Occlusal Assessment

Question 1

How to assess occlusion?

Answer 1

History
Pain - muscles, joints, movement, face
Clicking
Awareness of clenching or bruxing 
Difficulties in chewing

Dental history
Previous diagnoses
Repeated restoration failure/tooth fracture
Previous lenghty operative procedures/excessive amounts of dental work
Pt expectations

Medical
Rheumatoid/osteoarthritis
Trauma to head and neck 
Med condition that may contraindicate extensive tx
Use of meds which cause bruxism

General
Stress
Diet and acid intake
Occupation/social history
Suitability for complex tx 

General exam
Muscles
TMJ
General - angles/incisor classification, OB, OJ, skeletal pattern, crossbite, overerupted teeth

Detailed occlusal analysis

Question 2

What makes up a detailed occlusal analysis?

Answer 2

ICP contacts - shimstock +/- GHM paper
RCP contacts - manipulate to CR - note first contact with GHM paper
Slide from RCP to ICP - large or small?
Anterior guidance
- which teeth guide?
- Use shimstock +/- GHM paper - very slow movement
- Posterior disclusion - are any posterior contacts during protrusive excursion?
- Crossover interferences - some people can overlap upper teeth with lower incisors
Lateral excursions
- Guided by canine or group function
- Use shimstock +/= GHM to indicate contacts
- Ask pt to move jaw slowly
- Any non-working side contacts (look closely at palatal cusps of upper molars)

Question 3

What equipment is needed for analysis?

Answer 3

Shimstock foil - 8 microns thick

GHM paper - 19 microns thick

Question 4

Anterior guidance - what guides class I, II, III, AOB

Answer 4

Class I - guidance from anterior teeth
Class II div I - shallow anterior guidance, initial guidance may be on posteriors
Class ii div ii - very steep OB
Class III - very little/no/neg OB, very little guidance from anterior teeth, posterior teeth involved in guidance
AOB - no contact between anterior teeth, no guidance from anterior teeth

Question 5

Signs and symptoms of loss of occlusal harmony?

Answer 5

Mandibular dysfunction
Mobility of teeth
Drifting of teeth
Fracture of restorations
Fracture of cusps or teeth
Fremitus
Parafunction

Question 6

Why assess occlusion?

Answer 6

Assessment of current occlusal scheme to diagnose any current occlusal problems, be aware of potential future problem areas

Preop assessment prior to undertaking restorative work in order to conform with current occlusion if desired or alter any occlusal problems before tx