Simultaneous Reduction Malarplasty and Reduction Mandibuloplasty: Less Mandibular Hyperplasia with Masseter Elevation

Bone hyperplasia after reduction mandibuloplasty can impair the aesthetic outcome of the surgery which may require a revision. The adjacent masseter has been reported to be a decisive factor in postoperative mandibular hyperplasia. Our clinical practice suggested that simultaneous reduction malarplasty with zygomatic arch elevation may reduce masseter accumulation after reduction mandibuloplasty and contribute to less mandibular hyperplasia. Thus, a retrospective study was conducted to clarify our observation.

From September 2015 to April 2024, patients who underwent reduction mandibuloplasty with or without simultaneous reduction malarplasty with zygomatic arch elevation were retrospectively reviewed. Computed tomography data were utilized to measure the preoperative, immediate postoperative, and follow-up postoperative mandibular volume. The volume of resected mandibular bone and regenerated mandibular bone was calculated. The measurements of masseter thicknesses, elevation distance of the zygomatic arch, as well as correlations analysis between them were performed.

Fifty-two patients receiving reduction mandibuloplasty with simultaneous reduction malarplasty (combined-operation group) and 35 patients receiving reduction mandibuloplasty only (single-operation group) were included. After the operation, the masseter muscle in both groups became significantly thicker. The average masseter thickness increase was 0.89 ± 1.21 mm in the combined-operation group and 2.70 ± 1.10 mm in the single-operation group. Single-operation group had severer masseter thickening and mandibular hyperplasia. Pearson correlation analysis revealed that masseter thickening was positively correlated to mandibular resected volume, and that mandibular hyperplastic volume was positively correlated to masseter thickening with statistical significance.

Simultaneous reduction malarplasty with zygomatic arch elevation induced less masseter redundancy and mandibular hyperplasia. In maxillofacial contouring surgeries, if necessary, performing the two procedures simultaneously and applying the bracing technique with zygomatic arch elevation can effectively improve the aesthetic outcomes of reduction mandibuloplasty.

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