Zygomatic Complex Change After Reduction Malarplasty and Its Geometric Model: A Retrospective Clinical Study

To achieve optimal outcomes in reduction malarplasty, the amount of removed zygomatic bone must be planned accurately. This study aimed to analyze the associations between the width of bony resection and changes in zygomatic bony parameters, to propose a geometric model to guide surgical planning, and to objectively evaluate the surgical outcomes of reduction malarplasty based on computed tomographic (CT) images.This was a retrospective observational study of patients who underwent reduction malarplasty. Digitized CT images were used to evaluate the bony parameters of the zygomatic complex. A geometric model was proposed to guide surgical planning for malar reduction. The primary predictor variable was the width of the bony segment to be resected. The primary outcome variables were changes in malar prominence and attractiveness. Other variables included gender, age, and other bony parameters of the zygoma. Bivariate correlation analysis and multiple linear regression analyses were performed between predictor and outcome variables. Presurgical and postsurgical data were analyzed with paired-samples t test to evaluate surgical outcomes. Differences were considered statistically significant at a P value less than .05.Fifty-one patients who underwent reduction malarplasty with an L-shaped osteotomy from 2012 through 2014 were included in the study. Statistical analysis showed a significant decrease in malar prominence and increased attractiveness between presurgical and postsurgical images (P < .001). The width of bony resection was statistically associated with all outcome variables after adjusting for potential confounders.Reduction malarplasty with a modified L-shaped osteotomy resulted in a notable decrease in malar prominence and a statistical decrease in the zygomatic arch width. The amount of bone that must be removed from the zygoma to achieve a desired reduction can be calculated with geometric equations. The proposed methodology could assist surgical design and improve surgical accuracy.