Effects of Instructor on Orthodontic Treatment Outcome and Duration

The clinical result of orthodontic treatment can be attributed to both patient and practitioner factors. In order to optimize orthodontic treatment outcome, it is necessary to evaluate the role of the practitioner in treatment outcome. Objectives: The purpose of this study is to evaluate the effects of individual instructor assignment on differences in treatment outcomes of completed orthodontic cases at the Ohio State University and how they compare to other independent variables influencing orthodontic treatment outcome. Methods: 82 cases, completed by one class of orthodontic residents and their assigned faculty, were evaluated. A case was considered complete if active treatment had been finished and there were pre and post-treatment records available. Data taken from the record included both patient and practitioner factors. The independent variables recorded were: treatment duration, gender, age, decision to extract teeth, patient compliance score and faculty directing treatment for each case. The dependent variable was treatment outcome, measured by percent of PAR score reduction attained. All cases were PAR scored by the same calibrated examiner. The data was analyzed using factorial ANOVA. Results: Treatment duration was the only statistically significant independent variable (p< 0.05), related to percent PAR score reduction, with an estimate of 0.5436 percent greater PAR reduction per month of treatment. None of the other independent variables, including instructor, showed a statistically significant relationship with variance of PAR score reduction. Conclusions: 1) Differences in outcome are not directly attributable to differences in supervising faculty. 2)Other independent variables such as extractions and compliance did not have a positive effect on percent PAR reduction. 3)Treatment duration has a positive effect on PAR reduction.