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Replacement of the temporomandibular joint (RTJ) has undergone decades of technological improvements and is now an important treatment for end-stage temporomandibular joint (TMJ) disease. The main complications of RTJ include aseptic loosening, heterotopic ossification, postsurgical infection, hypersensitivity reaction, prosthesis loosening or malposition, nerve injury and severe bleeding. Improvement in clinical technique is now the key to resolving complications. In the future, improvements in prosthetic materials may be an important development for newer iterations. With the development and popularity of TMJ surgical techniques, prosthesis-related complications will increasingly come into clinical view. This article provides a systematic review of the complications of RTJ prosthesis replacement and the measures to deal with them, and looks forward to the direction of the development of this field from the perspective of reducing complications, so as to provide a reference for clinical work.

Growth disturbances of the temporomandibular Joint are characterized by mandibular asymmetry, sometimes with secondary maxillar disturbances. Although the clinical symptoms are sometimes quite severe, patients usually have no pain. There are several growth disturbances, but in this article we discuss three particular causes of facial asymmetry, namely hemimandibular growth defects; overdevelopment, underdevelopment and neoplasms of the mandibular joint. Hemimandibular overdevelopment (hyperplasia) is a growth disorder characterized by progressive asymmetry of the mandibula. Hemimandibular hypoplasia, on the other hand, is a growth disorder involving underdevelopment of the condyle mandibulae due to impingement of the growth center and ankylosing. A pronounced asymmetrical face can cause aesthetic problems and always requires diagnostics, because in addition to the hyperplasia and hypoplasia mentioned above, other causes can explain the asymmetry such as, for example, an osteoarthritis or even a tumor emanating from the base of the skull, mandibula or soft tissues.

Background: Orofacial trauma can encompass, isolated or not, several anatomical regions, namely facial, dental and temporomandibular joint (TMJ), one of the most complex joints in the human body. Evidence-based knowledge in the field of TMJ trauma and in temporomandibular joint disorders (TMD) diagnosis and treatment, provides the necessary data for medico-legal assessment., Objective: The aim of this study is to bring up epidemiological data referring to TMJ injuries and sequelae, in order to present a medico-legal approach of TMJ disability., Methods: An observational longitudinal exploratory study was performed in the database of the National Institute of Legal Medicine and Forensic Sciences, Portugal, between 2000 and 2017, regarding inclusion and exclusion criteria.Statistical significance was set as P‹0.05, Fisher's exact test, Binomial test and Goodman and Kruskal's test were used., Results: Post-traumatic orofacial reports (n = 2622) included 234 TMJ-injury and 149 TMJ-sequelae.Epidemiological data was presented regarding age,gender, professional status and etiology. There was a statistically significant association between TMJ injury and TMJ sequela, despite a weak relation (ƛ = 0.170). No statistically significant association was identified between TMJ-injury/TMJ-sequelae and the professional status, etiology., Conclusion: The TMJ sequela group is smaller than the TMJ-injury, reflecting that 2/3 of the injuries have been cured without a monetary compensation value and without Health costs. The association between TMJ injury and TMJ sequelae reinforces the necessity of preventive measures in TMJ trauma, namely in physical violence context and in medico-legal impairment., (Copyright © 2021 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.)

Background: Temporomandibular joint (TMJ) arthritis and involvement is commonly seen in Juvenile Idiopathic Arthritis (JIA). Therapy includes conservative measures, but also includes intraarticular corticosteroid injections (IASI) and systemic immunosuppressive therapy. Despite aggressive medical therapy, some patients develop arthritic changes and frank TMJ ankylosis that can result in persistent pain and limitation in range of motion (ROM). A surgical option is prosthetic TMJ replacement with concurrent correction of dentofacial deformities, which can be performed simultaneously. The objective of this study was to evaluate the outcomes of prosthetic TMJ replacement in a cohort of adolescent females with JIA and severe TMJ involvement., Methods: This is a retrospective case series that took place at one tertiary care center. Patients with a diagnosis of JIA who also underwent alloplastic TMJ replacement were identified through electronic medical record system (EMR) and reviewed. Chart review included analysis of all documents in the EMR, including demographic data, JIA history, surgical complications, ROM of TMJ measured by maximal incisal opening in millimeters (mm) and TMJ pain scores (4-point Likert scale: none, mild, moderate, severe) obtained pre- and postoperatively., Results: Five female patients, ages 15-17 year when TMJ replacement was performed, had nine total joints replaced with a post-operative follow-up period of 12-30 months. All patients had polyarticular, seronegative JIA and were treated with IASI and multiple immunosuppressive therapies without resolution of TMJ symptoms. One patient had bilateral TMJ ankylosis. Three of the five patients demonstrated significant dentofacial deformities, and all underwent simultaneous or staged orthognathic surgery. All patients had improvement in TMJ pain with most (80%) reporting no pain, and all had similar or improved ROM of their TMJ postoperatively. There was one delayed postoperative infection with Cutibacterium Acnes that presented 15 months after surgery and required removal and reimplantation of prosthesis., Conclusion: The sequelae of TMJ arthritis and involvement from JIA in the adolescent population can be difficult to treat. Current medical therapy can be successful, however, in select cases that develop chronic changes in the TMJ despite extensive medical therapy, early results show that prosthetic joint replacement maybe a reasonable surgical option. With prosthetic joint replacement pain levels were reduced and range of motion was maintained or improved for all patients.

Interleukin (IL)‑1β is a key promotor in the pathogenesis of temporomandibular joint osteoarthritis. Differentiation of stem cells to cartilage is a crucial repair mechanism of articular cartilage damage, and IL‑1β has been reported to impede the differentiation by upregulating the secretion of IL‑6, an important inflammatory factor. Long non‑coding RNAs (lncRNAs) regulate a number of physiological and pathological processes, but whether lncRNA AK094629 contributes to the IL‑1β mediated induction of inflammation remains unclear. Therefore, the aim of the present study was to investigate the effect of AK094629 on IL‑1β‑induced IL‑6 expression in synovial‑derived mesenchymal stem cells (SMSCs) of the temporomandibular joints. The results of the present study demonstrated that the expression of AK094629 in the synovial tissue of patients with osteoarthritis was positively correlated with IL‑1β. In addition, IL‑1β upregulated the expression of AK094629 in the SMSCs in vitro, and AK094629 knockdown inhibited the IL‑1β mediated upregulation of IL‑6. The present study also demonstrated that AK094629 knockdown downregulated the expression of the mitogen‑activated protein kinase kinase kinase 4 (MAP3K4), which is upregulated by IL‑1β, whereas knockdown of MAP3K4 did not affect the expression of AK094629, but reversed the upregulation of IL‑6 in SMSCs. In conclusion, AK094629 knockdown attenuated the expression of IL‑1β‑regulated IL‑6 in the SMSCs of the temporomandibular joint by inhibiting MAP3K4. Therefore, AK094629 may be a potential novel therapeutic target for the treatment of temporomandibular joint osteoarthritis.

Background and Purpose: This retrospective study evaluates the safety and effectiveness of preoperative endovascular embolization in patients who underwent temporomandibular joint (TMJ) replacement surgery., Material and Methods: We included all patients treated with preoperative embolization of the internal maxillary artery (IMAX) between June 2016 and January 2019. All patients were treated by the same surgeon using standard surgical approaches and procedures. Periprocedural adverse events, blood loss during surgery and clinical follow-up are reported., Results: Fourteen patients (12 females, median age 32.5) were treated with 21 embolizations of the IMAX (bilateral embolizations in seven patients) prior to TMJ replacement surgery with prosthetic joints (TMJ Concepts prostheses). Seven patients presented with TMJ ankylosis/degenerative joint disease/post-trauma deformity, four patients with Idiopathic Condylar Resorption and resultant mandibular displacement/hypoplasia, two patients with rheumatoid arthritis-associated condylar degeneration and resultant loss of mandibular position, and 1 patient being re-reconstructed following management of a prosthetic joint infection. Seven patients underwent bilateral prosthetic joint replacement. Four patients underwent additional facial skeletal surgery as part of their treatment. The mean blood volume loss during TMJ surgery was approximately 370 cc (range 100-800 cc). Joint space-specific blood loss was not recorded, but, as per the surgical team, was significantly decreased when compared to non-embolized patients. There were no intra-procedural complications. The median clinical follow-up was 3.5 months (range 1-24 months). The modified Rankin scale (mRS) was 0 before the procedure and at last clinical follow-up in all patients. After TMJ surgery, three patients reported paresthesia of the trigeminal nerve likely related to the residual condyle resection and two patients had mild facial nerve weakness (Temporal and/or Marginal Mandibular branch) related to the surgical exposures., Conclusion: Endovascular preoperative embolization of the IMAX is feasible, safe and likely effective in reducing blood volume loss in complex TMJ replacement surgery.

Objectives: Clinical and experimental studies show that the etiology of traumatic temporomandibular joint (TMJ) fibrous ankylosis and bony ankylosis are associated with the severity of trauma. However, how the injury severity affects the tissue differentiation is not clear. We tested the hypothesis that angiogenesis affects the outcomes of TMJ trauma, and that enhanced neovascularization after severe TMJ trauma would promote the development of bony ankylosis., Methods: Bilateral condylar sagittal fracture and discectomy were performed for each sheep, with the glenoid fossa receiving either severe trauma to induce bony ankylosis or minor trauma to induce fibrous ankylosis. At days 7, 14, 28, and 56 after surgery, total RNA was extracted from the ankylosed callus. Temporal gene expressions of several molecules functionally important for blood vessel formation were studied by real-time PCR., Results: Histological examination revealed a prolonged hematoma phase and a lack of cartilage formation in fibrous ankylosis. mRNA expression levels of HIF-1α, VEGF, VEGFR2, SDF1, Ang1, Tie2, vWF, CYR61, FGF2, TIMP1, MMP2, and MMP9 were distinctly lower in fibrous ankylosis compared with bony ankylosis at several time points., Conclusions: Our study indicates that inhibition of angiogenesis after TMJ trauma might be a promising strategy for preventing bony ankylosis in the future., (Copyright © 2019 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.)

Background: Concern over the impact of playing wind instruments on the stomatognathic system has increased in the last few decades with many health practitioners attending to an increasing number of musical instrument players., Objective: This study assessed the effects of playing wind musical instruments on the temporomandibular joints (TMJ) of male Nigerian adults., Methods: This was a descriptive cross-sectional study which was conducted in the Dental clinic of Aminu Kano Teaching Hospital, Kano. Fifty male Wind Instrument Players (WIPs) were recruited for the study and compared with fifty non-Wind Instrument Players (non-WIPs) of the same age, gender and environment. The temporomandibular dysfunction was assessed in both groups using Helkimo index. Reliability test demonstrated an excellent intra-rater correlation (Cronbach's Alpha; 0.98). Data was analyzed using SPSS version 17 and statistical significance set at p<0.05., Results: The majority of participants in the WIP group (32, 64%) had mild to severe anamnestic dysfunction score compared with (20, 40.0%) in the non-WIP group. The difference between the two groups was statistically significant (p<0.05). The class of instruments played, number of years and frequency of play had a significant negative impact on the anamnestic dysfunction of the TMJ with statistically significant difference (p<0.05). No statistically significant differences in clinical dysfunction scores were observed in the two groups (p>0.05)., Conclusions: Playing wind instruments including the class of instrument, number of years and frequency of playing affected the TMJ function, especially anamnesis. Clinical dysfunction was not affected by playing wind instruments.

Introduction: Intermaxillary fixation (IMF) is a classic method for immobilization of the mandible after mandibular fractures and corrective surgery. However, it has been suggested that IMF may be a risk for developing temporomandibular joint (TMJ)-related symptoms, especially when applied for longer periods., Objective: To evaluate the clinical function of TMJs and masticatory muscles 10-15 years after mandibular setback surgery and subsequent six weeks of IMF. The patients' self-reported TMJ and masticatory muscle symptoms were also addressed., Methodology: Thirty-six patients (24 women and 12 men) treated with intraoral vertical ramus osteotomies and subsequent six weeks of IMF, underwent a clinical examination of TMJs and masticatory muscles 10-15 years after surgery and completed a five-item structured questionnaire reporting subjective TMJ-related symptoms. Mean age by the time of clinical examination was 34.1 years (range 27.2-59.8 years). The clinical outcome was registered according to the Helkimo clinical dysfunction index. Descriptive and bivariate statistics were performed and level of significance was set to 5%., Results: Mean maximum unassisted mouth opening 10-15 years after surgery was 50.1 mm, (range 38-70 mm, SE 1.2), statistically significantly greater in men compared to women (p=0.004). Mean Helkimo dysfunction group was 1.5 (range 1-3, SE 0.10). Eighty-one percent experienced pain on palpation in either the masseter muscle, temporal muscle or both, and 31% experienced pain when moving the mandible in one or more directions. Thirty-one percent reported pain from palpating the TMJs. In the questionnaire, none reported to have pain during chewing or mouth opening on a weekly or daily basis, but 22% reported difficulties with maximum opening of the mouth., Conclusion: Ten to fifteen years after mandibular setback surgery the patient's mandibular range of movement is good. Despite clinically recognizable symptoms, few patients reported having TMJ- or masticatory muscle-related symptoms in their daily life.

Background: Diagnostic criteria reported in the expanded taxonomy for temporomandibular disorders include a standardised clinical examination and diagnosis (DC/TMD 3.B) of temporomandibular joint (TMJ) damage in patients with juvenile idiopathic arthritis (JIA); however, their validity is unknown., Objectives: To assess the validity of DC/TMD 3.B for the identification of TMJ damage in JIA-patients, using magnetic resonance imaging (MRI) as gold standard, and to investigate the relation between clinical findings and TMJ damage., Methods: Fifty consecutive JIA patients (9-16 years) were recruited. DC/TMD 3.B were compared with TMJs MRI (100 TMJs) performed maximum at 1 month from the visit. The severity of TMJ damage was scored in four grades. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), logistic regression models with odds ratio of DC/TMD 3.B and clinical findings respect to MRI were calculated., Results: The DC/TMD 3.B were inadequate in the identification of TMJ damage (sensitivity = 0.15, specificity = 0.92, PPV = 0.85, NPV = 0.28, P = 0.350). Chin deviation and TMJ crepitus were associated with worse TMJ damage (P = 0.006; P = 0.034). Reduced mouth opening (OR = 3.91, P = 0.039) and chin deviation (OR = 13.7, P = 0.014) were associated with the presence of TMJ damage. Combining "pain" (history of pain, TMJ pain, pain during movements) and "function" (TMJ crepitus, reduced mouth opening, chin deviation) clinical findings, the sensitivity and the specificity were 0.88 and 0.54., Conclusion: DC/TMD 3.B present a low sensitivity to diagnose TMJ damage. Chin deviation, reduced mouth opening and TMJ crepitus are associated with TMJ damage. We suggest combining "pain" and "function" findings for the evaluation of TMJ damage in JIA patients., (© 2019 John Wiley & Sons Ltd.)

Background: Adolescent internal condylar resorption (AICR) is a temporomandibular joint (TMJ) pathology that develops predominately in teenage females during pubertal growth (onset between ages 11 and 15 years), with a distinct clinical, radiographic, and magnetic resonance imaging (MRI) presentation. Clinical and imaging presentation: The condition usually occurs bilaterally with: (1) Progressive retrusion of the mandible; (2) High occlusal plane angle facial morphology; (3) Worsening Class II occlusion; and (4) TMJ symptoms such as pain, headaches, noises, etc. MRI imaging demonstrates decreased condylar head size and anterior disc displacement. Treatment protocol: AICR can be successfully treated when the condyles and discs are salvageable with the following surgical protocol: (1) Removal of bilaminar tissue surrounding the condyle; (2) Reposition the disc with the Mitek anchor technique; and (3) Orthognathic surgery to advance the maxillo-mandibular complex in a counterclockwise direction., Conclusion: AICR can be successfully treated using the specific protocol presented herein to provide stable and predictable outcomes.

Tissue engineering potentially offers new treatments for disorders of the temporomandibular joint which frequently afflict patients. Damage or disease in this area adversely affects masticatory function and speaking, reducing patients' quality of life. Effective treatment options for patients suffering from severe temporomandibular joint disorders are in high demand because surgical options are restricted to removal of damaged tissue or complete replacement of the joint with prosthetics. Tissue engineering approaches for the temporomandibular joint are a promising alternative to the limited clinical treatment options. However, tissue engineering is still a developing field and only in its formative years for the temporomandibular joint. This review outlines the anatomical and physiological characteristics of the temporomandibular joint, clinical management of temporomandibular joint disorder, and current perspectives in the tissue engineering approach for the temporomandibular joint disorder. The tissue engineering perspectives have been categorized according to the primary structures of the temporomandibular joint: the disc, the mandibular condyle, and the glenoid fossa. In each section, contemporary approaches in cellularization, growth factor selection, and scaffold fabrication strategies are reviewed in detail along with their achievements and challenges., (© 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

From an anatomic and functional point of view, the stomatognathic system and the upper cervical spine are closely connected. Together with the complex neuromuscular relationships, this generates an important field of cooperation between dentists and orthopedics. The aim of this case report was to demonstrate the improvements of temporomandibular joint (TMJ) function after orthopedic surgery in case of a patient with idiopathic scoliosis. A 15-year-old female patient who had adolescent idiopathic scoliosis was surgically treated in 2016. Functional analyses of the TMJ were performed before the day of the operation and 10 months after the surgery. For detection, an ultrasound-based testing machine was used. The analyses of the data showed that almost all ranges of motions (ROM) were improved. The deviation to the right side was reduced from 8 mm to 2 mm during mouth opening. The patient had limited left lateral movement before the operation, however, after 10 months following the operation, there were free motions towards both sides. The originally asymmetrical protrusion became almost completely symmetrical. Regarding the functions of the TMJ, the surgery was successful; this in itself had a beneficial effect on the range and the path of the mandibular movements without any other treatment. These improved functions are indirect evidences for the connection of the function of the spine and TMJ. Orv Hetil. 2018; 159(50): 2144-2149.

This article summarizes the temporomandibular joint (TMJ) rheumatoid arthritis (RA). In particular, TMJ-RAs are collected in a short summary by examining every aspect of RA; the treatment of TMJ-RA is also briefly mentioned. TMJ-RA is usually characterized by bilateral pain, tenderness and swelling, and limitation of jaw movements. Due to these symptoms, patients may experience limitations in their daily activities, such as eating, speaking, and swallowing. MEDLINE and Scopus databases were searched electronically using the terms "temporomandibular joint" and "rheumatoid arthritis." The electronic search includes articles or books published in English and December 2017. A search of the reference lists of selected articles was also carried out., Competing Interests: There are no conflicts of interest

Craniofacial secondary cartilages of the mandibular condyle and temporomandibular joint (TMJ) eminence grow in response to the local mechanical environment. The intervening TMJ disc distributes normal loads over the cartilage surfaces and provides lubrication. A better understanding of the mechanical environment and its effects on growth, development, and degeneration of the TMJ may improve treatments aimed at modifying jaw growth and preventing or reversing degenerative joint disease (DJD). This review highlights data recorded in human subjects and from computer modeling that elucidate the role of mechanics in TMJ ontogeny. Presented data provide an approximation of the age-related changes in jaw-loading behaviors and TMJ contact mechanics. The cells of the mandibular condyle, eminence, and disc respond to the mechanical environment associated with behaviors and ultimately determine the TMJ components' mature morphologies and susceptibility to precocious development of DJD compared to postcranial joints. The TMJ disc may be especially prone to degenerative change due to its avascularity and steep oxygen and glucose gradients consequent to high cell density and rate of nutrient consumption, as well as low solute diffusivities. The combined effects of strain-related hypoxia and limited glucose concentrations dramatically affect synthesis of the extracellular matrix (ECM), which limit repair capabilities. Magnitude and frequency of jaw loading influence this localized in situ environment, including stem and fibrocartilage cell chemistry, as well as the rate of ECM mechanical fatigue. Key in vivo measurements to characterize the mechanical environment include the concentration of work input to articulating tissues, known as energy density, and the percentage of time that muscles are used to load the jaws out of a total recording time, known as duty factor. Combining these measurements into a mechanobehavioral score and linking these to results of computer models of strain-regulated biochemical events may elucidate the mechanisms responsible for growth, maintenance, and deterioration of TMJ tissues.

Background: Arthritis involving the temporomandibular joint (TMJ) complicates 40 - 96% of cases of juvenile idiopathic arthritis (JIA), potentially leading to devastating changes to form and function. Optimal evaluation and management of this joint remains a matter of ongoing discussion., Methods: We performed a PubMed search for all articles with keywords "temporomandibular" and "arthritis", covering the dates 2002 through February 28, 2018. A separate PubMed search was performed for all articles with keywords "temporomandibular joint", "arthritis", and "treatment" covering the same dates., Findings: The TMJ is a particularly challenging joint to assess, both clinically and with imaging studies. Clinical assessment of the TMJ is hampered by the low sensitivity of joint pain as well as the absence of physical exam findings early in the disease process. As with all joints, plain radiography and computed tomography only detect arthritic sequelae. Additionally, there is mixed data on the sensitivity of ultrasound, leaving magnetic resonance imaging (MRI) as the optimal diagnostic modality. However, several recent studies have shown that non-arthritic children can have subtle findings on MRI consistent with TMJ arthritis, such as joint effusion and contrast enhancement. Consequently, there has been an intense effort to identify features that can be used to differentiate mild TMJ arthritis from normal TMJs, such as the ratio of the enhancement within the TMJ itself compared to the enhancement in surrounding musculature. With respect to treatment of TMJ arthritis, there is minimal prospective data on medical therapy of this complicated joint. Retrospective studies have suggested that the response to medical therapy of the TMJ may lag behind that of other joints, prompting use of intraarticular (IA) therapy. Although most studies have shown short-term effectiveness of corticosteroids, the long-term safety of this therapy on local growth as well as on the development of IA heterotopic bone have prompted recommendations to limit use of IA corticosteroids. Severe TMJ disease from JIA can also be managed non-operatively with splints in a growing child, as well as with surgery., Conclusion: In this review, we summarize literature on the diagnosis and management of TMJ arthritis in JIA and suggest a diagnostic and therapeutic algorithm for children with refractory TMJ arthritis.

Osteoarthritis induced by compressive mechanical force is characterized by decreased chondrocyte proliferation and degradation of the ECM. To examine underlying mechanisms of the pathological changes of mandibular cartilage induced by compressive mechanical force, an established animal model was used to examine Wnt signaling activation by glycogen synthase kinase-3 beta (GSK3β) inhibitor 6-Bromoindirubin-3'-oxime (BIO) injection in vivo. Histological changes in mandibular cartilage were assessed via hematoxylin & eosin (HE), masson, and alcian blue staining. Immunohistochemistry and real-time PCR were performed to evaluate activation of the Wnt signaling pathway and chondrocytes proliferation markers. Chondrocytes apoptosis was examined by TUNEL staining. During the compressive mechanical force loading-mediated process, Wnt signaling was largely inhibited, which showed the inhibited expression of β-catenin and the increased expression of GSK-3β. The expression of chondrocytes proliferation markers Ki67, and proliferating cell nuclear antigen (PCNA) also decreased. With BIO injection, the Wnt signaling was restored and the proliferation of mandibular chondrocytes was also increased in the late stage (7 days) of compressive mechanical force loading. Finally, the decreasing mandibular cartilage thickness, the degradation of extracellular matrix, and the erosion of bone trabecula were subsequently restored. Also, the changes of extracellular matrix markers such as collagen II and collagen X, matrix metalloproteases, and inflammatory cytokines were reversed followed by the injection of BIO. In summary, compressive mechanical force decreased endogenously Wnt signaling, leading to impaired proliferation in chondrocytes and degradation in cartilage matrix. Restoration of Wnt signaling largely recovered the proliferation defects and alleviated the pathological changes of mandibular cartilage. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:1228-1237, 2018., (© 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.)

Background: The aim of this study was to assess the influence of protraction facemask (PFM) on temporomandibular joint (TMJ) of skeletal Class III malocclusion patients., Method: Literature searches were carried out electronically in five English and three Chinese databases (Cochrane Database of Systematic Reviews, the Cochrane Central Register of Controlled Trials, PubMed, Embase, MEDLINE (via Ovid), Chinese Biomedical Literature Database, China National Knowledge Infrastructure, and VIP Database). The date of the most recent search was 22 March 2017. Randomized controlled trials, controlled clinical trials, cohort studies, and before-after studies comparing the effect of PFM and other treatments on TMJ were included. The data were collected and extracted by three authors. The risk of bias in the RCTs was assessed in accordance with the Cochrane Handbook for Systematic Reviews of Interventions. For the nonrandomized studies, the risk of bias was judged with Newcastle-Ottawa Scale., Results: For the 261 articles identified, 13 studies with 522 participants were included for the final qualitative analysis. Three studies were graded as high value of evidence, while seven studies and the other three studies were graded as moderate value and low value respectively. According to the available evidence, PFM contributed to the significant increase of CondAx-SBL and the significant decrease of CondAx-ML. Thin-plate spline (TPS) analysis showed a horizontal compression in condyles. Condyles tended to move superiorly and posteriorly. Concerning the occurrence of temporomandibular disorders (TMD), PFM was not involved in aggravating TMJ symptoms and signs., Conclusions: Clinical evidence suggests that PFM might contribute to the morphologic adaptation of TMJs and displacement of condyles, and PFM may well be not a risk factor for the development of TMD.

Purpose: Mandibular advancement devices are commonly used in the treatment of patients with mild to moderate obstructive sleep apnea (OSA). Designed to maintain the mandible in forced protrusion while being worn, mandibular advancement devices (MADs) are intended to increase the upper airway during sleep, thereby reducing OSA symptoms. Depending on the extent of mandibular protrusion, side effects including temporomandibular joint dysfunction are frequently reported. These are likely to reduce overall treatment success by affecting therapeutic adherence., Material and Methods: To investigate the biomechanical effects of an MAD on the temporomandibular joints, we used a biomechanical model of the human masticatory system. Alterations to the model were applied to mimic the effects of a titratable duoblock MAD. The extent of mandibular protrusion was simulated up to 10 mm in steps of 1 mm. Compression and shear stresses on the temporomandibular structures were predicted during an open-close maneuver and in neutral position., Results: As the extent of mandibular advancement increased, the mandibular condyle migrated anteriorly until passing the articular tubercle. Stress on the temporomandibular joint structures did not considerably increase in rest whatever the extent of mandibular advancement. However, closure of the jaw required extra muscle force as mandibular advancement increased., Conclusion: Results from this study suggest that temporomandibular dysfunction following MAD wearing might be related to altered muscle dynamics rather than changes due to increased stress in the temporomandibular joint itself., (Copyright © 2017 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.)

Background: Headache is a common complaint in all age groups and is a frequent cause of medical consultations and hospitalization., Objectives: The aim of this study was to evaluate the prevalence of bite and non-bite parafunctions as well as the signs and symptoms of temporomandibular disorder (TMD) in adolescents presenting with primary headaches., Material and Methods: Parents of adolescents presented with headaches to the Department of Developmental Neurology within a 12-month period were asked to complete a questionnaire developed by the authors of this study. Of the 1000 patients evaluated, 19 females and 21 males, aged 13 to 17 years, met the inclusion criterion - a confirmed clinical diagnosis of migraine or a tension headache according to the International Classification of Headache Disorders, 2nd edition. The diagnostic algorithm of the study group consisted of a full medical history, an assessment of the occurrence of bite habits and a physical examination based on the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD)., Results: Bite and non-bite parafunctions were found in 36 of the study group patients. A significant difference (p = 0.0003) between the number of bite parafunctions and non-bite parafunctions was found in females but not in males. However, bite parafunctions were more frequent in boys compared to girls (p = 0.01)., Conclusions: Our findings suggest that it may be useful for pediatricians and neurologists to include TMD dysfunctions as a part of a standard examination of adolescents presenting with persistent headaches.

Background: Up to 80% of children with juvenile idiopathic arthritis (JIA) develop arthritis involving their temporomandibular joint (TMJ). Recent studies have questioned the sensitivity of an abnormal MRI in the diagnosis of active arthritis., Methods: 122 children without arthritis undergoing contrast MRI of the head were prospectively consented to undergo a simultaneous contrast MRI of their TMJs. As a comparison point, the initial MRI of the TMJ of 35 newly diagnosed children with JIA were retrospectively scored. The presence and size of effusion and contrast enhancement were measured in the left TMJ in all subjects., Results: 62/122 (51%) controls compared to only 10/35 JIA (29%) patients had an effusion (p = 0.022). Contrast enhancement was present in ≥97% of both groups, although the size of the enhancement was, on average, 0.2 mm larger in controls (1.1 ± 0.24 vs 0.88 ± 0.27 mm, p <  0.001). Among JIA patients, the size of the enhancement correlated inversely with disease duration (r = - 0.475, p = 0.005). Chronic changes were present in none of the controls versus 2/35 (5.5%) of the JIA patients (p = 0.049)., Conclusion: Findings consistent with minimally active TMJ arthritis appear to be equally likely in children with JIA as compared to non-inflamed controls, while this and other studies confirm that chronic changes are specific to JIA. Thus, small amounts of effusion or contrast enhancement, in the absence of chronic changes, should be interpreted with caution.

Objective of the study was to evaluate the clinical status of the masticatory system in young adults with full permanent dentition and no stomatognathic system complaints. The study involved 186 randomly selected people with full dental arches with normal occlusal conditions corresponding to Angle's Class I aged 18 - 21 years with an average age of 19 years. Subjects were clinically examined and temporomandibular joint (TMJ) vibrations were recorded during open-wide and close movements using BioJVA. Then, patients were categorized into groups according to Piper's classification system. The TMJs of the subjects were categorized according to the values of the vibration energy and the Piper protocol. This detected 33.4% of the joints with loosened ligaments, subluxation in 8.28%, initial signs of disc dysfunction in 5.08% and disc displacement without locking in 1.6 %. Median frequency differed significantly (p < 0.05) between the group of subjects with initial signs of TMJ dysfunction and other groups. Peak Frequency differed significantly (p < 0.05) between the healthy joints and those with TMJ subluxation. In this group of young healthy people, the majority of study joints generated small vibrations. However, a subset of people manifested higher vibrations that may indicate an early stage of TMJ dysfunction. Median Frequency was an important parameter for detecting initial symptoms of TMJ dysfunction. Peak Frequency was an important characteristic parameter for detecting TMJ subluxation., Competing Interests: Competing Interests: The authors have declared that no competing interest exists.

Objective: Radiation-induced trismus, which is resulted from damage of the temporomandibular joint (TMJ), is one of the common late complications in nasopharyngeal carcinoma (NPC) patients after radical radiotherapy. This study investigated the radiation induced TMJ changes using ultrasonography in post-radiotherapy (post-RT) NPC patients., Methods: 114 NPC patients, who had completed radiotherapy for more than 4 years, were assessed with the maximum incisal distance (MID) and ultrasonography examination of TMJ from which the maximum disc thickness of the joint disc, the condyle irregularity (CI), joint vascularity (JV) and relative muscle echogenicity were assessed. The same assessments were conducted on 100 age-matched normal subjects. The results were compared among the patients with and without trismus, and the control group. The mean doses to the TMJ were estimated using the treatment planning system and their correlation with the magnitude of MID was also investigated by the Pearson correlation test., Results: 39 out of the 114 patients (34.2%) presented with trismus. The average mean TMJ for all patients was 41.4 Gy, in which patients with trismus was significantly higher than patients without trismus (p = 0.017). The mean MID of patient group was significantly lower than control group (p < 0.001). The mean maximum disc thickness of the patient group was significantly smaller than the control group, whereas the mean CI and JV were significantly higher in patient group. For relative muscle echogenicity, a higher percentage of the control group showed hyperechoic pterygoid muscle than the patient group. The mean total dose to the TMJs for the patient group was 41.4 Gy and there was a mild negative correlation between the mean TMJ dose and the MID (r = -350)., Conclusion: The TMJ in post-RT NPC patients showed reduction of disc thickness, increase of CI and JV. Patients with trismus demonstrated thinner disc thickness and higher JV than those without trismus. Advances in knowledge: Our study was the first cross-sectional comparative study involving over 100 patients and normal subjects that used ultrasound to assess the radiation-induced morphological changes of TMJ. Post-RT TMJ changes characterized by the reduction of disc thickness, increase of CI and JV were detected in the NPC patients. The parameters used in this study were able to detect the morphological differences between the patient group and control group, and therefore can be effectively used to monitor the TMJ condition of post-RT NPC patients.

Osteoarthritis is the most common joint disease affecting roughly one sixth of the human population. It is also the most common arthritis affecting the temporomandibular joint, often leading to severe pain and the inability to masticate. Animal models are essential to investigate the disease in part because they lend themselves to genetic manipulation and various treatments and also because of the lack of availability of human specimens from various stages of the disease. The wide range of osteoarthritis models alone are a proof of its multifactorial origin. Manipulation of collagen, cytokine, matrix metalloproteinase and small leucine-rich repeat proteoglycan genes can all have an effect on the development and persistence of arthritis. Surgical models also exist, highlighting the importance of normal anatomy and trauma. Here we review the English literature of murine models of temporomandibular joint arthritis with special attention to the genetic and molecular background of osteoarthritis., (Copyright © 2016 Société française de rhumatologie. Published by Elsevier SAS. All rights reserved.)

Objective: Juvenile idiopathic arthritis (JIA) frequently affects the temporomandibular joints (TMJs) and is often undetected by history, examination, and plain imaging. Qualitative assessment of gadolinium-enhanced magnetic resonance images (MRIs) is currently the standard for diagnosis of TMJ synovitis associated with JIA. The purpose of this study is to apply a quantitative analysis of synovial enhancement to MRIs of patients with and without JIA to establish a disease threshold and sensitivity and specificity for the technique., Methods: This is a retrospective case-control study of children (age ≤16 years) who had MRIs with gadolinium including the TMJs. Subjects were divided into a JIA group and a control group. From a coronal T1-weighted image, a ratio (enhancement ratio [ER]) of the average pixel intensity within three 0.2-mm 2 regions of interest (ROIs) in the TMJ synovium to that of a 50-mm 2 ROI of the longus capitis muscle was calculated. Receiver operating characteristic curves were used to determine the sensitivity and specificity. The inter- and intraexaminer reliability was evaluated with Bland-Altman plots and 2-way mixed, absolute agreement intraclass correlation coefficients., Results: There were 187 and 142 TMJs included in the JIA and control groups, respectively. An ER threshold of 1.55 had a sensitivity and specificity for detecting synovitis of 91% and 96%, respectively. The inter- and intraexaminer reliability was excellent., Conclusion: Calculating a ratio of pixel intensity between the TMJ synovium and the longus capitis muscle is a reliable way to quantify synovial enhancement. An ER of 1.55 differentiates normal TMJs from those affected by inflammatory arthritis., (© 2016, American College of Rheumatology.)

Purpose: Traumatic dislocation of the mandibular condyle into the middle cranial fossa is an extremely rare complication of maxillofacial injury. Management case of the of dislocation of the mandibular condyle complicated by bilateral temporomandibular joint ankylosis is presented., Materials and Methods: A 17year old male patient presented to the outpatient clinic complaining of inability to open his mouth following a motor vehicle accident 6 months prior. Examination revealed bilateral TMJ ankylosis following left condylar head fracture and dislocation of the right condylar head into the middle cranial fossa. Bilateral total alloplastic TMJ reconstruction was performed., Results: MIO at a three-year follow-up was 35mm, occlusion was intact and the patient was functioning optimally., (Copyright © 2016 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.)

Introduction: Dislocation of the mandibular condyle into the middle cranial fossa after a trauma is a rare event. The lack of appropriate treatment can lead to ankylosis of the temporomandibular joint (TMJ). We report about a case of TMJ ankylosis following intracranial dislocation of the mandibular condyle through the roof of the articular fossa., Case Report: A 9-year-old patient was referred for a severe limitation of mouth opening that began progressively one year before. A history of chin injury due to an accidental fall was found. Preoperative CT scan showed a TMJ ankylosis on the right side combined with a dislocation of the mandibular condyle into the middle cranial fossa. Treatment consisted in an intracranial resection of the mandibular condyle, partial removal of the ankylosis block and TMJ arthroplasty., Discussion: Our case is the second case of TMJ ankylosis following intracranial dislocation of the mandibular condyle and treated with arthroplasty alone published in the English literature. There is no consensus regarding the pathophysiology of TMJ ankylosis and regarding the attitude towards the ankylosis block. In our case, no recurrence was noticed after a one-year follow-up. An interdisciplinary approach is needed, including maxillofacial surgeon, neurosurgeon, physiotherapist and orthodontist., (Copyright © 2016 Elsevier Masson SAS. All rights reserved.)

Purpose: Most of the reports on instrumentalists' experiences of temporomandibular disorders (TMD) have been reported not by clinical examinations but by subjective questionnaires. The aim of this study was to investigate the clinical signs and subjective symptoms of TMD in a large number of instrumentalists objectively., Materials and Methods: A total of 739 musicians from a diverse range of instrument groups completed a TMD questionnaire. Among those who reported at least one symptom of TMD, 71 volunteers underwent clinical examinations and radiography for diag-nosis., Results: Overall, 453 participants (61.3%) reported having one or more symptoms of TMD. The most frequently reported symptom was a clicking or popping sound, followed by temporomandibular joint (TMJ) pain, muscle pain, crepitus, and mouth opening limitations. Compared with lower-string instrumentalists, a clicking or popping sound was about 1.8 and 2 times more frequent in woodwind and brass instrumentalists, respectively. TMJ pain was about 3.2, 2.8, and 3.2 times more frequent in upper-string, woodwind, and brass instrumentalists, respectively. Muscle pain was about 1.5 times more frequent in instrumentalists with an elevated arm position than in those with a neutral arm position. The most frequent diagnosis was myalgia or myofascial pain (MFP), followed by disc displacement with reduction. Myalgia or MFP was 4.6 times more frequent in those practicing for no less than 3.5 hours daily than in those practicing for less than 3.5 hours., Conclusion: The results indicate that playing instruments can play a contributory role in the development of TMD., Competing Interests: The authors have no financial conflicts of interest.

A prospective cohort study was performed to investigate concurrent and delayed temporomandibular joint (TMJ) injuries following different types of mandibular fracture using magnetic resonance imaging (MRI). One hundred adult male patients with a recent history of mandibular fracture were included. The patients were divided into five groups according to the site of fracture. The patients underwent MRI within 10 days of the primary injury. The same clinical, radiographic, and MRI examinations were performed 5 years later. The aetiological factor of the mandibular fractures was a road traffic accident in all cases. The results of the study suggest that there is no direct correlation between TMJ pain and the presence of MRI changes. Patients who had a condylar fracture associated with a fracture of the angle or body could develop more TMJ damage on both sides. TMJs on the same side as the fractures could develop internal derangement as a result of the acute stage of the trauma and its delayed consequences. Trauma caused more delayed TMJ derangement on the non-fractured side than on the fractured side of the mandible. Disturbances of the TMJ on the side of the fracture develop during both the acute stage and follow-up., (Copyright © 2016 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.)

Acute traumatic temporomandibular joint disc displacement (ATDD) and its sequelae are not familiar for most surgeons. This study is to discuss its sequelae in cases without disc reduction after failed conservative treatment. From 2010 to 2015, 26 patients with 34 joints were included in the study. All patients had at least 3 months conservative treatment. Their maximal incisor opening (MIO) was measured during follow-ups and MRI examination was used to check the condylar bone degeneration. The mean follow-up for conservative treatment after admission was 8.69 months, the patients reached an average of 25.7 mm MIO. MRI showed condylar bone intact in 8 joints (23.5%), condylar surface bone destruction (Wilks IV, V stages) in 14 joints (41.2%), and severe bone resorption in 12 joints (35.3%). 15 patients with 23 joints were asked for surgical treatment after a mean conservative treatment of 5.4 months (3-12 months) to improve mouth opening and relieve chronic pain. 12 joints had total joint replacement (TJR). 11 joints had disc repositioning. Their mean MIO before operation was 19.8 mm and significantly improved to 33.9 mm after operation (p = 0.0000). ATDD may cause severe osteoarthritis or ankylosis. Disc repositioning and TJR could significantly improve MIO.

Spontaneous herniation of the condylar head into the external auditory canal (EAC) through the foramen of Huschke is extremely rare, with approximately 30 cases reported in the international literature. The typical presentation is a constellation of non-specific symptoms including otalgia, temporomandibular joint (TMJ) pain, malocclusion, otorrhea, tinnitus while chewing, and hearing loss. Clinical examination may reveal pain, granulation tissue in the EAC, or the exposed mandibular condyle with the mouth closed. With mouth opening, the tissue or exposed bone retracts anteriorly leaving an often normal-appearing EAC. Having the patient open and close the mouth while performing otoscopy will show the displacement of tissue, which is critical for diagnosis of the condition. Radiographic examination with a computed tomography scan typically reveals a discontinuous anterior wall of the EAC with visible soft tissue in the protruding in the EAC. A case of spontaneous TMJ herniation into the EAC in a 54-year-old male patient with a history of otalgia and malocclusion is reported here. Total joint replacement therapy for the treatment of this rare condition is reported, and its importance in providing a posterior mechanical stop to prevent joint relapse is discussed., (Copyright © 2016 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.)

Abnormal pressure is an important factor that contributes to bone adaptation in the temporomandibular joint (TMJ). We determined the effect of the mitogen-activated protein kinases (MAPK) pathway on the pressure-induced synovial metaplasia procedure for the TMJ, both in vitro and in vivo. Synovial fibroblasts (SFs) were exacted from rat TMJs and exposed to different hydrostatic pressures. The protein extracts were analyzed to determine the activation of ERK1/2, JNK, and p38. Surgical anterior disc displacement (ADD) was also performed on Japanese rabbits, and the proteins of TMJ were isolated to analyze pressure-induced MAPK activation after 1, 2, 4, and 8 weeks. The results showed that the activation of ERK1/2 and JNK in SFs significantly changed with increasing hydrostatic pressure, whereas p38 activation did not change. Moreover, p38 was activated in animals 1 week after surgical ADD. The levels of p38 gradually increased after 2 and 4 weeks, and then slightly decreased but remained higher than in the control 8 weeks after surgical ADD. Nevertheless, JNK was rarely activated after the ADD treatment. Our findings suggest the involvement of MAPK activation in the pressure-induced synovial metaplasia procedure with pressure loading in TMJ.

Objective: Necrotising otitis externa is associated with high morbidity and mortality rates. This study investigated whether temporomandibular joint involvement had any prognostic effect on the course of necrotising otitis externa in patients who had undergone hyperbaric oxygen therapy after failed medical and sometimes surgical therapy., Methods: A retrospective case series was conducted of patients in whom antibiotic treatment and surgery had failed, who had been hospitalised for further treatment and hyperbaric oxygen therapy., Results: Twenty-three patients with necrotising otitis externa were identified. The temporomandibular joint was involved in four patients (17 per cent); these patients showed a constant gradual improvement in C-reactive protein and were eventually discharged free of disease, except one patient who was lost to follow up. Four patients (16 per cent) without temporomandibular joint involvement died within 90 days of discharge, while all patients with temporomandibular joint involvement were alive. Three patients (13 per cent) without temporomandibular joint involvement needed recurrent hospitalisation including further hyperbaric oxygen therapy; no patients with temporomandibular joint involvement required such treatment., Conclusion: Patients with temporomandibular joint involvement had lower rates of recurrent disease and no mortality. Therefore, we suggest considering temporomandibular joint involvement as a positive prognostic factor in necrotising otitis externa management.

Juvenile idiopathic arthritis is the most common inflammatory rheumatic disease of childhood and represents a series of chronic inflammatory arthritides of unknown cause. Involvement of the temporomandibular joint has been reported in up to 87% of children with juvenile idiopathic arthritis when based on magnetic tomography imaging; it can be asymptomatic and may lead to severe long term complications. In this review a summary of the contemporary literature of imaging of the temporomandibular joint in children with juvenile idiopathic arthritis will be provided, including ultrasound which is a valuable method for guided joint injections, but does not necessarily allow detection of acute inflammation, cone beam computed tomography, which has emerged as a feasible and accurate low-dose alternative as compared to conventional computed tomography to detect destructive change, and magnetic resonance imaging which is considered the method of choice for assessing acute, inflammatory change, although the lack of normative standards remains a challenge in children., (Copyright © 2016 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.)

Purpose: Trauma is the leading cause of temporomandibular joint (TMJ) ankylosis, and the treatment of this condition poses a considerable challenge because of the high incidence of recurrence. The author hypothesized that a treatment of ankylosis based on pathogenesis would result in a better outcome and a lower recurrence rate., Materials and Methods: The author designed and implemented a prospective clinical study. The sample was composed of patients with TMJ ankylosis. The predictor variables were the affected side and patient age and gender. The outcome variable was maximal interincisal opening (outcome MIO). Descriptive and bivariate statistics were computed, and the P value was set at less than .05. The protocol consisted of the following steps: 1) perioperative indomethacin for 2 weeks; 2) the creation of a minimal gap of 5 to 10 mm; 3) ipsilateral coronoidectomy and (if required) contralateral coronoidectomy; 4) pterygomasseteric sling and temporalis muscle release; 5) interpositional dermis fat graft fixed to the condylar stump; 6) insertion of a suction drain; 7) immediate aggressive physiotherapy for at least 6 months; 8) regular long-term follow-up; and 9) delayed reconstruction using distraction osteogenesis., Results: The sample was composed of 14 patients (3 male and 11 female). Of these patients, 9 and 5 exhibited unilateral and bilateral ankylosis, respectively, and their ages ranged from 12 to 38 years (median, 18.5 yr). The follow-up period ranged from 24 to 48 months (mean, 32.5 months). Intraoperative MIOs ranged from 38 to 52 mm (mean, 45.7 mm). Postoperative MIOs exhibited a minor decrease in mouth opening (mean, 43.5 mm). The outcome MIOs ranged from 35 to 55 mm (mean, 43.5 mm). Of all patients, 21.4% developed temporary facial nerve paresis (grade II)., Conclusions: The results of the present study suggest that this surgical protocol is effective in the treatment of the TMJ ankylosis and the prevention of re-ankylosis., (Copyright © 2015 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.)

Aim: To systematically search the literature and assess the available evidence for the influence of chin-cup therapy on the temporomandibular joint regarding morphological adaptations and appearance of temporomandibular disorders (TMD)., Materials and Methods: Electronic database searches of published and unpublished literature were performed. The following electronic databases with no language and publication date restrictions were searched: MEDLINE (via Ovid and PubMed), EMBASE (via Ovid), the Cochrane Oral Health Group's Trials Register, and CENTRAL. Unpublished literature was searched on ClinicalTrials.gov, the National Research Register, and Pro-Quest Dissertation Abstracts and Thesis database. The reference lists of all eligible studies were checked for additional studies. Two review authors performed data extraction independently and in duplicate using data collection forms. Disagreements were resolved by discussion or the involvement of an arbiter., Results: From the 209 articles identified, 55 papers were considered eligible for inclusion in the review. Following the full text reading stage, 12 studies qualified for the final review analysis. No randomized clinical trial was identified. Eight of the included studies were of prospective and four of retrospective design. All studies were assessed for their quality and graded eventually from low to medium level of evidence. Based on the reported evidence, chin-cup therapy affects the condylar growth pattern, even though two studies reported no significance changes in disc position and arthrosis configuration. Concerning the incidence of TMD, it can be concluded from the available evidence that chin-cup therapy constitutes no risk factor for TMD., Conclusion: Based on the available evidence, chin-cup therapy for Class III orthodontic anomaly seems to induce craniofacial adaptations. Nevertheless, there are insufficient or low-quality data in the orthodontic literature to allow the formulation of clear statements regarding the influence of chin-cup treatment on the temporomandibular joint., (© The Author 2014. Published by Oxford University Press on behalf of the European Orthodontic Society. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Temporomandibular disorders (TMD) are a heterogeneous group of musculoskeletal and neuromuscular conditions involving the temporomandibular joint complex, and surrounding musculature and osseous components. TMD affects up to 15% of adults, with a peak incidence at 20 to 40 years of age. TMD is classified as intra-articular or extra-articular. Common symptoms include jaw pain or dysfunction, earache, headache, and facial pain. The etiology of TMD is multifactorial and includes biologic, environmental, social, emotional, and cognitive triggers. Diagnosis is most often based on history and physical examination. Diagnostic imaging may be beneficial when malocclusion or intra-articular abnormalities are suspected. Most patients improve with a combination of noninvasive therapies, including patient education, self-care, cognitive behavior therapy, pharmacotherapy, physical therapy, and occlusal devices. Nonsteroidal anti-inflammatory drugs and muscle relaxants are recommended initially, and benzodiazepines or antidepressants may be added for chronic cases. Referral to an oral and maxillofacial surgeon is indicated for refractory cases.

This review summarises the articles relating to the temporomandibular joint (TMJ) that were published in the British Journal of Oral and Maxillofacial Surgery (BJOMS) between January 2011 and December 2012. In total 24 papers were published. Of these, 16 (67%) were full-length articles, which included prospective, retrospective, and laboratory-based studies as well as reviews. The remaining 8 papers were short communications, technical notes, and letters to the editor, which report on, amongst other things, unusual cases, rare complications, and novel surgical techniques., (Copyright © 2013 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.)

Chewing-side preference (CSP) may be associated with temporomandibular disorders. However, little information exists regarding whether CSP will lead to osseous changes of temporomandibular joint (TMJ) in asymptomatic participants. The aim of this study was to investigate the relationship between osseous morphology of TMJ in asymptomatic participants with CSP and without CSP. Of the 121 healthy dentate participants, 35 participants with left CSP, 38 with right CSP and other 48 without CSP were scanned by cone-beam computed tomography. The dimensions of the reconstructed images of opposing TMJs were compared. Statistical analyses were performed using spss 16.0 software. The results showed that there were no significant differences between the dimensions of bilateral structures of the TMJ (P1 > 0·05) in participants without CSP. However, the posterior-superior, posterior and lateral joint space of the preferred side were smaller than that of the unpreferred side in participants with CSP (P2 < 0·01) and bilateral TMJ in participants without CSP (P3 < 0·01). In addition, width of condylar neck of the unpreferred side both in sagittal and perpendicular to the long axis of condyle views was greater than that of the preferred side in participants with CSP (P2 < 0·01) and bilateral TMJ of participants without CSP (P4 < 0·01). Also, the inclination of articular eminence of the preferred side in view perpendicular to the long axis of condyle was less than that of the unpreferred side (P2 < 0·05). These findings suggest CSP affects osseous morphology of TMJ in asymptomatic participants., (© 2014 John Wiley & Sons Ltd.)

This article discusses hemifacial microsomia and Treacher Collins syndrome relative to the nature of these congenital deformities as well as the clinical, radiographic, and diagnostic characteristics. These patients often have severe facial deformities with hypoplasia or aplasia of the temporomandibular joints (TMJs) and mandible. The surgical treatment options are presented, including the advantages and disadvantages of autogenous tissues versus patient-fitted total joint prostheses to reconstruct the TMJs and mandible as well as counterclockwise rotation of the maxillomandibular complex., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Accumulating evidence from previous studies suggested that interleukin-1 (IL-1β) and tumor necrosis factor-α (TNF-α) play an important role in pathogenesis of temporomandibular disorders (TMD). However, the cell surface receptors and the intracellular signal pathways leading to these cytokines expression are not fully understood. In the current study, we investigated the roles of Toll-like receptor 4 (TLR4) and its adaptor myeloid differentiation factor 88 (MyD88) in the expression of IL-1β and TNF-α in synovial fibroblasts (SFs) separated from rat temporomandibular joint (TMJ) with lipopolysaccharide (LPS) stimulation. The results showed that treatment with LPS could increase TLR4, MyD88, IL-1β, and TNF-α expression at both mRNA and protein levels. In addition, increased expression of IL-1β and TNF-α could be blocked by treatment with TAK-242, a blocker of TLR4 signaling, and also by MyD88 inhibitory peptide (MIP). These findings suggested that maybe TLR4/MyD88 signal transduction pathway participates in enhanced expression of IL-1 and TNF-α in patients with TMD. The activation of TLR4/MyD88 signal transduction pathway which results in production of proinflammatory factors may play a role in the pathogenesis of TMD.

Synovial fibroblasts contribute to the inflammatory temporomandibular joint under pathogenic stimuli. Synovial fibroblasts and T cells participate in the perpetuation of joint inflammation in a mutual activation feedback, via secretion of cytokines and chemokines that stimulate each other. IL-17 is an inflammatory cytokine produced primarily by Th17 cells which plays critical role in the pathogenesis of numerous autoimmune and inflammatory diseases. Here, we investigated the roles of IL-17A in temporomandibular joint disorders (TMD) using genome-wide analysis of synovial fibroblasts isolated from patients with TMD. IL-17 receptors were expressed in synovial fibroblasts as assessed using real-time PCR. Microarray analysis indicated that IL-17A treatment of synovial fibroblasts upregulated the expression of IL-6 and chemokines. Real-time PCR analysis showed that the gene expression of IL-6, CXCL1, IL-8, and CCL20 was significantly higher in IL-17A-treated synovial fibroblasts compared to nontreated controls. IL-6 protein production was increased by IL-17A in a time- and a dose-dependent manner. Additionally, IL-17A simulated IL-6 protein production in synovial fibroblasts samples isolated from three patients. Furthermore, signal inhibitor experiments indicated that IL-17-mediated induction of IL-6 was transduced via activation of NFκB and phosphatidylinositol 3-kinase/Akt. These results suggest that IL-17A is associated with the inflammatory progression of TMD.

Traumatic temporomandibular joint (TMJ) ankylosis can be classified into fibrous, fibro-osseous and bony ankylosis. It is still a huge challenge for oral and maxillofacial surgeons due to the technical difficulty and high incidence of recurrence. The poor outcome of disease may be partially attributed to the limited understanding of its pathogenesis. The purpose of this article was to comprehensively review the literature and summarise results from both human and animal studies related to the genesis of TMJ ankylosis.

Objective: This study aimed to systematically review the available literature on the treatment of patients with juvenile idiopathic arthritis (JIA) with temporomandibular joint (TMJ) involvement., Study Design: According to the PRISMA statement (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, studies were included until August 2012., Results: A total of 40 articles were identified. TMJ involvement in patients with JIA varies between 17% and 87%. The mean age at diagnosis of JIA is 7.2 years. TMJ treatment can be divided into 2 main groups, an arthritis group and a dentofacial deformity group. The main treatment modalities are counseling, pharmaceutical interventions, physiotherapy, orthodontic treatment, surgery, or a combination of the aforementioned therapies., Conclusions: TMJ involvement in patients with JIA has a high incidence. There is no consensus on the treatment of TMJ pathology and dentofacial deformities in patients with JIA, and treatment varies from counseling to surgery. Treatment to improve aesthetics and function and to obtain pain reduction can be effective. However, the articles are heterogeneous, and the level of evidence is low (level IV)., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Introduction: Fractures of the zygomatic arch extended to the glenoid fossa are rare and seldom reported., Observation: A 26-year-old man with a slightly dislocated fracture of the zygoma associated with trismus, and localized pain in the right Temporo-Mandibular Joint (TMJ) on palpation, but without any condylar fracture. The craniofacial CT scan revealed a fracture of the zygoma extended to the glenoid fossa. The treatment was an intraoral reduction of the zygoma and screw fixation of the glenoid fossa lateral region., Discussion: The risk of delayed healing by mobilization of the bone fragments was opposed to the risk of TMJ ankylosis due to a prolonged immobilization of the joint. Osteosynthesis of the fracture was finally chosen., (Copyright © 2014 Elsevier Masson SAS. All rights reserved.)

Many surgical techniques for the management of temporomandibular joint (TMJ) ankylosis have been described in the literature. The purpose of this study was to report our experience using a lateral arthroplasty technique in the management of type III ankylosis. The records of 15 patients treated for TMJ ankylosis at our institution between 2007 and 2011 were reviewed. Pre- and postoperative information collected included age, gender, aetiology, ankylosis type/classification, existing facial asymmetry, maximum pre- and postoperative mouth opening, complications, and recurrence of ankylosis. The mean maximum inter-incisal opening in the preoperative period was 12.9 mm and in the postoperative period was 36.2mm. No major complication was observed in any patient. No recurrence was noted in any patient. Our working hypothesis was that for patients with ankylosis type III, the medially displaced condyle and disc can fulfil their role in mandibular function and growth after extirpation of the ankylozed mass. Although they are located in an awkward medial position, they should function exactly as they would after a properly treated, displaced condylar fracture., (Copyright © 2013 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.)