Symmetry recovery in zygomaticomaxillary complex fractures compared to normal unfractured population: A new reliable 3D evaluation

K Dubron; L H Yang; R Jacobs; C Politis; R Willaert; E Shaheen

doi:10.1016/j.jormas.2024.101857

Symmetry recovery in zygomaticomaxillary complex fractures compared to normal unfractured population: A new reliable 3D evaluation

J Stomatol Oral Maxillofac Surg. 2024 Mar 29:101857. doi: 10.1016/j.jormas.2024.101857. Online ahead of print.

Authors

K Dubron¹, L H Yang², R Jacobs³, C Politis¹, R Willaert¹, E Shaheen¹

Affiliations

¹ Department of Oral and Maxillofacial Surgery, University Hospitals Leuven, Belgium; OMFS IMPATH Research Group, Department of Imaging & Pathology, University Hospitals Leuven, Belgium.
² Department of Oral Health Sciences, KU Leuven and Dentistry, University Hospitals Leuven, Belgium.
³ OMFS IMPATH Research Group, Department of Imaging & Pathology, University Hospitals Leuven, Belgium; Department of Dental Medicine, Karolinska Institutet, Stockholm, Sweden. Electronic address: reinhilde.jacobs@ki.se.

PMID: 38556166
DOI: 10.1016/j.jormas.2024.101857

Abstract

Objective: This study aims to quantify the facial symmetry of surgically treated zygomaticomaxillary complex (ZMC) fractures through a new reliable three-dimensional evaluation method, which is crucial for improving post-operative aesthetic and functional outcomes.

Material and methods: Healthy patients and patients with surgically treated ZMC fractures were retrospectively reviewed. Using Brainlab Elements® the zygomatic bone and the orbit of each patient was segmented and mirrored. Subsequently, the mirrored side was matched with the other side via volume-based registration, using the segmented orbit as reference. Volumetric asymmetry was measured using 3-matic software, and a surface-based matching technique was used to calculate the mean absolute differences (MAD) between the surfaces of the two sides of the ZMC. The reliability of this novel method using volume-based registration was tested, and the intra-class correlation coefficient was assessed.

Results: The MAD between the surfaces of the left and right sides in the control group was 0.51 mm (±0.09). As for the ZMC fracture group, MAD was 0.78 mm (±0.20) and 0.72 mm (±0.15) pre- and post-operatively, respectively. The MAD showed statistically significant differences between pre- and post-operative groups (p = 0.005) and between control and post-operative groups (p < 0.001). The intra-class correlation coefficient was high (≥0.99).

Conclusions: This evaluation method using mirroring and volume-based registration to determine the symmetrical position of the ZMC is reliable. The surface-based measurements revealed an improved symmetry after surgery. However, the symmetry of the treated patients remained lower than the control group.

Keywords: Computer assisted image analysis; Facial asymmetry; Maxillofacial injury; Reconstruction; Trauma planning; Zygomatic fractures; Zygomaticomaxillary complex.