Third Molars Flashcards
What is the best way to determine orientation of impaction?
Draw lien through long axis of 7 and 8
What are the aspects of a ‘full marks’ radiographic report?
- Look for caries in crown
- Direction of impaction
- How impacted- moderately etc
- Roots- dilacerated, splaying, converging, divergent
- Interfering with canal- narrowing, darkening, interruption (anatomical or radiographic cause?)
- Is their a follicular/cystic change
-> Would you offer CBCT
What are the causes of not being able to see the IDC?
Outwith focal trough (radiographic error)
- Prominent chin
- Alignment issue
How much more radiation is given out by CBCT over OPT?
CBCT- 2.5 x times an OPT
- Consider whether it would change management- caries into the pulp (extract)
What is neuralgic pain described as when consenting patient for third molar surgery?
electric shock, comes and goes, debilitating
What are the percentage risks for different sensation alterations?
% for temporary altered sensation after wisdom teeth removal (low risk)
-> 5-10%
Permanent in low risk - <1%
High risk temporary- 25%
Permanent- 3-7%
What instruments can be used to keep the flap under tension to making lifting of it easier?
Mitchell’s
Howarths
What are the different types of retractors?
Rake (bowdler henry)- risk of macerating periosteum (more risk of bruising and swelling)
Minnesota- benign edge, reflects light into wound, gives cheek protection
What can occur if distal relieving incision is too distal?
- Can affect lingual nerve- as these can sit above alveolus (have it more buccal to avoid)
- Difficult suture
Why is lingual retraction not done routinely?
Lingual retraction- better access but risk to lingual nerve
What is the risk if the relieving incision does not release the papillae?
Risk of recession
-> care in anterior region
What is used for bone removal and why? What may be used in practice?
Electric handpiece with saline cooled tungsten carbide bur
-> air driven handpieces can cause surgical emphysema
In practice- slow speed with saline irrigation
How is the crown taken off when decoronating?
horizontal cut at ACJ (width of bur)
Go 2/3 way through middle, avoids adjacent structures
Compare size of bur to occlusal surface
Coupland’s in between- crack (warn)
What causes snapped tip in luxators?
Lateral forces
How is a 3 sided flap sutured
- 3 sided- suture distal reliving incision and mesial relieving incision
What is anatomical closure?
Leave defect (prevent fibrous scarring)
-> Primary closure- can cause tension resulting in scarring
What is a juxtaposition-apical area?
Juxta-apical area- PA around root of tooth in otherwise sound wisdom tooth
What is checked when examining Lower 8s?
- Caries
- Periodontal condition (check distal of 7 for communication even if tooth unerupted)
- Eruption status
- Angulation
- Depth of impaction
- Signs of infection
- Pericoronitis
- Relationship of tooth to IDC
- Relative position of upper 8s
- Working distance- distance from distal of 7 to ascending ramus (check on radiograph)
When is it unlikely that the 8 is causing an issue?
If no communication to oral cavity
Will be sent back if referred
Be careful what you say to patient
Double check for other pathology
What commonly occurs to the bone as a result of pericoronitis?
Distal bone loss
What can CBCT show us about relationship between 8 and IDC?
If there is compression of nerve by tooth
Nerve can perforate root- very rare
-> Coronectomy
If intervening bone present
What is the benefits of no treatment of impacted 8s?
Benefits- no risks of surgery (pain bleeding etc)
Risks- subsequent episodes/future pain, caries in 7 (esp mesioangular impaction)
What is the reoperation rate for coronectomy to remove roots?
4-5%
-> often easier procedure due to migration
