Dental trauma and avulsed teeth — structured clinical encounter

Candidate instructions

You are the paediatric registrar in the emergency department. You have ten minutes to assess this eight-year-old boy who has just knocked out a permanent upper central incisor, and to present your assessment and management plan to the examiner. You are expected to take the scene history that establishes the prognosis, examine the mouth and the whole child, recognise the time-critical emergency, and outline the immediate first-aid and definitive management. The examiner will then release a second scenario of a three-year-old who has knocked out a primary incisor, and will ask you to state the rule and the safeguarding consideration. [1]

Encounter

On taking the history, the tooth was knocked out about five minutes ago in a playground fall, and has been kept wrapped in a dry tissue since. The child is awake and alert, with no loss of consciousness, and is up to date with immunisations. On examination there is an empty blood-filled socket at the upper left central incisor, a small lip laceration, and no facial swelling; the tooth itself is an intact permanent incisor. The whole-child assessment reveals no head injury, facial fracture or other concern. [1] [9]

The candidate recognises a time-critical avulsion of a permanent tooth with a very short dry time, and acts immediately: the tooth is rinsed gently under running water for about ten seconds and replanted into its socket, and the child bites on gauze to seat it. The candidate confirms that had immediate replantation not been possible, the tooth would have been stored in cold milk or Hank's balanced salt solution, and that plain water, scrubbing the root, and drying are all contraindicated. [1]

Marking domains

Scene history and whole-child assessment (3 marks). The candidate elicits the time of injury and the dry storage in a tissue, the mechanism, the absence of head injury or loss of consciousness, and the immunisation status, and examines the mouth and the whole child for an associated head injury, facial fracture, aspirated tooth and safeguarding concerns. [1]

Immediate first-aid and storage media (4 marks). The candidate replants the permanent tooth immediately after a brief rinse, holding it by the crown only, and has the child bite on gauze to seat it. The candidate names cold milk or Hank's balanced salt solution as the preferred storage medium if replantation is not possible, and explains that plain water is hypotonic and ruptures the periodontal-ligament cells, and that scrubbing or drying the root destroys them. [1] [9]

Prognosis and definitive management (3 marks). The candidate names extra-alveolar dry time as the dominant prognostic factor, with under twenty minutes giving the best outcome and over sixty minutes a poor prognosis, and outlines the definitive dental management of a flexible splint for about two weeks, root canal treatment starting at seven to ten days for this closed-apex tooth, a systemic antibiotic course, tetanus prophylaxis for the contaminated wound, and weight-based analgesia, with urgent dental referral. [1] [7] [8]

The primary-tooth rule and safeguarding (2 marks). On release of the second scenario of a three-year-old who has knocked out a primary incisor, the candidate states that a primary tooth is never replanted because it risks the developing permanent successor, and that management is bleeding control, analgesia, reassurance and dental review. The candidate describes the safeguarding assessment when an oral injury is unexplained, delayed, repeated, or occurs in a non-mobile infant with a torn frenulum, examining the whole child and following local procedures. [3] [11] [12]