Static Occlusion Flashcards
Static occlusion
Max contact stationary mand teeth
Class one occlusion
MF cusp of max 1 molar opposed MB developmental groove on mand 1 molar
Mand teeth position to max
Mand teeth are 1/2 tooth in front of max teeth
Class 2
Mand teeth are much farther behind than max
Class 3
Mand teeth protrude in front of max
MIP
Maximum intercuspal position
When teeth are fully closed together
3 posterior rules of occlusion
- Max lingual occl line aligns with mand central line
- Max central line aligns with mand buccal line
- mand teeth are half tooth lingual and mesial to max teeth
Ideal class 1 relationship
Middle of each max tooth is distal to mand tooth of same type
Max teeth are facial to mand
Max incisors vertically overlap incisal edge of mand teeth
VDO
Vertical dimension of occlusion
Distance between two points on max and mand, when teeth are in MIP
Determined by supporting cusps
Supporting cusp
Cusps that contact the opposing teeth
Buccal cusps of mandible
Lingual cusps of max
Supporting cusp functions
Contact opposing in MIP
Support VDO
Broader more rounded cusps
Contact Near center of tooth
Non supporting cusps
Also called guiding/gliding/non centric cusps
Overlap opposing teeth
Buccal cusps of max
Lingual cusps of mand
More pointy and sharp
Non supporting cusp functions
Do not contact in MIP
Do not support VDO
Farther from center of tooth
Outer incline has no potential to contact opposing
Platform area
Diamond shape area formed my two adjacent marginal ridges
Platform area rule for MIP
IDEAL: during MIP, one tooth in opposing arch occludes in one platform area
What is the most stable tooth relationship
Tooth to two tooth occlusion
One tooth occludes with two teeth from opposite arch
Aka picket fence
Is tooth to one tooth occlusion ok?
Yes, it is less stable than tooth to two tooth occlusion though
Posterior supporting cusps are cradled where? Exception?
Cradled in the marginal ridge platform areas
EXCEPT these hit in CENTRAL FOSSA:
ML cusps of upper molars
DB cusps of lower molars
Where are non supporting cusps located?
In facial/lingual embrasures or in the developmental grooves of the opposing tooth
Overjet vs overbite
Overjet is horizontal overlap
Overbite is vertical overlap
Increase in VDO does what to overjet/bite
Increase VDO = decrease overjet/bite
VDR and freeway space
Vertical dimension of rest
Distance between two selected points on max and mand when mandible is at rest
Freeway space- space between max and mand at VDR, provides space for tongue
Aka interocclusal rest space
Effect of posture on rest position
Leaning back 30 degrees from horizontal plane increases the rest position of the jaw
Determinants of occlusion
Teeth
Musculature
TMJ
Normal vs premature contact stress of occlusion
Normal 300 psi
Premature contact can be over 2000 psi
