Role of magnetic resonance imaging in the clinical diagnosis of the temporomandibular joint

Temporomandibular joint (TMJ) abnormalities cannot be reliably assessed by a clinical examination. Magnetic resonance imaging (MRI) may depict joint abnormalities not seen with any other imaging method and thus is the best method to make a diagnostic assessment of the TMJ status. In patients with temporomandibular joint disorder (TMD) referred for diagnostic imaging the predominant TMJ finding is internal derangement related to disc displacement. This finding is significantly more frequent than in asymptomatic volunteers, and occurs in up to 80% of patients consecutively referred for TMJ imaging. Moreover, certain types of disc displacement seem to occur almost exclusively in TMD patients, namely complete disc displacements that do not reduce on mouth opening. Other intra-articular abnormalities may additionally be associated with the disc displacement, predominantly joint effusion (which means more fluid than seen in any asymptomatic volunteer) and mandibular condyle marrow abnormalities (which are not seen in volunteers). These conditions seem to be closely related. Nearly 15% of TMD patients consecutively referred for TMJ MRI will have joint effusion, of whom about 30% will show bone marrow abnormalities. In a surgically selected material of joints with histologically documented bone marrow abnormalities nearly 40% showed joint effusion. Disc displacement is mostly bilateral, but joint effusion seems to be unilateral or with a lesser amount of fluid in the contralateral joint. Abnormal bone marrow is also mostly unilateral. Many patients have unilateral pain or more pain on one side. In a regression analysis the self-reported in-patient TMJ pain side difference was positively dependent on TMJ effusion and condyle marrow abnormalities, but negatively dependent on cortical bone abnormalities. Of the joints with effusion only one fourth showed osteoarthritis. Thus, there seems to be a subgroup of TMD patients showing more severe intra-articular pathology than disc displacement alone, and mostly without osteoarthritis. It should, however, be emphasized that patients with TMJ effusion and/or abnormal bone marrow in the mandibular condyle seem to constitute only a minor portion (less than one fourth) of consecutive TMD patients referred for diagnostic TMJ imaging. The majority of patients have internal derangement related to disc displacement, but without accompanying joint abnormalities. In patients with rheumatoid arthritis and other arthritides TMJ involvement may mimick the more common TMDs. Using MRI it is possible, in most cases, to distinguish these patients from those without synovial proliferation.     

Prevalence and clinical signs of degenerative temporomandibular joint changes validated by magnetic resonance imaging in a non-patient group

The aim of this study is to investigate associations between degenerative bony changes of the temporomandibular joint (TMJ) evaluated by magnetic resonance imaging (MRI) and signs and symptoms of temporomandibular disorders (TMD) in a non-patient group. A total of 307 subjects (140 males and 167 females) were selected from the cross-sectional epidemiological study "Study of Health in Pomerania" (SHIP) for this evaluation. A clinical functional examination of the masticatory muscles and the TMJs was performed as well as an MRI examination of the TMJs. Another 77 subjects (25%) exhibited degenerative changes of one or both TMJs in the MRI. Clinical analysis revealed pain on palpation of the masticatory muscles in 113 subjects. Some 39 subjects had pain during palpation of the TMJs. There were significant associations between the MRI confirmed diagnosis of osteoarthrosis and some clinical signs (joint noises, joint palpation pain, reduced mouth opening) and symptoms (reported pain in the jaw and masticatory muscles) of TMD as well as further MRI diagnoses (disc displacement with and without reduction, fibrosis of the posterior ligament). Although there were some associations, clinical examination alone is not sufficient for diagnosing degenerative joint diseases. MRI is a necessary diagnostic adjunct for estimating the prevalence of TMD subgroups in non-patient populations.     

Subchondral bone resorption in temporomandibular joint disorders

Several tissues are involved in temporomandibular joint (TMJ) health, including synovial fluid, the TMJ disc, articular cartilage, and subchondral bone. This article focuses upon bone resorption in temporomandibular joint disorders (TMD) and has the following objectives: (1) to provide a brief review of the current understanding of bone formation and bone resorption (bone remodeling); (2) to present selected case studies which illustrate the spectrum of bone resorption patterns in TMD patients of various ages; (3) to review previous reports in the literature describing loss of subchondral bone in TMD, and (4) to discuss the interaction between osteoporosis and TMD and the potential role for antiresorbing agents in TMD therapy.     

颞下颌关节音分析的临床应用研究

目的：探讨以TMJ音分析作为TMJ损伤及病变临床诊断和病理研究方法的可行性。材料和方法：利用线性谱分析和非线性分形分析两种方法对健康人和TMD患者的TMJ音进行分析。结论：结果表明，两种方法均能正确识别健康人和TMD患者的TMJ音，但谱分析法仍需依靠医生的临床经验。     

Skeletal pattern in subjects with temporomandibular joint disorders

Introduction

To establish the skeletal pattern in subjects with malocclusions and temporomandibular disorders (TMD); to assess the relationship between craniofacial skeletal structures and TMD in subjects with malocclusions.

Material and methods

Sixty-four subjects with malocclusions, over 18 years of age, were included in the study. Temporomandibular disorders were clinically assessed according to the Helkimo Anamnestic Index. Subjects underwent a lateral cephalogram. Subjects were grouped according to the sagittal skeletal pattern (ANB angle) into class I, II and III. Parametric Student tests with equal or unequal variations were used (variations were previously tested with Levene test).

Results

Twenty-four patients with TMD (experimental sample); 40 patients without TMD (control group); interincisal angle was higher in class I and II (p < 0.05) experimental subjects; overjet was larger in experimental subjects; midline shift and Wits appraisal were broader in the experimental group in all three classes. In class III subjects, the SNB angle was higher in the experimental group (p = 0.01). Joint noises followed by reduced mandible mobility, muscular pain and temporomandibular joint (TMJ) pain were the most frequent symptoms in subjects with TMD and malocclusions.

Conclusions

Temporomandibular joint status is an important factor to consider when planning orthodontic treatment in patients with severe malocclusions; midline shift, large overjet and deep overbite have been associated with signs and symptoms of TMD.     

In vivo prediction of temporomandibular joint disc thickness and position changes for different jaw positions

Temporomandibular joint disorders (TMD) are common dysfunctions of the masticatory region and are often linked to dislocation or changes of the temporomandibular joint (TMJ) disc. Magnetic resonance imaging (MRI) is the gold standard for TMJ imaging but standard clinical sequences do not deliver a sufficient resolution and contrast for the creation of detailed meshes of the TMJ disc. Additionally, bony structures cannot be captured appropriately using standard MRI sequences due to their low signal intensity. The objective of this study was to enable researchers to create high resolution representations of all structures of the TMJ and consequently investigate morphological as well as positional changes of the masticatory system. To create meshes of the bony structures, a single computed tomography (CT) scan was acquired. In addition, a high‐resolution MRI sequence was produced, which is used to collect the thickness and position change of the disc for various static postures using bite blocks. Changes in thickness of the TMJ disc as well as disc translation were measured. The newly developed workflow successfully allows researchers to create high resolution models of all structures of the TMJ for various static positions, enabling the investigation of TMJ disc translation and deformation. Discs were thinnest in the lateral part and moved mainly anteriorly and slightly medially. The procedure offers the most comprehensive picture of disc positioning and thickness changes reported to date. The presented data can be used for the development of a biomechanical computer model of TMJ anatomy and to investigate dynamic and static loads on the components of the system, which could be useful for the prediction of TMD onset.     

Temporomandibular Joint: Disorders,Treatments, and Biomechanics

Temporomandibular joint (TMJ) is a complex, sensitive, and highly mobile joint. Millions of people suffer from temporomandibular disorders (TMD) in USA alone. The TMD treatment options need to be looked at more fully to assess possible improvement of the available options and introduction of novel techniques. As reconstruction with either partial or total joint prosthesis is the potential treatment option in certain TMD conditions, it is essential to study outcomes of the FDA approved TMJ implants in a controlled comparative manner. Evaluating the kinetics and kinematics of the TMJ enables the understanding of structure and function of normal and diseased TMJ to predict changes due to alterations, and to propose more efficient methods of treatment. Although many researchers have conducted biomechanical analysis of the TMJ, many of the methods have certain limitations. Therefore, a more comprehensive analysis is necessary for better understanding of different movements and resulting forces and stresses in the joint components. This article provides the results of a state-of-the-art investigation of the TMJ anatomy, TMD, treatment options, a review of the FDA approved TMJ prosthetic devices, and the TMJ biomechanics.     

Dental and temporomandibular joint alterations in rheumatoid arthritis patients and their association with salivary oxidative stress

Background/aim Rheumatoid arthritis (RA) is the most extensive inflammatory arthritis causing permanent deformities in the joint. Increasing evidence suggests that oxidative stress is a substantial factor in the pathogenesis of RA. This study aimed to examine the salivary oxidant-antioxidant status of RA and control groups and to compare these biomarkers by correlating them with disease activity, acute phase reactants, and clinical findings.Materials and methods Age and sex-matched 60 participants including 30 patients with RA and 30 control (50 females, 10 males; mean age: 42.62 ± 10.89 years) were evaluated. RA disease activity and severity were evaluated by the disease activity score 28-C reactive protein (DAS 28-CRP). Rheumatoid factor (RF) positivity, anticitrullinated protein antibodies (ACPA) positivity, erythrocyte sedimentation rate (ESR), CRP, tender and swollen joint counts, and medical treatment regimens of the patients (glucocorticoids, conventional or biologic disease-modifying antirheumatic drugs) were recorded. In the radiographic examination, dental findings, and bone alterations of the temporomandibular joint (TMJ) were recorded and compared for both groups. Saliva samples were obtained for analysis of total antioxidant status (TAS), total oxidant status (TOS), arylesterase (ARE), and oxidative stress index (OSI) levels. The data analysis was conducted by independent sample t-test and chi-square test.Results Condylar erosion was the most common radiographic change in TMJ of RA patients. Osteophyte formation was a prominent finding in the control group. Lower TAS and higher OSI levels were found in RA patients compared with controls (p = 0.013; p = 0.029, respectively). The effect of DAS 28-CRP score on the levels of oxidative stress biomarkers in RA patients was not significant. Conclusion Oxidative stress causes tissue damage in response to excessive mechanical loading, which in turn promotes TMD. However, disease activity has not a prominent impact on the salivary oxidative stress status of RA patients.     

Gender Difference in Prevalence of Signs and Symptoms of Temporomandibular Joint Disorders: A Retrospective Study on 243 Consecutive Patients

Background: This study evaluated the prevalence of the signs and symptoms of temporomandibular joint disorder (TMD) among patients with TMD symptoms. Methods: Between September 2011 and December 2011, 243 consecutive patients (171 females, 72 males, mean age 41 years) who were referred to the Department of Prosthodontics, Faculty of Dentistry, Karadeniz Technical University, Trabzon were examined physically and completed a questionnaire regarding age, gender, social status, general health, antidepressant drug usage, dental status, limited mouth opening, temporomandibular joint (TMJ) sounds, and parafunctions (bruxism, clenching). The data were analyzed using the chi-square test and binary logistic regression model (alpha = 0.05). Results: With a frequency of 92%, pain in the temporal muscle was the most common symptom, followed by pain during mouth opening (89%) in both genders. TMJ pain at rest, pain in the masseter muscle, clicking, grinding, and anti-depressant use were significantly more frequent in females than males. Age (p=0.006; odds ratio 0.954; 95% CI 0.922-0.987) and missing teeth (p=0.003; odds ratio 3.753; 95% CI 1.589-8.863) had significant effects on the prevalence of TMD. Conclusion: Females had TMD signs and symptoms more frequently than males in the study population. The most common problem in both genders was pain.     

'Friction and adhesive forces'--possible underlying causes for temporomandibular joint internal derangement

Since normal temporomandibular joint (TMJ) movements depend primarily on the disc freely sliding down the slope of the eminence, understanding how aberrations in the lubrication system contribute to TMJ dysfunction is clearly critically important. It provides a possible explanation for the genesis of disc displacement and helps make us familiar with the clinical appearance and ways of treating limited mouth opening caused by the anchored disc phenomenon (ADP) versus disc displacement without reduction, TMJ open lock versus dislocation and osteoarthritis. This understanding clarifies the efficiency of procedures such as joint hydraulic pump, arthrocentesis and arthroscopic lavage and lysis particularly in ADP, open lock and osteoarthritis.     

Temporal mandibular joint chondrocalcinosis (tophaceous pseudogout) diagnosed by ultrasound‐guided fine‐needle aspiration

Tophaceous pseudogout is a calcium pyrophosphate dihydrate crystal (CPPD) deposition disease that frequently affects elderly patient in the temporomandibular joint (TMJ). A diagnosis of CPPD deposition disease in the TMJ is challenging due to its mimicking of other benign and malignant entities. Surgical exploration followed by histologic examination is by far the most frequently used diagnostic modality. We present a case of an 87‐year‐old female who presented with a right TMJ mass. A final diagnosis of tophaceous pseudogout was made on cellular material obtained by ultrasound‐guided fine‐needle aspiration (US‐guided FNA). Based on our case and current available literature, ultrasound‐guided FNA is a reliable tool for diagnosing tophaceous pseudogout of the TMJ.     

Reduction of temporomandibular joint pain after treatment with a combination of methotrexate and infliximab is associated with changes in synovial fluid and plasma cytokines in rheumatoid arthritis

The aims were to investigate the effect of intravenous infusions of the tumor necrosis factor-alpha (TNF-alpha) antibody infliximab on symptoms and signs of temporomandibular joint (TMJ) involvement in relation to effects on synovial fluid and plasma proinflammatory TNF-alpha, interleukin-1beta (IL-1beta) and interleukin-6 as well as antiinflam matory soluble TNF receptor II (TNF-sRII), interleukin-1 receptor antagonist (IL-1ra), soluble IL-1 receptor II (IL-1sRII) and interleukin-10 (IL-10) in patients with active rheumatoid arthritis (RA). Nineteen patients with TMJ involvement taking methotrexate were included in the study. TMJ and general joint pain intensity as well as pain on mandibular movements, tenderness to digital palpation, pressure pain threshold and maximum mouth-opening capacity were assessed in a clinical examination. The effect of infliximab was assessed after 2 and 14 or 22 weeks. TMJ synovial fluid and venous blood were collected for cytokine analysis at all occasions while determination of erythrocyte sedimentation rate and C-reactive protein were performed at baseline and at long-term follow-up only. Reduction of TMJ pain was associated with raised levels of synovial fluid TNF-sRII and IL-1sRII as well as raised plasma levels of IL-1ra and IL-10. Decreased erythrocyte sedimentation rate was associated with decreased tenderness to digital palpation. Reduced general joint pain intensity was associated with reduced plasma levels of IL-6 and C-reactive protein. In conclusion, systemic treatment with a combination of infliximab and methotrexate reduces TMJ pain in RA in association with an increase in anti-inflammatory cytokines and receptors in synovial fluid and plasma.     

Fine needle aspiration of pigmented villonodular synovitis of the temporomandibular joint

Temporomandibular joint (TMJ) problems are usually the result of functional disorders. Tumors of the TMJ are rarer entities, the diagnosis of which may be delayed due to a clinical impression of a functional ailment. We report a case of a patient with a recurrent TMJ area lesion diagnosed cytologically as pigmented villonodular synovitis (PVNS), an entity that very rarely involves the TMJ and is usually diagnosed by histology. The differential diagnosis of PVNS in the context of its location in and around the TMJ is also discussed.     

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

The aim of this work was to define the diagnostic value of a method for 3D reconstruction of MRI images for the assessment of temporomandibular joint. Sixty subjects, 42 diagnosed with unilateral temporomandibular disorders (TMD) with disc displacement and 18 without signs or symptoms of TMD (control group) were included. All subjects had both temporomandibular joints scanned by MRI. Three-dimensional imaging reconstructions of temporomandibular joint were generated by segmentation software, allowing visualization of the components of temporomandibular joint (articular disc, condyle and temporal bone) on arbitrary planes. Disc displacement was observed in 83% of 3D reconstruction and 81% of conventional MRI. The agreement between 3D diagnosis and MRI findings was significant and high. The present analysis suggested that 3D reconstruction is a useful and accurate method for the assessment of the temporomandibular joint in TMD ID.     

颞下颌关节可复性盘前移患者的MR表现

目的:研究颞下颌关节可复性盘前移（ADDWR）患者的磁共振（MR）成像表现。方法:纳入颞下颌关节ADDWR患者55例作为观察组,另纳入30例牙齿排列整齐的健康志愿者作为对照组。所有研究对象均接受MR成像检查,记录颞下颌关节ADDWR患者关节盘前移程度,比较不同严重程度患者关节盘形态和关节渗出情况。结果:55例颞下颌关节ADDWR患者中,轻症35例,重症20例。对照组、轻症组及重症组关节盘形态分型比较,差异有统计学意义（P<0.05）。3组对象颞下颌关节渗出情况比较,差异有统计学意义（P<0.05）。不同程度关节渗出患者视觉模拟评分法（VAS）评分差异有统计学意义（P<0.05）。3组对象关节盘长度差异有统计学意义（P<0.05）。轻度组关节盘前移度较重症组显著减轻,差异有统计学意义（P<0.05）。结论:MR有助于颞下颌关节ADDWR患者病情判断,可为临床治疗提供依据。     

Comparison of cellular and protein changes in bronchial lavage fluid of symptomatic and asymptomatic patients with red cedar asthma on follow-up examination

Seventeen patients with occupational asthma due to western red cedar had bronchial lavage during follow-up examination after removal from exposure for at least 1 year. Seven patients were asymptomatic while ten continued to have symptoms of asthma requiring treatment. Symptomatic patients had evidence of airway inflammation, as reflected by a significantly higher total cell count, neutrophils and eosinophils, as well as an increase in protein and albumin in their bronchial lavage fluid compared to those without symptoms. Asymptomatic patients had no evidence of airway inflammation in the lavage fluid. There was no correlation between the degree of non-specific bronchial hyperresponsiveness and the number or percentage of inflammatory cells to suggest that cellular infiltration is the sole cause of persistent bronchial hyperresponsiveness.     

稳定咬合板治疗颞下颌关节紊乱病的临床疗效观察

目的:探讨佩戴稳定咬合板治疗颞下颌关节紊乱病（TMD）的临床疗效。方法:前瞻性研究。纳入甘肃医学院附属医院口腔科2018年6月—2020年2月收治的TMD患者84例,其中男9例、女75例,年龄16~70（29.5±12.0）岁,均佩戴稳定型咬合板治疗3个月。分别于治疗前和治疗后1周及1、2、3个月共5个时间点,对比患者...     

Genes that regulate morphogenesis and growth of the temporomandibular joint: A review

Compared with the joints of the limbs, our understanding of the genes that regulate development and growth in the temporomandibular joint (TMJ) is fairly limited. Because the morphogenesis of the secondary cartilage and other intra‐articular structures in the TMJ occurs later and in a different manner than in the limbs, the genetic control of TMJ development might reasonably be assumed to differ from that in the limbs. However, studies of the specific genes regulating TMJ morphogenesis and growth have only begun to appear in the literature within the last decade. This review attempts to survey and interpret the existing knowledge on this topic and to suggest fruitful avenues of investigation for the future. Studies to date using knockout and over‐expression of candidate genes suggest that a developmental hierarchy of joint structures exists, with condyle development primary. A hierarchy of gene expression also exists: Runx2 and Sox9 expression is critical for condylar cartilage formation. Several of the other genes discussed in this report may regulate TMJ morphogenesis by affecting Sox9 and Runx2 expression and control the ihh‐PTHrP axis by means of these genes. Developmental Dynamics 243:864–874, 2014. © 2014 Wiley Periodicals, Inc.     

Mefenamic acid decreases inflammation but not joint lesions in experimental osteoarthritis

Mefenamic acid is a non‐steroidal anti‐inflammatory drug able to control the symptoms of osteoarthritis (OA), but its effects on protection of cartilage and bone are still unclear. This study aimed to investigate whether the control of inflammation by mefenamic acid translates into decreased joint lesions in experimental OA in rats. OA was induced by injecting 1 mg of monosodium iodoacetate (MIA) into the joints of rats. The animals were treated with mefenamic acid (50 mg/kg, daily, oral gavage) either pre‐MIA injection (preventive) or post‐MIA injection (therapeutic). Joint swelling and hyperalgesia were evaluated at baseline and 1, 3, 14 and 28 days after induction of OA. Intra‐articular lavage and kinetics of cell migration into the synovium were measured 3 and 28 days after OA induction. Histopathological analysis, Osteoarthritis Research Society International (OARSI) score, total synovium cells count, cartilage area and levels of proteoglycans in joints were also evaluated. Mefenamic acid prevented joint oedema and hyperalgesia induced by MIA in the acute phase (3 days) of the disease. In the chronic phase (28 days), preventive and therapeutic regimens decreased the number of mononuclear cells in the joint cavity. In contrast, thickening of the synovium, bone resorption, loss of cartilage and levels of proteoglycans were unaffected by mefenamic acid when it was administered either preventively or therapeutically. Thus, mefenamic acid had anti‐inflammatory effects but did not reduce the progression of OA lesions, thereby indicating that it is only effective for symptomatic control of OA.     

On the involvement of the temporomandibular joint in rheumatoid arthritis

64 patients with rheumatoid arthritis (RA) were examined for temporomandibular joint (TMJ) symptoms as well as for the severity and incidence of their symptoms. In detailed interviews, a total of 34 patients (53.1%) reported TMJ symptoms, the main complaints being problems during opening and closing of the mouth (45.2%). RA patients with TMJ symptoms differed significantly from those without TMJ symptoms (p < 0.01) in the duration (121.7 +/- 100.5 months vs. 37.1 +/- 27.6 months) and the state of activity of the basic disease. The patients subjectively evaluated the severity of the TMJ symptoms as mild to moderate (grade: 2-3; severity: 241 +/- 1.01). Almost 70% reported occasional symptoms, 22.5% frequent symptoms and 10.6% permanent symptoms (p < 0.01). 61.8% (21/34) of the patients showed no radiographic change in the shape of the TMJ condyle, whereas 11.8% (4/34) demonstrated a change on one side an 26.4% (9/34) a change on both sides. There was no difference in the severity of the TMJ symptoms between patients with an unchanged condyle (n = 21; severity: 2.33 +/- 0.96) and patients with changes in condylar shape (n = 13; severity: 2.5 +/- 1.12). A frequent involvement of the temporomandibular joint in RA can be considered certain. The symptoms, which were generally moderate, can cause a marked impairment of daily used functions, such as chewing and speaking.