Recurrent pericoronitis from a mesioangular impacted lower third molar

§Chief complaint

Repeated painful swelling behind the last lower tooth, four episodes this year

§Medical & dental history

• 01Healthy; oral contraceptive pill
• 02Four episodes of pericoronitis treated with antibiotics
• 03Distal caries starting on 47

§Clinical examination

• 01Partially erupted 48 with an inflamed operculum, no active pus today
• 02Food stagnation between 47 and 48; distal cervical caries on 47
• 03Mouth opening 44 mm; no lymphadenopathy

§Figures

§Differential diagnosis

§Final diagnosis

Mesioangular impacted 48 with recurrent pericoronitis and distal caries of 47

Recurrent pericoronitis and caries in the adjacent tooth are accepted indications for third molar removal; imaging defines the impaction and the relationship to the inferior alveolar canal.

§Investigations

• 01OPG for impaction and root form
• 02CBCT when the OPG shows high-risk signs for nerve proximity

§Radiology

• 01OPG — mesioangular impaction, Pell and Gregory class II position B; darkening of the roots where the canal crosses them
• 02CBCT — canal runs buccal to the roots, no cortical loss between root and canal

§Treatment plan

• 01Surgical removal of 48 under local anaesthesia with informed consent covering nerve injury
• 02Restore the distal caries on 47 after healing

§Surgical procedure

• 01Envelope flap with distal relieving incision, lingual tissues protected
• 02Buccal bone removed with a bur under saline irrigation, crown sectioned and roots delivered separately
• 03Socket debrided and irrigated; closure with 3-0 resorbable sutures

§Follow-up & outcome

• 01Day 7 — healing well, normal lip and tongue sensation
• 02Week 4 — 47 restored
• 03No further pericoronitis

Outcome: Uncomplicated removal; infections stopped and 47 kept.

§Discussion

• 01Darkening of the root, a break in the canal outline and a narrowed or diverted canal on OPG predict nerve proximity and justify CBCT.
• 02Coronectomy is an alternative when the roots are in close contact with the nerve.

§Clinical pearls / learning points

• 01Section the tooth rather than remove large amounts of bone.
• 02Protect the lingual nerve — never place incisions over the lingual side of the retromolar area.

§Viva questions

§MCQs

§Related diseases

§Similar cases