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With advancements in radiology, endoscopic techniques, surgical treatments, cell biology and molecular biology, the understanding of temporomandibular disorders(TMD)has increased. The temporomandibular joint (TMJ) is a complex structure comprising both soft and hard tissues. Within the TMJ, the temporomandibular disc is a soft tissue structure that connects the mandible to the skull, providing cushioning and stability during joint movement. Different imaging techniques have their own advantages and limitations in the diagnosis and treatment of TMD. Therefore, using image registration technology to assess the condition and position of the articular disc provides new research perspectives for evaluating TMD, which may contribute to the diagnosis and treatment. This article reviews the latest advancements in TMJ imaging, explores the applications of various image registration techniques, particularly in the context of TMD diagnosis and treatment, and discusses future prospects. Combining the research results of some scholars at home and abroad with the author’s clinical experience, the article aims to provide valuable insights for clinicians.

Objective To investigate associations between three-dimensional(3D) morphology of cervical vertebrae and skeletal maturation by cone-beam computed tomography(CBCT) and establish corresponding regression models for quantitatively evaluating cervical vertebral maturation(CVM). Methods The analyzed sample consisted of 358 CBCT images (175 male, 183 female), of which 277 images were randomly selected as the model development group and 81 as the performance test group. Twenty-one 3D morphological parameters were defined and measured, incorporating all parts of the cervical vertebrae, including the cervical vertebral bodies, transverse processes, spinous processes, pedicles, lamina, and articular processes. The cervical vertebral maturation index (CVMI) was determined by experienced orthodontists as reference standard. Spearman’s rank correlation coefficient and multivariable stepwise regression analysis were used to identify the associations and build regression models. The performance test group was employed to examine each model’s reliability. Paired-samples Wilcoxon signed-rank test compared the CVMI of the model prediction with the reference standard. Results Three-dimensional morphological changes in various parts of the cervical vertebrae correlated with CVMI (P0.05). Conclusion New associations were found between 3D morphology of cervical vertebrae and skeletal maturation. The 3D-driven morphometric CVM assessment method and corresponding regression models exhibited good credibility and high consistency with experts.

Objectives: This study was aimed to investigate the accuracy of soft-tissue measurements obtained by two imaging modalities, three-dimensional (3D) photogrammetry and cone beam CT (CBCT) when confounded by influence factors (facial deformities and partitions)., Methods: 60 wax facial models from facially deformed patients were captured by 3D photogrammetry and CBCT. 19 linear distances on each image were measured and juxtaposed to reference values attained via a coordinate-measuring machine (CMM) as the gold-standard. Paired t -tests were used to compare linear accuracy of the test and reference systems. The influence of deformities and partitions (created by dividing the face with three vertical and five horizontal lines) on the measurement errors were analyzed by independent sample t -test and one-way ANOVA., Results: Statistically significant differences were found between linear accuracy of the test and reference systems. The test values obtained by 3D photogrammetry were closer to the reference values than CBCT's. 3D photogrammetry's measurement errors were significantly higher in deformed areas, unlike CBCT's. Both systems reported significantly lower errors within partitions 8 and 13 compared to other partitions; for CBCT, aside from partitions 8 and 13, the differences in the errors for partitions 6 and 10 were significant compared to partitions 8, 12, 13, 14., Conclusion: 3D photogrammetry showed a higher linear accuracy than CBCT in patients with facial deformities due to protuberances. Facial reconstruction by both test modalities was significantly influenced in different facial partitions, but facial deformities extensively affected the results from 3D photogrammetry.