The temporomandibular joint (TMJ) is frequently imaged in head and neck computed tomography (CT) and magnetic resonance imaging (MRI) studies. Depending on the indication for the study, an abnormality of the TMJ may be an incidental finding. These findings encompass both intra- and extra-articular disorders. They may also be related to local, regional or systemic conditions. Familiarity with these findings along with pertinent clinical information helps narrow the list of differential diagnoses. While definitive diagnosis may not be immediately apparent, a systematic approach contributes to improved discussions between clinicians and radiologists and better patient management.
Humans ; Temporomandibular Joint Disorders/pathology* ; Incidental Findings ; Temporomandibular Joint/pathology* ; Tomography, X-Ray Computed ; Magnetic Resonance Imaging

Objective: To explore the correlation between the attachment type of lateral pterygoid muscle (LPM) and the position of temporomandibular joint (TMJ) disc in patients with temporomandibular disorders (TMD) by using wireless amplified magnetic resonance imaging detector (WAND) coupled with conventional head and neck joint coil for high resolution imaging of TMJ. Methods: Eighty-five patients with TMD diagnosed by oral and maxillofacial surgeons of Guizhou Provincial People's Hospital from October 2019 to January 2022 were collected. A total of 160 TMJ were included. There were 16 males and 69 females, aged (32.7±14.2) years. All patients were scanned with open, closed oblique sagittal and coronal WAND coupled head and neck coils with bilateral TMJ. Based on TMJ and LPM high resolution imaging, to explore the correlation between LPM attachment types and the position of TMJ disc in TMD patients, and to evaluate the potential clinical value of LPM attachment types in TMD patients. χ² test and Pearson correlation analysis were used to evaluate the correlation between LPM attachment type and TMJ disc location. Results: There were three types of LPM attachment: type Ⅰ in 51 cases [31.9% (51/160)], type Ⅱ in 77 cases [48.1% (77/160)] and type Ⅲ in 32 cases [20.0% (32/160)]. There was a significant correlation between the type of LPM attachment and the position of articular disc (χ²=28.20, P=0.002, r=0.776). There was no statistical significance between the type of LPM attachment and the reversible displacement of articular disc (χ²=0.24, P=0.887, r=0.825). Conclusions: There is a correlation between the attachment type of LPM and the position of the disc in TMD patients. WNAD coupled with conventional head and neck joint coil TMJ high resolution scan can provide reliable imaging evidence for TMD patients in evaluating the type of LPM attachment and the location of disc.
Male ; Female ; Humans ; Temporomandibular Joint Disc/pathology* ; Pterygoid Muscles/pathology* ; Joint Dislocations ; Temporomandibular Joint Disorders/diagnostic imaging* ; Magnetic Resonance Imaging/methods* ; Temporomandibular Joint/pathology*

OBJECTIVES: This study aimed to use modified articular disc anchorage in treating old irreducible temporomandibular joint (TMJ) disc displacement with perforation and rupture, as well as to explore its efficacy. METHODS: A total of 31 patients (34 sides) with 47 TMJ disc perforations who underwent surgical treatment in the Affiliated Stomatolo-gical Hospital of Nanchang University from January 2018 to December 2021 were selected. According to the location of disc perforation, it has five types: posterior disc perforation (typeⅠ), anterior disc perforation (typeⅡ), lateral disc perforation (type Ⅲ), composite disc perforation, and destruction disc perforation. The modified methods of disc anchoring were divided into two types according to the location of the perforation. TypesⅠandⅢ disc perforation were trea-ted by posterior anchoring method. For posterior ancho-ring, a screw was implanted into the posterolateral side of the condylar neck, and the disc was fixed on the screw by horizontal mattress suture. TypeⅡdisc perforation and compo-site disc perforation combined typeⅡperforation were treated by anterior and posterior double-anchoring method. For anterior anchoring, anchor screws or holes were placed at the anterior edge of the condylar neck, and horizontal mattress suture was performed at the posterior edge of the anterior perforation with an anchor wire. The articular disc was then fixed on the anchor screws or holes. For the posterior anchoring method, it was the same as the previous one. Paired t test was used to analyze the visual analog scale (VAS), maximum interincisal opening (MIO), and TMJ disorder index (CMI) of the patient before surgery and 1, 3, and 6 months after surgery. Disk-condyle position relationship by magnetic resonance imaging and postoperative quality of life in postoperative were analyzed. RESULTS: The incidence of perforation was 41.2% (14/34) in typeⅠ, 11.8% (4/34) in typeⅡ, 8.8% (3/34) in typeⅢ, 29.4% (10/34) in composite type, and 8.8% (3/34) in destruction type. The VAS, MIO, and CMI at 3, 6 months after operation significantly improved compared with those before operation (P<0.05). The effective reduction rate of disc was 96.77% (30/31). The quality of life at 6 months after surgery was 47.22±2.13, and the rate of excellent evaluation was 96.4% (27/28). CONCLUSIONS Modified articular disc anchorage achieves a good curative effect for treating temporomandibular joint disc perforation and rupture. Nevertheless, its long-term effect requires further observation.
Humans ; Temporomandibular Joint Disc/surgery* ; Quality of Life ; Joint Dislocations/surgery* ; Temporomandibular Joint Disorders/surgery* ; Magnetic Resonance Imaging/methods* ; Temporomandibular Joint/pathology* ; Mandibular Condyle

Collagen is the building component of temporomandibular joint (TMJ) discs and is often affected by inflammation in temporomandibular disorders. The macromechanical properties of collagen are deteriorated by chronic inflammation. However, the mechanism by which inflammation influences disc function remains unknown. The relationship between the ultrastructure and nanomechanical properties of collagen in inflamed discs should be clarified. Seven-week-old female Sprague-Dawley rats were randomly divided into two groups. Chronic TMJ inflammation was induced by intra-articular injection of complete Freund's adjuvant, and samples were harvested after 5 weeks. Picrosirius staining revealed multiple colours under polarized light, which represented alternative collagen bundles in inflamed discs. Using atomic force microscopy scanning, the magnitude of Young's modulus was reduced significantly accompanied with disordered collagen fibril arrangement with porous architecture of inflamed discs. Transmission electron microscopy scanning revealed a non-uniform distribution of collagen fibres, and oversized collagen fibrils were observed in inflamed discs. Fourier transform infrared microspectroscopy revealed a decrease in 1 338 cm/amide II area ratio of collagen in different regions. The peak positions of amide I and amide II bands were altered in inflamed discs, indicating collagen unfolding. Our results suggest that sustained inflammation deteriorates collagen structures, resulting in the deterioration of the ultrastructure and nanomechanical properties of rat TMJ discs.
Animals ; Collagen ; ultrastructure ; Female ; Fibrillar Collagens ; ultrastructure ; Freund's Adjuvant ; adverse effects ; Inflammation ; chemically induced ; metabolism ; pathology ; Injections, Intra-Articular ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Temporomandibular Joint ; Temporomandibular Joint Disc ; physiopathology ; ultrastructure ; Temporomandibular Joint Disorders ; physiopathology

BACKGROUND: Pain, limitations in opening, asymmetrical jaw movements, and temporomandibular joint (TMJ) sounds are the most common findings in temporomandibular joint disorders (TMDs), which causes excruciating pain, inflammation of the surrounding muscles, posterior fibers, and synovial fluid. This study aimed to evaluate and compare the effects of ultrasound heat therapy and low-level laser therapy (LLLT) in reducing TMD-related pain. METHODS: This prospective study included 42 patients (age range, 25–45 years), who were divided into two groups of 21 patients each. All patients were prescribed a non-steroidal anti-inflammatory drug (NSAID) twice a day for 5 days for temporary relief of pain prior to the commencement of treatment. Patients were kept on a soft diet and asked to restrict mouth opening during the same period. Fifteen sessions of LLLT (Group A) or ultrasound therapy (Group B) were administered to the affected side. RESULTS: Post-therapy, the mean visual analog scale score for group A and group B was 4.81 (2.01) and 6.19 (1.20), respectively; the difference was statistically significant and favoring the LLLT group. Similarly, the mean mouth opening for group A and group B was 3.99 (0.40) and 3.65 (0.41), respectively; the difference was statistically significant and favoring the LLLT group. CONCLUSION: Our study recommends LLLT for treating TMD-related pain with no underlying bony pathology.
Diet ; Hot Temperature ; Humans ; Inflammation ; Jaw ; Low-Level Light Therapy ; Mouth ; Muscles ; Pathology ; Prospective Studies ; Synovial Fluid ; Temporomandibular Joint Disorders ; Temporomandibular Joint ; Ultrasonic Therapy ; Ultrasonography ; Visual Analog Scale

Anterior disc displacement is a common subtype seen in temporomandibular disorders (TMD) patients. It may cause mandibular movement disorders, such as clicking of joint, intermittent closed lock, limitation of mouth opening, etc. These disorders may affect the life qualities of patients. Anterior disc displacement may also cause mandibular malformations, especially among adolescents, which may affect the growth of condyle, therefore may have a correlation with mandibular retrusion or mandibular deviation when grown up. This paper going to review the influences of anterior disc displacement on oral mandibular function and morphology and their biological mechanisms.
Adolescent ; Humans ; Mandible ; abnormalities ; pathology ; Mandibular Condyle ; growth & development ; Mandibular Diseases ; etiology ; Movement ; Retrognathia ; etiology ; Temporomandibular Joint Disorders ; etiology ; physiopathology

OBJECTIVEThis study investigates the effect of temporomandibular joint osteoarthritis (TMJOA) on different stages of condylar three-dimensional position and provides a theoretical basis for clinical application.

METHODSThe cone beam computed tomography (CBCT) images of 108 TMJOA patients were analyzed and divided into four stages based on the stage standard of osteoarthrosis X-ray performance proposed by Xuchen Ma in 2005. A total of 28 defect-free temporomandibular joint disorders were used as the control group. Differences in condylar position and condylar axis horizontal angle were evaluated and compared.

RESULTSNo significant differences were found in terms of sagittal relationship, but condylar axis horizontal angle showed a significant difference (F = 3.872, P = 0.005). The horizontal angle values of stage 1 in the TMJOA group were lower than those in stages 2 and 3 (P = 0.027, P = 0.000), whereas the horizontal angle values of stage 2 and control groups were lower than those of stage 3 group (P = 0.004, P = 0.047).

CONCLUSIONCondylar horizontal angle differed in each stage of TMJOA, but no significant difference between the parasagittal positions of the condyles was observed in each stage.

Case-Control Studies ; Cone-Beam Computed Tomography ; Humans ; Mandibular Condyle ; Osteoarthritis ; diagnostic imaging ; Temporomandibular Joint ; diagnostic imaging ; pathology ; Temporomandibular Joint Disorders ; diagnostic imaging

OBJECTIVEThis study aims to evaluate the effectiveness of arthrocentesis on Wilkes III stage patients. Clinical examinations and magnetic resonance imaging (MRI) findings before treatment and six months after treatment were compared and analyzed.

METHODSA total of 137 outpatients diagnosed with temporomandibular joint internal derangement (TMJID) associated with Wilkes III stage through clinical examination and MRI findings from January 2013 to December 2013 were randomly included. All the patients were successfully treated with arthrocentesis. Moreover, all the patients accepted clinical and MRI examination before arthrocentesis treatment and six months after. Clinical examination included visual analogue scale and opening degree, whereas MRI examination included articular disc morphology and effusion in the upper compartments. Statistical analysis was performed using SPSS 20.0.

RESULTSResults showed that the average score of visual analogue scale six months after treatment was significantly lower than that before treatment (P < 0.05). The success rate was 78.1% (107/137). The rate of disc deformity after arthrocentesis treatment was higher than that before the treatment. By contrast, the positive rate of effusion after arthrocentesis was significantly lower than that before the treatment (P < 0.05). Bilaminar zone adaptive changes (disk-like) were found in seven cases (5.1%, 7/137) after treatment.

CONCLUSIONArthrocentesis could effectively relieve pain of the TMJID patients. Furthermore, MRI results indicated that arthrocentesis could significantly decrease articular effusion. Arthrocentesis was effective for the treatment of Wilkes III stage in the short term. Adaptive changes in bilaminar zone occurred in a few patients. However, serious disc deformity with the passage of time is a trend that has been observed.

Arthrocentesis ; Humans ; Joint Dislocations ; Magnetic Resonance Imaging ; Outpatients ; Range of Motion, Articular ; Temporomandibular Joint Disc ; pathology ; surgery ; Temporomandibular Joint Disorders ; diagnosis ; surgery ; Treatment Outcome ; Visual Analog Scale

Temporomandibular joint (TMJ) disorder is clinically important because of its prevalence, chronicity, and therapy-refractoriness of the pain. In this study, we investigated the effect of infliximab in a mouse model of TMJ pain using a specially-engineered transducer for evaluating the changes in bite force (BF). The mice were randomly divided into three groups (7 mice per group): the control group, the complete Freund's adjuvant (CFA) group, and the infliximab group. BF was measured at day 0 (baseline BF). After measuring the baseline BF, CFA or incomplete Freund's adjuvant was injected into both TMJs and then the changes in BF were measured at days 1, 3, 5, 7, 9, and 13 after the TMJ injection. For measuring the BF, we used a custom-built BF transducer. Control, CFA, and infliximab groups showed similar baseline BF at day 0. From day 1, a significant reduction in BF was observed in the CFA group, and this reduction in BF was statistically significant compared to that in the control group (P < 0.05). This reduction in BF was maintained until day 7, and BF started to recover gradually from day 9. In the infliximab group also, the reduction in BF was observed on day 1, and this reduction was maintained until day 7. However, the degree of reduction in BF was less remarkable compared to that in the CFA group. The reduction in BF caused by injection of CFA into the TMJ could be partially alleviated by the injection of anti-tumor necrosis factor alpha, infliximab.
Animals ; Antirheumatic Agents/*therapeutic use ; *Bite Force ; Disease Models, Animal ; Freund's Adjuvant/toxicity ; Infliximab/*therapeutic use ; Male ; Mice ; Mice, Inbred ICR ; Temporomandibular Joint/pathology ; Temporomandibular Joint Disorders/chemically induced/*drug therapy/pathology ; Time Factors

In temporomandibular disorders (TMD), pain takes place when neuropeptides stimulate synovial tissue to produce several cytokines such as interleukin (IL)-1β, IL-6 and tumor necrosis factor (TNF)-α, which activate neurons and glia of synovial membrane at the bilaminar regions of temporomandibular joint (TMJ). It has been reported that, after neurogenic differentiation, the synovial mesenchymal stem cells (SMSCs), deriving from TMJ, possess the same cytological features as the neuronal cells. This study examined the ability of substance P (SP) and calcitonin gene-related peptide (CGRP) to stimulate SMSCs and neurogenic SMSCs secreting inflammatory cytokines during TMD, evaluated the mutual effects of inflammatory cytokines and neuropeptides and tested the analgesic effect of hyaluronic acid (HA). The levels of IL-1β, IL-6 and TNF-α in SMSCs and neurogenic SMSCs in the presence of neuropeptides were measured by ELISA. SP and CGRP produced by SMSCs and neurogenic SMSCs were determined by RT-PCR and Western blotting. The results showed that the expression of SP and CGRP was significantly enhanced in the neurogenic SMSCs in response to IL-1β, IL-6 and TNF-α, and the effect was remarkably inhibited by HA. IL-1β, IL-6 and TNF-α, in return, could be enhanced in the neurogenic SMSCs upon stimulation by SP and CGRP. Neuropeptides and inflammatory cytokines might work mutually on the TMD pain. The HA-mediated analgesic effect may be implicated in the inhibition of SP and CGRP expression in neurogenic SMSCs.
Calcitonin Gene-Related Peptide ; biosynthesis ; Cells, Cultured ; Cytokines ; biosynthesis ; Female ; Humans ; Male ; Mesenchymal Stromal Cells ; metabolism ; pathology ; Substance P ; biosynthesis ; Synovial Membrane ; metabolism ; pathology ; Temporomandibular Joint ; metabolism ; pathology ; Temporomandibular Joint Disorders ; metabolism ; pathology