Self-inflicted gingival injury in a 15-month-old infant.

A case is described of self-inflicted oral injury in a 15-month-old infant. The child had a habit of posturing the mandible forwards and biting the gingiva lingual to the mandibular primary incisors with the maxillary incisors, causing marked ulceration. It is suggested that the habit may have been initiated by irritation from erupting mandibular primary canines. The habit was abandoned as the canines erupted and the ulcerated area healed completely.