Faculty, Staff and Student Publications
Language
English
Publication Date
4-1-2022
Journal
Journal of Oral and Maxillofacial Surgery
DOI
10.1016/j.joms.2021.11.016
PMID
34942153
PMCID
PMC8983510
PubMedCentral® Posted Date
4-1-2023
PubMedCentral® Full Text Version
Author MSS
Abstract
Purpose: A facial reference frame is a 3-dimensional Cartesian coordinate system that includes 3 perpendicular planes: midsagittal, axial, and coronal. The order in which one defines the planes matters. The purposes of this study are to determine the following: 1) what sequence (axial-midsagittal-coronal vs midsagittal-axial-coronal) produced more appropriate reference frames and 2) whether orbital or auricular dystopia influenced the outcomes.
Methods: This study is an ambispective cross-sectional study. Fifty-four subjects with facial asymmetry were included. The facial reference frames of each subject (outcome variable) were constructed using 2 methods (independent variable): axial plane first and midsagittal plane first. Two board-certified orthodontists together blindly evaluated the results using a 3-point categorical scale based on their careful inspection and expert intuition. The covariant for stratification was the existence of orbital or auricular dystopia. Finally, Wilcoxon signed rank tests were performed.
Results: The facial reference frames defined by the midsagittal plane first method was statistically significantly different from ones defined by the axial plane first method (P = .001). Using the midsagittal plane first method, the reference frames were more appropriately defined in 22 (40.7%) subjects, equivalent in 26 (48.1%) and less appropriately defined in 6 (11.1%). After stratified by orbital or auricular dystopia, the results also showed that the reference frame computed using midsagittal plane first method was statistically significantly more appropriate in both subject groups regardless of the existence of orbital or auricular dystopia (27 with orbital or auricular dystopia and 27 without, both P < .05).
Conclusions: The midsagittal plane first sequence improves the facial reference frames compared with the traditional axial plane first approach. However, regardless of the sequence used, clinicians need to judge the correctness of the reference frame before diagnosis or surgical planning.
Keywords
Anatomic Landmarks, Computers, Cross-Sectional Studies, Facial Asymmetry, Humans, Imaging, Three-Dimensional, Orthognathic Surgery, Computer-Aided Surgical Simulation, Virtual Surgical Planning, Reference Frame, Cartesian Coordinate System, Midsagittal Plane, Axial Plane, Facial Asymmetry, Orbital Dystopia, Auricular Dystopia
Published Open-Access
yes
Recommended Citation
, "Midsagittal Plane First: Building a Strong Facial Reference Frame for Computer-Aided Surgical Simulation" (2022). Faculty, Staff and Student Publications. 56.
https://digitalcommons.library.tmc.edu/uthdb_docs/56