An avulsed immature incisor carried dry in a tissue
A 9-year-old boy is brought to the clinic 150 minutes after falling from a bicycle. His upper right central incisor (11) was avulsed. His mother found it on the ground after about 80 minutes and has carried it dry in a tissue since. On examination the tooth has an open apex with about 2 mm of root still to form, and the socket is intact. The upper left central incisor (21) is extruded about 2 mm and mobile, with no displacement of the adjacent teeth. There is a laceration of the upper lip. There was no loss of consciousness and no vomiting, and the boy is systemically well and cooperative. His tetanus status is unclear; his parents say he had a booster at about age 5. The clinic has no facilities for immediate referral and the parents want the tooth put back.
1. Should 11 be replanted? Justify your answer using the dry time and the open apex.
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On the evidence, replantation is not recommended - but this is a judgement to explain, not a rule to recite.
The decisive variable is the condition of the periodontal ligament. The tooth has been out for 150 minutes and dry for roughly 70 of those. After about 60 minutes of dry storage, the great majority of periodontal ligament cells are non-viable; there is nothing left on the root surface to reattach.
In a tooth with an open apex the consequences are worse than in an adult. Without a viable ligament the healing mode is ankylosis and replacement resorption. In a growing child, an ankylosed incisor cannot erupt with the alveolus; it becomes infra-occluded, and the alveolar ridge fails to develop vertically, creating a defect that complicates any future implant. The tooth then has to be removed - or decoronated - later anyway.
So my plan is:
- Explain to the parents why replanting would very probably produce an ankylosed, infected, infra-occluded tooth rather than a functioning one.
- If, after that explanation, they still want the tooth replaced, replant it with a clear, documented consent that it is an interim space-filler with a poor prognosis, and plan for decoronation rather than extraction at the appropriate time.
- In either case, manage the space and the socket, and follow up the alveolar ridge.
2. If the parents insist on replantation, describe the procedure, the splint and the drug and aftercare regimen.
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Procedure:
- Local anaesthesia; inspect the socket for clot, debris or a fractured labial plate; irrigate gently with saline - do not curette the socket walls.
- Handle the tooth only by the crown; if the root surface is grossly contaminated, rinse with saline, do not scrape it.
- Replant with gentle, steady axial pressure, checking the position against the adjacent teeth and the contralateral incisor.
- Flexible splint: a 0.016-inch round wire or orthodontic wire bonded with composite to the two adjacent teeth, kept clear of the gingival margin.
- Suture the lip laceration.
Splint duration: about 2 weeks for an avulsed tooth; longer is associated with ankylosis. Review at 2 weeks for splint removal.
Drugs: systemic antibiotics are not routinely indicated for avulsion alone, and are not a substitute for prompt replantation; I would prescribe only if there is an associated soft-tissue or bony injury requiring it, in the correct paediatric dose. Chlorhexidine 0.12% rinse twice daily for a week is appropriate. Analgesia with paracetamol/ibuprofen by weight.
Tetanus: his booster was at age 5. For a tetanus-prone wound, the current status should be checked with the physician; a booster is generally needed if more than 5 years have elapsed since the last dose in a contaminated wound. Refer rather than assume.
Aftercare: soft diet, no toothbrushing over the splinted teeth (chlorhexidine instead), and written instructions.
3. How would you manage 21, and what follow-up schedule and long-term expectations would you give the parents for both teeth?
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21 - extrusion with an open apex:
- Reposition the tooth into its normal position under local anaesthesia, applying pressure to the crown.
- Flexible splint for about 2 weeks (extrusion is a less severe injury than lateral luxation, which needs 4 weeks).
- Because the apex is open, do not start root canal treatment. Pulp sensibility testing may be negative initially and is unreliable in an immature tooth; monitor instead.
- If pulp necrosis with apical periodontitis develops, the options are revascularisation/regenerative endodontic procedures or apexification - not immediate conventional obturation of a wide open apex.
Follow-up schedule (both teeth): 1–2 weeks (splint removal and soft tissue healing), 4 weeks, 3 months, 6 months, 1 year, then annually until the tooth is mature or until 21 has been followed through eruption. At each visit: sensibility testing, percussion, mobility, radiograph for root development, inflammatory resorption and ankylosis.
What I would tell the parents:
- 21 has a good chance of survival; the risk is loss of the pulp and arrested root development, which we can treat if it appears.
- 11 will not be replaced with a permanent implant until growth is complete - a growing child's implant will become infra-occluded. The interim options are a removable partial denture or an adhesive bridge, and the alveolar ridge must be monitored.
- The most important message is preventive: a mouthguard for cycling and sport, and prompt first aid - milk or saline, never dry - if another tooth is ever avulsed.