Indications for autotransplantation in cases of missing premolars.

The postoperative behavior of premolars transplanted before completion of root formation and the long-term prognosis for such teeth have recently been studied. After postoperative observation periods ranging between 3 years 4 months and 13 years 9 months, all of the thirty-four teeth in question were found to still be in place. Root formation had continued, supporting tissues had developed, and the teeth had erupted. In most instances they had functioned normally without giving rise to problems of any kind. Their status during the re-examination implied that most of them would function normally for many years to come, perhaps for a lifetime. Autotransplantation of missing premolars in many cases is the only alternative to prosthetic substitution, and it is our method of preference. However, substitution by autotransplantation cannot be applied unless a suitable transplant is available. Any premolar destined to be extracted for orthodontic reasons is a possible transplant. In young patients it is also a suitable one. In orthodontic extraction cases, therefore, suitable transplants are usually available. In nonextraction cases, none is available unless teeth in other dental arch quadrants are "sacrificed." In the present report six cases are presented as examples of solutions to the problem of missing premolars by autotransplantation. The main combinations of missing teeth and types of malocclusion in which premolars extracted for orthodontic reasons can advantageously be used as substitutes for other premolars are defined. Also, the justification for "sacrificing" a premolar in one quadrant to the advantage of another quadrant is discussed.