Occlusion Revision Questions Flashcards
What is border position
One determined by the anatomy of the TMJ and associated musculature
Posselts Envelope
Border movement in the sagittal plane
ICP
intercuspal position - centric occlusion, tooth position regardless of condylar position, comfortable bite, tips of palatal/lingual cusps of upper posterior teeth should occlude with surface of lower
E
Edge to edge - teeth slide forward from ICP glding on palatal surface of anterior teeth, incisal edge of upper and lowers touch (translating movement)
Pr
Protrusion - condylar moves forwards and downwards on articular eminnenece, only incisors and canines touch, no posterior tooth contact leading to eventually no tooth contact
T
Max opening - no tooth contact, mouth wide open, full translation of condyle over the articular eminence
R
Retruded axis position - reproducible jaw position, no tooth contacts, most superior anterior position of the condylar head in the fossa, terminal hinge axis
RCP
retruded contact position - first tooth contact when mandible is in retruded axis position, ICP approx 1mm anterior to RCP
What is the biologic width
2mm
Open
Protrusion and depression
Close
Retraction and elevation
What does static occlusion include
Incisor relationship Molar relationship OJ/OB Crossbites Openbites Individual tooth contacts RCP - ICP slide
Sagittal condylar guidance
an angle formed in horizontal plane when downward movement of condyle during protrusion
Viewed lateral aspect
What is the Bennetts Angle
Formed by the sagittal plane and the path of the mandibular condyle during lateral movement when viewed in a horizontal plane
Movement of non working condyle in horizontal plane during lateral movement
What does the non working side do?
Moves downwards, forwards and medially
What does the working condyle do?
Rotation about vertical axis
Canine guidance?
Mandibular moves to working side and contact only between canines and no posterior contacts
Group function
Mandible moves to working side and multiple teeth in contact, seen in toothwear patients
What is fremitus?
Excessive vibration of tooth due to premature contact
Some mobility can occur
Press index finger on each maxillary tooth moving forward, get patient to tap teeth and check movement
Bruxism
Parafunctional grinding of teeth that leads to occlusal trauma
Toothwear, mobility, tooth migration, hearache, earache, pain, stiffness in TMJ
Recording occlusion using articulator
Use facebow transfer and inter-occlusal registration for lower cast
acron
average value - bennet angle = 15 degrees, condylar guidance = 30 degrees
semi adjustable
What is conformative approach
The resotration is in harmony with exising jaw relationship
Occlusion of new resotration is provided in a way that the occlusal contacts of other teeth remain unaltered
When do you not use the conformative approach
Increase in vertical height needed to make space for resotrations
Teeth severly out of position
Change in appearance wanted
History of occlusally related failure or # of exisitng resotrations
What is the reogranised approach
Plan to provide new resotration on different occlusion
patient guided into a terminal hinge closure to detect intial tooth contacts
taken at a slightly increased OVD
Must use registration medium
What records for mounting casts?
Jaw reg and occlusal rims
tooth shade and mould
Freeway space
RVD-OVD
if negative - due to increased OVD - denture clicking
if teeth contact during speech - not enough interoccusal space so OVD needs reudced to make more freeway space
What is Christensen’s Phenomenon
A gap that appears between posterior ends of opposing flat occlusal rims when mandible is protruded
Leads to instability in full denture unless compensating curves are placed
What is a facebow?
Records relationship of maxialla to the hinge axis of rotation of mandible
Transferring angle of occusal plane, relative to horizontal reference plane
