Avulsed immature upper central incisor with delayed presentation
A 9-year-old boy is brought to the emergency department at 7 pm on a Friday, 90 minutes after a fall on a climbing frame. His upper right central incisor (11) was knocked completely out. The mother picked it up, rinsed it briefly under tap water and kept it in a carton of milk. Extraoral dry time was about 20 minutes and the tooth has been in milk since. The tooth has an open apex with incomplete root formation and appears intact. The adjacent upper left central incisor (21) is mobile but not displaced, the upper lip has a 1 cm laceration, and the child is crying and uncooperative with examination. He has no relevant medical history, no allergies, and his last tetanus booster was six years ago. The on-call dental resident is 40 minutes away, and the emergency physician asks whether the tooth should be replanted at all given the delay.
1. Should the tooth be replanted? Justify your answer and list what you would check first.
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Yes. Replantation is the treatment of choice for an avulsed permanent tooth with an open apex and an intact root, provided the socket is viable and there is no contraindication.
The prognosis is not hopeless. Extraoral dry time of about 20 minutes is within the favourable window, and milk is an appropriate storage medium because its osmolality and pH support periodontal ligament cell survival better than water. The open apex offers the possibility of revascularisation, although with 20 minutes dry and about 70 minutes in milk the pulp is unlikely to revascularise fully; the realistic outcomes are pulp canal obliteration, pulp necrosis with inflammatory resorption, or ankylosis. Even with those risks, replantation preserves alveolar bone and gingival architecture in a child who cannot receive an implant until growth is complete, and leaving the space has its own consequences for the occlusion and for the developing arch.
Before replanting, confirm: the tooth is the correct tooth and is intact with no root fracture; the socket is not collapsed and the alveolar bone is not comminuted; there is no severe caries or periodontal disease; there is no immunosuppression or uncontrolled systemic disease; and there are no other injuries needing priority. Check the lip laceration for embedded tooth fragments and assess 21, which is mobile and may have a subluxation injury or a root fracture requiring radiographs. The child's cooperation, not the clock, is the practical limiting factor.
2. Describe the replantation procedure, splinting and prescriptions, including what you would avoid.
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Procedure. Obtain radiographs of the socket and the tooth and of 21. Provide local anaesthesia and gain cooperation, using a child-friendly approach; do not let the delay become an excuse for rushed handling. Handle the tooth by the crown only. Rinse it with saline; do not scrub the root, do not curette or scrape the socket, and do not remove the socket clot aggressively, since the periodontal ligament remnants matter. Replant with gentle, steady apical pressure and check the position clinically and radiographically. Suture any gingival laceration.
What to avoid. Do not extirpate the pulp immediately in an immature open-apex tooth; revascularisation may still occur. Do not soak the root in doxycycline or use systemic tetracyclines in a 9-year-old, because of the staining risk, and do not use a rigid splint.
Splinting. A flexible splint, such as 0.014-inch NiTi wire or nylon bonded with composite to the adjacent teeth, for about two weeks. Check that the tooth is not in traumatic occlusion in centric or excursion; adjust if it is.
Prescriptions and instructions. Amoxicillin at 15 mg/kg or 250 mg three times daily for seven days, paracetamol for pain, and chlorhexidine 0.12% applied twice daily for a week. A tetanus booster is indicated because the wound is contaminated and the last booster was more than five years ago; refer to the emergency physician. Soft diet, no contact sports, and soft brushing for two weeks.
3. What follow-up would you arrange, and what would you tell the parents about prognosis and possible future treatment?
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Follow-up. Review at two weeks for splint removal and clinical and radiographic check; then at four weeks, three months, six months, 12 months, and yearly for at least five years. At each visit assess mobility, percussion response, probing depth, colour, sinus tract, infraposition, and the radiographic periodontal ligament space, periapical status and canal width. Use cone-beam CT if inflammatory resorption or ankylosis is suspected and plain films are equivocal. Monitor 21 as well, since a subluxated immature incisor may become necrotic.
Possible future treatment. If the pulp becomes necrotic with infection, an immature tooth requires revascularisation or apexification rather than conventional treatment; inflammatory resorption requires prompt root canal treatment with a calcium hydroxide dressing. Ankylosis may lead to infraposition as the child grows and may eventually require decoronation or extraction, with replacement delayed until growth is complete.
What to tell the parents. Be honest that the prognosis is guarded. The tooth may survive for many years, may need root canal treatment, may fuse to the bone and appear to sink as the face grows, or may be lost and need replacing after growth. Do not quote a single success figure. Explain that replantation still gives the best chance of preserving bone and a normal-looking gum margin, that follow-up attendance is essential because most complications are asymptomatic early, and that the lip laceration will heal but should be reviewed. Give written instructions and an out-of-hours contact.