The aim of the presentation is to clarify if there is relationship between Transient Apical Breakdown (TAB) and orthodontic treatment.

Force application to a tooth during orthodontic treatment evokes a biological response to the periodontal ligament (PDL) and the dental pulp. Numerous studies have described the reaction of the PDL, fewer have dealt with pulpal changes.

The pulpal response to orthodontic forces involves cell damage, inflammation and wound healing which are process that could adversely affect the dental pulp. A consequence of the injury to the pulp tissue could be: Transient Apical Breakdown (TAB). The breakdown process is related to the type of injury and the stage of root development. It is usually caused by moderate injuries to the pulp such as subluxation, extrusions and lateral luxations or as a result of orthodontic treatment and occlusal trauma. The crown may display some discoloration and radiographical a periapical radiolucency associated with the affected tooth. The discoloration and apical lesion frequently later resolve itself without complications. Therefore, no endodontic treatment is needed.

The exact mechanism of TAB is not fully understood. Clinically however misdiagnosis may result in unnecessary endodontic treatment.

Cases with TAB in relation to orthodontic treatment will be presented and methods for diagnosis and treatment will be discussed.