RESUMO
A case of fourteen year old healthy girl with complaint of a discharging sinus on the lower right side of face is reported. All teeth were vital and there was no evidence of periodontitis. There was no history of extraction of a tooth. Total leucocyte count, differential leucocyte count, fasting blood sugar, chest x-ray and routine urine examination were within normal limits. Actinomycosis and scrofuloderma which simulate such a condition were ruled out by culture study. The intraoral periapical x-ray of mandibular molar showed questionable periapical changes at the time of presentation. But definite osteolysis was observed in the repeat radiograph after three months. It was decided to extract the second molar and curette the sinus tract. The extraction proved to be difficult. On examination of the extracted tooth, it was found that the mandibular second molar and second premolar were fused together. The radiograph of the tooth taken after extraction showed confluence of the premolar pulp with the periodontal membrane. On follow up, the lesion was found to heal satisfactorily.