Morgan Nermin, Shujaat Sohaib, Jazil Omid, Jacobs Reinhilde
OMFS IMPATH Research Group, Department of Imaging and Pathology, Faculty of Medicine, KU Leuven and Oral and Maxillofacial Surgery, University Hospitals Leuven, Kapucijnenvoer 33 bus 7001, 3000, Leuven, Belgium.
Department of Oral Medicine, Faculty of Dentistry, Mansoura University, Mansoura, Egypt.
Int J Comput Assist Radiol Surg. 2023 Apr;18(4):611-619. doi: 10.1007/s11548-022-02775-0. Epub 2022 Oct 22.
Quantification of skeletal symmetry in a healthy population could have a strong impact on the reconstructive surgical procedures where mirroring of the contralateral healthy side acts as a clinical reference for the restoration of unilateral defects. Hence, the aim of this study was to three-dimensionally assess the symmetry of skeletal midfacial complex in skeletal class I patients.
A sample of 100 cone beam computed tomography (CBCT) scans (50 males, 50 females; age range: 19-40 years) were recruited. Automated segmentation of the skeletal midfacial complex was performed to create a three-dimensional (3D) virtual model using a convolutional neural network (CNN)-based segmentation tool. Thereafter, the segmented model was mirrored and registered to quantify skeletal symmetry using a color-coded conformance mapping based on a surface part comparison analysis.
Overall, the mean and root-mean-square (RMS) differences between complete true and mirrored models were 0.14 ± 0.12 and 0.87 ± 0.21 mm, respectively. Female patients had a significantly more symmetrical midfacial complex (mean difference: 0.11 ± 0.1 mm, RMS: 0.81 ± 0.17 mm) compared to male patients (mean difference: 0.16 ± 0.13 mm, RMS: 0.94 ± 0.23 mm). No significant difference existed between left and right sides irrespective of the patient's gender.
The comparison between true and mirrored complete and left/right split midfacial complex showed symmetry within a clinically acceptable range of 1 mm, which justifies the applicability of using the mirroring technique. The presented data could act as a reference guide for surgeons during planning of reconstructive surgical procedures and outcome assessment at follow-up.
量化健康人群的骨骼对称性可能会对重建外科手术产生重大影响，在这类手术中，对侧健康侧的镜像作为修复单侧缺损的临床参考。因此，本研究的目的是三维评估骨骼I类患者的中面部骨骼复合体的对称性。
招募了100例锥形束计算机断层扫描（CBCT）（50例男性，50例女性；年龄范围：19 - 40岁）。使用基于卷积神经网络（CNN）的分割工具对中面部骨骼复合体进行自动分割，以创建三维（3D）虚拟模型。此后，对分割后的模型进行镜像和配准，以基于表面部分比较分析使用颜色编码的一致性映射来量化骨骼对称性。
总体而言，完整真实模型与镜像模型之间的平均差异和均方根（RMS）差异分别为0.14±0.12和0.87±0.21毫米。与男性患者（平均差异：0.16±0.13毫米，RMS：0.94±0.23毫米）相比，女性患者的中面部复合体对称性明显更高（平均差异：0.11±0.1毫米，RMS：0.81±0.17毫米）。无论患者性别如何，左右两侧之间均无显著差异。
真实模型与镜像的完整及左右分开的中面部复合体之间的比较显示，对称性在临床上可接受的1毫米范围内，这证明了使用镜像技术的适用性。所呈现的数据可为外科医生在重建外科手术规划和随访结果评估期间提供参考指导。
