Avulsed immature central incisor with a long extraoral dry time
A 9-year-old boy is brought to your practice at 4:45 pm on a Friday. He fell from his bicycle at about 3:15 pm and his upper right central incisor (11) was avulsed. The tooth lay on the playground surface for roughly 45 minutes before a teacher briefly rinsed it and placed it in a cup of full-cream milk. The boy has no loss of consciousness, no other injuries and no relevant medical history. On examination the socket is intact with an intact buccal plate, 11 is missing, and the adjacent teeth are not mobile or tender. The tooth in the cup has an apparently intact root surface and, as far as you can see, an open apex. There are no retained root fragments in the socket radiographically.
1. What is your recommendation about replantation, and how do you justify it to the parents?
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Recommend replantation, but with an explicitly guarded prognosis.
The reasoning turns on two variables: extraoral dry time and root maturity.
- Total extraoral time here is about 90 minutes, of which roughly 45 minutes was dry. Dry time beyond 60 minutes means the periodontal ligament is largely non-viable. For a mature tooth with a closed apex, replantation after more than 60 minutes dry is generally not recommended, because predictable ankylosis and replacement resorption will occur.
- This tooth has an open apex and thin dentine walls. Replantation is still recommended for immature teeth even after prolonged dry storage, because retaining the root and the alveolar bone in a growing child preserves the ridge and the socket for later management, and avoids the space and bone consequences of early loss. The expected outcome is ankylosis and eventual replacement resorption requiring later extraction and definitive replacement after growth.
- The parents must be told this plainly: the tooth is being kept, not necessarily saved, and the realistic aim is bone and space preservation rather than a normal periodontal healing.
- The alternative - not replanting - should also be offered: a prosthesis or space maintainer now and an implant or auto-transplant after growth ceases. The decision is a shared one and should be documented.
- Storage in milk was the correct choice and improves the odds somewhat; it should be noted in the record.
2. Describe your immediate clinical management, including handling, splinting, prescribing and referral.
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Tooth handling
- Hold the tooth by the crown only. Do not scale, curette or scrub the root - this destroys any surviving PDL cells.
- If visibly contaminated, rinse briefly with saline; do not soak in anything other than an isotonic storage medium.
- Do not remove the pulp; revascularisation potential depends on preserving the canal environment.
Socket and replantation
- Local anaesthetic, gentle irrigation of the socket with saline to remove the clot, no curettage of the walls.
- Replant with light digital pressure, checking the position clinically and radiographically.
Splinting
- Flexible splint (wire or nylon, composite) on 11 and 12/21 for 2 weeks - avulsion splints are shorter than the 4 weeks used for root fracture. A rigid splint encourages ankylosis.
Adjunctive
- Systemic amoxicillin (penicillin if no allergy), weight-appropriate dose; note tetracyclines are avoided at this age for staining.
- Check tetanus status and refer to the GP if not current.
- Chlorhexidine 0.12% rinse twice daily for 2 weeks; soft diet; no toothbrushing over the splint; analgesic advice.
Referral and follow-up
- Refer to a paediatric dentist or endodontist. Review at 1-2 weeks, 4 weeks, 3 months, 6 months, 1 year, then annually.
- Monitor for signs of infection or inflammatory resorption, which would prompt endodontic intervention; ankylosis is monitored clinically for infraocclusion.
3. At the 6-month review the tooth is infraoccluded, has a metallic percussion note and shows no periapical radiolucency. What does this mean and what is your management?
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This is replacement resorption (ankylosis), which is the expected outcome given the dry time.
The reasoning:
- Ankylosed root is directly fused to bone, so the tooth does not erupt with the growing alveolus - hence infraocclusion at 6 months in a 9-year-old.
- The metallic percussion note reflects the loss of the periodontal ligament and direct bone contact.
- Absence of a periapical radiolucency argues against infection-related (inflammatory) resorption, which is the type that responds to endodontic treatment. Therefore root canal treatment is not indicated now.
Management:
- Explain that this is the predicted course and that the resorption is progressive and untreatable.
- Do not attempt heroic intervention. Monitor clinically and radiographically at least annually.
- Plan timing of removal and replacement around growth: an ankylosed incisor can be retained with the crown built up to maintain the ridge while growth continues, but this may cause the tooth to appear increasingly short and may displace adjacent teeth. Removal is usually timed to when definitive replacement (implant after growth cessation, or a resin-bonded bridge) can be provided, decided jointly with a paediatric dentist or orthodontist.
- Keep the parents informed at each visit and document the discussion; unexpected later extraction is the common source of complaint in these cases.