Ultrasonography in the Diagnosis of Temporomandibular Disorders: A Meta-Analysis

Morphologic characteristics of temporomandibular joint on the patients with anterior disc displacement without osteoarthritis: a case-based research

We investigated the effect of anterior disc displacement without osteoarthritis (ADDwoOA) on the morphology of the temporomandibular joint (TMJ) utilizing three-dimensional (3D) models of 23 asymptomatic individuals and 30 ADDwoOA patients. Statistical analyses between the groups were performed by measuring 10 morphological parameters. ADDwoOA patients showed significantly decreased levels of the sagittal ramus angle (SRA) and joint spaces compared with asymptomatic subjects. Moreover, the patients who had recovered exhibited normal joint spaces levels. Consequently, ADDwoOA caused the condyles to move backward and upward, approaching the articular fossa. Joint spaces can serve as an important observation during the treatment of ADD.

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.

Intraoperative ultrasonography for the reposition of the condylar process during bilateral sagittal osteotomy of the mandible-A case report

INTRODUCTION

Ultrasonography (USG), being a safe, quick and relatively cheap examination, is used to diagnose various pathologic conditions. The application of ultrasound to assess the position of the condyle during bilateral sagittal split osteotomy (BSSO) may improve the treatment results.

CASE PRESENTATION

A 33-year-old patient, who was operated for a skeletal defect of maxilla and mandible with BSSO and Le Fort I maxillary osteotomy is discussed in this case report. The procedure was complicated with a mandibular head dislocation. The split segment was repositioned under ultrasound guidance, and a repeat osteosynthesis was performed.

CONCLUSIONS

The ultrasound method is useful for the intraoperative assessment of the condylar process' position. The use of ultrasound in the diagnosis of complications and for intraoperative monitoring should be promoted.

Intra-articular injections in the TMJ inferior joint space: A scoping review

OBJECTIVE

To perform a scoping review to identify the available evidence regarding intra-articular injections in the inferior joint space (IJS) of the temporomandibular joint (TMJ).

METHODS

An electronic search of the PubMed, Web of Science and Scopus databases was performed using the following terms: "Arthrocentesis", "injection", "joint injection", "technique", "Temporomandibular joint", "Temporomandibular joint disorder". Full-text articles were obtained from the records after applying the inclusion/exclusion criteria. Only articles with full-text access were included.

RESULTS

Thirteen articles were included for analysis-one technical note, three cadavers studies, one animal study, two case reports, five randomised clinical trials and one retrospective study; studies were classified as 'patients-based studies' and 'non-patients-based studies'. Most 'patients-based studies' show moderate or high risk of bias. Techniques were categorised as 'anatomical technique' and 'image-guided technique'. Most 'patients-based studies' show favourable outcomes such as pain reduction, increase in maximum mouth opening, improvement in quality of life and improvement in TMJ dysfunction indexes for the treatment of arthrogenic TMDs. Comparisons between superior and IJS injections are scarce. On the other hand, 'non-patients-based' studies show that image-guided or ultrasound-checked injection techniques achieved a higher effectiveness for needle location than anatomical (or blind) techniques.

CONCLUSION

The amount of available evidence is scarce, heterogeneous in design, and most 'patients-based studies' show moderate or high risk of bias, which demands the generation of new research to obtain definitive conclusions. The tendency observed suggests that intra-articular injections for the IJS of the TMJ are able to relieve TMJ pain, increase mouth opening and improve TMJ dysfunction, and image-guided injection techniques seem to be more effective than anatomical techniques to locate the needle in the IJS.

Diagnostic accuracy of ultrasonography compared with magnetic resonance imaging in diagnosing disc displacement of the temporomandibular joint: A systematic review and meta-analysis

STATEMENT OF PROBLEM

Diagnosing temporomandibular disorders without an adjunctive chairside diagnostic tool has made the management of temporomandibular disorders challenging and subjective. The use of magnetic resonance imaging, considered the standard imaging modality, is hindered because of high cost, a long learning curve, availability, and a longer examination time.

PURPOSE

The purpose of this systematic review and meta-analysis was to determine whether ultrasonography could be a chairside tool to help clinicians diagnose disc displacement in temporomandibular disorders.

MATERIAL AND METHODS

An electronic search was conducted of the PubMed (including MEDLINE) and Cochrane Central database and the Google Scholar search engine for articles published from January 2000 to July 2020. Studies were chosen based on the inclusion criteria, which included the diagnostic technique's sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) with respect to imaging the displacement of the articular disc. The quality assessment of diagnostic accuracy studies (QUADAS- 2) tool was applied to assess the risk of bias for the included studies. The Meta-Disc 1.4 and RevMan 5.3 software program were used to conduct the meta-analysis.

RESULTS

Seventeen articles were included in this systematic review, and a meta-analysis of 14 articles was done after applying the inclusion and exclusion criteria. None of the included articles were considered to have applicability concerns; however, 2 articles had a high risk of bias. The sensitivities and specificities for the different selected studies vary substantially from 21% to 95% with a good pooled sensitivity estimate of 71% while the specificities varied from 15% to 96% with a good pooled specificity estimate of 76%.

CONCLUSIONS

This systematic review and meta-analysis suggested that ultrasonography may have clinically acceptable diagnostic accuracy in diagnosing disc displacement of the temporomandibular joint, allowing the treatment of patients with temporomandibular disorders with greater assurance and success. Additional training in the operation and interpretation of ultrasonography is required to reduce the learning curve and make the use of ultrasonography relevant, straightforward, and routine in dentistry to supplement clinical examination and diagnosis in patients with suspected disc displacement of the temporomandibular joint. The evidence acquired needs to be standardized, and further research is required to provide stronger evidence.

Use of ultrasonography in the diagnosis of temporomandibular disorders: a prospective clinical study

OBJECTIVES

Panoramic radiographs, computed tomography, and magnetic resonance imaging (MRI) are traditionally used for imaging temporomandibular joint (TMJ) and its pathologies. Besides these radiographic techniques, the recent use of ultrasonography (US) in diagnosing joint diseases has been introduced. However, there is no prospective clinical study examining the application of US in imaging of Temporomandibular Disorders (TMD) patients. Therefore, this study aimed to determine the features of the joint and surrounding structures in the US in TMD patients.

METHODS

320 patients fulfilled the inclusion criteria, and 100 of these individuals accepted to participate in the study. This study evaluated 200 TMJ; including the right TMJ and left TMJ of 100 patients. The study was designed as a clinical single-blind observational device trial.

RESULTS

It has been seen that women are 3.54 times more likely to have muscle pain than men. It has been determined that the probability of joint pain increased as the joint space with the mouth closed increased. It has been seen that women are 3.61 times more likely to experience headaches than men.

CONCLUSIONS

The US, which is becoming increasingly common in dentistry, can be used as an aid in TMD diagnoses. US will not be sufficient when it is desired to evaluate the TMJ joint area more precisely and clearly in patients who will be planned for advanced surgical intervention. Therefore, it may be necessary to refer for MRI. The values of our findings will be a reference in TMD diagnoses.

CLINICALTRIALS

GOV ID

NCT04452110.

Shear Wave Elastography in Bruxism-Not Yet Ready for Clinical Routine

Ultrasound shear wave elastography (SWE) is an emerging modality for the estimation of stiffness, but it has not been studied in relation to common disorders with altered stiffness, such as bruxism, which affects almost one-third of adults. Because this condition could lead to an increased stiffness of masticatory muscles, we investigated SWE in bruxism according to a proof-of-principle and feasibility study with 10 patients with known bruxism and an age- and gender-matched control group. SWE of the left and right masseter muscles was estimated under three conditions: relaxed jaw, 50% of the subjective maximal bite force, and maximal jaw opening. Rejecting the null hypothesis, SWE was significantly increased during relaxed jaw (bruxism 1.92 m/s ± 0.44; controls 1.66 m/s ± 0.24), whereas for maximal mouth opening, the result was vice versa increased with 2.89 m/s ± 0.93 for bruxism patients compared with 3.53 m/s ± 0.95 in the healthy control, which could be due to limited jaw movement in chronic bruxism patients (bruxism 4.46 m/s ± 1.17; controls 5.23 m/s ± 0.43). We show that SWE in bruxism is feasible and could be of potential use for diagnostics and monitoring, though we also highlight important limitations and necessary methodological considerations for future studies.

Role of Ultrasound Evaluation of Temporomandibular Joint in Juvenile Idiopathic Arthritis: A Systematic Review

Background: Juvenile idiopathic arthritis (JIA) is childhood’s most frequent chronic rheumatic disease. JIA is a broad term that includes all arthritides starting before 16 years, lasting at least six weeks, and of unknown cause. The temporomandibular joint (TMJ) could be involved in JIA both at onset and during the disease course. The presence of TMJ synovitis might severely impair dentofacial maturation in pediatric patients. The ultrasound (US) application to detect early signs of TMJ synovitis in children with JIA has provided contradictory results. We sought to assess the current role of TMJ US in JIA through a systematic literature review. Methods: The systematic review was conducted according to the recommendations of the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA). Results: The literature search found 345 records. After duplicates removal, 253 records were screened, 20 full-text articles were reviewed to assess their eligibility, and 7 of them were included in the qualitative analysis. Joint effusion was the most recorded parameter, followed by bony condylar abnormalities. Compared to contrast enhancement MRI, the capability to detect signs of active synovitis of TMJ by US is low, especially at the early stages. Conclusion: Understanding how US may help diagnose and manage children with JIA is advisable for several reasons. MRI cannot be frequently repeated, may need sedation, and is expensive. The constant technical improvement of US will undoubtedly allow for better evaluation of what, in the past, was not clear or not even captured by sonography. So far, the role of US in the assessment of TMJ involvement in JIA is indubitably secondary to the MRI. Even so, we think that a baseline MRI of TMJ and the repetition of the sonography over time might both help the interpretation of US images and intercept significative changes.

Imaging of the Temporomandibular Joint

Temporomandibular disorder (TMD) is a common musculoskeletal condition that causes pain and disability for patients and imposes a high financial burden on the healthcare system. The most common cause of TMD is internal derangement, mainly secondary to articular disc displacement. Multiple other pathologies such as inflammatory arthritis, infection, and neoplasm can mimic internal derangement. MRI is the modality of choice for evaluation of the TMJ. Radiologists need to be familiar with the normal anatomy and function of the TMJ and MR imaging of the internal derangement and other less common pathologies of the TMJ.

Influence of Ultrasound Examination on Diagnosis and Treatment of Temporomandibular Disorders

Background: Disorders of the masticatory muscles and temporomandibular joints as well as the surrounding craniofacial structures are called temporomandibular disorders. These are dental diseases affecting an increasing number of people with a multifactorial etiology. Noninvasive ultrasonography imaging of temporomandibular joints was performed to obtain more detailed information on joint pathologies. Material and Methods: The aim of the study was to assess the influence of ultrasound examinations of the temporomandibular joints on the diagnosis and treatment planning in patients with temporomandibular disorders. The study included 110 patients examined with the use of the Research Diagnostic Criteria for Temporomandibular Disorders questionnaire, axis I and II, after which the initial treatment plan was created. All patients underwent an ultrasound examination of the temporomandibular joints. Results: The results reveal numerous morphological changes within the joint structures in all treatment groups. Comparative statistical analyses of symptoms were performed between study groups. Conclusions: The number of pathologies in the myofascial pain group was much higher than expected and required introduction of additional treatment procedures. Further studies confirming these results and the effectiveness of ultrasound diagnostic of temporomandibular disorders are recommended.

VALUE OF ULTRASONOGRAPHY METHOD IN THE DIAGNOSIS OF TEMPOROMANDIBULAR DISORDERS AND PATIENT MANAGEMENT MONITORING. CASE REPORT

Value of ultrasonography method in the diagnosis of temporomandibular disorders and patient management monitoring is underestimated. Application of ultrasonography in the diagnosis of patients with temporomandibular disorders in many countries is limited. The main advantage and feature of the method is the ability to conduct examination in dynamics (during the function). Its safety and availability allow applying the method often and at different stages of diagnosis and treatment. So, ultrasonography fully satisfies the needs of primary diagnosing. MRI remains the recognized «gold standard» for the diagnosis of temporomandibular disorders. A case report which is presented, demonstrates the relevance and scope of diagnostic information obtained by ultrasonography, and their verification and clarification with the use of magnetic resonance imaging. Upon comparing the results of USG and MRI described in the clinical case report, we can conclude that ultrasound is quite sensitive and specific in diagnosing anterior disc displacement and blocked movement of the head of the mandible.

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.

Correlation between MRI-diagnosed joint effusion and demographic, clinical, imaging, and arthroscopic findings of the temporomandibular joint

Our study aimed to evaluate the diagnostic accuracy of MRI in cases of joint effusion and documented its relationship with clinical and arthroscopic findings. A cross-sectional study was carried out, using the following selection criteria: clinical, radiological, and MRI-based diagnosis of joint pathology; joint pain; and indication for minimally invasive management with arthroscopy. Arthroscopic analysis, included synovitis, adhesions, chondromalacia, and disc perforations. These variables were recorded and compared with MRI findings of effusion. Data were analyzed using chi-square and Fisher's exact tests. In total, 44 temporomandibular joints were studied, of which 38 corresponded to women; 21 cases were diagnosed as Wilkes IV-V, with effusion found in all of them. The presence of effusion was significantly related to synovitis (p = 0.031) and adherences (p = 0.042). Pain was significantly related to the presence of effusion (p = 0.002), Wilkes advanced stages (p = 0.006), synovitis (p = 0.031), and adherences (p = 0.004). Regarding maximum mouth opening, there was no significant correlation with the variables studied, aside from gender and Wilkes classification. There was a significant correlation between the presence of joint effusion detected by MRI and clinical and arthroscopic findings. This suggests that effusion diagnosed by magnetic resonance has a significant value. Therefore, an adequate presurgical examination should be considered before submitting the patient to an invasive diagnostic procedure.

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 .

Temporomandibular Disorders: Current Concepts and Controversies in Diagnosis and Management

Temporomandibular disorders (TMD) are a group of orofacial pain conditions which are the most common non-dental pain complaint in the maxillofacial region. Due to the complexity of the etiology, the diagnosis and management of TMD remain a challenge where consensus is still lacking in many aspects. While clinical examination is considered the most important process in the diagnosis of TMD, imaging may serve as a valuable adjunct in selected cases. Depending on the type of TMD, many treatment modalities have been proposed, ranging from conservative options to open surgical procedures. In this review, the authors discuss the present thinking in the etiology and classification of TMD, followed by the diagnostic approach and the current trend and controversies in management.

The evaluation of agreement between high-frequency ultrasonography and research diagnostic criteria for the diagnosis of temporomandibular joint internal derangements

Aim

The aim of this study is to compare the diagnosis of patients with temporomandibular joint (TMJ) internal derangements which had been diagnosed using Research Diagnostic Criteria/Temporomandibular Disorders (RDC/TMD) with the dynamic high resolution sonography findings.

Settings and Design

Axis I section of RDC/TMD form had been applied to participants. Participants were divided into three groups as healthy TMJ, disc displacement with reduction, and disc displacement without reduction. The diagnoses had been compared with the dynamic high-resolution sonography findings.

Materials and Methods

Twelve of the patients had been treated with laser therapy, whereas 13 patients were treated with stabilization splint. Seventeen patients were treated with anterior repositioning splint (n = 42). After the application of different treatment modalities, the position of the articular disc had been determined with Axis I of RDC/ TMD form and dynamic high-resolution sonography. The findings were compared and statistically analyzed.

Statistical Analysis Used

Statistical analyses of data were analyzed with Turcosa Cloud (Turcosa Ltd Co, Turkey).

Results

For the right TMJ, pretreatment and posttreatment ultrasonography (USG) diagnoses and RDC/ TMD clinical diagnoses were found similar (κ = 0.125-0.008). No statistically significant relationship was found (P > 0.05). For the left TMJ, pretreatment USG diagnosis and RDC/TMD clinical diagnose were found similar (κ = 0.070). No statistically significant relationship was found (P > 0.05). For the left TMJ, posttreatment USG diagnosis and RDC/TMD clinical diagnose were compared. A statistically significant difference was found (κ = 0.256). A statistically significant relationship was found (P < 0.05).

Conclusions

Axis 1 of RDC/TMD form which is used for the diagnosis of internal derangements and dynamic high resolution sonography was not found in the agreement.

Shear wave elastography of temporomandibular joint disc and masseter muscle stiffness in healthy children and adolescents: a preliminary study

OBJECTIVES

Shear wave elastography (SWE) are promising techniques in diagnosing temporomandibular joint (TMJ) disc and masseter muscle disorders. To investigate normative stiffness values of the TMJ disc and masseter muscle by SWE in children and adolescents.

METHODS

This prospective study evaluated 123 TMJ discs and masseter muscles in 123 subjects. The stiffnesses of anterior, middle, and posterior parts of the disc and the masseter muscle were measured. This study investigated differences in mean elasticity [kilopascal (kPa)] and velocity [metre/second (m/s)] values of the different disc parts and the masseter muscle in closed and open mouth positions, and the correlations of these SWE values with age, body mass index (BMI), height, and weight of the subjects.

RESULTS

The median stiffness disc values of all participants were 28.7 kPa (elasticity) and 3.07 m/s (velocity) for the anterior, 29.10 kPa and 3.07 m/s for the middle, and 23.2 kPa and 2.77 m/s for the posterior parts. Posterior stiffness was significantly lower than other body regions in all subjects and across all age groups. The mean stiffness values of the muscle were 16.96 ± 9.01 kPa and 2.33 ± 1.2 m/s for the closed mouth, and 28.7 ± 10.2 kPa and 3.23 ± 1.32 m/s for the open mouth.

CONCLUSION

The stiffness of the TMJ disc was significantly lower in the posterior part than in the anterior or middle parts. The mean stiffness was significantly higher in the open mouth than in the closed mouth position. Neither elasticity nor velocity were associated with age, height, weight, or BMI.

Effects of rapid maxillary expansion on temporomandibular joints

OBJECTIVE

To evaluate the impact of rapid maxillary expansion (RME) on the condylar position, disc joint, joint space, and interarticular relationship in growing patients.

MATERIALS AND METHODS

A systematic search was performed in nine databases. The clinical studies selected included those with pre- and post-magnetic resonance, conventional computed tomography or cone beam tomography in growing patients. Risk of bias assessment was performed using the Cochrane Collaboration tool for controlled clinical studies and National Heart, Lung, and Blood Institute (NHLBI) Quality Assessment for Before-After Studies With No Control Group.

RESULTS

Initially, 4303 records were identified. Only eight studies fulfilled the criteria and were included in the qualitative analysis. Of those, two were controlled clinical studies with a risk of uncertain to high bias. The remaining papers had a low to moderate risk of bias. Results showed that RME in children and adolescents promoted the following: remodeling in the head and or condylar branch, changes in condylar position and joint space, maintenance of improved symmetry between the condyles, and no ability to modify the position or shape of the articular disc.

CONCLUSIONS

RME in growing patients is able, in the short term, to modify the condyle-fossa relationship but does not change the position or shape of the articular disc. The intercondylar symmetric relationship is maintained or improved. Although the NHLBI score shows low to moderate risk of bias, the clinical relevance of these review findings is limited by Cochrane and Grades of Recommendation, Assessment, Development and Evaluation scores.

Shear Wave Elastography in the Evaluation of Temporomandibular Joint Disorders

We aimed at verifying the usefulness of shear wave elastography in determining the temporomandibular disc stiffness in patients with a temporomandibular disorders (TMDs). The study included 37 patients with confirmed TMDs and 208 healthy volunteers. Patients presented with significantly greater stiffness of the intermediate zone of the disc (region of interest [ROI] 1) and significantly lower stiffness of its anteriorly displaced portion (ROI 3). A receiver operating characteristics analysis indicated that a decrease in the stiffness in ROI 3 less than 8.667 KPa provided 100% sensitivity, 97.3% specificity, 100% positive predictive value (PPV) and 99.5% negative predictive value (NPV) in distinguishing between patients with TMDs and without. Whereas an increase in ROI 1 stiffness to at least 54.33 KPa provided high specificity and NPV, both the sensitivity and the PPV of this predictor equaled zero. Findings suggest that a decrease in anteriorly dislocated disc stiffness less than 8.667 kPa can accurately identify patients with TMDs.

Reliability and accuracy of segmentation of mandibular condyles from different three-dimensional imaging modalities: a systematic review

OBJECTIVE

To critically synthesize the literature surrounding segmentation of the mandibular condyle using three-dimensional imaging modalities. Specifically, analyzing the reliability and accuracy of methods used for three-dimensional condyle segmentation.

METHODS

Three electronic databases were searched for studies reporting the reliability and accuracy of various methods used to segment mandibular condyles from three-dimensional imaging modalities. Two authors independently reviewed articles for eligibility and data extraction.

RESULTS

Nine studies fulfilled the inclusion criteria. Eight studies assessed the condylar segmentation from CBCT images and limited studies were available on non-CBCT three-dimensional imaging modalities. Threshold-based volume segmentation, manual segmentation, and semi-automatic segmentation techniques were presented. Threshold-based volume segmentation reported higher accuracy when completed by an experienced technician compared to clinicians. Adequate reliability and accuracy were observed in manual segmentation. Although adequate reliability was reported in semi-automatic segmentation, data on its accuracy were lacking.

CONCLUSION

A definitive conclusion with regards to which current technique is most reliable and accurate to efficiently segment the mandibular condyle cannot be made with the currently available evidence. This is especially true in terms of non-CBCT imaging modalities with very limited literature available.

Temporomandibular joint disc displacement with reduction: a review of mechanisms and clinical presentation

Disc displacement with reduction (DDWR) is one of the most common intra-articular disorders of the temporomandibular joint (TMJ). Factors related to the etiology, progression and treatment of such condition is still a subject of discussion. This literature review aimed to address etiology, development, related factors, diagnosis, natural course, and treatment of DDWR. A non-systematic search was conducted within PubMed, Scopus, SciELO, Medline, LILACS and Science Direct using the Medical Subjective Headings (MeSH) terms “temporomandibular disorders”, “temporomandibular joint”, “disc displacement” and “disc displacement with reduction”. No time restriction was applied. Literature reviews, systematic reviews, meta-analysis and clinical trials were included. DDWR is usually asymptomatic and requires no treatment, since the TMJ structures adapt very well and painlessly to different disc positions. Yet, long-term studies have shown the favorable progression of this condition, with no pain and/or jaw locking occurring in most of the patients.