Management of ectopic lower 8

Question 1

What are the indications for removing a ectopic lower 8?

Answer 1

• Two or more episodes of pericoronitis
• Un-restorable
• Untreatable apical pathology
• Internal / external root resorption
• Fracture of tooth
• Disease of follicle including cyst / tumour
• Field of tumour resection

Question 2

What is pericoronitis?

Answer 2

Inflammation of the operculum surrounding a partially erupted wisdom tooth.
Food packing occurs under the operculum.
Causes a dull aching pain.

Question 3

What is the treatment for mild pericoronitis vs severe pericoronitis?

Answer 3

Mild = analgesics, warm water rinse, good OH

Severe = antibiotics (met 400mg 3 days), analgesics, warm water rinse, OH, refer for extraction

Question 4

What clinical and radiological assessment do we need for wisdom teeth?

Answer 4

Clinical assessment
- Patient age: younger have less co-morbidities and heal better
-Patient complaint: pain, how many episodes, can they tolerate extraction under LA
- Social history: escort needed if treatment under sedation or GA
- Medical history: immunodeficient, mobility of patient
- Dental history
o Extra and intra oral
- Mouth opening
- TMJ pain
- Partially erupted tooth
- Caries lower 8 and 7
- Pocketing lower 7
- Evidence of pericoronitis: swollen red operculum +- pus or white area over the operculum from previous episode

Radiological assessment
- Indications for removal – caries/periapical pathology, cyst, recurrent pericoronitis (distal bone loss of 8)
- Sectional DPT commonly taken to see location to inferior alveolar nerve
- Difficulty of extraction & risk assessment
- Tooth angulation (mesio-angular, distal angular)
- Root morphology
- Related teeth
- Anatomical structure location
- Depth of impaction
- Surrounding bone
- Risk assessment
- Surgical difficulty
- Consent – potential risks, treatment options

Question 5

What factors make a wisdom tooth extraction challenging?

Answer 5

• Partially erupted
• Bony impaction
• Long thin roots
• Dense bone
• Divergent, curved and multiple roots
• Contact with IDN
• Close contact with second molar

Question 6

What features on x ray suggest close proximity to ID nerve?

Answer 6

• Loss of IDC cortication (cortical bone surrounding canal break in bone due to root of tooth in the way of the canal)
• Interruption or IDC cortication – look at lingual and IV cortication lines and should be able to see both
• Narrowing of the canal
• Diversion of inferior alveolar canal
• Darkening of root
• Juxta-apical area