[Consideration on the treatment of transposition of the teeth]

The two cases with the transposition of the teeth were treated orthodontically. One was a case in which the teeth which had changed places with each other were aligned in irregular sequence, the other was one with the teeth which had erupted at the unusual position were repositioned in order of the tooth number. Those causes and some problems involved in diagnosis and treatment were discussed. 1. The causes of transposition of the teeth in the two cases reported herein seemed to be premature loss of primary teeth and the malposition of permanent tooth germs, respectively. 2. At the time of the planning of the treatment, the following must be considered. 1) Perfect transposition or imperfect. 2) The positions of root apexes and axial inclinations of the teeth irregularly erupted. 3. Root paralleling is most important for the stability of the treatment results. Moreover, in case of unusual alignment, prevention of premature contact in jaw movement and improvement of appearance must be endeavored.