Comparison of conventional MRI and 3D reconstruction model for evaluation of temporomandibular joint

Improving TMJ MRI diagnostics in juvenile idiopathic arthritis: a comparative evaluation of image enhancement filters

OBJECTIVES

To assess the effectiveness of two enhancement filters for magnetic resonance images of temporomandibular joint (TMJ) in patients with juvenile idiopathic arthritis (JIA).

MATERIAL

Magnetic resonance image (MRI) of 44 patients with JIA (15 males and 29 females) was analysed using OnDemand 3D® software. Two experienced evaluators who were previously calibrated and blinded to the images assessed them subjectively regarding the use of Sharpen 1 and Sharpen 2 filters. The quality of the images after using the two different enhancement filters was compared to each other as well as to images without filter.

RESULTS

There was no statistically significant difference between Sharpen 1 and Sharpen 2 filters. Both filters provided significantly better images compared to images without filter (P = 0.000), resulting in a greater constancy of images with excellent diagnostic conditions. As for the evaluation of the articular eminences, Sharpen 2 filter provided images with better sharpness, despite the lack of a statistically significant difference.

CONCLUSION

The use of enhancement filters in MRI of patients with JIA was shown to be a valuable means to improve the diagnostic quality. Both Sharpen 1 and Sharpen 2 filters significantly enhanced the visualisation of mandibular condyles and articular eminences, thus potentially facilitating the detection and follow-up of JIA-related changes in these structures.

Three-dimensional visualization of temporomandibular joint after occlusal changes using facial scanning techniques combined with single cone beam computed tomography

OBJECTIVE

Current cone beam computed tomography (CBCT) methods cannot demonstrate the temporomandibular joint fossa-condyle relationship in real time. This study aimed to print a simple guide plate with marker points and capture a single CBCT scan based on positional changes of the marker points to align the maxilla and mandible positions.

METHODS

The three groups were divided into the intercuspal position, 5 mm unilateral elevation, and 10 mm bilateral elevation to simulate different patient occlusal situations after treatment. The maxillary and mandibular positions were aligned according to points marked on the reference plate. Then, the deviation was compared between the three-dimensional images obtained employing this method and those reconstructed from CBCT. A one-way analysis of variance was conducted, and post hoc analyses were performed using the Tamhane's T2 multiple comparison test (α = 0.05).

RESULTS

The intercuspal position had a mean deviation value of - 0.1313 with an RMS of 0.4411. The unilateral elevation had a mean deviation value of 0.3253 with an RMS of 1.2707. The bilateral elevation had a mean deviation value of - 0.0537 with an RMS of 1.281. There were no statistical differences among the three groups at α = 0.05.

CONCLUSION

This method can reduce the number of CBCT scans to one and predict the relative positions of the maxilla and mandible when changes in joint position occur from occlusion. This method can increase the accuracy of treatment, assist novice doctors to adjust the occlusal height, provide a visual means to extract and verify the treatment effect, reduce the number of diagnoses and treatments to a certain extent, reduce the radiation damage during treatment, and can be better applied to the chair side, providing convenience for patients and doctors.

CLINICAL SIGNIFICANCE

The method described in this study used a face scan, reference plate, and the first CBCT of the participant combined with 3D reconstruction to clinically observe the temporomandibular joint. This method can reduce the number of CBCT scans required, amount of radiation exposure, patient burden, and number of clinic visits while increasing the comfort level of patients.

Deep learning-based automated diagnosis of temporomandibular joint anterior disc displacement and its clinical application

Introduction

This study aimed to develop a deep learning-based method for interpreting magnetic resonance imaging (MRI) scans of temporomandibular joint (TMJ) anterior disc displacement (ADD) and to formulate an automated diagnostic system for clinical practice.

Methods

The deep learning models were utilized to identify regions of interest (ROI), segment TMJ structures including the articular disc, condyle, glenoid fossa, and articular tubercle, and classify TMJ ADD. The models employed Grad-CAM heatmaps and segmentation annotation diagrams for visual diagnostic predictions and were deployed for clinical application. We constructed four deep-learning models based on the ResNet101_vd framework utilizing an MRI dataset of 618 TMJ cases collected from two hospitals (Hospitals SS and SG) and a dataset of 840 TMJ MRI scans from October 2022 to July 2023. The training and validation datasets included 700 images from Hospital SS, which were used to develop the models. Model performance was assessed using 140 images from Hospital SS (internal validity test) and 140 images from Hospital SG (external validity test). The first model identified the ROI, the second automated the segmentation of anatomical components, and the third and fourth models performed classification tasks based on segmentation and non-segmentation approaches. MRI images were classified into four categories: normal (closed mouth), ADD (closed mouth), normal (open mouth), and ADD (open mouth). Combined findings from open and closed-mouth positions provided conclusive diagnoses. Data augmentation techniques were used to prevent overfitting and enhance model robustness. The models were assessed using performance metrics such as precision, recall, mean average precision (mAP), F1-score, Matthews Correlation Coefficient (MCC), and confusion matrix analysis.

Results

Despite lower performance with Hospital SG's data than Hospital SS's, both achieved satisfactory results. Classification models demonstrated high precision rates above 92%, with the segmentation-based model outperforming the non-segmentation model in overall and category-specific metrics.

Discussion

In summary, our deep learning models exhibited high accuracy in detecting TMJ ADD and provided interpretable, visualized predictive results. These models can be integrated with clinical examinations to enhance diagnostic precision.

Contribution of the complex comprising the masticatory fascia, disc, and capsule to temporomandibular joint stabilization: An anatomical study

BACKGROUND

Anterior displacement of the temporomandibular joint (TMJ) disc is the most typical pathological condition of TMJ disorders. Structures attached to the articular disc may support the disc in various directions and contribute to stabilizing the TMJ. However, the relationship between the articular disc, capsule, and masticatory muscles remains unclear. Therefore, this study aimed to clarify the relationship between the masticatory muscles, related masticatory fascia, articular disc, and capsule.

METHODS

We examined 10 halves from adult Japanese cadavers, with five halves macroscopically analyzed and the remaining five histologically analyzed. The TMJ was dissected from the lateral aspect for gross anatomical analysis. For histological analysis, the relationship between the temporal and masseteric fasciae and the articular capsule was observed in the coronal section. Additionally, we evaluated relationships among the disc, capsule, temporal fascia, and masseteric fascia in 10 living and healthy volunteers using magnetic resonance imaging.

RESULTS

The articular disc was attached to the capsule without a clear border. The capsule continued into the masseteric and temporal fasciae. Consequently, the articular disc, capsule, masseteric, and temporal fasciae were considered a single complex.

CONCLUSIONS

The single complex of the temporalis, masseter, capsule, masticatory fascia, and disc may antagonize the force in the posterolateral direction through the fascia.

A Three-branch Jointed Feature and Topology Decoder guided by game-theoretic interactions for temporomandibular joint segmentation

Segmentation of the temporomandibular joint (TMJ) disc and condyle from magnetic resonance imaging (MRI) is a crucial task in TMJ internal derangement research. The automatic segmentation of the disc structure presents challenges due to its intricate and variable shapes, low contrast, and unclear boundaries. Existing TMJ segmentation methods often overlook spatial and channel information in features and neglect overall topological considerations, with few studies exploring the interaction between segmentation and topology preservation. To address these challenges, we propose a Three-Branch Jointed Feature and Topology Decoder (TFTD) for the segmentation of TMJ disc and condyle in MRI. This structure effectively preserves the topological information of the disc structure and enhances features. We introduce a cross-dimensional spatial and channel attention mechanism (SCIA) to enhance features. This mechanism captures spatial, channel, and cross-dimensional information of the decoded features, leading to improved segmentation performance. Moreover, we explore the interaction between topology preservation and segmentation from the perspective of game theory. Based on this interaction, we design the Joint Loss Function (JLF) to fully leverage the features of segmentation, topology preservation, and joint interaction branches. Results on the TMJ MRI dataset demonstrate the superior performance of our TFTD compared to existing methods.

A Comprehensive Review of Vision-Based 3D Reconstruction Methods

With the rapid development of 3D reconstruction, especially the emergence of algorithms such as NeRF and 3DGS, 3D reconstruction has become a popular research topic in recent years. 3D reconstruction technology provides crucial support for training extensive computer vision models and advancing the development of general artificial intelligence. With the development of deep learning and GPU technology, the demand for high-precision and high-efficiency 3D reconstruction information is increasing, especially in the fields of unmanned systems, human-computer interaction, virtual reality, and medicine. The rapid development of 3D reconstruction is becoming inevitable. This survey categorizes the various methods and technologies used in 3D reconstruction. It explores and classifies them based on three aspects: traditional static, dynamic, and machine learning. Furthermore, it compares and discusses these methods. At the end of the survey, which includes a detailed analysis of the trends and challenges in 3D reconstruction development, we aim to provide a comprehensive introduction for individuals who are currently engaged in or planning to conduct research on 3D reconstruction. Our goal is to help them gain a comprehensive understanding of the relevant knowledge related to 3D reconstruction.

Flexed elbow, abducted shoulder, forearm supinated (FABS) reconstruction from three-dimensional elbow MRI: diagnostic performance assessment in biceps head anatomy and pathology

AIM

To determine inter-reader analysis and diagnostic performance on digitally reconstructed virtual flexed, abducted, supinated (FABS) imaging from three-dimensional (3D) isotropic elbow magnetic resonance imaging (MRI).

MATERIALS AND METHODS

Six musculoskeletal radiologists independently evaluated elbow MRI images with virtual FABS reconstructions, blinded to clinical findings and final diagnoses. Each radiologist recorded a binary result as to whether the tendon was intact and if both heads were visible, along with a categorical value to the type of tear and extent of retraction in centimetres where applicable. Kappa and interclass correlation (ICC) were reported with 95% confidence intervals. Areas under the receiver operating curve (AUC) were reported.

RESULTS

FABS reconstructions were obtained successfully in all 48 cases. With respect to tendon intactness, visibility of both heads, and type of tear, the Kappa values were 0.66 (0.53-0.78), 0.24 (0.12-0.37), and 0.55 (0.43-0.66), respectively. For the extent of retraction, the ICC was 0.85 (0.79-0.91) when including the tendons with and without retraction and 0.78 (0.61-0.91) when only including tendons with retraction. For tear versus no tear, AUC values were 0.82 (0.74-0.89) to 0.96 (0.91-1.01).

CONCLUSION

Digital reconstruction of FABS positioning is feasible and allows good assessment of individual tendon head tears and retraction with high diagnostic performance.

Eccentric movements of temporomandibular joint and upper airway volume: Three-dimensional segmentation using cone beam computed tomography

OBJECTIVE

The purpose of the present investigation was to assess whether possible changes in the dynamic movements of the TMJ might cause a greater variation between the volumes of the upper airways in open- and closed-mouth positions.

METHODS

CBCT scans of 92 subjects were used to assess the TMJ bilaterally. All scans were acquired in closed (CM) and maximum mouth opening (MMO) positions. The difference in the volume of the oropharyngeal cavity obtained by subtracting the CM volume from the MMO volume (delta volume or volume variation) was calculated. The resulting volume was analyzed by Mann-Whitney test for variation in rotation.

RESULTS

A significant difference was found (p-value = 0.0188) on the right side regarding changes in the rotational movement of the condyle (Mann-Whitney test).

CONCLUSION

This study showed a relationship between degree of abnormal or limited rotation and variation in the upper airway volume on one side.

Effect of TMJ disc position on condylar bone remodeling after arthroscopic disc repositioning surgery

PURPOSE

The objective of this study was to analyze the effect of TMJ disc position on condylar bone remodeling after arthroscopic disc repositioning surgery.

METHODS

Nine patients with anterior disc displacement without reduction (ADDWoR, 15 sides) who underwent arthroscopic disc repositioning surgery were included. Three-dimensional (3D) reconstruction of the articular disc and the condyle in the closed-mouth position was performed using cone-beam computed tomography (CBCT) and magnetic resonance imaging (MRI) data. Then, the CBCT and MRI images were fused and displayed together by multimodal image registration techniques. Morphological changes in the articular disc and condyle, as well as changes in their spatial relationship, were studied by comparing preoperative and 3-month postoperative CBCT-MRI fused images.

RESULTS

The volume and superficial area of the articular disc, as well as the area of the articular disc surface in the subarticular cavity, were significantly increased compared to that before the surgical treatment（P < 0.01）. There was also a significant increase in the volume of the condyle (P < 0.001). All condyles showed bone remodeling after surgery that could be categorized as one of two types depending on the position of the articular disc, suggesting that the location of the articular disc was related to the new bone formation.

CONCLUSIONS

The morphology of the articular disc and condyle were significantly changed after arthroscopic disc repositioning surgery. The 3D changes in the position of the articular disc after surgery tended to have an effect on condylar bone remodeling and the location of new bone formation.

Magnetic resonance imaging evaluation of the disc morphology of temporomandibular joint in patients with severe hemophilia

OBJECTIVES

This study aimed to assess the morphological differences in the articular disc (AD) between hemophilic patients and healthy individuals of the control group for further association with signs and symptoms.

METHODS

Fourteen severe hemophilic patients had their AD evaluated by magnetic resonance imaging (MRI). The morphological findings were compared to those of a control group consisting of 14 healthy individuals. MRI was used to evaluate all the components of the temporomandibular (TMJ), including the AD, resulting in sequential T1-weighted parasagittal images. All the images were acquired with teeth in maximum intercuspation position.

RESULTS

Morphological alterations showed significant statistical differences (P-value = 0.0068), whereas no statistical differences were found in the other variables, including TMJ pain, headache, bruxism and mouth opening limitation. In the group of non-hemophilic individuals, only two (14.29%) presented AD with non-biconcave features, whereas in the group of hemophilic patients, nine (64.29%) presented AD with a morphology other than biconcave.

CONCLUSIONS

In patients with severe hemophilia, there seems to be a pattern of morphological alterations in the articular disc over time. The standard biconcave morphology of AD tends to change into other ones, particularly biplanar, hemiconvex and folded.

Three-dimensional evaluation of mandibular condyle and coronoid process according to sex, age, and skeletal deformities

OBJECTIVE

To correlate the volume of the mandibular condyle (MC) and the coronoid process (CP) with sex, age, and skeletal deformities.

METHODS

The structures were visualized through semi-automatic segmentation of the 3D model and complemented with manual segmentation, using the ITK-SNAP 3.0 software. Mann-Whitney, Kruskal-Wallis, and the Dunn test were performed (p < 0.05).

RESULTS

The MC volume showed statistical differences between sex and skeletal deformities. Men and Class III patients showed higher values. CP volume was not influenced by age or skeletal deformities. However, statistical differences were found between sex, with higher values for men.

CONCLUSION

MC volume was influenced by sex and skeletal deformities, while CP was influenced only by sex. Women have smaller volumes for these structures. Age is not correlated with the volume of MC and CP. The highest and lowest values of condylar volume were found for Class III and II individuals, respectively.

Temporomandibular joint segmentation in MRI images using deep learning

OBJECTIVES

Temporomandibular joint (TMJ) internal derangements (ID) represent the most prevalent temporomandibular joint disorder (TMD) in the population and its diagnosis typically relies on magnetic resonance imaging (MRI). TMJ articular discs in MRIs usually suffer from low resolution and contrast, and it is difficult to identify them. In this study, we applied two convolutional neural networks (CNN) to delineate mandibular condyle, articular eminence, and TMJ disc in MRI images.

METHODS

The models were trained on MRI images from 100 patients and validated on images from 40 patients using 2D slices and 3D volume as input, respectively. Data augmentation and five-fold cross-validation scheme were applied to further regularize the models. The accuracy of the models was then compared with four raters having different expertise in reading TMJ-MRI images to evaluate the performance of the models.

RESULTS

Both models performed well in segmenting the three anatomical structures. A Dice coefficient of about 0.7 for the articular disc, more than 0.9 for the mandibular condyle, and Hausdorff distance of about 2mm for the articular eminence were achieved in both models. The models reached near-expert performance for the segmentation of TMJ articular disc and performed close to the expert in the segmentation of mandibular condyle and articular eminence. They also surpassed non-experts in segmenting the three anatomical structures.

CONCLUSION

This study demonstrated that CNN-based segmentation models can be a reliable tool to assist clinicians identifying key anatomy on TMJ-MRIs. The approach also paves the way for automatic diagnosis of TMD.

CLINICAL SIGNIFICANCE

Accurately locating the articular disc is the hardest and most crucial step in the interpretation of TMJ-MRIs and consequently in the diagnosis of TMJ-ID. Automated software that assists in locating the articular disc and its surrounding structures would improve the reliability of TMJ-MRI interpretation, save time and assist in reader training. It will also serve as a foundation for additional automated analysis of pathology in TMJ structures to aid in TMD diagnosis.

Subjective analysis of the application of enhancement filters on magnetic resonance imaging of the temporomandibular joint

OBJECTIVE

The aim of this study was to investigate the effect of enhancement filters on magnetic resonance imaging (MRI) of the temporomandibular joint (TMJ).

STUDY DESIGN

In total, 66 MRI scans of the TMJ were analyzed without filtration and with the application of 2 filters: Sharpen 1 and Sharpen 2 (OnDemand software). Two dentomaxillofacial radiologists examined the original and filtered images individually. Intra- and interobserver concordance was measured by using generalized estimating equations. The observers evaluated the subjective image quality and the visibility of 3 components of the TMJ: disk, condyle, and articular eminence. The images were ranked on a 4-point scale, from poor to excellent. The image quality of all filtered images was compared by using the χ² test and Bonferroni correction for multiple comparisons.

RESULTS

Intra- and interobserver concordance was good. The images filtered with Sharpen 1 and Sharpen 2 provided better definition of the structures compared with nonfiltered images, providing the highest scores for subjective image quality for all structures (P < .0001).

CONCLUSIONS

The use of enhancement filters led to improved subjective quality and may improve the diagnostic efficacy of MRI in TMJ evaluation.

Inclination of the condylar long axis is not related to temporomandibular disc displacement

AIM

The aim of the present study was to correlate the angle formed by inclination of the condylar long axis and median sagittal plane to the presence of internal disc derangement, as well as changes in eccentric mandibular positions.

METHODS

The sample consisted of magnetic resonance images of 35 temporomandibular joint (TMJ) acquired with a 1.5T magnetic resonance imaging system with surface coils of 8.5 cm in diameter. Parasagittal images were used according to the following parameters: TMJ disc position with mouth closed, TMJ disc position with mouth open, TMJ disc function, and degrees of rotation and translation of the condyle. Next, we determined the angles between the condyle long axis and median sagittal plane by using axial images.

RESULTS

The results showed correlations between TMJ disc position and disc function (P = 0.009), as well as between disc position and degree of condylar rotation (P = 0.008). The main purpose of the present study was to assess the angle of the condylar long axis, with no statistical correlation being found between this variable and disc position (P = 0.787), disc function (P = 0.091), condylar translation (P = 0.808), and condylar rotation (P = 0.115).

CONCLUSION

There was no relationship between inclination of the condyle long axis and parameters of internal derangements.

Three-dimensional volumetric analysis of mandibular condyle changes in growing subjects: A retrospective cross-sectional study

OBJECTIVE

The purpose of this study is to analyze the mandibular condylar volumein a sample of subjects 11-26 years old.

METHODS

CBCT condylescans from 94 patients (mean age 18.2 ± 4.5 y) acquired with areconstructed layer thickness of 0.5 mm and a 512×512 matrix were examined. Data on condylar volume were compared among three groups with different age ranges: 11-16 years, 17-21years, and 22-26 years. Condylar volumetric measurements were performed with Mimics™ software.

RESULTS

A significant increase in condylar volume from puberty to young adulthood was detected (p < 0.01). Females showed a higher condylar volume in the 17-21 y group compared with the 11-16 y group. Males showed differences among all three groups.

CONCLUSION

The mandibular condyle growth seems to continue at least until 17-21 years in males but seems to stop before 17 years in females.

Assessment of condyle, masseter and temporal muscles volumes in patients with juvenile systemic lupus erythematosus: A cross-sectional study

AIMS

The purpose of this study was to evaluate the effect of the corticosteroid therapy for both treatment of juvenile systemic lupus erythematosus and disease activity on two masticatory muscles and condyle of the temporomandibular joint.

METHODS

A total of 21 controls and 48 juvenile systemic lupus erythematosus patients were investigated. Volumes of the temporal and masseter muscles and condyle of the subjects were assessed by using a 3D reconstruction in magnetic resonance imaging. The ITK-SNAP, a medical imaging software, was used for 3D reconstruction. A dental examination with registration of occlusion was performed in subjects. Data were statistically analyzed by means of the Dahlberg's test associated with paired t-test, Fisher's exact test and Chi-square.

RESULTS

There was a positive correlation between temporalis muscle and age (p = 0.032), masseter volume (p = 0.029) and condyle volume (p = 0.013). The mean volume measurements of temporal and masseter muscles and condyle were not statistically associated with juvenile systemic lupus erythematosus regarding disease activity and corticosteroid therapy (p > 0.05). There were no significant differences between malocclusion and volume of muscles and condyle.

CONCLUSION

This study suggested that volume of the target structures has no correlation with cumulative corticosteroid dose, disease activity, and malocclusion.

3D Morphology Analysis of TMJ Articular Eminence in Magnetic Resonance Imaging

Purpose

The objective of this study was to evaluate the computational reconstruction of the articular eminence of the temporomandibular joint (TMJ) based on magnetic resonance imaging (MRI) and semiautomatic volumetric segmentation techniques for morphological classification of the TMJ structure.

Materials and Methods

A total of 36 MRI scans of TMJ individuals were selected and formatted by using the ITK-SNAP software, consisting of MRI segmentation and generation of 3D models. The TMJ articular eminences were also classified according to the morphology analysis of the articular eminence in 3D reconstructions. Two independent trained and calibrated investigators performed the image analysis, which was repeated after thirty days.

Results

There was no association between sex and eminence shape (p = 0.456). Fisher's test revealed no statistically significant association between disc classification and eminence shape on both sides (p = 0.629). Chi-square test showed a significant statistically association between disc classification and disc displacement (p = 0.000). Intra- and interrater correlation coefficients showed excellent reproducibility values.

Conclusions

Anatomical variability of the sample investigated was found, with predominantly round shape and presence of correlation between this shape and normal disc position. The correlation of flattened and convex shapes with disc position reduction indicated that type of disc derangement is more prevalent.

Three-dimensional volumetric analysis of ghost cell odontogenic carcinoma using 3-D reconstruction software: a case report

OBJECTIVE

Ghost cell odontogenic carcinoma is a very rare malignant neoplasm. Tumor volume may be a more precise alternative for determining size, which is usually measured by maximum linear dimension. The purpose of this case report is to highlight the importance of obtaining 3-dimensional (3-D) images of the tumor for volumetric analysis to improve the chances of surgical success. This report presents a case of ghost cell odontogenic carcinoma infiltrating the maxillary sinus through the palate. The lesion was surgically treated and subsequently selected for volumetric reconstruction and analysis of the tumor by using InVesalius software. In this case report, we describe the use of a pictorial technique in which the tumor volume was calculated to help predict the surgical results.

RESULTS

The tumor could be visualized in 3-D, with color improving the image of the segmented volume and thus increasing the perception of boundaries and depth.

CONCLUSIONS

Recognition of the lesion shape by volumetric analysis can provide the surgical team with clearer information, thereby helping in surgical planning and consequently increasing the chances of surgical success.

Biometry of the temporomandibular joint using computerized tomography

PURPOSE

In the present study, we performed biometric characterization of the temporomandibular joints (TMJs) of clinically normal subjects.

METHODS

Fifty-one healthy volunteers underwent high-resolution computerized tomography examination of the TMJs in the position of maximal intercuspidation according to a standardized protocol. Frontal and sagittal reconstructions were then performed to obtain measurements and indexes in three planes of space.

RESULTS

Correlations are observed with age, gender, amplitude of mouth opening and presence of dental abrasion. The lateral stability index reflects the degree of mobility of the temporo-discal compartment of the joint. The coverage index reflects how much the mandibular condyle is inserted into the articular fossa and may be related to the risk of occurrence and severity of regressive remodeling phenomena.

CONCLUSIONS

This study supports the interest in examining morphological aspects of the TMJ and performing intra-articular measurements. The biometric examination of the TMJ has important applications in the domain of TMJ pathology.

A proposed diagnostic classification of patients with temporomandibular disorders: implications for physical therapists

SYNOPSIS

Physical therapists have an important role on the interprofessional team to provide care for people with temporomandibular disorders (TMDs). Diagnostic classification is a challenge in this population, given the complexities inherent in presentations of headache and orofacial pain, and is critical to selecting the appropriate intervention. The objectives of this paper were (1) to characterize the epidemiology and pathophysiology of the TMDs most commonly seen in the outpatient clinic, (2) to describe a systems screen to be used in the physical therapy examination to determine the need for interprofessional referral, and (3) to propose an approach for physical therapists to examine, evaluate, and classify patients with TMDs, based on previously validated methodologies. A modification of the diagnostic framework of the International Headache Society has provided the basis for the systems screen of people presenting with orofacial pain. The physical therapy examination and evaluation is based on the Diagnostic Criteria for TMD, developed and validated by a consortium of specialists from the American Academy of Orofacial Pain.

LEVEL OF EVIDENCE

Diagnosis, level 5.

Temporomandibular joint model: anatomic and radiologic comparison between rat and human

PURPOSE

The temporomandibular joint (TMJ) is a complex anatomic structure with various pathologies as fractures, ankylosis or degenerative diseases. Few animal models already exist and the current study aims at demonstrating that rats' TMJ could be considered as a model, using anatomic dissection and radiology.

METHODS

Five adult Wistar rats were dissected to explore the soft and bone anatomy of the TMJ. Five more adult Wistar rats underwent a CT scan to measure size and angles of the condyle.

RESULTS

The angles between the condyle and the mandible corpus were observed to be different both in the sagittal plane (150° vs. 125° in human) and the transversal plane (140° vs. 180°). The condyle axis is sagittal and drop-shaped and there is no anterior eminence in rats' temporal fossa. However, the other anatomic structures proved to be quite similar.

CONCLUSIONS

The temporomandibular joints in human and rat are close and only few anatomic differences have been reported. Rats thus appear as an interesting and cheap alternative to model TMJ.

Clinical and MRI investigation of temporomandibular joint in major depressed patients

OBJECTIVE

The aim of the present study was to describe the clinical and MRI findings of the temporomandibular joint (TMJ) in patients with major depressive disorders (MDDs) of the non-psychotic type.

METHODS

40 patients (80 TMJs) who were diagnosed as having MDDs were selected for this study. The clinical examination of the TMJs was conducted according to the research diagnostic criteria and temporomandibular disorders (TMDs). The MRIs were obtained bilaterally in each patient with axial, parasagittal and paracoronal sections within a real-time dynamic sequence. Two trained oral radiologists assessed all images. For statistical analyses, Fisher's exact test and χ(2) test were applied (α = 0.05).

RESULTS

Migraine was reported in 52.5% of subjects. Considering disc position, statistically significant differences between opening patterns with and without alteration (p = 0.00) and between present and absent joint noises (p = 0.00) were found. Regarding muscular pain, patients with and without abnormalities in disc function and patients with and without abnormalities in disc position were not statistically significant (p = 0.42 and p = 0.40, respectively). Significant differences between mandibular pathway with and without abnormalities (p = 0.00) and between present and absent joint noises (p = 0.00) were observed.

CONCLUSION

Based on the preliminary results observed by clinical and MRI examination of the TMJ, no direct relationship could be determined between MDDs and TMDs.

Diagnostic accuracy of clinical tests and signs of temporomandibular joint disorders: a systematic review of the literature

STUDY DESIGN

Systematic review.

OBJECTIVE

To summarize the research on accuracy of individual clinical diagnostic signs and tests for the presence of temporomandibular disorder (TMD), and for the subclassifications affiliated with TMD.

BACKGROUND

Diagnosis of TMD through clinical diagnostic measures has been reported in many studies; however, few of these studies have identified individual clinical tests or signs that can aid in the diagnosis of TMD or differentiate between the subclassifications of TMD.

METHODS

Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed for this review. Computerized and hand searches were completed to locate articles on the diagnostic accuracy of clinical tests and signs. To be considered for review, the study required (1) an assessment of individual clinical measures of TMD, (2) a report of the diagnostic accuracy of these measures, and (3) an acceptable reference standard for comparison. Quality assessment of studies of diagnostic accuracy (QUADAS) scores were completed on each selected article. Sensitivity and specificity and negative and positive likelihood ratios were calculated for each diagnostic test described.

RESULTS

The search strategy identified 131 potential articles, which were narrowed down to 7 that met the criteria for this review. After assessment using the QUADAS score, 3 of the 7 articles were of high quality. All 7 studies used tests to differentiate subclassifications of TMD. The 7 studies included (1) diagnostic tests/signs of joint sounds, (2) joint movements, or (3) clinically oriented pain measures. There were no studies that investigated TMD versus a competing, non-TMD condition.

CONCLUSION

Only 3 studies presented in this literature review were of high quality. Because all of the included studies assessed diagnostic accuracy among subclassifications of individuals suspected of having TMD, the ability of any of these tests to distinguish between patients with TMD versus patients without TMD remains unknown. Because of the lack of clear findings indicating compelling evidence for clinical diagnosis of TMD, and because of the low quality of most of these studies, the data are insufficient to support or reject these tests.

LEVEL OF EVIDENCE

Diagnosis, level 2a-.

Quantification of condylar resorption in temporomandibular joint osteoarthritis

OBJECTIVE

This study was performed to determine the condylar morphologic variation of osteoarthritic (OA) and asymptomatic temporomandibular joints (TMJs) and to determine its correlation with pain intensity and duration.

STUDY DESIGN

Three-dimensional surface models of mandibular condyles were constructed from cone-beam computerized tomography images of 29 female patients with TMJ OA (Research Diagnostic Criteria for Temporomandibular Disorders group III) and 36 female asymptomatic subjects. Shape correspondence was used to localize and quantify the condylar morphology. Statistical analysis was performed with multivariate analysis of covariance analysis, using Hotelling T(2) metric based on covariance matrices, and Pearson correlation.

RESULTS

The OA condylar morphology was statistically significantly different from the asymptomatic condyles (P < .05). Three-dimensional morphologic variation of the OA condyles was significantly correlated with pain intensity and duration.

CONCLUSION

Three-dimensional quantification of condylar morphology revealed profound differences between OA and asymptomatic condyles, and the extent of the resorptive changes paralleled pain severity and duration.