An 8Y10M-old Japanese boy was referred to our clinic and he had a complaint of pain and prolonged ulcer on bilateral buccal mucosa. Two months before the first visit, he bit the left buccal mucosa, and then he started to have habitual jaw move from side to side and repeatedly thrust his finger or tongue into the wound. As a result, deep bilateral ulcers were formed and became infected. He suffered from systemic prostration because of pain and he was hospitalized to control the local and systemic symptoms for 1 month. Even after being discharged, he still screamed in pain and took analgesics very often.
We prepared and set the bite plate on his upper jaw to avoid touching the upper and lower first molar cusps. The wound healed in 2 weeks, and his mental and physical conditions became stable. However, after the appliance was removed, he bit again and formed multiple ulcers on the tongue, lower lip as well as bilateral buccal mucosa. These ulcers healed in only 2 weeks with oral disinfectant irrigation without special appliances. Seven months after the first visit, he bit the right buccal mucosa severely and this resulted in infection with fever, hemi-facial cellulitis in the right, and dehydration. The patient was supplied with electrolytic water and antibiotics by intravenous instillation, and the soft resin splint (Erkopress splint®) was set over the upper dental arch simultaneously. This treatment enabled him to make a quick recovery without hospitalization.
The local cause of the bite injury in this case was considered to be malposition of the erupting first molars. However, the self-mutilating habit induced complicated and prolonged oral as well as systemic symptoms. The patient was neither mentally retarded nor had organic disorders.
Children may manifest self-mutilating behavior as a means of gaining attention or as a sign of various emotional disturbances, and such a behavior can be thought to be neurotic self-excoriation. In this case, it was important for the success of the treatment to support the patient mentally and psychologically. A bite plate or a soft resin splint like those used in the present case can be applied effectively to control or prevent oral multilation.