SURVIVAL OF AUTOTRANSPLANTED TEETH WITH OPEN APICES, A RETROSPECTIVE COHORT STUDY

Abstract Purpose Autotransplantation of teeth is an alternative treatment method in growing patients suffering from hypodontia or impacted teeth. The purpose was to investigate the occurrence of and predictors for the loss of transplanted teeth in children and young adults. Methods All patients who had undergone tooth transplantation at the Department of Oral and Maxillofacial Diseases, Turku University Hospital during the time period October 1st 2009 and January 5th 2017 were identified from the hospital´s database. The outcome variable was the survival of the transplanted tooth. The predictor variables were the type of transplantation, the donor tooth, the maturity of the donor tooth, the number of roots of the donor tooth, the recipient’s jaw, the need for extra-oral storage of the donor tooth during surgery, continuation of root development during follow-up and institution experience. One tooth was randomly selected from each subject. The Kaplan-Meier method of survival analysis and the Cox proportional hazards regression analysis were used to assess the association between survival and risk factors Results The sample was composed of 36 subjects with a mean age of 14.3 years and 33.3 % were male. 45 teeth were transplanted, the median follow-up time was 1.3 years. The one-year survival rate was 87% (95% CI: 75-99%). A significant predictor for tooth survival was the continuation of root development (HR=21.3; 95% CI: 2.1-215.0; p=0.009). Although not statistically significantly, more favorable prognoses were for distant than transalveolar transplantations, for one-rooted than multi-rooted teeth, for premolars than molars, for teeth not stored in an extra-oral media, and for teeth that had been transplanted later during the study period. Conclusion Experience of the professional team, use of open apex premolars and postsurgical continuation of root development of the transplant are factors that associate with a favorable outcome. Transplants could benefit from the use of 3-dimensional replicas during surgery .