Occlusion Flashcards
Occlusion - what is it? variation? Influence?
What is it: - the contact between teeth Variations: - in different ways with diff consequences and significance Influence: - the masticatory function and system
Occlusion - types (definition)?
Types:
- static (between teeth when the mandible is closed and stationary) (intercuspal position)
- dynamic (between teeth when mandible is moving relative to maxilla)
Occlusion - intercuspal position - defintion?
Defintion:
- when the teeth fit together in maximum intercuspation
- the natural position of teeth in biting (most comfortable occlusion)
- best fit regardless of condylar position
Occlusion - defects?
Defects:
- overjet (horizontal overlap)
- overbite (vertical overlap)
- openbite (teeth don’t contact each other)
Occlusion - intercuspal position - class I (how teeth touch?
How teeth touch:
- mand incisal edges over/just in front ofncingulaum of max incisors (MB cusp of max)
- first molar in the MB groove on mand first molar
Occlusion - intercuspal position - class II (how teeth touch? Div 1? Div 2?
How teeth touch:
- mand incisal edges behind the cingulum of the max incisors
- MB cusp of max first molar ant to the MB groove on mand first molar
Div 1:
- max ant are further ahead very protruding maxilla
Div 2:
- max teeth retroincline (hug max central incisors)
Occlusion - intercuspal position - class III (how teeth touch?
How teeth touch: malocclusion;
- mand incisal edges far ant to the cingulum of max incisors or in reverse relation to incisal edges
- MB cusp of max first molar post to the MB groove on mand first molar
Occlusion - functional cusps - how they touch? Why like this?
2mm normal for an overjet How they touch: - palatal cusps of the maxillary post teeth - buccal cusps of mand teeth Why like this: - maintain vertical dimension of occlusion - transmit occulusal forces axially - involved in interference
Occlusion - dynamic occlusion - why movement? Movement influenced by? Guidance 2 systems?
Why move: - moved by the muscles attached to mandible Movement infleunce: - by 2 guidance systems Guidance systems: - posterior and anterior determinants
Occlusion - post/ant determinants - what are they?
2 TMJ systems
Posterior are the condyles
Anterior are the teeth
Posterior determinants learn the head anatomy critically
Occlusion - scissor and cross bites
Answer
Occlusion - movements of TMJ - overview? How it works? Joint type?
Rotation and translation
Rotation:
- initial opening move the TMJ rotates within the joint space
- final stage of closing movement the TMJ roattes within the joint space
Joint type:
- hinge
Occlusion - functional cusps (max and mand)
Max - palatal cusps
Mand - buccal cusps
ANATOMY IS CRITICAL
Occlusion - TMJ - translation (defintion)
Translation:
- movement of the head of the condyle downwards and dowards along the distal face of the articular eminence of the glenoid fossa on the intra-articular disc, at the end if the rotator movement as the mandible is open further
Occlusion - anterior determinants - what is it? Touching? Teeth? Openbite/class 3 ICP?
What is it: - the teeth Touching: - maxillary and mandibular teeth are touching each other during the mandibular excursions then the those teeth are providing guidance to the mandivualr movement Teeth: - all ant to the TMJ Openbite: - possible that an individual may have ant guidance in a molar teeth on protrisce movement (such as openbite and class 3)
Occlusion - mandible - working side?
- The side of the mandible towards which the mandible is moving during lateral excursion
- Greatest amount if teeth to teeth contact
Occlusion - mandible - non-working side?
- The side away from which the mandible is moving in lateral excursion
- However, the non working side condyle that undergoes most movement in lateral excursion
Occlusion - anterior guidance - lateral excursion?
- to move to the left or the right side
Occlusion - anterior guidance - canine guidance?
- dynamic occlusion that occurs on the canine in the working side in lateral excursion
- working side is the side to.whixh the mandible moves
Occlusion - anterior guidance - group function?
Group function:
- dynamic occulsuoj is shared by several teeth on the working ISD in lateral excursion
- generally premolars
- guidance to be towards the front of the mouth (premolars as opposed to molars)
- take notes if are molar
Occlusion - disocclusion in excursion - what is it?
What is it:
- lateral excursions the working side guidance (either canine or group) cause the teeth in the non-working side to disocclude
Occlusion - mutually protected occlusion - what is it?
What is it:
- dynamic occlusal relationship in which the posterior teeth contact in maximum ICP, but not in lateral or protrusive movements
- posterior teeth protect ant from occlusal forces
- ant teeth protect the post teeth during excursive movements
Occlusion - Christensen’s phenomenon - what is it?
What is it:
- triangular space between max and mandible posterior teeth bilaterally during protrusion
- caused by incline of the articular eminence
Occlusion - occluslal interference - what is it?
What is it:
- any occlusal contact during mand excursions that may interfere with the smooth movements and guidance of the mandible in relation to maxilla
- causes an abrupt movements of the mandible away from the guidance provided by the posterior TMJ and the ant determinants (guidance)
Occlusion - working side interference - what is it?
What is it:
- any occlusal contacts on the working side towards the back of the mouth (molars), whilst still providing anterior teeth guidance, may interfere with the movement of the non-working side condyle
- because the contact occurs closer to the condyle and therefore is likely to interfere with the movement of the non-working side condyle down the articular eminence
- if the guiding contact between max and mand teeth on the working side occurs towards the first of thr mouth (pre/canine) then such contacts are unlikely to interfere with the movements of the non-working side condyle
Occlusion - non-working side interference - what is it?
What is it:
- interference from the post teeth on the non working side during lateral excursion
Occlusion - applied occlusion - what is it?
What is it:
- on restorations, in time that restoration will fail
