Occlusion 2 - Dynamic and Static Occlusal Contacts Flashcards
What articulating paper should be used to mark tooth contacts ?
40 microns.
Can use two different colours to mark dynamic or static contacts.
What are Millers forceps ?
For holding articulating paper to record tooth contacts.
When should tooth contacts be marked ?
Before preparing tooth or removing restoration.
After placement of crown or restoration.
Define functional cusps.
Cusps that occlude with opposing teeth in ICP i.e. lingual cusps of upper posterior teeth and buccal cusps of lower posterior teeth.
Define non-functional cusps.
Cusps that do not occlude with opposing teeth in ICP i.e. buccal cusps of upper posterior teeth and lingual cusps of lower posterior teeth.
Define fossa.
Depression or concavity on tooth surface i.e. where functional cusp of tooth contacts the fossa of the opposing tooth.
What are possible problems in static occlusion ?
Incisor relationship.
Overbite.
Crossbite.
Overjet.
Open bite.
What classification is used to describe incisor classification ?
Angles classification.
Class I, Class II div 1, Class II div 2, Class III.
What is the difference between Class II div 1 vs. Class II div 2 ?
Class II div 1 - overjet.
Class II div 2 - overbite.
Define overbite.
Vertical overlap of incisors.
What is normal value of overbite ?
2-4mm.
Define overjet.
Relationship between upper and lower teeth in horizontal plane.
Define crossbite.
Can be anterior or posterior.
Condition where one or more teeth may be abnormally malpositioned buccal or lingually or labially with reference to opposing teeth.
Define anterior open bite.
Lack of vertical overlap of anterior teeth when posterior teeth are in full occlusion.
What can cause anterior open bite ?
Digit sucking.
Instrument players.
Anatomical abnormalities preventing development of maxilla.
Define posterior open bite.
Failure of contact between the posterior teeth when the teeth are in full occlusion.
Why is canine guidance preferable ?
Longest and largest roots (crown/root ratio).
Dense compact bone supporting tooth.
Fewer muscles active when canines contact during eccentric movements.
Dissipate horizontal forces while disoccluding posterior teeth.
What is canine guidance i.e. mutually protected occlusion ?
When mandible moves laterally, contact remains only between canines with no posterior tooth contacts (freeway space).
Define freeway space.
Lack of posterior tooth contacts during canine guidance latero-excursive movements.
What are the four parts to a ‘gold standard’ mutually protected occlusion ?
Canine guidance.
Posterior disclusion in lateral excursions.
No non-working or working side contacts.
No protrusive interferences.
Define group function.
Multiple teeth remain in contact on later-excursive movements of mandible.
Define protrusion.
Condyle moves forwards and downwards on articular eminence.
What tooth contacts should be seen in ‘gold standard’ occlusion when mandible in protruded position ?
Only incisors (+/- canines) in contact.
No posterior tooth contacts.
Define occlusal interference.
Undesirable tooth contacts that may produce mandibular deviation during closure to ICP or may hinder smooth passage to and from ICP.
What are two types of bruxism ?
Eccentric - dynamic position - parafunctional grinding of teeth.
Centric - static position - clenching.
What are clinical signs and symptoms of bruxism ?
Toothwear - shortened crowns and loss of occlusal tooth anatomy.
Fractured restorations.
Tooth migration.
Tooth mobility in absence of periodontal disease.
Muscle pain and fatigue.
Headache or earache.
Pain or stiffness around TMJ and surrounding muscles.
Define fremitus.
Palpable or visible movement of a tooth when subjected to occlusal forces.
Define primary occlusal trauma.
Intact periodontium and movement of teeth due to occlusal trauma.
Define secondary occlusal trauma.
Reduced periodontium and movement of teeth due to occlusal trauma.
What are the six components to examination checklist of assessment of occlusion ?
Incisor relationship.
Guidance.
Overjet/overbite.
ICP contacts.
Working, non-working and protrusive contacts.
Pathology.
