Impacted Tooth Pain: Etiology, Clinical Features, and Management

An impacted tooth fails to erupt into its functional position due to obstruction (bone, soft tissue, adjacent tooth) or aberrant eruption path. Third molars (wisdom teeth) and maxillary canines are most commonly impacted.

Pain Mechanisms

• Pericoronitis: Infection/inflammation of the operculum (flap) over partially erupted tooth. Bacterial accumulation (anaerobes) → pain, swelling, trismus, purulence, lymphadenopathy. Most common acute cause.
• Pressure on adjacent structures: Resorption of adjacent tooth roots (2nd molar), periodontal ligament compression, bone expansion.
• Cyst / tumor formation: Dentigerous cyst (follicular), keratocystic odontogenic tumor — expansile, often asymptomatic until large.
• Caries: Distal surface of 2nd molar (inaccessible) or impacted tooth itself.
• Referred pain: To ear, temple, throat, neck (via trigeminal/cervical pathways).
• Neuropathic: Inferior alveolar nerve (IAN) compression by mandibular 3rd molar → paresthesia, dysesthesia.

Clinical Presentation

• Localized pain, swelling, erythema (pericoronitis).
• Trismus (limited opening) — medial pterygoid involvement.
• Halitosis, bad taste (purulent discharge).
• Regional lymphadenopathy (submandibular).
• Asymptomatic — discovered on routine radiograph.

Diagnostic Imaging

• Panoramic radiograph (OPG): Screening; assess position, angulation, root morphology, proximity to IAN/canal.
• CBCT: 3D relationship to IAN, lingual plate, maxillary sinus, adjacent roots — indicated for surgical planning.

Management

Conservative (Pericoronitis Acute Phase)

• Irrigation (saline, chlorhexidine, povidone-iodine) under operculum.
• Analgesia (NSAIDs), antibiotics if systemic signs (fever, lymphadenopathy, trismus > 30 mm) — Amoxicillin/Metronidazole.
• Operculectomy (excise flap) if recurrent.

Definitive: Surgical Extraction

• Indications: Recurrent pericoronitis (≥ 2 episodes), caries, periodontal defect on 2nd molar, cyst/tumor, orthodontic indication, prosthetic interference, prophylaxis (controversial — NICE: only if pathology).
• Technique: Flap, bone removal, sectioning, elevation, primary closure.
• Risk: IAN injury (temporary 1–5%, permanent < 1%), lingual nerve injury, dry socket, infection, fracture.

Alternative: Coronectomy

• Remove crown, leave vital roots near IAN. Indicated when roots encircle/cross canal on CBCT.
• Root migration/supereruption may require later removal.

Referral criteria: High-risk anatomy (CBCT), medical complexity, sedation needs, patient anxiety → Oral & Maxillofacial Surgeon.