Assessment of facial symmetry by three-dimensional stereophotogrammetry after mandibular reconstruction: A comparison with subjective assessment.

Abstract

Introduction: The assessment of facial symmetry, after mandibular reconstruction, currently relies on subjective esthetic assessment by an evaluator. The present study aimed to compare conventional subjective assessment with quantitative evaluation by three-dimensional (3D) stereophotogrammetry of facial cosmetic symmetry. Methods: This retrospective study enrolled 20 patients who underwent mandibular reconstruction with free fibula flap after segmental resection between 2014 and 2018. Subjective assessments were performed by seven clinicians at 6-12 months after surgery. Simultaneously, lower face symmetry was measured by 3D stereophotogrammetry with the VECTRA H1 system and recorded as the root mean square deviation (RMSD). Data from the subjective and quantitative evaluations were compared using Spearman's rank correlation coefficient. Results: The results showed that subjective assessments were strongly and negatively correlated with RMSD (P=0.00000128). This confirmed that RMSD, obtained by 3D stereophotogrammetry, reflected the subjective assessment of symmetry in our cohort. Conclusions: Three-dimensional stereophotogrammetry of facial cosmetic symmetry will be an available quantitative method for patients with head and neck cancer after mandibular reconstruction.