Cranial nerves and foramina
Occlusion
Intraarch— prox contact betw teeth tooth inclination: inclined to receive closing force along axes occlusal plane curvature (Curves of Spee & Wilson) Spee— anteroposterior mand canine→along buccal cusp tips affects posterior cusp height **protects against protrusive interferences
Wilson—translateral curve lingual inclination of mand posteriors **protects against lateral interferences
Interarch— arch length: max and mand arches the same arch width: max slightly > mand Centric cusps—i.e. functional cusps: mand=buccal max=lingual fnxn: vertical dimension of occlusion (VDO) support of facial height aligned with opposing for mastication Non-centric cusps—i.e. non-functional cusps: mand=lingual max=buccal fnxn: ↓tissue impingement maintain bolus of food on occlusal table mand stability in MI (max intercuspation)
some rules: (remember we’re speaking about the functional cusps only!)
mand mesial cusp occludes w/: max marg ridge mand distal cusp occludes w/: max fossa max mesial cusp occludes w/: mand central fossa max distal cusp occludes w/: mand distal marg ridge mand tooth# + max tooth # = 33 (to deduce which teeth are in occlusion)
mandibular movement pattern determined by: Anterior guidance & TMJ guidance
Groove rules: 1. Working grooves are at right angles to the central groove 2. Non-working grooves are usually oblique to the central groove 3. During protrusive mvmt, centric cusp usually moves parallel to central groove
Three axis of reference for mandibular mvmt: 1. Horizonal axis: occurs in sagittal plane open/close first 20-25 mm = pure rotation 2. Vertical axis: occurs in horizontal plane lateral movements doesn’t occur naturally
3. Sagittal axis: occurs in frontal
Intraarch— prox contact betw teeth tooth inclination: inclined to receive closing force along axes occlusal plane curvature (Curves of Spee & Wilson) Spee— anteroposterior mand canine→along buccal cusp tips affects posterior cusp height **protects against protrusive interferences
Wilson—translateral curve lingual inclination of mand posteriors **protects against lateral interferences
Interarch— arch length: max and mand arches the same arch width: max slightly > mand Centric cusps—i.e. functional cusps: mand=buccal max=lingual fnxn: vertical dimension of occlusion (VDO) support of facial height aligned with opposing for mastication Non-centric cusps—i.e. non-functional cusps: mand=lingual max=buccal fnxn: ↓tissue impingement maintain bolus of food on occlusal table mand stability in MI (max intercuspation)
some rules: (remember we’re speaking about the functional cusps only!)
mand mesial cusp occludes w/: max marg ridge mand distal cusp occludes w/: max fossa max mesial cusp occludes w/: mand central fossa max distal cusp occludes w/: mand distal marg ridge mand tooth# + max tooth # = 33 (to deduce which teeth are in occlusion)
mandibular movement pattern determined by: Anterior guidance & TMJ guidance
Groove rules: 1. Working grooves are at right angles to the central groove 2. Non-working grooves are usually oblique to the central groove 3. During protrusive mvmt, centric cusp usually moves parallel to central groove
Three axis of reference for mandibular mvmt: 1. Horizonal axis: occurs in sagittal plane open/close first 20-25 mm = pure rotation 2. Vertical axis: occurs in horizontal plane lateral movements doesn’t occur naturally
3. Sagittal axis: occurs in frontal