Intro to Occlusion Exam 1 [Guidance and Dynamic Tooth Contacts]

Maximal Intercuspal Position (MIP)

The complete intercuspation of the opposing teeth independent of condylar position, sometimes referred to as the best fit of the teeth regardless of the condylar position

MIP is independent of

condylar position

Centric relation

Dependent on condylar position and independent of tooth contacts

Centric cusps (Functional)

Maxillary lingual cusps

Mandibular buccal cusps

Non-centric cusps (non-functional)

Maxillary buccal cusps

Mandibular lingual cusps

Centric cusps functions

Mastication of food

Maintains fascial height

Non-centric cusps functions

Minimize tissue impingement

Maintain bolus on occlusal table

Guidance

The influence on mandibular movements by the contacting surfaces of the maxillary and mandibular anterior teeth

Posterior teeth protect anterior teeth in

MIP

Anterior teeth protect posterior teeth in

Excursion

Mutually protected occlusion

An occlusal scheme in which the posterior teeth prevent excessive contact of the anterior teeth in maximal intercuspal position, and the anterior teeth disengage the posterior teeth in all mandibular excursive movements

What is guidance influenced by

- Anterior teeth

- Posterior teeth

- Both

Both

Lateral movement

Lateral=away from the midline

Working side

always the side to which the mandible is moving

Canine guidance

Maxillary and mandibular canines only on the working side in contact as the mandible slides towards the working side

Group function

The simultaneous contact of multiple teeth on the working side as we make lateral movement

- Instead of the canine alone

Interferences

Antero-poterior movements

- Protrusion

- Retrusion

Lateral movement

- Mediotrusion

- Laterotrusion

Laterotrusion

Condylar movement on the working side in the horizontal plane

Mediotrusion

A movement of the condyle medially; syn, non-working-side movement

Laterotrusion always happens on the

Working side

Mediotrustion always happens on the

Non-working side

Laterotrusive interference

Outer inclines of our maxillary lingual cusps against inner incline mandibular lingual cusps

and/or

Inner incline of maxillary buccal cusps against outer incline of mandibular buccal cusps

Mediotrusive interference

Usually found at inner incline of maxillary lingual cusps against inner incline mandibular buccal cusp

TIP if you find interferences of an inner incline against an inner incline that means its probably a

mediotrusive interference

TIP: If you have an outer incline against an inner incline, that means its probably a

Laterotrusive interference

Protrusive interference

Usually found at distal incline of maxillary cusps against mesial incline mandibular cusps

Retrusive interference

This type of interference you see when CR and MIP are not coincident

Usually found at mesial incline of maxillary cusps against distal incline mandibular cusps

Condylar guidance

The way in which the condyle slides down the slope at the base of the skull as the mandible slides forward

- Cannot be altered with restorations unlike lateral guidance and anterior guidance

- Measured with a protrusive record

- How shallow/steep it is can impact the occlusal morphology of restorations

The steeper the condylar guidance =

taller the posterior cusps can be

The shallower the condylar guidance =

shorter the cusps must be

Understand how the crows foot picture of cusp pathway works

I recommend going back through the video where we did the typodont exercise

Time: 1:06 on panapto