Imaging of the Temporomandibular Joint

Unlocking the Temporomandibular Joint: CT, MRI, and Arthroscopic Correlation

The temporomandibular joint constitutes a synovial connection between the mandible and the skull base and plays a pivotal role in functions such as jaw movement, chewing, and verbal and emotional expression. Temporomandibular joint dysfunction is observed in about 30% of the population, with a higher prevalence in young to middle-aged women. Interestingly, a majority of individuals affected do not report pain, and only 5%-10% of symptomatic cases necessitate therapeutic intervention. The most common temporomandibular joint disorder manifests as pain in the masticatory muscles and is referred to as myofascial syndrome. However, articular disorders are also very common, usually due to disk displacement and degenerative or inflammatory arthropathies. Less frequently, the temporomandibular joint may be affected by a range of congenital and acquired conditions such as trauma and neoplasms. Imaging becomes necessary for the small percentage of patients who do not respond to conservative management or when there is uncertainty in the diagnosis. A comprehensive understanding of the normal imaging appearance of the temporomandibular joint as well as the wide range of potential pathologic conditions is essential for conducting an accurate radiologic assessment. Moreover, collaboration among multidisciplinary teams and the correlation of imaging findings with arthroscopic observations are crucial to advancing the diagnosis and treatment of temporomandibular joint dysfunction. ©RSNA, 2024 Supplemental material is available for this article.

Ultrasound-Guided Vs Non-Guided Prolotherapy for Internal Derangement of Temporomandibular Joint. A Randomized Clinical Trial

OBJECTIVES

This randomized clinical trial study aims to compare ultrasound-guided versus non-guided Dextrose 10% injections in patients suffering from internal derangement in the temporomandibular joint (TMJ).

MATERIAL AND METHODS

The study population included 22 patients and 43 TMJs suffering from unilateral or bilateral TMJ painful clicking, magnetic resonance imaging (MRI) proved disc displacement with reduction (DDWR), refractory to or failed conservative treatment. The patients were divided randomly into two groups (non-guided and ultrasound (US)-guided groups). The procedure involved injection of 2 mL solution of a mixture of 0.75 mL 0.9% normal saline solution, 0.3 mL 2% lidocaine and 0.75 mL dextrose 10% using a 25G needle in the joint and 1 mL intramuscular injection to the masseter muscle at the most tender point. The Visual Analogue Score (VAS) was used to compare joint pain intensity over four different periods, beginning with pre-injection, 1-, 2-, and 6-months postinjection.

RESULTS

Twenty-two patients 5 males (n = 5/22, 22.7%) and 17 females (n = 17/22, 77.2%) were included in this study. The mean age was 27.3 ± 7.4 years (30.2 ± 7.0) for the non-guided group and 24.3 ± 6.9 for the US-guided group. The dextrose injection reduced intensity over time in both groups with statistically significant improvement (P value <.05) at 2 and 6 months in both groups. There was no statistically significant difference in VAS assessment between both groups.

CONCLUSION

Intra-articular injection of dextrose 10% for patients with painful clicking and DDWR resulted in reduced pain intensity in both US-guided and non-guided groups with significant symptomatic improvement over time in both groups. US guidance allowed accurate anatomical localization and safe procedure with a single joint puncture.

Therapeutic challenges in temporomandibular disorders

Background and aims

This study aimed at evaluating the etiology and treatment challenges of temporomandibular disorders (TMDs).

Methods

160 subjects with TMDs, 38 males (23.8%) and 122 females (76.3%) were studied. A personalized coefficient was designated, which included the resolution of the main symptom, correction of secondary symptoms, patient collaboration (emotional parameter), treatment duration, and cost.

Results

The most frequent cause for consultation was muscle impairment (42.5%), or limitation of mouth opening, followed by joint impairment (23.1%). Muscle pain was noticed, particularly in the masseter (57.5%) and lateral pterygoid muscles (51.9%). Tooth pain or gingival retraction was frequently associated with tooth wear (48.1%) and dental abfraction (31.3%). Remote symptomatology was dominated by otologic symptomatology. Iatrogenic etiology was highest (69.4%), followed by untreated missing teeth (66.9%). Treatment options included muscle relaxation, occlusal balancing (equilibration), kinesitherapy, medication, and swallowing re-education. Most patients benefited from four to seven different types of therapy, which resulted in a higher cost and a longer and more uncomfortable treatment. The primary symptom was relieved in 82.3% of cases, with recurrence occurring in 15.7%.

Conclusion

The treatment of temporomandibular joint dysfunction is time-consuming, demanding, and intricate. Most patients required four to seven different types of therapy, which increased the expense, treatment duration, and suffering.

Contrast arthrography of the equine temporomandibular joint

Background

Disorders of the equine temporomandibular joint (TMJ) cause clinical problems and detailed investigations of this joint are becoming more common. Specialist radiographic projections have the potential to highlight osseous abnormalities; however, the ability to assess the intra-articular soft tissue structures is currently limited to computed tomography (with, or without contrast enhancement) or magnetic resonance imaging. Both modalities are expensive and not readily accessible.

Objective

To develop a technique of contrast arthrography of both compartments of the equine TMJ in cadavers and then perform the refined technique in three living horses as a proof-of-principle.

Study design

A descriptive, experimental, study.

Methods

Contrast arthrography of the discomandibular and discotemporal joint compartments of both TMJs was performed in 12 cadaveric equine heads using needles placed in the caudal pouches of the respective joint compartments. Radiographs were taken using previously published techniques, repeated with the mouth open and after air had been injected into the joints, to perform a double-contrast study. The TMJs of three healthy horses were subsequently examined to determine the validity of the procedure in live animals.

Results

Single and double-contrast arthrography allowed delineation of the dorsal and ventral surfaces of the intra-articular disc in addition to filling the rostral and caudal joint pouches of the independent joint compartments. Contrast extravasation was common, and in two instances iatrogenic disc penetration resulted in the false diagnosis of pathologic disc perforation. The techniques were well tolerated in all three live horses.

Main limitations

Low number of horses.

Conclusion

Contrast arthrography allows interpretation of intra-articular soft tissue structures, but caution is advised in diagnosing intra-articular disc perforation. Even with experience, accessing the discomandibular joint can be challenging.

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.

Editorial on Special Issue "Skeletal Radiology"

Musculoskeletal (MSK) disorders are among the top five contributors to disability-adjusted life years (DALYs) worldwide [...].

High-Field Magnetic Resonance Imaging of the Temporomandibular Joint Low Agreement with Clinical Diagnosis in Asymptomatic Females

(1) Background: The aim of this study was to investigate the agreement between a clinical diagnosis based on research diagnostic criteria/temporomandibular disorders (RDC/TMD) and high-field magnetic resonance imaging (MRI) findings of temporomandibular joints (TMJs) in asymptomatic females. (2) Methods: A prospective study on 100 females (200 TMJs) was performed, using clinical examinations (RDC/TMD) and same-day MRIs of TMJs on a 3T MR unit. The inclusion criteria were as follows: females, age > 18, the presence of upper and lower incisors, and an understanding of the Serbian language. Descriptive statistics (means and standard deviations) and ANOVA with a post hoc Tukey test for differences among the patient subgroups was performed. The agreement between the clinical and MRI findings was determined using Cohen's kappa coefficient (k < 0.21 slight, 0.21-0.4 fair, 0.41-0.6 moderate, 0.61-0.8 substantial, and 0.81-1 almost perfect). The statistical significance was set at p ≤ 0.05. (3) Results: Normal findings were observed in 86.7%, disc dislocation (DD) was observed in 9.2%, and arthralgia/osteoarthritis/osteoarthrosis was observed in 2.6% of TMJs using RDC/TMD. On the MRI, normal findings were observed in 50.5%, disc dislocation was observed in 16.3%, and arthralgia/osteoarthritis/osteoarthrosis was observed in 23.5% of TMJs. The anterior DD with reduction showed fair agreement of the clinical and MRI findings (k = 0.240, p < 0.001) compared with the DD without reduction (k = 0.355, p < 0.001). Both showed high specificity (94.9% and 99.4%) but low sensitivity (24.2% and 25.0%). The sensitivity in osteoarthritic changes was low (4.8%), but the specificity remained high (96.2%). (4) Conclusions: The sensitivity of the clinical examination remains low compared with 3T MRI, especially in osteoarthritic changes and anterior DD with reduction. However, the number of false positive diagnoses using RDC/TMD is low in asymptomatic patients. RDC/TMD remains a sensible method for establishing a clinical diagnosis and avoiding the overtreatment of asymptomatic patients.

Management of temporomandibular joint diseases: a rare case report of coexisting calcium pyrophosphate crystal deposition and synovial chondromatosis

BACKGROUND

The coexistence of calcium pyrophosphate dihydrate crystal deposition (CPP) and synovial chondromatosis (SC) in the temporomandibular joint (TMJ) is rarely reported. CPP disease (CPPD) is complex arthritis synonymous with excessive pyrophosphate production and variable aberrations in mineral and organic phase metabolism of the joint cartilage, leading to local inundated CPP and crystal deposition of partially deciphered predispositions. Meanwhile, SC is a rare benign synovial joint proliferative disease of unclear etiology and has a low risk of malignant transformation. However, SC manifests severe joint disability and dysfunction because of connective tissue metaplasia of the synovial membrane, which forms cartilaginous nodules with or without calcifications or ossifications. These nodules often detach and form intra-articular loose bodies and very rarely within extraarticular spaces.

CASE PRESENTATION

We report the case of a 61-year-old man to expand the body of literature on these unusual coexisting arthropathies of the TMJ. The patient presented to our hospital in 2020 with complaints of pain in the right TMJ and trismus for over 6 months. Radiographic assessments of the TMJ provided a preoperative provisional diagnosis of SC. However, the histopathology of the open biopsy revealed tumor-like lesions comprising several deposits of rhomboid and rod-shaped crystals that displayed positive birefringence in polarized light, confirming a coexistence of CPPD. A second-stage operation was performed for the complete removal of the loose bodies and chalk-like lesions including synovectomy. No evidence of recurrence was recorded after a follow-up of nearly 1.5 years.

CONCLUSIONS

Isolated CPPD and SC of the TMJ are prevalent in the literature however, monoarticular coexistence of these diseases is rare, due to the lack of consistency in the diagnostic criteria in clinical practice. Moreover, optimal treatment depends on several considerations. This report delineated the molecular etiopathology and underscored the need for continued deciphering of the causal mechanisms of coexisting CPPD and SC of the TMJ. In addition, the importance of confirmatory testing for accurate diagnosis, and appropriate management of these diseases were discussed.

Temporomandibular Joint Osteoarthritis: Pathogenic Mechanisms Involving the Cartilage and Subchondral Bone, and Potential Therapeutic Strategies for Joint Regeneration

The temporomandibular joint (TMJ) is a specialized synovial joint that is crucial for the movement and function of the jaw. TMJ osteoarthritis (TMJ OA) is the result of disc dislocation, trauma, functional overburden, and developmental anomalies. TMJ OA affects all joint structures, including the articular cartilage, synovium, subchondral bone, capsule, ligaments, periarticular muscles, and sensory nerves that innervate the tissues. The present review aimed to illustrate the main pathomechanisms involving cartilage and bone changes in TMJ OA and some therapeutic options that have shown potential restorative properties regarding these joint structures in vivo. Chondrocyte loss, extracellular matrix (ECM) degradation, and subchondral bone remodeling are important factors in TMJ OA. The subchondral bone actively participates in TMJ OA through an abnormal bone remodeling initially characterized by a loss of bone mass, followed by reparative mechanisms that lead to stiffness and thickening of the condylar osteochondral interface. In recent years, such therapies as intraarticular platelet-rich plasma (PRP), hyaluronic acid (HA), and mesenchymal stem cell-based treatment (MSCs) have shown promising results with respect to the regeneration of joint structures or the protection against further damage in TMJ OA. Nevertheless, PRP and MSCs are more frequently associated with cartilage and/or bone repair than HA. According to recent findings, the latter could enhance the restorative potential of other therapies (PRP, MSCs) when used in combination, rather than repair TMJ structures by itself. TMJ OA is a complex disease in which degenerative changes in the cartilage and bone develop through intricate mechanisms. The regenerative potential of such therapies as PRP, MSCs, and HA regarding the cartilage and subchondral bone (alone or in various combinations) in TMJ OA remains a matter of further research, with studies sometimes obtaining discrepant results.

What is the image appearance of juvenile idiopathic arthritis in MRI, CT, and CBCT of TMJ? A systematic review

OBJECTIVE

We performed a systematic review to investigate the appearance of imaging signs on magnetic resonance imaging (MRI), cone-beam computed tomography (CBCT), and conventional computed tomography (CT) scans of the temporomandibular joints (TMJs) of patients with juvenile idiopathic arthritis (JIA).

MATERIALS AND METHODS

We performed electronic searches of the PubMed, Embase, Web of Science, Scopus, Lilacs, and the Cochrane Library databases to identify studies investigating JIA and its related imaging findings. Inclusion criteria were as follows: original article studies based on humans and systematic reviews, studies enrolling patients under 18 years of age with a diagnostic of JIA, the use of International League of Associations for Rheumatology (ILAR) criteria and one type of medical imaging (MRI, CBCT, or CT), and papers published in the English language.

RESULTS

A total of six studies met the inclusion criteria, four involving MRI and two involving CBCT. Additionally, all six studies analyzed the imaging findings of pathological TMJ affected by JIA. The results showed that synovial membrane enhancement, condylar erosions, and condylar flattening were the most prevalent imaging findings in JIA.

CONCLUSION

MRI examinations are more specific for detecting anomalies in the TMJ than CBCT and CT. Additionally, these results must be correlated with clinical signs to verify the correct diagnosis.

CLINICAL RELEVANCE

This study identified the most prevalent imaging signs of JIA to provide an early and correct diagnosis of the disease.

Role of magnetic resonance imaging in temporomandibular joint ankylosis - An evaluative study

Introduction

Temporomandibular joint (TMJ) ankylosis is a pathologic condition where the mandible is fused to the fossa by bony or fibrotic tissues. Haemorrhage is one of the major complications during TMJ surgery especially in ankyloses due to altered anatomy. The aim of the study was to analyse the proximity of the vasculature to the TMJ region in TMJ ankylosis patients using magnetic resonance imaging (MRI)

Materials and Methods:

Noncontrast-enhanced MRI images of seven patients were assessed. The distance between maxillary artery and neck of condyle/ankylotic mass was measured using coronal sections and distance between the internal carotid artery (ICA), internal jugular vein (IJV) and medial edge of condyle/bony mass were measured using axial sections.

Results:

The mean distance of internal maxillary artery (IMA) to medial edge of ankylotic mass was 1 ± 0.57 mm and 2 ± 1.2 mm-left and right condylar regions respectively (range: 0–4 mm).The mean distance from lateral aspect of ankylotic mass to IMA was 8.2 ± 1.4 mm and 8.7 ± 2.8 mm–right and left condylar regions respectively (range: 3–11 mm).The mean distance from medial edge of condyle to ICA was 18.8 ± 1.3 mm and 18.2 ± 1.1 mm-right and left condylar regions respectively (range: 17 mm–20 mm).The mean distance from the medial edge of condyle to IJV was 16.4 ± 1.1 mm and 14.5 ± 2.9 mm-right and left condylar regions (range: 11 mm–19 mm).

Discussion:

These measurements were used as a guide to plan the steps during surgery in order to minimise the intraoperative haemorrhagic complications. Hence, MRI may be considered as a valuable tool in assessing the juxtaposition of vascular bed to TMJ region, though contrast MRI and a larger sample is needed to standardise.