Introduction to OcclusionIntroduction to OcclusionFundamentals of Occlusion & Articulation

Course Introductionand

Characteristics of an Ideal Occlusion

Course Textbook & Course Textbook & ReferencesReferences

► Textbook:Textbook: Management of Management of Temporomandibular Disorders and Temporomandibular Disorders and Occlusion; Jeffrey P. Okeson. 5Occlusion; Jeffrey P. Okeson. 5thth Edition Edition

► Secondary Reference:Secondary Reference: Textbook Textbook ► Main Reference:Main Reference: PowerPoint Files PowerPoint Files

All examination questions will be obtained from the

PowerPoint files that all students have access to.

Textbook reading is secondary, but still somewhat

essential to the understanding of the material. Exam questions are multiple

choice format (40 for mid-term and 50 for final

examination).

Exam Format andUse of References:

Date Morning (8 am - 12 pm) Afternoon (1 - 5 pm)

Wednesday Feb. 23, 2011Dr. Arcoria

Ironwood lecture hall; no SimLab1. Introduction to Occlusion2. Characteristics of An Ideal Occlusion (Chapter 5, pp. 109-125

Ironwood lecture hall; SimLab available3. TMJ Anatomy4. Muscles of Mastication (Chapter 1 pp. 1-26)5. Verification of Articulator mountings and settings

Thursday Feb. 24, 2011 Dr. Arcoria

Ironwood lecture hall; no SimLab1. Articular Disc Displacement2. Review for Quiz #1

Ironwood lecture hall; SimLab available3. Video/PowerPoint of waxing technique for occlusal contacts and cusp/fossa relationships4. Lab Project 1: Wax-up teeth # 8 and # 9 (Pass or Fail)

Friday Feb. 24, 2011 Dr. Arcoria  

Ironwood lecture hall; SimLab available1. Quiz #1 on 2/23 & 2/24 material2. Quiz #1 follow-up and discussion3. Lab Project 2: Wax-up tooth # 12 (Pass or Fail)

Ironwood lecture hall; no SimLab4. Interferences & Muscle Responses/Actions5. Review for Occlusion Exam 1

Occlusion Course ScheduleDr. Arcoria’s session

Occlusion Course ScheduleDr. Krupp’s session

Monday Feb. 28, 2011 Dr. Krupp

Ironwood lecture hall; no SimLab1. Occlusion Exam 1 (covers Feb 23 – 25 material)2. Mandibular Movement (Chapter 4 pp. 93-108)

Ironwood lecture hall; no SimLab3. Alignment, Static and Moving Occlusion (Chapter 3: pp. 67-91)4. Determinants of Occlusal Morphology(Chapter 6 pp. 127-146)

Tuesday Mar. 1, 2011 Dr. Krupp 

Ironwood lecture hall; SimLab available1. Quiz #2 Review2. Laboratory Project 3: Wax-up tooth # 3 (Pass or Fail)

Ironwood lecture hall; SimLab available3. Project 4: Wax-up tooth # 19 (Pass or Fail)4. Review for Laboratory Practical Exam

Wednesday Mar. 2, 2011 Dr. Krupp

Ironwood lecture hall; SimLab availableNeed to finish at 11:30 and be back at 1:30 (vendor fair)

1. Quiz 2 on 2/28 material2. Articulators (Chapter 18 pp. 567-588)3. Review for Occlusion Exam 2

Ironwood lecture hall; SimLab available4. Laboratory Practical Exam: Static and Moving Occlusion5. Project 5: Wax-up tooth # 6 (Pass or Fail)

Monday Mar. 7, 2011 Faculty

1. Occlusion Exam #2 (covers Feb 28 – Mar 2 material)  

Date Morning (8 am - 12 pm) Afternoon (1 - 5 pm)

Introduction to OcclusionIntroduction to OcclusionOcclusion Course Evaluation

Assessment Methods % of total Grade

Exam # 1 25 %

Exam # 2 25%

Quiz # 1 10%

Quiz #2 10%

Practical Exam 20%

Sim-clinic projects 10% Pass*

Total 100%

Range Final Grade

90-100% A

85-89% B+

80-84% B

75-79% C+

70-74% C

All successfully remediated

modules

 D

69% or below

I*

69% or below

F**

Occlusion Course Description

Static & Moving Occlusion Diagrams Practical Examination:You will be given a flash card booklet with quadrant diagrams displaying various mandibular movements. This booklet will be the entire basis of the moving occlusion practical examination. The National Board has about 3 or 4 of these questions on the exam every year.

Interferences and Muscle Actions Concept on Lecture Examination #1:It is important for the student to know the location of various mandibular-maxillary tooth interferences and which muscles are involved as a result of these types of interferences.

D-1 Occlusion Download Site:D-1 Occlusion Download Site:http://www.carcoria.com/asdoh-d1-occ/asdoh-d1-occ.htmhttp://www.carcoria.com/asdoh-d1-occ/asdoh-d1-occ.htm

Constant Communication from me to you. Updated every day during the course.

Right click on your mouse and save the files to your drive

**Note: this is a different web-site than the Dental Anatomy Course

Introduction to OcclusionIntroduction to OcclusionCriteria for Optimum Functional OcclusionCriteria for Optimum Functional Occlusion

Key Anatomical Landmarks:Temporal Bone: a portion of this bone forms the glenoid or mandibular fossa. The shape of this fossa determines many of the limits of mandibular movement

Mandible: a moveable structure which is suspended by musculature and whose movement is limited by ligaments.

Condyle: the portion of the mandible that articulates in the mandibular fossa. There is a right and left condyle, about which movement of the mandible occurs. The shape of the heads of the condyles determine many of the limits of mandibular movement. The mandible is the only bone in the human body that possesses two axes of rotation.

Dentition: the size, shape and alignment of the teeth determine many of the limits of mandibular movements. The role of the dentition is considered to be secondary to the role of muscles, ligaments and the bony structures which comprise the temporomandibular joint.

Basic Structure of the TMJBasic Structure of the TMJ

Two TMJ: When one moves, the other must move as well.

Basic Structure of the Basic Structure of the TMJTMJ

Glenoid or mandibular fossa

Articular eminenceMovement is characterized by position of condyle in

glenoid fossa

Basic Structures of the Basic Structures of the Temporomandibular JointTemporomandibular Joint

Condyle

Articular Disc

>Mandibular/Glenoid Fossa>Articular eminence: 1) Posterior slope, 2) Steepness/flatness guides movement

>Synovial cavities: 1) Joint lubrication, 2) boundary lubrication from motion

Ligaments Supporting the Ligaments Supporting the TMJ and the MandibleTMJ and the Mandible

Lateral Side of Mandible (outside)Medial Side of Mandible (inside)

•Limit movement

•Protect muscles

•Non-elastic

The Temporomandibular The Temporomandibular JointJoint

Basic StructuresBasic StructuresCondyleCondyle

Anatomic Anatomic variations guide variations guide mandibular mandibular movementmovement

► Retrodiscal tissueRetrodiscal tissue elasticityelasticity Highly innervated Highly innervated

and vascularand vascular Loading is painfulLoading is painful Trauma can cause Trauma can cause

inflammationinflammation

The Temporomandibular DiscThe Temporomandibular Disc

► Fibrous connective Fibrous connective tissuetissue

► Interface between Interface between bones, somewhat bones, somewhat pliablepliable

► Bi-concave shapeBi-concave shape► Collateral Collateral

ligamentsligaments► No InnervationNo Innervation► No VascularizationNo Vascularization

Terminology Related to Terminology Related to Mandibular Position and Tooth Mandibular Position and Tooth

PositionPositionBasic Premises:Basic Premises:

► When the mandible closes against When the mandible closes against the maxilla:the maxilla:

1.1. There is an ideal way for the teeth to There is an ideal way for the teeth to contactcontact

2.2. There is an ideal place for the condyle There is an ideal place for the condyle and disc to be situated.and disc to be situated.

Our task is to accomplish these two criteria in as non-obtrusive fashion as possible

Terminology Describing Terminology Describing ToothTooth Position: Position:

MAXIMUM INTERCUSPATIONMAXIMUM INTERCUSPATION► a.k.a. centric occlusion a.k.a. centric occlusion

(CO)(CO)► Habitual occlusion, Habitual occlusion,

habitual centrichabitual centric► Maximum intercuspation Maximum intercuspation

describes an describes an occlusalocclusal relationshiprelationship

► Teeth are contacting in a Teeth are contacting in a position that the patient position that the patient finds the most finds the most comfortablecomfortable

► Easily achievable, but Easily achievable, but not always reproducible, not always reproducible, by the patientby the patient

MAXIMUM INTERCUSPATIONMAXIMUM INTERCUSPATIONWhat is considered Ideal?What is considered Ideal?

Angle Class I: 1Angle Class I: 1stst Molars and Canines Molars and Canines relationshiprelationship

Adequate OverlapAdequate Overlap Long axis of teethLong axis of teeth Simultaneous Simultaneous

contactcontact► Posterior tooth Posterior tooth

dominancedominance► Anterior tooth Anterior tooth

“passive” contact“passive” contact► Multiple contacts on Multiple contacts on

all teeth adequately all teeth adequately distributes forcesdistributes forces

Term Describing Term Describing MandibularMandibular PositionPosition

CENTRIC RELATIONCENTRIC RELATION► Centric RelationCentric Relation

A A condylarcondylar positionposition Superior and AnteriorSuperior and Anterior Thin portion of discThin portion of disc Describes the most Describes the most

stable position of the stable position of the condylecondyle

Superior and anterior Superior and anterior position of the position of the mandible with the mandible with the disc properly disc properly interposedinterposed

Terms Describing Mandibular Terms Describing Mandibular PositionPosition

► Centric RelationCentric Relation Why a superior Why a superior

and anterior and anterior position?position?

The Muscles of The Muscles of Mastication drive Mastication drive this processthis process

In an Ideal Occlusion, CR and In an Ideal Occlusion, CR and MI Occur Simultaneously.MI Occur Simultaneously.

► An occlusal positionAn occlusal position► If CR and MI do not If CR and MI do not

coincide, the patient coincide, the patient will have a “slide”will have a “slide”

► Most patients have Most patients have some degree of a some degree of a slide into maximum slide into maximum intercuspation intercuspation (approximately 1-2 (approximately 1-2 mm)mm)

► MI is simultaneous MI is simultaneous contactcontact

► Forces concentrated Forces concentrated on long axison long axis

► Posterior contacts Posterior contacts should dominateshould dominate

Maximum IntercuspationMaximum Intercuspation

Slide from CR to MISlide from CR to MI► Only 15% of the Only 15% of the

population have no CR population have no CR to MI discrepancyto MI discrepancy

► After the first contact in After the first contact in CR (usually on 2 or CR (usually on 2 or more posterior teeth), more posterior teeth), the patient continues to the patient continues to close, and the teeth close, and the teeth come together more come together more completely (MI). The completely (MI). The condyles condyles mustmust move move out of their most ideal out of their most ideal position when the teeth position when the teeth come fully together.come fully together.

An ideal occlusion…An ideal occlusion…

Basic Premises:Basic Premises:

► When the mandible closes,When the mandible closes,

1.1. There is an ideal way for the teeth to There is an ideal way for the teeth to contactcontact

2.2. There is an ideal place for the condyle There is an ideal place for the condyle and disc to be situated.and disc to be situated.

The condyle seats in CR simultaneous with The condyle seats in CR simultaneous with the teeth occluding in MI. No slide occurs.the teeth occluding in MI. No slide occurs.

Characteristics of an Ideal Characteristics of an Ideal OcclusionOcclusion

Terms for Describing Terms for Describing Eccentric Movements of the Eccentric Movements of the

MandibleMandible

► Protrusive -Protrusive - anterior anterior movement of the movement of the mandiblemandible

► Retrusive -Retrusive - posterior posterior movement of the movement of the mandiblemandible

► Eccentric -Eccentric - movement movement away from a centric away from a centric position (CR or MI)position (CR or MI)

Protrusive

Terms for Describing Terms for Describing Eccentric Movements of the Eccentric Movements of the

MandibleMandible

In an ideal occlusion, protrusive In an ideal occlusion, protrusive movement is guided by anterior teeth.movement is guided by anterior teeth.

Early lateral movements are ideally canine-guided.

Terms for Describing Terms for Describing Eccentric Movements of the Eccentric Movements of the

MandibleMandible

Lateral movements-Lateral movements-moving the moving the mandible to the mandible to the left or to the right.left or to the right.

Shown is a “left lateral movement”

Terms for Describing Terms for Describing Eccentric Movements of the Eccentric Movements of the

MandibleMandibleLateral movements-Lateral movements-

During a left lateral During a left lateral movement, the movement, the leftleft sideside of the of the arch is considered arch is considered to be the to be the “working side”.“working side”. Shown is a “left lateral movement”

Terms for Describing Terms for Describing Eccentric Movements of the Eccentric Movements of the

MandibleMandibleLateral movements-Lateral movements-

During a left lateral During a left lateral movement, the movement, the right right side side is considered to is considered to be the be the “balancing “balancing side” side” or or ”non-”non-working” side.working” side. Shown is a “left lateral movement”

Terms for Describing Terms for Describing Eccentric Movements of the Eccentric Movements of the

MandibleMandible

Lateral movements are guided by either:Lateral movements are guided by either:

group function group function (secondary choice)(secondary choice)

canine guidance (ideal)canine guidance (ideal)

Terms for Describing Terms for Describing Eccentric Movements of the Eccentric Movements of the

MandibleMandibleCrossoverCrossover is an extreme movement where the is an extreme movement where the mandibular canine “crosses over” the maxillary mandibular canine “crosses over” the maxillary

canine.canine.

• This position is outside the envelope of function

•It is critical to the success of anterior restorations.

Extended lateral movements should smoothly transfer from the canines to the incisors

Summary of Characteristics of Summary of Characteristics of an Ideal Occlusionan Ideal Occlusion

►CR and MI occur simultaneouslyCR and MI occur simultaneously►All teeth contact simultaneouslyAll teeth contact simultaneously►All occlusal forces are longitudinalAll occlusal forces are longitudinal►Posterior tooth contacts dominatePosterior tooth contacts dominate►Eccentric movements are anterior-Eccentric movements are anterior-

guidedguided►No cross-over contacts on No cross-over contacts on

posterior teethposterior teeth

Summary of Criteria for an Summary of Criteria for an Optimal Functional OcclusionOptimal Functional Occlusion

► Condylar position-Condylar position- Centric relation Centric relation► Tooth position-Tooth position- Maximum intercuspation Maximum intercuspation► ProtrusiveProtrusive movements are guided by movements are guided by

anterior teethanterior teeth► LateralLateral movements are canine guided.movements are canine guided.► Axial loading of occlusal forcesAxial loading of occlusal forces► In MI, posterior tooth contacts dominate.In MI, posterior tooth contacts dominate.► During During crossovercrossover,, guidance is smoothly guidance is smoothly

transferred to the incisors.transferred to the incisors.