Risk factors affecting third molar autotransplantation during 5 and 10 years.

The aim of this study was to investigate risk factors affecting 5- and 10-year survival in autotransplantation of third molars with complete root formation at dental clinics. Participating dentists were requested to provide information on transplantations performed between 1 January 1990 and 31 December 2009. After data screening and elimination, 183 teeth in 171 men aged 20-72 years (mean, 44.8 years) and 205 teeth in 189 women aged 20-74 years (mean, 42.0 years) were included in the study. A single-factor analysis using the log-rank test revealed that the following factors had a significant influence (p<0.05) on 5-year survival in transplanted teeth in men: recipient site in the maxilla and fewer than 25 present teeth; those for 10-year survival, on the other hand, were recipient site tooth extraction due to periodontal disease, recipient site in the maxilla, fewer than 25 present teeth, and Eichner index Group B1 to C. Cox regression analysis revealed that the odds ratio for 5-year survival for recipient site in the maxilla was 2.873 (95% CI, 1.073-7.695), while that for 10-year survival was 3.713 (95% CI, 1.601-8.609) for recipient site extraction due to periodontal disease, 2.190 (95% CI, 1.021-4.700) for recipient site in the maxilla, and 3.110 (95% CI, 1.470-6.581) for fewer than 25 present teeth. In women, the log-rank test indicated experience of less than 10-year in performing treatment as a significant factor (p <0.05) in 5-year survival. These results suggest that medium-term survival in transplanted teeth is influenced by operational risk factors in women, while long-term survival in transplanted teeth is influenced by individual oral status in men.

Survival rate in autotransplanted premolars with complete root formation: a retrospective clinical survey.

The purpose of this study was to analyze the survival rate in autotransplanted premolars with complete root formation in dental clinics. Participating dentists were requested to provide information on transplantations they had undertaken between 1 January 1990 and 31 December 2010. Data on a total of 708 teeth from 637 patients were collected. Data for other tooth types and for teeth with incomplete root formation were eliminated. In this study, data on 40 teeth in 35 patients were analyzed. Participants consisted of 17 men and 18 women ranging from 24 to 79 years in age (mean age, 43.7 years). The cumulative survival rate was 100% at the 5-year mark and 72.7% at 10 years, as calculated by the Kaplan-Meier method. Single-factor analysis revealed that "transplanted to the molar regions" was a significant risk factor (p<0.05) influencing the survival of transplanted teeth. However, a Cox regression analysis showed no significance. The results of this study suggest that, in cases where there is a suitable donor tooth and the oral condition is good, premolar autotransplantation is a viable treatment option, even when there is complete root formation in the donor teeth.

Procedures for treating spaces vacated by loss of transplanted teeth.

The main reasons for loss of autotransplanted teeth are different from those involved in natural teeth loss. The aim of this study was to investigate which procedures were employed to treat spaces vacated when autotransplanted teeth were lost. Participating dentists were requested to provide information on transplantations they had undertaken. A total of 614 teeth in 552 patients (37 dentists) ranging in age from 17 to 79 years (mean age: 44.1 years) were examined. A total of 102 transplanted teeth were lost during the observation period. Procedures for treatment of spaces vacated were not influenced by main reason for transplanted tooth loss. The procedure used to treat depended on the original prosthodontic treatment of the transplanted teeth. For single crowns, the spaces were left empty (33.9%) or replaced by bridge work (30.5%), implants (20.3%), or dentures (10.2%). For single crowns in the upper and lower second molar regions, the spaces were usually left empty (upper 100%, lower 71.4%), while for those in the upper and lower first molar regions, the spaces were often replaced by bridge work (upper 41.7%, lower 50.0%). For bridge abutments, spaces were replaced by dentures (42.9%), implants (33.3%), or left empty (14.3%), and in the lower second molar region, they were mostly replaced by implants (5 cases, 41.7%). For most denture abutment cases, the spaces were replaced by dentures (88.9%). During the survival period of the transplanted teeth, the masticatory burden on the other teeth is reduced and the adjacent teeth are supported by the transplanted tooth. Even if transplanted teeth are eventually lost, traditional procedures can be performed to fill the vacated space.

Relationship between Eichner Index and number of present teeth.

The aim of this study was to determine the percentage of participants in each of the six Eichner Index groups by number of present teeth (PT). The data were obtained from a periodontal disease examination carried out under a health promotion law in a city located northeast of Tokyo, Japan, in 2005. Data from a total of 1,549 (524 male and 1,025 female) 60-year-old participants were analyzed in this study. Number of occlusal supports was counted by analyzing dental charts. The Eichner Index was used to group the participants into six groups based on distribution of occlusal support teeth. The percentage of patients in Group A with 24 PT was 31.4%; none in Group A had fewer than 19 PT. The percentage in Groups A, B1, and B2 with between 20 and 28 PT was above 50%; the number of participants in these groups with fewer than 20 PT decreased rapidly. Those with fewer than 16 PT were almost found in Groups B3, B4 and C. Only a few patients in Group C had between 10 and 14 PT; those with fewer than 9 PT were only found in Groups B4 or C. Based on these results, the Eichner Index category of a given participant can be estimated from number of PT.