally

Mild Curve of spee in maxillary archwire and RCS in mandibular archwire

If initial open bite or reduced overbite, flat archwires are made

Compensatory buccal crown torque in anterior segment to restore zero torque

Pretorqued archwire 0.0215” X 0.028” rectangular archwire with lingual

crown torque (5° maxillary,8° mandibular) for deep bite cases

Centre line markings:Black—maxillary

Red--mandibular

Round or Rectangular archwires?? Severe anteroposterior discrepancy round wires

for stage III Also when molar torque or selective labiolingual

root positioning of canine or mandibular incisor is not required

Rectangular wires should not be used until the torque has been established by use of torquing auxiliary

Final finishing Use of rectangular wire during this stage Beginning with 0.019”X0.025” ,then 0.021”X0.028” for total

tooth control. Rectangular wires should pass through the rectangular

tube Tip edge rings can maintain or even capture the tip angles

in all bracket slots

All stage III objectives ,especially anterior root torque must be entirely completed before going to rectangular finishing archwires

Second molar alignment During Stage III, preliminary

alignment by a simple sectional device suggested by Dr Tom Rocke.

Straight 0.016”high tensile S-S sectionals

It runs through the channel of the gingival tie wing of the first molar, without being attached to it.

Mesially ends with a small occlusally inclined loop which hooks over the main archwire

Occlusal seating 0.019X0.025” braided

archwire and seating elastics

3 weeks later

Sectioning the main archwire Cut distal to each canine Molars and premolars, canine to canine tied

together to prevent spacing Light rhomboid elastics to allow settling of buccal

section

Tooth Positioners

Pre-Fit positioners come in different sizes (for extraction and non-extraction cases)

Inappropriate for individual tooth size discrepancies

Conclusion The tip edge bracket provides varying degrees of

tooth control not previously available in an edgewise type bracket.

Control ranges from a simple one-point contact and 100% interbracket distance with a round archwire to predetermined control in three planes with rectangular arch wire and a Tip-Edge ring.

It also offers advantages over ribbon-arch (Begg) brackets through ease of manipulation provided by the horizontally facing slot plus predetermined limitation of initial crown tipping and control of final root uprighting.

References

Tip Edge guide and the Differential Straight Arch Technique. Peter C Kesling

Orthodontics by Graber Vanarsdall. Tip Edge Othodontics.Parkhouse Dynamics of the Tip-Edge

bracket.PeterCKesling.AJODO1989;96:16-25 Treatment with Tip-Edge brackets and Differential

tooth movement.KeslingPC,Rocke TR,KeslingCK.AJODO1991;99:387-401

The Tip –Edge Concept:Eliminating Unnecessary Anchorage Strain.Kesling CK.JCO1992;26:165-178.

Thank U