Comparison of treatment duration between conventional three-stage method and surgery-first approach in patients with skeletal Class III malocclusion.

The purpose of this retrospective study was to compare the durations of total treatment (TT), and preoperative orthodontic treatment (Pre-OP-OT) and postoperative orthodontic treatment (Post-OP-OT) between conventional 3-stage method (CTM) and surgery-first approach (SFA). The subjects consisted of skeletal Class III patients who were treated with non-extraction and 2-jaw surgery and had lateral cephalograms taken at initial visit (T0), 1 month before surgery (T1), immediately after surgery (T2), and at debonding (T3). They were allocated into group 1 (CTM, n = 26) and group 2 (SFA, n = 18, including the subjects with Pre-OP-OT shorter than 100 days). Statistical analysis was performed after measuring skeletodental variables in the T0 lateral cephalogram, the amount of surgical change (ΔT2-T1), and the durations of TT, Pre-OP-OT, and Post-OP-OT. There were no significant differences in skeletodental variables at the T0 stage or in ΔT2-T1 between groups 1 and 2. Therefore, differences in durations of TT and Post-OP-OT between groups 1 and 2 could be attributed to the difference in treatment methods (CTM vs. SFA). TT and Pre-OP-OT were significantly longer in group 1 than those in group 2 (324.2 days and 385.7 days, respectively; all P < 0.001). Although Post-OP-OT was longer in group 2 than in group 1, the difference was not significant (63.3 days; P > 0.05). In group 1, the negative correlation between durations of Pre-OP-OT and Post-OP-OT was not verified, which means that Post-OP-OT was not shortened despite longer Pre-OP-OT. The results from this study can be used as a guideline in diagnosis and treatment planning for SFA.