Perception of the malar midface of patients with class III malocclusion after Le Fort I osteotomy.

INTRODUCTION

Maxillo-zygomatic hypoplasia is common in patients with a Class III malocclusion, resulting in a flat and concave appearance of the midface. Le Fort I osteotomy is considered to be an effective treatment for occlusal and facial aesthetic but there are discrepancies regarding its impact on the volume of the maxillo-zygomatic region, while several studies reported no volumetric impact. The aim of the study was to assess the impact of Le Fort I osteotomy on the malar midface of patients with Class III malocclusion, based on the perceptions of maxillofacial surgeons (MFS) and laypersons.

MATERIALS AND

METHODS

MFS and laypersons evaluated the maxillo-zygomatic volume based on the photographs of 26 patients with Class III malocclusion, treated with or without conventional Le Fort I osteotomy. The questionnaire focused on the subjective analysis of the malar midface and the participants were asked to rate the maxillo-zygomatic volume using a Likert scale ranging from 1 to 5. The results were modelled to test the different distributions of the 5 scores between the pre-operative and post-operative assessment of the photographs.

RESULTS

A total of 78 evaluators responded to the questionnaire; age and sex distributions were similar between the two groups. According to all evaluators, 52.5% of patients still presented insufficient maxillo-zygomatic volume after Le Fort I osteotomy; there was no significant difference regarding a decrease in the flat maxillo-zygomatic volume score between operated (17.1%) and non-operated patients (23.7%; p = 0.320). Laypersons significantly reported lower flat and insufficient volumes (scores 1-2; 45.0%) compared to MFS (61.8%; p = 0.003).

CONCLUSIONS

Approximately half of patients with Class III malocclusion still present insufficient maxillo-zygomatic volume after Le Fort I osteotomy. Subjective perception of malar volume may remain insufficient in a substantial proportion of patients following conventional Le Fort I osteotomy leading to the need of additional surgical treatments on the maxillo-zygomatic region. Sex, ethnic, morphology and age should be considered in the therapeutic strategy for the midface.