Avulsed Immature Central Incisor With Replacement-Resorption Risk
A 9-year-old boy is brought to your clinic 80 minutes after his upper left central incisor (21) was avulsed in a fall at school. The tooth was picked up by the crown, kept dry in a tissue for 45 minutes, then placed in milk. On examination the crown is intact, the socket is empty with an intact buccal plate, and the adjacent teeth are uninjured. A periapical radiograph shows an open apex with a root length of about 8 mm and thin dentinal walls. The boy is healthy, his tetanus immunisation status is unclear, and he weighs 30 kg. His mother asks whether the tooth can be saved and whether he will need a denture if it fails.
1. Describe your immediate management, including replantation, splinting, medication and follow-up, and state the prognosis you will give the mother.
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Prognosis first. Forty-five minutes of dry storage means most periodontal ligament cells on the root surface are non-viable. Replantation is still the right action - it preserves the socket, the alveolar bone and the gingival architecture, and in a growing child that matters for the eventual implant - but the expected outcome is ankylosis with replacement resorption over months to years, not a normal periodontal ligament. I would say this plainly to the mother without removing hope: the alternative, leaving the space, causes bone loss and much greater difficulty later.
Immediate steps. (1) Local anaesthesia with 2% lidocaine 1:100,000, limited to about 1.8 mL for a 30-kg child. (2) Handle the tooth by the crown only, do not curette or scrape the root, and irrigate the socket gently with saline while removing the clot by suction. (3) Replant with light digital pressure, checking the labial contour and the occlusion; confirm position radiographically. (4) Flexible splint - 0.016-inch wire or nylon line bonded to 11 and 22 - for 2 weeks, with instructions to avoid biting on the tooth, eat soft food for 2 weeks, and rinse with 0.12% chlorhexidine twice daily for 2 weeks. (5) Systemic antibiotics: amoxicillin at 25–50 mg/kg/day in divided doses for 7 days is appropriate; doxycycline is the drug recommended for avulsion in adults but carries a staining risk in young children, so at 9 years the choice should be discussed with the parent. (6) Check tetanus status and refer for a booster if not current.
Do not start root canal treatment today. The pulp of an immature tooth may revascularise, and the decision between a regenerative procedure and apexification is made once necrosis is established. Review at 2 weeks (splint removal), 4 weeks, 3 months, 6 months, and then annually to at least 5 years, looking for signs of infection-related resorption, ankylosis and arrested root development.
2. At the 6-month review, tooth 21 is grade II mobile with a buccal sinus tract, arrested root development and external inflammatory resorption with a periapical radiolucency. Compare the management options and justify your recommendation.
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Diagnosis. Infection-related (inflammatory) external root resorption secondary to pulp necrosis in an immature tooth, with a sinus tract indicating an established intraradicular infection. The tooth is failing, but it is not yet lost.
Options. (1) Regenerative endodontic procedure (revascularisation): indicated for immature permanent teeth with necrotic pulp and open apex, including those with apical periodontitis. Protocol: minimal instrumentation, 1.5% sodium hypochlorite 20 mL per canal to limit stem-cell toxicity, 17% EDTA 20 mL for 5 minutes to release growth factors, a low-concentration triple antibiotic paste or calcium hydroxide as interim dressing, then induction of a blood clot, a 3-mm bioceramic or MTA coronal plug and a composite seal. It offers the only realistic chance of arresting resorption while allowing continued root development and thickening of dentinal walls. (2) MTA apical plug (apexification): more predictable in achieving apical closure and healing, but it halts root development and leaves thin walls with a high long-term fracture risk. (3) Long-term calcium hydroxide: effective against infection but weakens dentine and requires many visits. (4) Extraction: in a 9-year-old this means years of space maintenance and bone loss before an implant can be considered after growth.
Recommendation. Attempt a regenerative procedure first, because this is the only option that combines infection control with a chance of continued root development, and it has a reasonable record of arresting inflammatory resorption. Consent must include the possibility of failure and the need for a second procedure. If the tooth remains infected or resorption progresses after 6–12 months, convert to an MTA apical plug to stabilise it. If it becomes ankylosed and infra-occluded during growth, decoronation is the appropriate later option. Mobility alone is not an indication for splinting; splint only if there is progressive increase or trauma recurrence.