Relationship between Clinical Symptoms and Magnetic Resonance Imaging in Temporomandibular Disorder (TMD) Patients Utilizing the Piper MRI Diagnostic System

Association between Clinical Manifestations in Temporomandibular Joint Disorders and Corresponding Radiographic Findings

Background: Temporomandibular disorders are common conditions characterized by discomfort within the temporomandibular joints, acoustic changes, and restricted mandibular movement. Accurate diagnosis and subsequent treatment rely heavily on clinical examination, but it is often necessary to add radiological examinations to the diagnostics. Magnetic Resonance Imaging (MRI) is the gold standard for visualizing the disc, while cone-beam computed tomography (CBCT) is primarily used for evaluating condylar morphology. Ultrasound (US) serves as a real-time imaging modality for soft tissues. The objective of the present study was to explore the association between clinical manifestations observed in patients with temporomandibular joint disorders and corresponding radiographic findings. Methods: A total of 63 adult patients (51 female and 12 male) with temporomandibular joint disorders were included in this cross-sectional study. Each patient underwent a clinical examination, followed by appropriate radiological examinations (MRI, CBCT, or US). The level of statistical significance was set at an alpha of 0.05. The Shapiro-Wilk test assessed the normality of numerical variables. The Wilcoxon rank sum test compared two independent groups with non-normally distributed data. Relationships between categorical variables were evaluated using the Pearson chi-square test or Fisher's exact test. The Kendall tau (τ) method analyzed the correlation between two binary variables. Results: The analysis included 63 patients with TMD, predominantly females (80.95%). Ages ranged from 18 to 74 years with a median of 39 years. In the CBCT study, we observed rarefied changes in the left bone structures in patients with bruxism (p = 0.010). MRI and ultrasound imaging revealed changes in patients with limited jaw opening: erosions in the right mandibular head on ultrasound (p = 0.008) and abnormal right bone structures on MRI (p = 0.009). In CBCT, asymmetry in the left joint space was correlated with a high incidence of right side muscle tension (p = 0.004). Additionally, both CBCT and ultrasound showed a correlation between muscle tension and erosion (p = 0.040 in ultrasound, p = 0.020 in CBCT). Acoustic changes, when compared with radiological imaging, were evident in all three studies, like temporomandibular joint pain or palpation. Conclusions: Our study compared three radiographic imaging methods with clinical examinations to assess their correlation with clinical symptoms. Each imaging technique provided unique insights depending on the specific symptoms presented. The observed correlations varied, highlighting the unique contributions of each modality to the diagnostic process. This underscores the importance of employing multiple diagnostic approaches for a thorough assessment of the temporomandibular joint. However, a limitation of our study is the small sample size and the uneven distribution of participants among the groups. Additionally, not all patients underwent every imaging modality.

Association between clinical symptoms and MRI image findings in symptomatic temporomandibular joint (TMJ) disease: A systematic review

To evaluate the association between clinical signs and symptoms of temporomandibular joint (TMJ) and magnetic resonance image (MRI) findings in patients with temporomandibular disorders (TMD). Relevant articles on humans over 18 years of age were obtained from five databases (Ovid MEDLINE, PubMed, Scopus, Web of Science, and Google Scholar) up to August 2022. Risk of bias assessment was completed using the Joanna Briggs Institute critical appraisal tools. The GRADEpro (Grading of Recommendations, Assessment, Development, and Evaluation) instrument was applied to assess the level of evidence across studies in a GRADE Summary of Findings table. In total, 22 studies were included in this systematic review. Of these, 11 studies highlighted that joint pain was positively associated with particular MRI findings: joint effusion, bone marrow edema, disk displacement with/without reduction, and condylar erosion. Masticatory muscle pain was found to have a strong positive correlation with disk displacement in four studies. Five studies found no significant association between MRI findings and masticatory muscle pain. Range of motion and MRI findings were examined in six studies. Limited mouth opening was found to be correlated with disk displacement in five studies. Of the 11 studies evaluating the correlation between joint noise and MRI findings, eight reported a significant association between disk displacement and TMJ noise. The results suggested that patients with joint pain and limited range of motion may benefit from MRI. Patients exhibiting primarily muscle pain are unlikely to benefit clinically from MRI. Future studies with improved quality are warranted.

A New Mechanical Mouth Opener for Dynamic Magnetic Resonance Imaging of the Temporomandibular Joint

(1) Background: During the magnetic resonance imaging (MRI) of the temporomandibular joint (TMJ), it is necessary to scan the joints in the closed- and open-jaw position, as well as in the maximally open-jaw position. In order to examine both joints in these positions, an MRI compatible mouth opener is required, which allows the articular surfaces to maintain their position stably. (2) Methods: In this study, we included 200 patients aged 18 to 65, with various levels of clinical severity. The mouth opener is made of polymethyl methacrylate and used for dynamic imaging of TMJ. It is in the form of an arrow, with incisures on upper and lower surfaces 1 mm apart and these match possible variations in jaw opening. All the patients were scanned with mouth opener and, immediately after this scanning, with syringe (20 ccm) as a standard device used for mouth opening in clinical setting. (3) Results: A total of 200 MR examinations of TMJs were performed and the mechanical mouth opener was successfully applied without artifacts in all patients. The mouth opener device proved to be adequate in case of MRI of the TMJ for different ranges of mouth opening with the proper protocol for provoked imaging, because the incisures are located at a distance of 1 mm and no objective artifacts were observed in any examination that degraded the diagnostic quality of the examination. (4) Conclusions: The design of the acrylate mouth opener is precisely defined, and it has a purpose in the MRI diagnosis of TMJ disorders.

Comparison of imaging findings of 714 symptomatic and asymptomatic temporomandibular joints: a retrospective study

BACKGROUND

The correlation between temporomandibular disorders (TMD) and imaging features remains unclear. This study compared the cone beam computed tomography (CBCT) and magnetic resonance imaging (MRI) features in the temporomandibular joints (TMJs) with and without TMD symptoms.

METHODS

The participants were recruited from the TMJ Diagnosis and Treatment Center from March 2022 to September 2022. Condylar morphology and condylar position were evaluated by CBCT. Disc morphology, disc position, and joint effusion were evaluated by T2-weighted image of MRI. The Chi-Square test and binary logistic regression analysis were carried out.

RESULTS

Eighty-two patients with bilateral symptoms, 196 patients with unilateral symptoms, and 79 asymptomatic participants received MRI and CBCT examination. There were significant differences in the distribution of sex, age, condylar morphology, condylar position, disc morphology, disc position, and joint effusion in symptomatic and asymptomatic TMJs (P < 0.05), which showed a positive correlation with symptoms (P < 0.05). In multiple logistic regression, 19-30-year-age group, > 30-year-age group, abnormal condylar morphology, posterior condylar position, disc displacement with reduction (DDWR), and disc displacement without reduction (DDWoR) were found to be statistically significant (P < 0.05). The odds of having symptomatic TMJ were 1.952 higher in the 19-30-year-age group and 1.814 higher in the > 30-year-age group when compared to those aged ≤ 18-year-age group. The odds of having symptomatic TMJ were 2.360 higher in persons with abnormal condylar morphology when compared to those with normal condylar morphology. The odds of having symptomatic TMJ were 2.591 higher in persons with posterior condylar position when compared to those with the normal condylar position. The odds of having symptomatic TMJ were 2.764 higher in persons with DDWR and 4.189 higher in persons with DDWoR when compared to those with normal disc position. The area under the curve of the model was 0.736 ± 0.019 (95% CI 0.700-0.773, P = 0.000), which indicated that the model has a good fitting effect.

CONCLUSIONS

The imaging findings of TMJs were significantly different between symptomatic and asymptomatic TMJs. TMD is affected by multiple factors including > 19-year-age, abnormal condylar morphology, posterior condylar position, DDWR, and DDWoR, which could be risk factors for the development of TMD symptoms. Trial registration This study was retrospectively registered on 28/03/2022 and endorsed by the Ethics Committee of Affiliated Stomatology Hospital of Guangzhou Medical University (LCYJ2022014).

Automatic detection of anteriorly displaced temporomandibular joint discs on magnetic resonance images using a deep learning algorithm

OBJECTIVES

This study aimed to develop models that can automatically detect anterior disc displacement (ADD) of the temporomandibular joint (TMJ) on MRIs before orthodontic treatment to reduce the risk of developing serious complications after treatment.

METHODS

We used 9009 sagittal MRI of the TMJ as input and constructed three sets of deep learning models to detect ADD automatically. Deep learning models were developed using a convolutional neural network (CNN) based on the ResNet architecture and the "Imagenet" database. Five-fold cross-validation, oversampling, and data augmentation techniques were applied to reduce the risk of overfitting the model. The accuracy and area under the curve (AUC) of the three models were compared.

RESULTS

The performance of the maximum open mouth position model was excellent with accuracy and AUC of 0.970 (±0.007) and 0.990 (±0.005), respectively. For closed mouth position models, the accuracy and AUC of diagnostic Criteria 1 were 0.863 (±0.008) and 0.922 (±0.009), respectively significantly higher than that of diagnostic Criteria 2 with 0.839 (±0.013) (p = 0.009) and AUC of 0.885 (±0.018) (p = 0.003). The classification activation heat map also improved our understanding of the models and visually displayed the areas that play a key role in the model recognition process.

CONCLUSION

Our CNN model resulted in high accuracy and AUC in detecting ADD and can therefore potentially be used by clinicians to assess ADD before orthodontic treatment, and hence improve treatment outcomes.