Lecture 3: Alignment and Occlusion Part 1 Flashcards
- Terminology - Factors that determine tooth position - intrarch tooth alignment - interarch tooth alignment
What word is defined as the static relationship of teeth and is basic to all aspects of dentistry? It also refers to the relationship of the max. and mand. teeth when they are in functional contact activity of the mandible.
Occlusion
What are some dental procedures that require knowledge of occlusion?
complete/partial dentures, fixed restorations, implant restorations
What are the occlusal determinants?
joints, muscles, and teeth
What is maximum intercuspation?
the complete intercuspation of the opposing teeth independent of the condylar position. (basically means we can set the two arches of our impression together w/o having to factor in our joint)
What is centric relation?
the maxillomandibular relationship when the the properly aligned condyle-disk asselbies are in the most superior position against the articular eminence irrespective of tooth position or vertical dimension (which basically means the teeth do not have to contact)
What determines centric relation, and what type of position is the condylar head in the mandibular fossa?
determined by ligament, and in the most UNSTRAINED position
What is centric occlusion?
occlusion of opposing teeth when the mandible is in centric relation. May or may not coincide w/ maximum intercuspation (remember that this is when you don’t consider the condylar postition)
What are the two types of vertical dimension?
occlusal vertical dimension (VDO), rest vertical dimension (VDR)
What is the occlusal vertical dimension?
the distance measured between two points when the occluding members are in contact (most closed position)
In health, the vertical dimension of occlusion is maintained by what teeth?
posterior teeth
What is the rest vertical dimension?
the distance betw two selected points measured when the mandible is in the physiologic rest position
In respect to mandibular position, when is your teeth/occlusion at physiologic rest? (3 reasons/bullet pts)
- head in UPRIGHT position
- involved muscles, particularly ELEVATOR & DEPRESSOR groups, are in equilibrium in tonic contraction
- condyles in a NEUTRAL, UNSTRAINED position
87% of patients have an interocclusal rest space approx of how many mm?
3mm
The vertical position of each tooth is adaptable to what?
the space provided
What force causes teeth to meet until they have equal opposite force?
eruptive force
If the opposing force is greater than the eruptive force, what happens?
the teeth are intruded until the eruptive force equals the resistive force against them
What are the factors that determine tooth position? (5)
- arch width
- arch form
- tooth size
- controlled by forces surrounding soft tissues
- habits
Arch Width definition?
distance across the arch; mand. less than maxillary.
For arch forms and arch length, which arch is usually smaller?
Mand. is smaller than mx.
what is the neutral position/space/zone?
position in the oral cavity where the labio-lingual and buccolingual forces are equal. In this position, tooth stability is achieved.
An example of abnormal forces affecting neutral zone?
tongue thrusting
what are examples of oral habits?
- playing musical instruments, pipe smoking, etc
What helps maintain the teeth in normal alignment?
proximal occlusal and contact
Loss of a single tooth and its proximal contact allows molars to drift and tip _____.
mesially (aka mesial drift)
