BACKGROUND: Traumatic injury to a primary tooth may damage the underlying permanent tooth germ and affect its development. The extent of the malformation depends upon the developmental stage of the permanent tooth and the intensity of trauma. Discoloration and hypoplasia of the crown, dilaceration, root angulation and disturbances in eruption are commonly seen developmental disturbances following trauma. However, partial or complete arrest of root formation is a rare developmental sequela of trauma to primary teeth. Attempt should be made to retain these natural teeth during the mixed dentition period.
METHODS: A case is presented of a young boy with rare occurrence of arrested root formation of permanent mandibular incisors, following trauma to the primary predecessors. Clinically these teeth exhibited mobility and radiographic examination showed absence of root formation in relation to the incisors. The treatment plan was to retain the natural permanent teeth for a maximum period and to stabilize them until a more permanent replacement could be carried out. As the patient had mixed dentition, immediate stabilization was done using fiber reinforced splint until further definitive treatment is carried out. Early diagnosis of developmental disturbances in permanent teeth resulting from trauma at a young age is necessary. Regular follow-up appointments, through clinical and radiographic examination and timely intervention may minimize or even avoid harm to the developing tooth.