7 - Third molars 2 Flashcards
What HPC is required for the assessment of third molars?
- how long?
- how many episodes?
- how often?
- severity?
- antibiotics?
Describe the EO exam for third molars.
- TMJ
- limited mouth opening
- lymphadenopathy
- facial asymmetry
- MOM
Describe the IO exam for third molars.
- STE
- condition of dentition
- M2M prognosis and working space
- eruption status of M3M
- occlusion +/- operculum
- OH
- caries and perio status
When is an OPT appropriate for third molar assessment?
Only when surgical removal is being considered
What should be assessed on an OPT for third molar surgery?
- presence/absence of disease
- anatomy of third molar
- depth of impaction
- orientation of impaction
- working distance
- follicular width
- perio status
- proximity of upper third molars to sinus
- proximity of lower third molars to ID canal
What does follicular width on an OPT indicate?
- radiolucency around third molar
- if larger than 2.5-3mm then indicative of a cyst
What third molar anatomy can be observed on an OPT?
- crown size
- shape
- condition
- root formation
- crown to root ratio
What is the working distance?
Distal of lower 7 to ramus of mandible
What are the different ways that the M3M can be related to the ID canal radiographically?
- interruption of white lines of canal
- darkening of root where crossed by canal
- diversion/deflection of ID canal
- deflection of root
- narrowing of ID canal
- narrowing of root
- dark and bifid root
- juxta apical area
Which radiographic signs are associated with increased risk of nerve injury during third molar surgery?
- diversion of ID canal
- darkening of root where crossed by canal
- interruption of white lines of canal
What is meant by a bifid root?
Root appears to spilt or divide around ID canal
What is a juxta apical area?
- well defined radiolucent area lateral to root
- corticated margin
- lamina dura still intact
- not pathological
When is further imaging indicated?
- close relationship of M3M to ID canal, CBCT may be beneficial
- caries, PA may benefit
Define a transverse third molar.
Roots are placed buccal or lingual
Define an abberant third molar.
In unusual place ie lower border of mandible or half way up ramus
