Intra-alveolar fracture of a developing permanent incisor.

A longitudinal complicated crown-root fracture of an unerupted permanent incisor following trauma to primary teeth is reported. The development of the affected permanent tooth was not disturbed during a follow-up period of six years. Traumatic injuries to primary teeth can be transmitted to the permanent dentition because of the close relationship between the apices of primary teeth and the developing permanent successors. Intra-alveolar crown fracture of developing permanent dentition following trauma to primary teeth is considered rare. The common findings due to such injuries are discoloration of enamel, enamel hypoplasia, crown dilaceration, abnormal root angulation, or disturbances in eruption (Andreasen 1981). The present report describes a longitudinal crown-root fracture of an unerupted incisor following traumatic injury to the primary dentition and its long-term follow-up.