Tooth Avulsion

Tooth avulsion is complete displacement of a tooth out of its socket after trauma. It makes up about 1 to 16% of dental injuries in permanent teeth, and the maxillary central incisor of children aged 7 to 11 years is the commonest tooth.

Prognosis depends mainly on the time the tooth is out of the socket and the storage medium. It is an emergency, and immediate replantation gives the best outcome.

Pathophysiology. Force tears the periodontal ligament and the neurovascular bundle at the apex. Cells on the root surface begin to die within 15 to 30 minutes when dry, and after about 60 minutes of dry time most are non-viable.

Healing after replantation is by periodontal ligament regeneration, or by ankylosis with replacement resorption when the ligament is dead. Infection of a necrotic pulp drives inflammatory resorption.

An empty socket with bleeding, with or without a fractured socket wall. History of the time out of the mouth, where the tooth was kept, how it was handled, and where the injury took place (soil contamination).

Check the lips, gingiva and floor of the mouth for the missing tooth or fragments, since the tooth may be aspirated or embedded. Check other injuries and tetanus status.

Airway concern, head injury, breathing difficulty after possible aspiration, multiple fractures and heavily contaminated wounds need urgent assessment.

• Clinical diagnosis from the empty socket and history. Confirm the tooth is a permanent tooth and that its apex is open or closed.
• Periapical and occlusal radiographs to exclude intrusion, root remnants and alveolar fracture. Chest radiograph if aspiration is possible.
• Examine the tooth: root surface, apex (open or closed) and any fracture, without touching the root.
• Cone beam CT for associated alveolar fracture.
• Tetanus status.

Differential diagnosis.

• Intrusive luxation (the tooth appears missing)
• Exfoliation of a primary tooth
• Alveolar fracture with tooth displacement
• Tooth aspirated or swallowed
• Congenitally missing tooth
• Root fracture with a retained apical fragment

At the scene (advise by telephone):

• Find the tooth and pick it up by the crown only. If dirty, rinse for about 10 seconds with milk or saline and do not scrub or use water for long.
• Replant immediately, press it fully into the socket, and bite on gauze. If the person cannot replant, store the tooth in cold milk, saline or a tooth storage solution, or in the cheek (older children and adults only), and go to a dentist or emergency department at once.
• Primary teeth are not replanted, because of the risk to the permanent tooth germ.

In the clinic:

• Dry time under 60 minutes: replant after gentle rinsing with saline, without scraping the root. Irrigate the socket with saline and reposition any fractured socket wall. A tooth kept in a suitable medium can wait up to 30 minutes in that medium before replantation. Do not curette the socket.
• Dry time over 60 minutes: replantation is still done for aesthetic and space reasons, accepting the likelihood of ankylosis. Soak in sodium fluoride 2% for 20 minutes, with the understanding that long term survival is poor.
• Flexible splint for 2 weeks (4 weeks with an alveolar fracture), suture gingival lacerations, and check the occlusion.
• Root canal treatment of closed apex teeth: begin 7 to 14 days after replantation and before splint removal, with calcium hydroxide dressing for 1 to 4 weeks, then root filling. Open apex teeth: no root canal treatment unless signs of necrosis or infection appear, because revascularisation is possible.
• Antibiotics: doxycycline 100 mg orally twice daily for 7 days in patients aged 12 years and over, taken upright with water, and avoided in pregnancy, breastfeeding and renal impairment (with reduced absorption by calcium, iron and antacids). Alternative: amoxicillin 500 mg orally three times daily for 7 days (reduce to 500 mg every 12 hours at eGFR 10 to 30). 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, for 7 days.
• 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, careful brushing, 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 in simple cases) and 4 weeks, then at 3, 6 and 12 months and yearly for at least 5 years, with radiographs, percussion and mobility. Infraocclusion in a growing patient suggests ankylosis. Inflammatory resorption needs prompt root canal treatment.

Referral and escalation. Refer to a dental trauma service or oral and maxillofacial surgery for the same day. Urgent referral for suspected aspiration, alveolar fracture or heavy contamination.