Comparison of different midsagittal plane configurations for evaluating craniofacial asymmetry by expert preference

Abstract

INTRODUCTION: In this study, we aimed to compare 8 candidate midsagittal planes (MSPs) constructed from different median landmarks to determine the most appropriate one for evaluating craniofacial asymmetry.

METHODS: We included 30 patients (18 men, 12 women; mean age, 25.7 ± 6.03 years) who visited the National Health Insurance Service Ilsan Hospital in Gyeonggi-do, Korea, with a complaint of facial asymmetry. Four MSPs passing through 2 median landmarks perpendicular to the Frankfort horizontal plane and 4 other MSPs passing through 3 median landmarks were constructed. Menton, anterior nasal spine, and anterior nasal spine-to-posterior nasal spine line deviations were evaluated using these 8 MSPs. Eight MSPs from 30 subjects were shown to 6 experts, who selected the planes that they considered the most appropriate.

RESULTS: Experts most frequently selected the plane passing through nasion and basion perpendicular to the Frankfort horizontal plane (66 of 180 times; P <0.05). In evaluating craniofacial asymmetry, using MSPs passing through 3 median landmarks in the cranial base can lead to underestimation of the asymmetry of the menton, anterior nasal spine, and anterior nasal spine-to-posterior nasal spine line.

CONCLUSIONS: We suggest using MSPs perpendicular to the Frankfort horizontal plane or a plane passing through anterior nasal spine in clinical practice.