Occlusion Flashcards
Give the features of the intercuspal position
- the comfortable bite
- best fit for teeth
- also known as centric occlusion
- maximum interdigitation of teeth
Give the features of an edge to edge occlusion
- teeth slide forward from intercuspal guiding on palatal surfaces of anterior teeth
- incisal edges of upper and lower incisors touch
give the features of mandibular protrusion
- no posterior tooth contacts (only incisors and sometimes canines)
- eventually no tooth contacts
- condyle moves forwards and downwards on articulator eminence
Give the features of maximum opening
- no tooth contacts
- mouth wide open
- full translation of condyle over articular eminence
Give the features of a retruded axis position
- no tooth contacts
- most superior anterior position of condylar head in fossa
- terminal hinge axis
Give the features of a retruded contact position
- first tooth intact when the mandible is in retruded axis position
- ICP is approximately 1mm anterior to RCP in 90%
what is the Bennet movement?
lateral translation of the mandible
what causes lateral movement of the mandible?
- contraction of one lateral pterygoid muscle
- when one contracts the mandible moves to opposite side
what are functional cusps?
cusps that occlude with opposing teeth in the intercuspal position
- lingual cusps of upper posteriors
- buccal cusps of lower posteriors
what are non functional cusps?
cusps that do not occlude with opposing teeth in the intercuspal position
- buccal cups of upper posteriors
- lingual cusps of lower posteriors
What is the fossa of a tooth?
- depression or concavity on tooth surface
- functional cusp of a tooth contacts fossa of opposing tooth
What is an overbite?
vertical overlap of incisors
What’s an overjet?
The relationship between the upper and Lower teeth in a horizontal plane
What is a cross bite?
A condition where one or more teeth may be abnormally malpositioned buccal or lingually or labially with reference to the opposing teeth
what is an anterior open bite?
lack of vertical overlap of anterior teeth when posterior teeth are in full occlusion
what is a posterior open bite?
failure of contact between Posterior teeth when teeth are in full occlusion
What is canine guidance (mutually protected occlusion)
When mandible moves to working side:
- only the canines contact
- no posterior tooth contacts leaving a space between them
What is group function?
mandible moves to working side
- multiple teeth in contact on working side
- bilateral group function frequently seen in toothwear
Name the types of occlusal interference
- working side
- non-working side
- protrusive
What is protrusive interference?
- any posterior contact during protrusion
What are the 2 types of bruxism?
- eccentric
- centric
what is eccentric bruxism?
- the parafunctional grinding of teeth
- oral habit consisting of involuntary rhythmic, spasmodic or functional gnashing, grinding or clenching in teeth other than chewing movements of mandible
- may lead to occlusal trauma
what is centric bruxism?
- clenching
- pressing and clamping of jaws and teeth together
- associated with acute nervous tension
Give the clinical signs of bruxism
- tooth wear
- fractured restorations
= tooth migration - tooth mobility often in absence of Perio disease
- muscle pain and fatigue
- headache
- earache
- pain and stiffness in TMJ and surrounding mucles
Name the different types of tooth wear
- multifactorial
- abrasion
- attrition
- erosion
- abfraction
