Treatment efficiency and stability of skeletal Class III malocclusion with a surgery-first approach

Objectives: To compare treatment duration in skeletal Class III malocclusion patients managed with a 2-step treatment (surgery-first approach, SFA) and conventional 3-step treatment, and to compare stability of surgical outcomes between segmentation and non-segmentation in the 2-step treatment group. Setting and Sample Population: The sample population consisted of 37 patients who completed orthognathic surgery (OGS) and orthodontic correction at the Charm Aesthetic Surgery Clinic (Taipei, Taiwan) between 2012 and 2015. Of these, 26 received 2-step treatment and 11 received 3-step treatment. Materials and Methods: To compare treatment efficiency and stability, three time points were analysed: T ₀, before treatment (before OGS in the 2-step group and before orthodontic treatment in the 3-step group); T ₁, after OGS but before orthodontic correction (cone beam computed tomography (CBCT) was obtained within 2 weeks of OGS); and T ₂, after orthodontic correction (CBCT was obtained on the day of bracket removal). The post-OGS (T ₁) CBCT items were individually superimposed on the pre-treatment (T ₀) CBCT items to determine the distance of B point migration. Results: A significant difference was found in treatment times between 2-step treatment and conventional 3-step treatment. In addition, no significant difference was found when comparing B-X (mm) and B-Y (mm) at T ₂-T ₁ for the segmentation and non-segmentation groups. Conclusions: Using SFA for skeletal Class III malocclusions saves approximately 6 months of treatment time over 3-step treatment; the stability of the segmentation group was comparable to that of the non-segmentation group, a result that is possibly associated with the fixation of 2 miniplates.