Prediction of the outcome of orthodontic treatment of Class III malocclusions--a systematic review

Abstract

The purpose of this study was to systematically review the orthodontic literature to assess the effectiveness of a prediction of outcome of orthodontic treatment in subjects with a Class III malocclusion. A structured search of electronic databases, as well as hand searching, retrieved 232 publications concerning the topic. Following application of inclusion and exclusion criteria, 14 studies remained. Among other data, sample ethnicity, treatment method, age at the start and completion of treatment, age at follow-up, outcome measures, and identified predictors were extracted from the relevant studies. A subjective assessment of study quality was performed. The heterogeneity of the samples and treatment methods prevented carrying out a meta-analysis. Thirty-eight different predictors of treatment outcome were identified: 35 cephalometric and three derived from analysis of study casts. Prediction models comprising three to four predictors were reported in most studies. However, only two shared more than one predictor. Gonial angle was identified most frequently-in five publications. The studies were of low or medium quality. Due to the large variety of predictors and differences among developed prediction models, the existence of a universal predictor of outcome of treatment of Class III malocclusions is questionable.

Retrospective 25-year follow-up of treatment outcomes in Angle Class III patients

“…However, the parameters that were used across these studies varied widely. Some of them have been analyzed in a review by Fudalej et al [10], who evaluated 14 studies for predictors and identified 38 variables. Most authors used combinations of three or four parameters for prognosis, gonial angle and Wits appraisal being the most common, followed by mandibular length and the SNA, SNB, and ANB angles.…”

Outcome stability of orthopaedic treatment of Skeletal Class III Malocclusion: A study of prognostic agreement between three models

“…However, a noteworthy difference in terms of prediction models has been reported in the previous studies 11 with no evidence of prognostic agreement among the proposed models. Such a lack of evidence implies the choice of the prediction model to be empirical.…”

“…However, agreement among prognostic models does not imply per se prognostic accuracy; it only implies that models yields to similar outcomes and, therefore, a given model may be preferred on the basis of easiness of landmark identification. In this regard, previous investigations 11,20 reported that stability of the orthopaedic treatment outcome of skeletal Class III malocclusion depends on several factors such treatment modality, timing, outcome evaluation, severity of malocclusion and individual patient responsiveness, making questionable the existence of a universal predictor.…”

“…A previous systematic review 11 concluded that a universal predictor of outcome of orthopaedic treatment of skeletal Class III malocclusion may be questionable. Such a conclusion was based on the evidence that different studies reported different models, lacking an analysis on the agreement between prediction models.…”

“…Such a conclusion was based on the evidence that different studies reported different models, lacking an analysis on the agreement between prediction models. Moreover, the review 11 was not restricted to investigations using discriminant analysis.…”