OB9 - Dynamic Occlusion Flashcards
(28 cards)
what is occlusion?
The contact relationships of teeth or equivalent
what is articulation?
The dynamic relationships of the teeth when in sliding contact
what is the jaw relationship?
Positional relationship which the mandible bears to the maxilla
Name all the vertical jaw relationships and dimensions? (6)
- rest/ postural position
- intercuspal position
- retruded contact position
- occlusal vertical dimension
- rest vertical dimension
- freeway space
what is the rest/postural position?
teeth are not together/slightly apart
What muscles hold the mandible in place? (3)
- masseter
- temporalis
- medial pterygoid
what is important about the rest position?
it remains reproducible throughout life in both dentate and edentulous subjects
what is the intercuspal posistion?
maximal intercuspation / interdigitation
What is retruded in the glenoid fossa in the retruded contact posistion?
condyles
what is the clinical significance of the RCP?
- symmetrical retrusion
– gives a reproducible relationship between the maxilla
and mandible
How far can the jaw retrude?
1-2mm posterior to ICP
1-2mm posterior to ICP
Posterior fibres of the temporalis
what is the occlusal vertical dimension?
the face height with the teeth in ICP measured between two arbitatry points governed by the height of the teeth
What instrument could you use to measure the occlusal vertical dimension?
willis gauge
what is the rest /Postural Vertical Dimension?
he face height with mandible in rest/ postural position that is measured between two arbitrary points and should not alter significantly throughout life
what is the freeway space?
the space between teeth in rest position which is the difference between RVF and OVD
what is the value range of the freeway space?
2-5mm
What anatomical guide planes are involved in protrusion of the jaw? (3)
- incisal guidance
- cuspal inclines
- TMJ
what is the working side?
• The side to which the teeth move
what is the guidance of the working side?
•canine guidance •group function
what is the non-working side?
The side away from which the teeth move
What movement does the jaw undergo in wide opening?
Hinge (bottom compartment) and slide (top compartment)
Explain what the condyle does on the working side when the jaw moves to the side?
The condyle rotates around the vertical axis and there is lateral bodily movement (bennett movement)
Explain what the condyle does on the non- working side when the jaw moves to the side?
The condyle moves downwards, forwards over the eminence and medially
