Transient apical breakdown of a maxillary lateral incisor during orthodontic treatment: Case report

Transient apical breakdown (TAB) is a form of external root resorption resulting from dental trauma or orthodontic forces. The association between TAB and orthodontic movements has been poorly described in the literature. In this case report, we present a TAB in a maxillary left lateral incisor five weeks after the installation of fixed metal orthodontic appliances. The affected tooth exhibited a purplish discoloration at the cervical level, did not respond to pulp sensitivity tests and radiographically showed a slightly widened apical periodontal ligament space. Orthodontic forces were discontinued, and periodic endodontic evaluations were conducted without initiating active treatment. After nine weeks, the tooth returned to its original color and exhibited decreased response to pulp sensitivity tests. This case suggests that coronal discoloration during orthodontic treatment may be indicative of transient apical breakdown (TAB), potentially avoiding unnecessary endodontic interventions.