Evaluation of tooth position, occlusion, and interproximal contacts after transplantation of immature third molars.

The aim of the present investigation was to examine position, occlusion, and interproximal contacts of 139 transplanted third molars in 136 patients (94 females, 42 males) with a mean age of 17.6 years at the time of transplantation. Ninety-two teeth were placed directly into favourable positions and left to erupt spontaneously. Forty-seven teeth were transplanted into atrophied jaw sections and underwent post-operative orthodontic adjustment. According to the post-operative treatment performed, the sample was divided into two groups: transplants with or without subsequent orthodontic treatment. The mean post-operative observation time was 4.4 years. Study models were obtained from all patients and the American Board of Orthodontics Objective Grading System was adapted for evaluation of position, occlusion, and interproximal contacts of the transplanted teeth. A Mann-Whitney U-test was used to determine significant intergroup differences with respect to the final scores and the various evaluated criteria. Absence of occlusal contacts was found in more than 30 per cent, absence of both interproximal contacts in more than 15 per cent, and inadequate position in more than 40 per cent of the transplants without subsequent orthodontic treatment. The poorest results were observed for maxillary teeth transplanted into the mandible. The results of the present study show that incorrect positioning with absence of occlusal and interproximal contacts are frequent findings in transplanted teeth. Short-term orthodontic adjustment, especially of maxillary transplants into the mandible, seems to be advisable in order to obtain correct positioning and function of these teeth.