The odontoma is a hamartomatous lesion consisting of enamel, dentin, pul and cementum. They are observed in the form of a tooth or as a mass of agglomerated teeth. Most of these occur during the period of development of normal teeth and grow to some extent. The fused tooth was the developmental abnormality of the teeth and the hard tissues of the adjacent teeth were combined. In general, these two lesions are not related, but two problems can occur together with systemic or local causes in the morphological differentiation period. We report a case of a 6 - year - old boy who visited our clinic for the eruption of a calcified mass in the mouth. The patient was diagnosed by the fusion of a odontoma and a mandibular permanent anterior tooth. And then, fused odontoma was removed surgically and the mandibular permanent anterior was restored by using composite resin. Calcified material was diagnosed as a composite tooth. After 6 months, the permannant teeth was satisfactory eruption and did not show any pathological problems in periapical radiography.

• 오성동(원광대학교 치과대학 소아치과학교실) | Sungdong Oh (Department of Pediatric Dentistry, College of Dentistry, Wonkwang University)
• 이제우(원광대학교 치과대학 소아치과학교실) | Jewoo Lee (Department of Pediatric Dentistry, College of Dentistry, Wonkwang University)
• 라지영(원광대학교 치과대학 소아치과학교실) | Jiyoung Ra (Department of Pediatric Dentistry, College of Dentistry, Wonkwang University) Corresponding author