The diagnostic value of high-resolution ultrasonography for the detection of anterior disc displacement of the temporomandibular joint: a meta-analysis employing the HSROC statistical model

Comparison between ultrasound and magnetic resonance imaging of the temporomandibular joint in juvenile idiopathic arthritis: A systematic review

OBJECTIVES

The objectives of this systematic review were to evaluate the correlation between Ultrasound (US) and Magnetic Resonance Imaging (MRI) in patients with JIA and to investigate the association with Temporomandibular Disorders (TMD).

MATERIALS AND METHODS

The protocol was registered in PROSPERO (CRD42022312734). Databases Medline, Embase, Cochrane Central Register of Controlled Trials, Scopus, Web of Science, Latin American and Caribbean Health Sciences Literature were searched. Eligibility criteria were patients with JIA subjected to diagnostic evaluation using US and MRI. No language restrictions were applied. After duplicate study selection, data extraction and risk of bias assessment according to Cochrane were conducted. Data extraction of patients was conducted by two independent authors.

RESULTS

Five observational studies were included with 217 participants (153 females and 64 males; mean age 11.3 years). The quality of the studies was overall satisfactory. The correlation between US and MRI in children with JIA was 'moderate' in acute arthritis while the chronic arthritis correlated positively in two studies.

CONCLUSIONS

Even if MRI remains the more accurate imaging modality for the detection of TMJ of patients with JIA, US may be useful to early detect pathological conditions and to address the patient with JIA and putative TMJ involvement to a more accurate diagnosis with MRI and consequent appropriate treatment management.

CLINICAL RELEVANCE

MRI should be deemed necessary only secondary to less-invasive assessments with US just to confirm the diagnosis or to increase sensitivity, accuracy of positive predictive values detected.

The Role of Ultrasound in Temporomandibular Joint Disorders: An Update and Future Perspectives

Temporomandibular joint (TMJ) disorder is the second most common chronic pain condition affecting the general population after back pain. It encompasses a complex set of conditions, manifesting with jaw pain and limitation in mouth opening, influencing chewing, eating, speaking, and facial expression. TMJ dysfunction could be related to mechanical abnormalities or underlying inflammatory arthropathies, such as rheumatoid arthritis (RA) or juvenile idiopathic arthritis (JIA). TMJ exhibits a complex anatomy, and thus a thorough investigation is required to detect the TMJ abnormalities. Importantly, TMJ involvement can be completely asymptomatic during the early stages of the disease, showing no clinically detectable signs, exposing patients to delayed diagnosis, and progressive irreversible condylar damage. For the prevention of JIA complications, early diagnosis is therefore essential. Currently, magnetic resonance imaging (MRI) is described in the literature as the gold standard method to evaluate TMJ. However, it is a high-cost procedure, not available in all centers, and requires a long time for image acquisition, which could represent a problem notably in the pediatric population. It also suffers restricted usage in patients with claustrophobia. Ultrasonography (US) has emerged in recent years as an alternative diagnostic method, as it is less expensive, not invasive, and does not demand special facilities. In this narrative review, we will investigate the power of US in TMJ disorders based on the most relevant literature data, from an early screening of TMJ changes to differential diagnosis and monitoring. We then propose a potential algorithm to optimize the management of TMJ pathology, questioning what would be the role of ultrasonographic study.

Hand-Carried Ultrasonography Instrumentation in the Diagnosis of Temporomandibular Joint Dysfunction

Internal derangement (ID) in the temporomandibular joint (TMJ) is defined as a mechanical problem of the joint that interferes with its function. It is attributed to an abnormal interaction among the articular disc, condyle, and joint eminence. The aim of this study is to evaluate diagnostic efficacy of non-invasive hand-carried ultrasonography instrumentation (US) to provide high-level images for a correct diagnosis of ID. Twenty-eight ID patients, 15 female and 13 males, were examined both clinically and by MRI images in order to achieve a diagnosis of ID (using Helkimo index). Then, they were submitted to US examination with a 12 MHz transducer by using hand-carried instrumentation by a clinician that was blind to their diagnosis and clinical data. TMJ US examination was performed with the mouth closed and mouth open, with proper technique. Each position was then evaluated with two different orientations of the transducer. US showed acceptable results in identifying bone structures. Lower values of diagnostic efficacy were obtained for disc position during joint movements with respect to MRI images. MRI still represents the gold standard for the identification of joint structures. If not corroborated by clinical and anamnestic data, the diagnostic efficacy of US in identifying the position of the disc during opening and closing jaw movements appears limited than compared to MRI.

Quantitative assessment of temporomandibular disc and masseter muscle with shear wave elastography

PURPOSE

To assess the normal stiffness values of temporomandibular joint disc (TMJ) and masseter muscle by shear wave elastography (SWE) in a healthy adult population. This may be helpful in diagnosing and understanding the mechanism of temporomandibular disorders (TMD).

METHODS

This prospective study evaluated a total of 160 healthy adult volunteers (77 males, 83 females). The stiffness values of anterior, intermediate and posterior parts of the TMJ disc and masseter muscle were measured. Study cohort was classified into four groups based on age. Additionally, we investigated the changes in mean shear wave elasticity (kPa) and shear wave velocity(m/s) values of disc parts and masseter muscle in closed and open mouth positions, and the correlation of these SWE values with age and gender.

RESULTS

Mean stiffness values of the disc were 37.02 ± 23.75 kPa and 3.28 ± 1.09 m/s in the anterior part, 30.47 ± 18.89 kPa and 2.97 ± 1.04 m/s in the intermediate part, 22.61 ± 13.97 kPa and 2.55 ± 0.88 m/s in the posterior part. Stiffness values showed significant decrease in the posterior part compared to the rest of the disc both in males and females. No significant differences in mean stiffness values of masseter muscle related to mouth position, age or gender.

CONCLUSION

This study provides the normative quantitative elasticity values of disc and masseter muscle which could be a reference point for upcoming studies. Disc elasticity values are higher in women than men. Maybe this is one of the reason why TMD is more common in women. TMJ disc stiffness was significantly lower in the posterior part. SWE is a useful imaging method that can be used with routine ultrasonography in evaluation of the TMJ disc and masticatory muscles .

Imaging of the temporomandibular joint

Temporomandibular disorders are common, especially in young to middle-aged women, and most settle with supportive treatment. Imaging is indicated for the small percentage of cases that do not respond to conservative management and when the diagnosis is no doubt. The temporomandibular joint (TMJ) is a bilateral synovial articulation between the mandible and skull base. It has an intra-articular disc dividing the joint into superior and inferior compartments and the articular surfaces are lined with fibrocartilage. The normal imaging anatomy of the TMJ is described and illustrated. Different movements occur in each joint compartments: a hinge movement in the inferior joint space and translation or gliding in the superior joint space. Internal derangement is the commonest disorder affecting the TMJ and is most commonly due to disc displacement, followed by osteoarthritis and inflammatory arthritides. The imaging findings, primarily on magnetic resonance imaging (MRI) and computed tomography (CT), of internal derangement and less common disorders of the joint, are reviewed and illustrated. Optimal imaging protocols are discussed with detailed reporting guidelines.

Impression of Subgingival Dental Preparation Can Be Taken with Ultrasound

Because of its ability to capture hard structures behind soft tissue, ultrasound-based micro-scanning may be a promising alternative for taking digital impressions of teeth, especially in the case of subgingival margin preparations. The aim of this study was to assess the accuracy of ultrasound impressions taken of subgingivally prepared teeth compared with digital optical impressions. Ten extracted human teeth (7 pre-molars, 3 molars) were prepared for crowns with chamfer finish line and then digitized using two different intra-oral scanners (Cara Trios, 3 Shape, Heraeus Kulzer, Hanau, Germany; and Lava COS; 3M ESPE, Seefeld, Germany) and one extra-oral scanner (Cares CS2, Straumann, Basel, Switzerland). Afterward, the preparation margin was covered with porcine gingiva (thickness ranged between 0.3 and 0.9 mm), and every sample was scanned with a high-frequency ultrasound scanner under experimental subgingival conditions. Optical scanning processes were performed without gingiva. The data sets were superimposed on each other for pairwise comparisons, and deviations between different scans were determined using a 3-D evaluation software (CloudCompare). Kruskal-Wallis and post hoc tests (Dunn-Bonferroni) were applied to detect significant differences at p ≤ 0.05. The ultrasound scanner was able to detect subgingival preparation margins. Mean deviations for all comparisons ranged from 12.34 to 46.38 µm. There were no statistically significant differences between superimpositions of intra-oral and extra-oral scans (Trios-Lava, Lava-CS2, Trios-CS2), whereas in comparisons between intra-/extra-oral scans and ultrasound scans, mean deviations were statistically significantly higher. There were no significant differences with respect to type of tooth (pre-molar and molar). However, gingiva thickness was significantly correlated with the quality of the ultrasound scan; thin layers had better image quality than thicker layers. Ultrasound was able to scan tooth preparation margins covered with gingiva, although with less accuracy than achieved by conventional optical scanners (non-covered margins). Gingiva thickness may play an important role in ultrasound scan accuracy.

Diagnostic ultrasound assessment of temporomandibular joints: a systematic review and meta-analysis

OBJECTIVES:

The purpose of this systematic review was to determine the diagnostic capability of ultrasound to assess TMJ alterations as disc displacement (DD), joint effusion (JE) and condylar changes (CC) using 3D imaging modalities as reference standard.

METHODS:

Studies were gathered by searching several electronic databases and partial grey literature up to January eighth, 2018 without restrictions of language and time. The risk of bias was evaluated using the second version of Quality Assessment Tool for Diagnostic of Accuracy Studies-2 (QUADAS-2). The grading of Recommendation, Assessment, Development and Evaluation (GRADEpro system) instrument was applied to assess the level of evidence across the studies.

RESULTS:

After applying the eligibility criteria, 28 studies were identified and synthesized. All studies were methodologically acceptable presenting low applicability concerns, although none of them fulfilled all QUADAS-2 criteria. The quantitative analysis included 22 studies, 2829 joints in total. The quality of the evidence evaluated by GRADE system suggested moderate confidence in estimating the outcomes.

CONCLUSION:

This systematic review demonstrated the ultrasound has acceptable capability to screen for DD and JE in TMD patients. For screening of condylar changes, ultrasound needs further studies using CT or CBCT as reference standard to support its use. More advanced imaging such as MRI can thereafter be used to confirm the diagnosis if deemed necessary.

Diagnostic value of ultrasonography for the detection of disc displacements in the temporomandibular joint: a systematic review and meta-analysis

Objectives

The aim was to assess the added diagnostic value of ultrasonography (US) for establishing the presence or absence of disc displacements (DDs) in temporomandibular joints (TMJs).

Materials and methods

Pubmed and EMBASE were searched electronically to identify diagnostic accuracy studies that assessed the diagnostic value of US for the diagnosis of DD, using Magnetic resonance imaging (MRI) as the reference standard. Meta-analyses were performed with Metadisc 1.4 and RevMan 5.3.

Results

A total of 16 studies qualified for meta-analyses. For the diagnosis of DD at closed mouth position (DD-CM) and DD at maximum mouth-opening position (DD-MMO), the added values of a positive result with US for ruling in DD-CM and DD-MMO were 22 and 41%, while those of a negative result with US for ruling out DD-CM and DD-MMO were 30 and 20%. For the diagnosis of DD with reduction (DDWR) and DD without reduction (DDWoR), the added values of a positive result in US for ruling in DDWR and DDWoR were 35 and 41%, while those of a negative result in US for ruling out DDWR and DDWoR were 21 and 27%.

Conclusions

Using MRI as reference standard, the added values of both positive predictive values and negative predictive values of US for ruling in and ruling out DDs are sufficient in the decision-making in dental practice.

Clinical relevance

US can be a good imaging tool to supplement clinical examination findings in patients with suspected DDs. Combined static and dynamic examinations using high-resolution US should be preferred.

Review on the applications of ultrasonography in dentomaxillofacial region

Use of ultrasonography (US) in dentomaxillofacial region became popular in recent years owing to increasing radiation dose concerns and economic limitations. It helps to visualize fine detail of the surface structure of the oral and maxillofacial tissues without ionizing radiation. In diagnostic ultrasound, high frequency sound waves are transmitted into the body by a transducer and echoes from tissue interface are detected and displayed on a screen. Sound waves are emitted via piezoelectric crystals from the ultrasound transducer. US technique can be used in dentomaxillofacial region for the examination of bone and superficial soft tissue, detection of major salivary gland lesions, temporomandibular joint imaging, assessment of fractures and vascular lesions, lymph node examination, measurement of the thickness of muscles and visualization of vessels of the neck. It has the potential to be used in the evaluation of periapical lesions and follow up of periapical bone healing. Also, it may be used for the evaluation of periodontal pocket depth and for the determination of gingival thickness before dental implantology.