大臼歯部への第三大臼歯自家移植の臨床的検討

tooth autotransplantation

北海道歯学会

北海道歯学雑誌

Tooth autotransplantation is one of the valuable treatments for recovering the occlusal function of missing teeth. The purpose of this study is to analyze treatment outcomes and prognosis factors of autotransplantation of the third molar to the molar region and to reflect on the result in clinical practice. Patients and methods : Study 1 comprised of patients with transplants from July 1997 to March 2015 at Hokkaido University hospital, and third molars transplanted to the molar region. The subjects that the transplanted teeth were extracted or fell out were defined as the extraction group, the others were defined as the survival group. Among them, the survival case had a follow-up period of over 6 months and were described in study 2. The patients conditions were followed up regularly at 1, 2, 3, 6 and 9 months and at 1, 1.5 and 2 years postoperatively and afterwards once a year, clinically and radiographically. Among the survival group, the cases that clinical findings and radiographic findings were good were termed the good-outcome group, and the cases with some problems were termed the poor-outcome group. For Study 1, we calculated the overall survival rate and compared the difference in the survival rate in various factors (age, sex, transplantation method, type, root formation, eruption status of donor tooth, region of recipient site, and classification of missing tooth). For Study 2, we examined the relationship of the type of donor teeth and the region of recipient site. Results : 　Study 1 was 552 cases and 615 teeth, and the study 2 was 341 cases and 390 teeth. All 1-year survival rate was 97.7%, and the 5-year survival rate was 86.2%. There were recognized significant difference in sex, transplantation method, type of donor tooth, and region of recipient site by single variable analysis, and the type of donor tooth, region of recipient site and a classification of missing tooth by multivariate analysis. When transplanting the third molar to the molar region of the same quadrant, the ratio of the good group was the highest. Conclusion : 　By this result, it is thought that the transplantation of the lower third molar to the second molar region of the same quadrant resulted in good treatment outcomes.