Tooth Extrusion

Tooth extrusion, or extrusive luxation, is partial displacement of a tooth out of its socket along its long axis, with tearing of the periodontal ligament and often the apical blood supply. It makes up about 2 to 6% of dental injuries in permanent teeth.

It is more common in the maxillary central incisors of young children and in primary teeth. The tooth looks elongated and is loose.

Pathophysiology. An oblique or axial force pulls the tooth partly out of the socket. The periodontal ligament is torn and the apical vessels are stretched, so pulp necrosis is likely in mature teeth, with revascularisation possible in immature teeth.

Healing may be complete, or complicated by pulp necrosis, inflammatory resorption, ankylosis or loss of marginal bone.

An elongated tooth, with a gap at the socket and a displaced crown, marked mobility, bleeding from the gingival sulcus, pain on biting and malocclusion with premature contact on the injured tooth.

Record the degree of extrusion in millimetres, mobility, and stage of root development. Check other dental, alveolar and facial injuries and tetanus status.

Head injury, airway concern, other fractures and heavy contamination need urgent assessment.

• Clinical examination: tooth height, mobility, percussion and occlusion.
• Periapical and occlusal radiographs showing a widened periodontal ligament space apically, and a lateral view in primary teeth to assess relationship to the permanent germ.
• Cone beam CT where alveolar fracture or root fracture is suspected.
• Pulp sensibility tests are unreliable at first and are repeated.
• Tetanus status.

Differential diagnosis.

• Lateral luxation
• Subluxation
• Avulsion in progress
• Root fracture with a mobile coronal segment
• Alveolar fracture
• Mobility from periodontal disease
• Pathological mobility from a cyst or tumour

• Permanent teeth: under local anaesthesia, gently reposition the tooth back into the socket by slow axial pressure, check occlusion, and stabilise with a flexible splint for 2 weeks. Repositioning becomes harder as the clot forms, so treat early.
• Primary teeth: if extrusion is under 3 mm and there is little mobility, allow the tooth to realign. If extrusion is over 3 mm or the tooth is loose, extract it to protect the permanent tooth and prevent aspiration.
• Pulp management: immature teeth are monitored for revascularisation, with root canal treatment only for necrosis or infection. Mature teeth often need root canal treatment, started after 2 weeks if signs of necrosis appear, with calcium hydroxide dressing for 1 to 4 weeks.
• Antibiotics are not routinely needed. Give them for contaminated wounds or associated injuries: amoxicillin 500 mg orally three times daily for 5 to 7 days (reduce to 500 mg every 12 hours at eGFR 10 to 30), or doxycycline 100 mg orally twice daily for 7 days in patients aged 12 years and over. Children under 12: amoxicillin 125 mg three times daily at 1 to 11 months, 250 mg at 1 to 4 years and 500 mg at 5 to 11 years.
• Tetanus toxoid 0.5 mL intramuscularly if vaccination is incomplete or the last dose was over 10 years ago, with tetanus immunoglobulin 250 IU intramuscularly (500 IU after 24 hours or heavy contamination) when status is unknown or incomplete.
• Chlorhexidine 0.12% mouthwash 10 mL twice daily for 1 week, soft diet for 2 weeks, and no contact sport.
• Analgesia: paracetamol 1 g every 6 hours (maximum 4 g daily) with ibuprofen 400 mg every 8 hours with food. Children use paracetamol 15 mg/kg every 4 to 6 hours (maximum 75 mg/kg daily) and ibuprofen 5 to 10 mg/kg every 6 to 8 hours.

Monitoring. Review at 2 weeks (splint removal), 4 weeks, 6 to 8 weeks, 6 months, 1 year, and yearly for 5 years, with radiographs, percussion and sensibility tests. Watch for pulp necrosis, inflammatory resorption and ankylosis.

Referral and escalation. Refer to a dental trauma service or paediatric dentistry. Urgent referral for associated alveolar fracture, multiple tooth injuries or contamination.