International comparisons of professional assessments in orthodontics: Part 2--treatment outcome

The opinion of 97 orthodontists in 9 countries has been surveyed with respect to the judgment of treatment outcome. Ninety-eight pretreatment and posttreatment study casts were examined by each orthodontist who gave a judgment of the degree of improvement and whether they thought the result was acceptable. It was found that there was at least 80% agreement on the acceptability of the outcome for only 45.5% of the sample. Logistic regression was used to identify predictive indicators for the judgment of acceptance. It was found that the posttreatment scores for dental esthetics, crossbite, buccal segment sagittal relation, lower arch crowding, centerline, and left and right buccal segment vertical relationship were most important predictor variables. These six traits correctly assigned the decision with 70% accuracy. The judgment of outcome did not seem to take account of the treatment complexity as judged by the practitioners. It was also found that judgments are significantly affected by the country and payment methods, practice environment, and experience of the practitioner. The occlusal traits identified can be usefully incorporated into a index for assessing both treatment need and outcome, and may serve the purposes for audit and research in orthodontics.