Examining the variability of bone and soft tissue morphology in Hemifacial Microsomia: A case series of 8 patients

Aim of the study: Patients with Hemifacial Microsomia (HFM) exhibit highly variable skeletal and soft tissue asymmetries. The purpose of this study was to evaluate soft tissue discrepancies in patients with HFM and correlate them to the skeletal discrepancy. Eight patients were selected and studied retrospectively using 3-dimensional (3D) superimposition and color mapping of the soft and hard tissues. The skeletal and soft tissue facial structures were segmented and mirrored, resulting in a perfectly symmetric skull and face. Original and mirrored 3D models were superimposed. Differences between the affected and normal side were assessed in seven areas: frontal, endocanthion, exocanthion, malar, maxillary frontal, mandibular frontal and gonion area. The correlations between the skeletal and soft tissue asymmetry were evaluated by Pearson correlations. Hard tissue asymmetry ranged from 1.4 mm (Endocanthion) to 5.5 mm (Gonion), while soft tissue asymmetry ranged from 1.5 mm (Endocanthion) to 5.6 mm (Malar). Correlation between skeletal and soft tissue deficiency were highly variable, with the highest correlation at gonion and the lowest at exocanthion. Bone and soft tissue hypoplasia were highly correlated at the gonion and the malar area, while the remaining evaluated areas demonstrated poor correlation between skeletal and soft tissue asymmetries. Future studies will determine if target treatment can reliably improve bone and soft tissue hypoplasia in this area. (C) 2021 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

Automated summary

This study aimed to evaluate soft tissue discrepancies in patients with HFM and correlate them to skeletal discrepancies. The correlation between skeletal and soft tissue asymmetry was found to be highly variable, with different areas of the skull and face showing varying levels of correlation. Future studies will determine if target treatment can reliably improve these asymmetries.