Temporomandibular Joint Space Dimensions among Saudi Patients with Temporomandibular Disorders: MRI-Based Retrospective Study

Diagnostic significance and evaluation of alterations in the superior joint space for temporomandibular joint fracture detection

OBJECTIVE

To comprehensively assess the diagnostic significance of variations in the superior joint space (SJS) of the temporomandibular joint (TMJ) for the detection of TMJ fractures through spiral computed tomography (CT) scans.

METHODS

A retrospective analysis was conducted of CT scans of 32 patients with clinically confirmed TMJ fractures and 30 controls without fractures. The SJS was meticulously measured using the Kamelchuk method. Statistical analyses, including the Wilcoxon signed-rank test for paired comparisons, the Mann-Whitney U test for comparisons between groups, and ROC curve analysis for evaluating diagnostic performance, were performed to rigorously quantify the diagnostic importance of SJS changes. Binary logistic regression modeling was also applied to validate the accuracy of the assessment and determine the odds ratio (OR).

RESULTS

In the fracture group, statistically significant differences were observed in the SJS of bilateral TMJs (p < 0.05), whereas no significant difference was noted in the control group. The mean SJS on the fractured side was 3.75 mm, notably greater than the bilateral mean of 3.03 mm in the control group (p < 0.001). The discrepancy in SJS between sides in the fracture group (0.82 mm) significantly surpassed that of the control group (0.19 mm, p < 0.001). Utilizing an optimal threshold SJS difference of 0.62 mm, the diagnostic sensitivity was 63.30%, specificity was 86.70%, and accuracy was 76.70%, with an OR of 21.00 (95% CI: 4.198-105.038).

CONCLUSION

This study found that changes in the SJS caused by TMJ fractures have significant diagnostic value in fracture detection, serving as a reliable tool for early and accurate diagnosis. By utilizing early identification and diagnosis via spiral CT, the study evaluated the changes in the SJS induced by fractures, providing crucial diagnostic information for clinical practice. This discovery emphasizes the pivotal role of SJS changes in identifying TMJ fractures and offers new diagnostic methods and insights for clinical practice.

Relationship between temporomandibular joint space and articular disc displacement

OBJECTIVE

Analyse the correlation between the changes in joint space of TMJ and the displacement and degree of articular disc for clinical diagnosis.

METHODS

Two hundred sixteen TMJs of 108 temporomandibular disorders (TMD) patients with clinical symptoms and MRI examination were included in the study. 30 of these patients had undergone CBCT before MRI. According to the degree of articular disc displacement, the 216 joints are divided into five groups. Group A: no disc displacement (40 cases); group B: mild anterior disc displacement (44 cases); group C: moderate anterior disc displacement (36 cases); group D: severe anterior disc displacement (52 cases); group E: posterior displacement (44 cases). The 132 sides of these anteriorly displaced discs (ADD) were further divided into two groups, anterior disc displacement with reduction (ADDwR) and anterior disc displacement without reduction (ADDwoR). We analysed the concordance of the joint space measured by MRI and CBCT, and explored the relationship between joint space, ln(P/A) values and joint disc displacement.

RESULTS

There was no statistically significant difference between the joint spaces measured by CBCT and MRI (P > 0.05). The anterior joint space in group B (2.7 ± 0.72 mm) and C (2.82 ± 0.88 mm) was larger than group A (1.82 ± 0.50 mm) (P < 0.05), and ln(P/A) value in group B (-0.52 ± 0.34) and C (-0.62 ± 0.43) was smaller than group A (0.04 ± 0.15) (P < 0.05). The posterior joint space (3.33 ± 1.28 mm) and ln(P/A) value (0.74 ± 0.33) in group E was larger than group A (P < 0.05). There was no significant difference in the anterior, superior and posterior joint space and ln(P/A) value between group D and A (P > 0.05). The ADDwR group had a larger anterior joint space (2.72 ± 0.83 mm) than group A (P < 0.05), while having a smaller posterior joint space (1.61 ± 0.49 mm) and ln(P/A) value (-0.52 ± 0.39 mm) (P < 0.05). Compared with group A, there was no significant difference in the anterior joint space and ln(P/A) value in the ADDwoR group(P > 0.05).

CONCLUSION

There is no significant change in anterior, supra, and posterior joint space in severe anterior disc displacement. The anterior joint space increases in mild to moderate anterior disc displacement, but does not change in severe anterior disc displacement-the posterior joint space increases when the joint disc is displaced posteriorly. The position of the joint disc cannot be accurately inferred by observing the joint space through CBCT, and a combination of MRI and clinical examination is required to make a definitive judgement.

Deep Learning for Ultrasonographic Assessment of Temporomandibular Joint Morphology

BACKGROUND

Temporomandibular joint (TMJ) disorders are a significant cause of orofacial pain. Artificial intelligence (AI) has been successfully applied to other imaging modalities but remains underexplored in ultrasonographic evaluations of TMJ.

OBJECTIVE

This study aimed to develop and validate an AI-driven method for the automatic and reproducible measurement of TMJ space width from ultrasonographic images.

METHODS

A total of 142 TMJ ultrasonographic images were segmented into three anatomical components: the mandibular condyle, joint space, and glenoid fossa. State-of-the-art architectures were tested, and the best-performing 2D Residual U-Net was trained and validated against expert annotations. The algorithm for joint space width measurement based on TMJ segmentation was proposed, calculating the vertical distance between the superior-most point of the mandibular condyle and its corresponding point on the glenoid fossa.

RESULTS

The segmentation model achieved high performance for the mandibular condyle (Dice: 0.91 ± 0.08) and joint space (Dice: 0.86 ± 0.09), with notably lower performance for the glenoid fossa (Dice: 0.60 ± 0.24), highlighting variability due to its complex geometry. The TMJ space width measurement algorithm demonstrated minimal bias, with a mean difference of 0.08 mm and a mean absolute error of 0.18 mm compared to reference measurements.

CONCLUSIONS

The model exhibited potential as a reliable tool for clinical use, demonstrating accuracy in TMJ ultrasonographic analysis. This study underscores the ability of AI-driven segmentation and measurement algorithms to bridge existing gaps in ultrasonographic imaging and lays the foundation for broader clinical applications.

[Features of the temporomandibular joint morphology and function in the adults with different growth patterns]

THE AIM OF THE STUDY

Was to improve methods for diagnosing the morphofunctional state of the TMJ in individuals with normal occlusion with various types of facial skull growth.

MATERIALS AND METHODS

The study comprised 35 volunteers aged 18-45 years (average age 25.6±4.8 years) with normal occlusion and intact dentition. Telerentgenography (TRG), cone beam computed tomography (CBCT), magnetic resonance imaging, and ultrasound examination of the TMJ were performed.

RESULTS

Horizontal type of growth of the facial part of the skull was established in 13 people; 12 had neutral type and 10 had vertical type. According to CBCT data, in patients with horizontal growth type, the highest values of the parameters of the width of the articular head, the smallest parameters of the length of the condyle process and the size of the articular gap in the upper-anterior and upper-posterior sections were determined. In patients with the vertical type, an inverse correlation of values was established, which may be due to the anatomical features of the TMJ structure: the articular head is narrower and longer, and the articular gap is wider. According to MRI data, in all patients, regardless of the type of growth of the facial part of the skull, the posterior thickening of the articular disc was located at «11-12 hours» mark in the sagittal plane, and the poles of the articular disc did not extend beyond the poles of the articular head of the same name in the coronal plane. According to ultrasound data, the indicators of the size of the articular gaps were fully consistent with the conclusions obtained from CT and MRI. The smallest length of the articular pathway was found in patients with vertical growth type, the largest in patients with horizontal growth type.

CONCLUSION

Statistically significant differences in morphometric (the size of the articular gap) and functional (the length of the trajectory of the articular heads) parameters of the TMJ were established for various types of growth of the facial part of the skull, which confirms the need to study the state of the TMJ, considering the identified differences.

Intra-Articular Physiological Saline in Temporomandibular Disorders May Be a Treatment, Not a Placebo: A Hypothesis, Systematic Review, and Meta-Analysis

Background: Intra-articular injections reduce pain in patients with temporomandibular joint (TMJ) disorders who are unresponsive to conservative treatment. Hyaluronic acid, blood products, and medications provide rapid relief when administered this way, although their mechanisms of action remain unclear. In control groups, which are intended to be untreated, 0.9% NaCl is typically delivered. The hypothesis that "normal saline injections in TMJ cavities produce a therapeutic effect" is proposed, with an exploration of its potential verification, alongside a systematic review and meta-analysis of studies on intra-TMJ 0.9% NaCl. Methods: Randomized controlled trials (RCTs) on patients with TMJ internal derangement, arthritis, or degeneration were selected under PRISMA 2020 and assessed with RoB2. Results: Seven RCTs with 359 patients were included. Weekly follow-ups revealed a decrease in articular pain by 23.72% (SE: 0.84%; 95% CI: 24.38-21.06%; p < 0.01), and monthly follow-ups indicated a decrease of 34.01% (SE: 1.09%; 95% CI: 36.16-31.86%; p < 0.01) compared to the baseline values. These findings were grounded in low-risk-of-bias evidence on 267 patients in five RCTs and 222 patients in four RCTs, respectively. Conclusions: The hypothesis warrants further testing to determine whether, in addition to the known biological activity of typical injectables, the mechanical action also contributes to pain relief.

Relationships between functional temporomandibular joint space and disc morphology, position, and condylar osseous condition in patients with temporomandibular disorder

OBJECTIVE

To investigate the correlations between joint space and temporomandibular joint (TMJ) components and the compressive states of the disc and condyle subsequent to joint space changes.

MATERIALS AND METHODS

A total of 240 TMJs were categorized according to disc morphology, disc position, and condylar osseous condition. The two-dimensional (2D) and three-dimensional (3D) measurements were compared. The functional joint space (FJS) and disc areas on closed- and open-mouth images (DA-C and DA-O) were also calculated, and the joint space was measured in five directions. Different groups of TMJ components were compared. A spring model was used to simulate the effect of condylar displacement on the disc and condyle.

RESULTS

Disc morphology was strongly correlated with its position. The measurements were equivalent between 2D and 3D methods. DA-C and FJS differed significantly between groups. The DA-C to FJS ratio differed between the Class 2 and Class 3 groups and between disc displacement groups with and without reduction. Altered disc morphology and position were correlated with significant changes in joint space in the 60°, 90°, and 120° directions. Despite minor discrepancies among condylar osseous conditions, reduced joint space was correlated with bone destruction at the corresponding site. The spring model stimulation revealed that condylar displacement caused elevated stresses on the disc and condyle.

CONCLUSIONS

Condylar displacement causes joint space alterations while exerting compressive pressure on both the disc and condyle.

CLINICAL RELEVANCE

Proper condylar positioning within the fossa is recommended to ensure sufficient articular disc accommodation.

A comprehensive patient-specific prediction model for temporomandibular joint osteoarthritis progression

Temporomandibular joint osteoarthritis (TMJ OA) is a prevalent degenerative disease characterized by chronic pain and impaired jaw function. The complexity of TMJ OA has hindered the development of prognostic tools, posing a significant challenge in timely, patient-specific management. Addressing this gap, our research employs a comprehensive, multidimensional approach to advance TMJ OA prognostication. We conducted a prospective study with 106 subjects, 74 of whom were followed up after 2 to 3 y of conservative treatment. Central to our methodology is the development of an innovative, open-source predictive modeling framework, the Ensemble via Hierarchical Predictions through Nested cross-validation tool (EHPN). This framework synergistically integrates 18 feature selection, statistical, and machine learning methods to yield an accuracy of 0.87, with an area under the ROC curve of 0.72 and an F1 score of 0.82. Our study, beyond technical advancements, emphasizes the global impact of TMJ OA, recognizing its unique demographic occurrence. We highlight key factors influencing TMJ OA progression. Using SHAP analysis, we identified personalized prognostic predictors: lower values of headache, lower back pain, restless sleep, condyle high gray level-GL-run emphasis, articular fossa GL nonuniformity, and long-run low GL emphasis; and higher values of superior joint space, mouth opening, saliva Vascular-endothelium-growth-factor, Matrix-metalloproteinase-7, serum Epithelial-neutrophil-activating-peptide, and age indicate recovery likelihood. Our multidimensional and multimodal EHPN tool enhances clinicians' decision-making, offering a transformative translational infrastructure. The EHPN model stands as a significant contribution to precision medicine, offering a paradigm shift in the management of temporomandibular disorders and potentially influencing broader applications in personalized healthcare.