The temporomandibular joint (TMJ) consists of bone, cartilage, ligaments, and associated masticatory muscles and tendons that coordinate to enable mastication in mammals. The TMJ is innervated by the trigeminal nerve (CNV), containing axons of motor and somatosensory neurons. Somatosensation includes touch, temperature, proprioception, and pain that enables mammals to recognize and react to stimuli for survival. The somatosensory innervation of the TMJ remains poorly defined. Disorders of the TMJ (TMD) are of diverse etiology and presentation. Some known symptoms associated with TMD include facial, shoulder, or neck pain, jaw popping or clicking, headaches, toothaches, and tinnitus. Acute or chronic pain in TMD stems from the activation of somatosensory nociceptors. Treatment of TMD may involve over- the-counter and prescription medication, nonsurgical treatments, and surgical treatments. In many cases, treatment achieves only a temporary relief of symptoms including pain. We suggest that defining the sensory innervation of the temporomandibular joint and its associated tissues with a specific focus on the contribution of peripheral innervation to the development of chronic pain could provide insights into the origins of joint pain and facilitate the development of improved analgesics and treatments for TMD.

Inflammation and loss of articular cartilage are considered the major cause of temporomandibular joint osteoarthritis (TMJOA), a painful condition of the temporomandibular joint (TMJ). To determine the cause of TMJ osteoarthritis in these patients, synovial fluid of TMJOA patients was compared prior to and after hyaluronic lavage, revealing substantially elevated levels of interleukin (IL) 1β, reactive oxidative stress (ROS), and an overload of Fe3+ and Fe2+ prior to lavage, indicative of ferroptosis as a mode of chondrocyte cell death. To ask whether prolonged inflammatory conditions resulted in ferroptosis-like transformation in vitro, we subjected TMJ chondrocytes to IL-1β treatment, resulting in a shift in messenger RNA sequencing gene ontologies related to iron homeostasis and oxidative stress-related cell death. Exposure to rat unilateral anterior crossbite conditions resulted in reduced COL2A1 expression, fewer chondrocytes, glutathione peroxidase 4 (GPX4) downregulation, and 4-hydroxynonenal (4-HNE) upregulation, an effect that was reversed after intra-articular injections of the ferroptosis inhibitor ferrostatin 1 (Fer-1). Our study demonstrated that ferroptosis conditions affected mitochondrial structure and function, while the inhibitor Fer-1 restored mitochondrial structure and the inhibition of hypoxia-inducible factor 1α (HIF-1α) or the transferrin receptor 1 (TFRC) rescued IL-1β-induced loss of mitochondrial membrane potential. Inhibition of HIF-1α downregulated IL-1β-induced TFRC expression, while inhibition of TFRC did not downregulate IL-1β-induced HIF-1α expression in chondrocytes. Moreover, inhibition of HIF-1α or TFRC downregulated the IL-1β-induced MMP13 expression in chondrocytes, while inhibition of HIF-1α or TFRC rescued IL-1β-inhibited COL2A1 expression in chondrocytes. Furthermore, upregulation of TFRC promoted Fe2+ entry into chondrocytes, inducing the Fenton reaction and lipid peroxidation, which in turn caused ferroptosis, a disruption in chondrocyte functions, and an exacerbation of condylar cartilage degeneration. Together, these findings illustrate the far-reaching effects of chondrocyte ferroptosis in TMJOA as a mechanism causing chondrocyte death through iron overload, oxidative stress, and articular cartilage degeneration and a potential major cause of TMJOA.

Condylar osteomyelitis is a long-standing infection of the condylar head of the mandible. The chronic progression of this disease can lead to the destruction of surrounding bony structures and can ultimately affect function. Currently, in English Literature, there have been few cases published on condylar osteomyelitis. Interestingly, regardless of proximity, there have only been two other reported cases of condylar osteomyelitis subsequent to extractions of the upper maxillary third molar. We report a case of a 27-year-old female who presented with an acute episode of condylar osteomyelitis after a simple extraction of an upper left third molar. Several courses of antibiotics did not alleviate her severe trismus, paresthesia, or extensive preauricular collection. Three surgical interventions showed negative growth on numerous swabs. However, CT scans and an MRI confirmed extensive osteomyelitis along the left head, neck, and the angle of the mandible. Following inpatient IV antibiotics, the patient was discharged with a PICC line to allow for long-term treatment. An improvement in function, pain, and swelling was seen on discharge. However, due to the nature of this disease she was monitored for 2 years and due to joint collapse has been listed for alloplastic replacement.

Temporomandibular disorders include a wide spectrum of extra-articular and intra-articular conditions affecting the temporomandibular joint (TMJ). In salvage cases involving intra-articular end-stage disease, alloplastic temporomandibular joint replacement (TMJR) is a management option which can be utilised to rehabilitate a disabled joint\'s function and form. Whilst post-TMJR infection is rare, it is one of the most serious complications. The principles governing TMJR surgery antibiotic prophylaxis have been based on those established in orthopaedic surgery literature. Antibiotic resistance due to antibiotic over-use is a significant concern, therefore antibiotic stewardship has been developed to deal with this world-wide public health concern. The TMJ\'s anatomical proximity to the external auditory canal and oral cavity creates the potential for bacterial contamination. The aim of this study was to explore the views of 39 sub-specialist TMJ surgeons across nine nations usual approach to antibiotic prophylaxis and their management of TMJR infection. To accomplish this, an international survey was developed and conducted using Google Forms. The results demonstrated that 97.4% of the respondents employ prophylactic antibiotics at TMJR surgery, 83.8% on discharge. Variability in antibiotic choice with additional antimicrobial perioperative practices were also reported. Opinions on the management of a TMJR infection also varied. This survey establishes there is an agreement on the use of antibiotic prophylaxis, However the variability in choice, timing, course, duration of antibiotic use as well as the management of a postoperative TMJR infection demonstrates the need for further study leading to development of standardised antibiotic prophylaxis and infection management protocols for TMJR surgery.

BACKGROUND: Temporomandibular disorders (TMD) affect the masticatory muscles, temporomandibular joints (TMJs) and associated structures. The relationship between occlusion and TMD is a contentious issue in the dental field.
OBJECTIVE: Although there is a strong argument against invasive and irreversible therapeutic TMD procedures, the TMD biopsychosocial model is still not accepted by some clinicians. Hence, this study aimed to verify whether malocclusions are related to TMD pain.
METHODS: The study included 49 adult patients with one or multiple TMD diagnoses and without any other diseases that could mimic TMD. A reliable investigator diagnosed the patients using the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) protocol. The sample was divided into pain and non-pain TMD groups, and the predictor of malocclusion was categorized as the dependent variable. There were 33 patients in the TMD pain group and 16 patients in the non-pain TMD group. Analyses were conducted at a significance level of 0.05. The χ2 test (with Yates\' correction for 2 × 2 matrix) was used to compare qualitative variables between the groups.
RESULTS: Malocclusion was present in 13 patients in the pain group and 7 patients in the non-pain group.
CONCLUSIONS: According to our study, there is no correlation between malocclusion and TMD pain.

Temporomandibular disorder (TMD) is a multifaceted disorder impacting the temporomandibular joint (TMJ), causing substantial discomfort and functional limitations. This systematic review aims to comprehensively assess the effectiveness of non-invasive treatment modalities for TMJ dysfunction, prioritizing a definitive protocol to ensure patient safety and enhance quality of life. Employing the PRISMA guidelines, we meticulously analyzed 20 studies from a pool of 1,417 articles sourced from databases such as PubMed, Google Scholar, ScienceDirect, and Medline. These studies underscore the multifarious nature of TMD and the varied responses to treatments such as physical therapy, laser therapy, ultrasound and electrical stimulation, splint therapy, injections, and arthrocentesis. Notably, the review highlights the paramount importance of precise diagnosis, often through surface electromyography, followed by a tailored treatment approach integrating manual therapy, counseling, and splint therapy. The systematic analysis revealed that while certain treatments such as transcutaneous electrical nerve stimulation and low-level laser therapy showed limited efficacy, combination therapies, especially those involving manual therapy, counseling, and splint therapy, demonstrated substantial improvement in reducing pain, depression, and anxiety. The findings advocate for a non-invasive, patient-centric approach, emphasizing education and symptom management before considering more invasive procedures such as injections and arthrocentesis. The review identifies the need for more comprehensive, longitudinal studies to establish a standardized, evidence-based treatment protocol for TMJ dysfunction, aiming to improve patient outcomes holistically.

This study assessed the current evidence for the use of TMJR reconstruction in skeletally immature patients. A systematic review was conducted according to PRISMA guidelines. An electronic search in PubMed and Embase was performed. Meta-analysis randomized controlled trials (RCTs), cohort studies, observational studies, case series, and case reports were eligible for inclusion. Case reports were also included due to the limited number of publications identified with the predefined terms. Exclusion criteria were: (1) studies written in a language other than English; (2) full-text unavailability (i.e., posters and conference abstracts). The selected studies were assessed for risk of bias. A meta-analysis was not performed as it necessitates a substantial between-study design homogeneity; hence, a descriptive synthesis of data was performed. There were 9 TMJR device reconstruction studies involving 14 subjects 13 years of age or younger. Follow-up ranged from 7 months to 120 months. All papers reported significant decrease in pain and improvement of diet. All prostheses were functional. No material failures of the prosthesis components were observed. The mandible continued to show limited growth following TMJR and most of the cases required no secondary or revision surgery even when the patient reached skeletal maturity. This systematic review had some limitations. The studies included had a low level of evidence and a high risk of bias. Most of the studies had a small patient sample, and no study had a control group. The literature reviewed supports the use of TMJR devices in the restoration of mandibular function and form in skeletally immature patients.

Temporomandibular Joint Magnetic Resonance Imaging (TMJ MRI) is crucial for diagnosing temporomandibular disorders (TMDs). This study advances the use of inductively coupled wireless coils to enhance imaging quality in TMJ MRI. After investigating multiple wireless resonator configurations, including a 1-loop design with a loop diameter of 9 cm, a 2-loop design with each loop having a diameter of 7 cm, and a 3-loop design with each loop having a diameter of 5 cm, our findings indicate that the 3-loop configuration achieves the optimal signal-to-noise ratio (SNR), surpassing other wireless arrays. Bilateral deployment of wireless coils further amplifies SNR, enabling superior visualization of TMJ structures, particularly with the 3-loop design. This cost-effective and comfortable solution, featuring a detunable design, eliminates the need for system parameter adjustments. The study indicates broad adaptability across MRI platforms, enhancing TMJ imaging for routine clinical diagnostics of TMDs.

UNASSIGNED: The temporomandibular joint (TMJ) is the most commonly used joint in the human body. Recent studies have shown pathologic relationships between inflammation, diabetes, and musculoskeletal disorders (MSDs). Chewing disorder is a significant sign of dysfunction in the masticatory system. This study investigated dietary pattern changes in response to TMJ inflammation in diabetic rats.
UNASSIGNED: This experimental study was carried out on 30 male rats. The rats were fed concentrated 20-mg dietary tablets. Complete Freund\'s adjuvant (CFA) was used to induce TMJ inflammation and streptozotocin (STZ) was used to induce diabetes. The animals were randomly divided into three groups (n=10), including group I (CFA+STZ), group II (healthy rats+CFA), and group III (healthy rats, no injection). Parameters such as overall food intake, food intake duration, food intake frequency, and the interval between meals were recorded in a checklist and analyzed by Mann-Whitney and Kruskal-Wallis tests (P<0.05).
UNASSIGNED: The results showed no significant difference between groups in overall food intake and food intake frequency on days 0 and 1, but this difference was significant from day 2 to day 7. Regarding the time and end of food intake, there was a significant difference between the three groups from day 1 to day 7, but this difference was not significant on day zero.
UNASSIGNED: Dietary pattern changes were similar in the diabetic TMJ inflammation and TMJ inflammation groups. These changes can be used as a behavioral marker for TMJ inflammation in rats.

Temporomandibular disorders (TMDs) and headache disorders are highly prevalent in the population. TMDs can present headache symptoms as a secondary headache and, in addition, be comorbid with primary headache disorders. This overlap has significant clinical implications for which it is essential for the physician to be aware, and they should screen for the potential presence of TMDs in a headache patient. Bruxism is a parafunctional behavior also prevalent in the population which has a role in TMDs and may influence headache symptomatology, but it is still necessary to clarify this relationship.