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Question 1

Occlusion?

Components include:?

Answer 1

Occlusion – how mx and mnd teeth function together and how the masticatory systems work in chewing. Components include:
 Teeth: Posterior and Anterior teeth + alv bone
 Skeletal structures: Mx and Mnd
 TMJ: mx glenoid fossa and mnd condyles
 Dynamic neuromusculature

Question 2

Posterior Teeth:

Answer 2

 Crushing surface. They also give stable contact points which establishes the vertical dimension (base of nose to chin) of the lower face. They are also acting as vertical stops and contribute to the MIP. MIP is the position which the teeth bilaterally contact evenly and maximally a.k.a., the Centric Occlusion (CO). MIP should equal the Centric Relation in ideal occlusion (explained later). Posteriors disocclude during protrusive and excursive movements.

Question 3

Anterior Teeth:

Answer 3

 Cutting and tearing. These are the anterior determinants of occlusion. Provides anterior guidance giving a gliding surface to guide the mandible for protrusive and lateral excursive movements. Movements cause the posteriors to disocclude except in MIP! (Prevents wearing down of posteriors).
 Anterior guidance is a result of an overbite and overject (mx are more facial, mnd more lingual)

Question 4

Alveolar Bone

Answer 4

Teeth reside in the sockets of the Alveolus of the Mx/Mnd which provide a nearly immobile condition formed by the cementum, PDL, and Lamina Dura. (allows for shock

Question 5

o Glenoid Fossa

Answer 5

o Glenoid Fossa – articular surface that slopes superior TO inferior/anterior position. Also has medial wall on the non-working side to limit medial movement (Bennett movements

Question 6

o Condyles

Answer 6

o Condyles – mandibular extensions that articulate with the glenoid fossa

Question 7

Posterior determinants of

Answer 7

Allows for mandibular movements or ‘gliding’ via first by a rotational hinge movement, then movement translates inferiorly and anteriorly. This determines the angulations of the elevations on the occlusal surfaces. If TMJ and anterior teeth are uncoordinated, you get impedance of occlusal function = occlusal interferences.

Question 8

During evolution, the spinal cord shifted anteriorly and caused restriction on esophagus and airway when the mouth opened… what prevents this?

Answer 8

translational movement

Question 9

Centric Relation

Answer 9

 The position of the TMJ/jaw when the fully closed or when the condyle is in the most superior/anterior position in the fossa. This does not depend on mx/mnd tooth positions but the CR = MIP in ideal occlusion

Question 10

Ideal MIP occlusion

Answer 10

 Mnd are ½ step ANTERIOR to the Mx
 Buccal groove of the lower 6’s should align with the MB cusps of the upper 6’s
 Distal slope of the mandibular canine is positions along the mesial slope of the maxillary canine.
 Anterior teeth have overbite and overjet
 Midlines of mx/mnd line up
 Mx posteriors are more buccal than mnd. The ML/DL cusps of mx teeth contact the central fossa and the central part of the marginal rides of the mandibular posteriors
 The buccal cusps of the mnd teeth contact the central fossa and the central parts of the marginal ridges of the mx posteriors

Question 11

Occlusal Plane

Answer 11

Occlusal Plane (CURVE OF OCCLUSION = SPEE + WILSON)

Question 12

Curve of Spee

Answer 12

 Curve of Spee: anterior to posterior curvature. Begins @ canine to all posterior teeth. Allows lower teeth to align parallel with its arc of closure and causes he last molar to be very inclined. (allows force on the crown to go through long axis of root)

Question 13

 Curve of Wilson

Answer 13

 Curve of Wilson: mediolateral curve that contacts B/L cusps. Results from the lingual tilt of mandibular posteriors

Question 14

1st reason for curve of wilson

Answer 14

: Alignment with chewing function: loading force is on the posteriors during the outside-inward/front-backward chewing stroke thus they are aligned with the internal pterygoid muscle. Forces are directly on the tooth’s long axis and gives the best resistance to the loading force. The curve of Wilson allows food on the tongue or on the cheeks to be moved onto the occlusal surface, buccinators muscles squeeze inward to put cheek food onto occlusal surface.

Question 15

Immediate lateral shifts may cause occlusal interferences with the mx L cusps and mnd B cusps. Bennett Movements prevent this. Here, the working condyle only rotates and the non-working side functions against a medial articular wall on the glenoid fossa to translate down/forward/medially allowing the non-working side to open up and prevent these occlusal interferences

Answer 15

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