Treatment Decision for Borderline Class III Malocclusion in Adults; Orthodontic Camouflage versus Orthodontic Orthognathic Surgery

Objectives: Determining the optimal treatment approach for adult borderline Class III malocclusion, whether orthodontic camouflage or orthodontic-orthognathic surgery, remains clinically challenging. This study aimed to distinguish between these two treatment options using lateral cephalometric analysis.

Methods: Pretreatment lateral cephalograms of 60 adult patients with borderline Class III malocclusion were analyzed, comprising 30 patients in the camouflage group and 30 in the surgery group. The Mann-Whitney U test was used to compare cephalometric variables between the two groups. Stepwise discriminant analysis was employed to identify the variables that best differentiated the treatment groups. An equation was then generated using the canonical discriminant function coefficients of the selected variables and a constant to calculate a critical score for treatment categorization.

Results: Stepwise discriminant analysis identified four key variables and generated the following equation: Individual score = –13.684+0.138(SN)+0.312(Wits)+0.068 (L1-MP)+0.179(H angle). A critical score of 0 was established. Patients with scores above 0 were considered suitable for orthodontic camouflage, while those with scores below 0 were better suited for orthodontic-orthognathic surgery. The overall classification accuracy of the model was 86.7%.

Conclusions: Four cephalometric variables including SN length, Wits appraisal, L1-MP angle, and H angle were effective in distinguishing appropriate treatment modalities for adult borderline Class III malocclusion patients.