OBJECTIVES: To analyze factors related to pre-treatment malocclusion, the patient, and treatment to determine if they are predictive of treatment outcome and treatment efficiency.
METHODS: Cases consisted of 151 records selected from the orthodontic archives at the Ohio State University that had complete measurements including; gender, treatment phases, extractions, change in PAR score, pre-treatment PAR, age, angle ANB, overjet, and molar classification. Treatment outcome was designated as change in PAR score (pre-PAR- post-PAR= delta PAR), and treatment efficiency was calculated as delta PAR divided by treatment duration. Multiple regression analysis was performed separately for treatment outcome and treatment efficiency.
RESULTS: Treatment outcome model: pre-treatment overjet, extractions, class II and class III molar relationship significantly contributed to treatment outcome (model R2= 0.31, p < 0.0001). Treatment efficiency model: this model did not reach statistical significance (model R2 = 0.08, p=0.1471).
CONCLUSIONS: Of the four variables related to treatment outcome, presence of Angle class III molar classification was the greatest predictor of treatment outcome with an average of 7.2 units of change in PAR during treatment associated with this factor. The overall results of this data analysis show that there may be promise in creating a model to effectively predict treatment outcome resulting from orthodontic therapy. However, it may be more difficult to define factors that are predictive of treatment efficiency
This research was supported through the NIH/NIDCR T32 training grant.