Lecture 9- Optimal Functional Occlusion Flashcards
what do we need to know for optimal function occlusion
- optimal occlusion in a stationary position: position of teeth, TMJ, muscles
- optimal occlusion during excursive movements of the mandible
- occlusal philosophies during excursive movements such as canine guidance, group function, balanced occlusion
what is the baseline for evaluating the patients occlusion
-teeth
-TMJ
- musculature
even though a patient may have an othodontically ideal angles class I occlusion what does this not mean
the patient has optimal occlusal contacts, optimal condyle/mandibular position, and ideal/optimal contacts in excursive movements
patients may have a less than ideal occlusion however it may still be a ____ or _____
functionally acceptable occlusion or a physiologically acceptable occlusion
to determine if occlusal treatment is required what should you assess
-the masticatory system for evidence of pathology - tooth wear, tooth mobility, TMJ dysfunction, muscle dysfunction
-adaptive capacity of the patient
- if treatment is rendered what is the optimal position for the joints, muscles and teeth
when are the TM joints in an optimum orthopedically stable joint position_____
when the mandible is in CR
what is centric relation used to define
a position in the condyles in relation to the disc and fossa
what is CR
when the condyles are in the most anteriorsuperior position in the glenoid fossa braced up on the intermediate zone of the disc and the mandible is free to rotate about the terminal hinge axis (up to but not including the point of first tooth contact
what does CR refer to
the joints not the teeth
how does the mandible move in CR
freely arc up and down along the terminal hinge axis
what is it called when the teeth cannot contact in CR
deflection
what is CR the ideal position
- musculature in CR
-TMJs in CR
the muscles ____ in CR
function harmoniously
why is the joint stable in CR
because the muscles attached to the joint prevent dislocation of the articular surfaces
what are the muscles that stabilize the TMJs and what does their contraction result in
-the masseters and the medial pterygoids
- contraction results in antero superior vector of force (stability)
what muscles are the most relaxed in CR
lateral pterygoids
describe the condyles in relation to the articular eminence in CR
condyles rest against the posterior slope of the articular eminence therefore can tolerate higher stresses
in the most retruded position:
-the retrodiscal tissues are innervated and would not tolerate stress
- the posterior wall of the articular fossa is very thin
in CR TMJs are stable even when
heavy loads/forces are applied
CR is the position to which we restore
- completely edentulous patients
- partially edentulous patients, when there are so few teeth remaining that there is not a stable MIP
- dentate patients who are going to receive extensive restorations which will alter their occlusion completely
what should the posterior teeth be described as in CR for optimal functional occlusion
multiple, even, bilateral and simultaneous occlusal contacts with the mandible
how are the posterior teeth loaded for optimal functional occlusion
loaded along the long axis of the tooth called axial loading
why are mutliple posterior teeth contacts importatn
the more teeth that contact the more stress is distributed throughout the arch
why are even posterior teeth contacts important
ALL posterior teeth should contact evenly because it distributes the stress over all the teeth
