BACKGROUND: The present study is to evaluate the clinical characteristics of patients with temporomandibular disorders (TMD).
METHODS: A total of 3362 TMD patients were included. Each participant had complete medical records according to the diagnostic criteria for temporomandibular disorders (DC/TMD). The clinical characteristics including symptoms and signs in relation to age and gender were analyzed.
RESULTS: The mean age of the patients seeking care was 29.89 ± 13.73Y, and 68.6% of patients were aged 16-35 years. The female-to-male ratio of patients was 2.2: 1, and the average age of males was significantly lower than that of females. The prevalence of clicking symptoms decreased with age, while the prevalence of pain symptoms and limitations in jaw movement increased with age. Females were more likely to have limitations in jaw movement than males. Among the patients with pain, the average visual analogue scale (VAS) was 2.96 ± 1.23. The average VAS score of acute TMD patients (≤ 3 months) was significantly higher than that of chronic TMD patients (> 3 months).
CONCLUSIONS: The majority of TMD patients seeking care were young people. The number and average age of female patients was higher than the males. Female patients were more likely to have limitations in jaw movement than males.

BACKGROUND: Currently, there is still controversy surrounding the relationship between temporomandibular disorders (TMDs) symptoms and jaw functional limitations. We investigated the distribution of TMDs in senior high school students, including both the number and types of symptoms, and assessed their association with jaw functional limitations. Furthermore, we explored sex differences in these associations.
METHODS: This study was conducted at a public high school in Hefei, Anhui Province, China, with data collected from September to October 2022. All subjects completed questionnaires assessing the anamnestic symptoms of TMDs and the Jaw Functional Limitation Scale (JFLS), and examinations were performed by trained dentists according to the Diagnostic Criteria for TMD. Data were analysed using the Kruskal-Wallis, Mann-Whitney U, and Chi-square tests.
RESULTS: The mean age of the participants (N = 2890) was 17.2 ± 0.14 years and 38.9% were females (61.1% were males). Limitations in self-assessed jaw function were associated with the presence of TMDs (P < .05). Participants with more symptoms reported significantly high levels of functional limitations (P < .05). Compared to male adolescents, female adolescents more commonly experienced TMDs pain and tended to have more symptoms (P < .05). However, no sex differences were observed in most associations between TMDs and jaw functional limitations.
CONCLUSIONS: TMDs-positive symptoms are common in adolescents. Female adolescents were more affected by TMDs symptoms than male adolescents. Individuals with more TMDs symptoms have greater jaw functional limitations.

Septic arthritis of the temporomandibular joint (SATMJ), primarily caused by bacterial infections, is a rare condition with a diverse etiology that is inadequately documented in the literature, resulting in the absence of standardized treatment protocols. Its nonspecific clinical presentation often leads to misdiagnosis as other temporomandibular disorders, delaying diagnosis and treatment and potentially causing severe complications in the absence of established therapeutic guidelines. The main objective of this article is to report a case of a 61-year-old female with diabetes who was undergoing prolonged corticosteroid therapy and presented with pain, swelling in the right pre-auricular area, and progressive limitation in mouth opening, with no history of facial trauma, where the early diagnosis and isolation of Staphylococcus aureus after a single-port arthrocentesis prompted the timely adjustment of the treatment regimen, significantly influencing the outcome by mitigating the risk of complications. Additionally, this report includes a comprehensive literature review, highlighting the crucial importance of this prompt intervention to achieve a favorable clinical outcome.

The factors differentiating temporomandibular disorders (TMD) pain from tooth pain is of interest to dentists. Prior to receiving therapy, participants answered the six-question TMD Pain Screener questionnaire. Applying validated Diagnostic Guidelines for TMD (DC/TMD), an orofacial pain specialist and endodontic resident with board certification performed endodontic and TMD examinations. In our study, sensitivity was higher for TMD screener regarding identification of all types of TMDs (0.94 (0.80-0.97), TMD pain not referring to teeth (0.94 (0.76-0.98), TMD pain referring to teeth only (0.94 (0.64-1.00)). TMD Pain Screener questionnaire can be applied in identification of TMDS in patient seeking endodontic therapy.

Background: Dentists, who frequently encounter potentially infected patients, have experienced significant changes worldwide due to the COVID-19 pandemic. The aim of this study was to evaluate the impact of the fear of COVID-19, depression, anxiety and stress on the presence of temporomandibular disorders (TMD), taking into account possible confounding variables, in Peruvian dental students during the post-pandemic period. Methods: This analytical cross-sectional study assessed 607 Peruvian dental students from two regions of Peru. The study utilized the Depression Anxiety Stress Scales-21 (DASS-21), the Fear of COVID-19 Scale (FCV-19S) and the Short Form of the Fonseca Anamnestic Index (SFAI). Possible confounding variables were sex, age, year of study, marital status, place of origin, area of residence, history of mental illness and living with people vulnerable to COVID-19. For the multivariable analysis, we utilized a Poisson regression model with an adjusted robust variance. The significance level was set at p < 0.05. Results: The rates of depression, anxiety, stress, fear of COVID-19 and temporomandibular disorders were 47.0%, 50.4%, 35.9%, 30.6% and 54.2%, respectively. Moreover, the study revealed that students with depression and anxiety were 38% and 75% more likely to have temporomandibular disorders compared to those without depression (APR = 1.38, 95% CI: 1.15-1.66) and anxiety (APR = 1.75, 95% CI: 1.44-2.13), respectively. Similarly, the likelihood of presenting temporomandibular disorders was 55% higher in women than in men (APR = 1.55, 95% CI: 1.28-1.87). Furthermore, we found that stress and fear of COVID-19 did not determine the development of temporomandibular disorders (p > 0.05). Conclusions: Almost half of the dental students experienced depression, anxiety and TMD in the post-pandemic period. In addition, depression and anxiety were influential factors in the occurrence of TMDs, with the female gender being a risk factor. However, factors such as fear of COVID-19, stress, age, year of study, marital status, place of origin, area of residence, history of mental illness or living with people vulnerable to COVID-19 were not significant.

BACKGROUND: Changes in the fatty infiltration and/or muscle volume of neck muscles can alter cervical spine alignment and cranial load distribution, which may cause pain in the orofacial region.
OBJECTIVE: The aim of the study was to examine the muscle volume and fatty infiltration of neck muscles in patients with temporomandibular disorders (TMD).
METHODS: This case-control study included 18 patients with TMD and 18 ageand sex-matched controls. The muscle volume and fatty infiltration of the neck muscles of the participants were measured using magnetic resonance imaging (MRI) and ITK-SNAP software. The 3D models of the sternocleidomastoid (SCM), splenius capitis (SPLC), semispinalis cervicis (SC)-semispinalis capitis (SCP), and multifidus (M) muscles within the C3-C7 range were created using ITK-SNAP, a semi-automatic segmentation software. The models were used to determine the volumes and fatty infiltration levels. The Neck Disability Index (NDI) was used to assess neck pain-related disability. The severity of TMD was determined using the Fonseca Anamnestic Index (FAI), while jaw-related disability was measured with the Jaw Functional Limitation Scale-20 (JFLS-20). Pain levels were recorded at rest and during chewing using the numeric rating scale (NRS).
RESULTS: There were no statistically significant differences in total muscle volume, fatty infiltration volume and fatty infiltration percentage of the SCM, SPLC, SCP, SC, and M muscles between the 2 groups (p > 0.05). The patient group had higher NDI scores compared to the controls (p < 0.001). The NDI scores correlated positively with the JFLS-20 (r = 0.831, p < 0.001), FAI (r = 0.815, p < 0.001) and NRS scores at rest (r = 0.753, p < 0.001) and during chewing (r = 0.686, p < 0.001).
CONCLUSIONS: The present study did not identify any significant differences in the neck muscle volume or fatty infiltration between the TMD patients and controls. However, the severity of neck disability was found to correlate with jaw function, pain and TMD levels.

Driving stress is a multifaceted phenomenon, and the experience of driving invokes stress. Driving causes the activation of stress-response mechanisms, leading to short-term and long-term stress responses resulting in physiological and behavioral changes. The aim of this study was to evaluate driving stress-initiated effects on orofacial functions and health behaviors in the Riyadh population. A cross-sectional survey was conducted in Riyadh using a pre-validated set of questionnaires for habitual information, a driving stress assessment using a driving-behavior inventory, and an assessment of parafunctional habits and effects on orofacial functions. The results indicate that nearly 50% of the sample spends more than two hours commuting, and more than 50% of the sample has inadequate sleep and insufficient exercise. Oral parafunctional habits like nail biting (p = 0.039) and lip or object biting (p = 0.029) had a significant correlation with aggressive driving behaviors, whereas the grinding of teeth (p = 0.011), the clenching of jaws (p = 0.048), lip or object biting (p = 0.018), and pain in mastication (p = 0.036) had a positive correlation with driving dislikes. Driving stress can be detrimental to one\'s health and not only impacts health behaviors but also induces oral parafunctional habits and adversely affects orofacial regions and functions. Acute driving stress responses may be transient. However, prolonged driving stress can be maladaptive and can increase the risk of chronic diseases including chronic temporomandibular joint disorders and parafunctional habit-related changes in the oral cavity.

UNASSIGNED: This study aims to investigate the relationship between five sleep traits (insomnia, sleep duration, getting up in morning, snoring, and daytime nap) and temporomandibular disorders (TMD) using bi-directional Mendelian randomization.
UNASSIGNED: The bi-directional Mendelian randomization study was conducted in two stages. Initially, sleep traits were examined as exposures while TMD was evaluated as an outcome, whereas the second step was reversed. The inverse variance weighted (IVW) method and other Mendelian randomization methods were used for analysis. Furthermore, we performed the MR-Egger intercept, MR-PRESSO, Cochran\'s Q test, and \"Leave-one-out\" to assess the levels of pleiotropy and heterogeneity.
UNASSIGNED: The IVW method indicates that getting up in the morning reduces the risk of developing TMD (OR = 0.50, 95% CI 0.30-0.81, p = 0.005), while insomnia may increase the risk of TMD (OR = 2.05, 95% CI 1.10-3.85, p = 0.025). However, other sleep traits are not associated with the risk of TMD, and having TMD does not alter an individual\'s sleep traits. After removing outliers, the results remained robust, with no pleiotropy detected.
UNASSIGNED: Genetically determined difficulty in getting up in the morning and insomnia can increase the risk of TMD. By optimizing sleep, the risk of developing TMD can be reduced. This underscores the importance of sleep in preventing TMD.

BACKGROUND: Syndecan 4 (SDC4), a type I transmembrane proteoglycan, serves as a critical link between chondrocytes and the extracellular matrix.
OBJECTIVE: This study aimed to explore the role of SDC4 in cartilage degeneration of temporomandibular joint osteoathritis (TMJOA).
METHODS: Condylar chondrocytes were stimulated with varying concentrations of recombinant rat interleukin-1β (rrIL-1β) and SDC4 small interfering RNA (si-SDC4). Anti-SDC4 ectodomain-specific antibodies or IgG were intra-articularly administrated in a TMJOA model rats. SDC4 conditional knockout (SDC4-cKO) and Sdc4flox/flox mice were induced TMJOA. Cartilage degeneration was assessed using haematoxylin & eosin (H&E) and safranin O (SO) staining. Protein levels of SDC4, matrix metalloproteinases (MMPs), a disintegrin and metalloproteinase with a thrombospondin motifs 5 (ADAMTS5), tumour necrosis factor α (TNFα), type II collagen (Col-II), aggrecan (ACAN), cleaved caspase 3 (CASP3), Ki67 and related pathways in condylar cartilage were evaluated by immunohistochemical (IHC) staining or western blot assays.
RESULTS: SDC4 expression was evidently increased in MIA-model animals compared to control groups. rrIL-1β stimulation increased the expression of SDC4, MMP3 and ADAMTS5 expression in chondrocytes, while decreasing the expression of Col-II. These effects were reversed by si-SDC4 in vitro. In vivo, SDC4 blockade reduced the death of chondrocytes and the loss of cartilage matrix, which was evidenced by increased expression of Col-II and ACAN, and a decrease in SDC4, MMP13 and cleaved-CASP3-positive cells. Furthermore, the protein levels of ACAN and Ki67 were elevated, and the ERK1/2 and P38 signalling pathways were activated following SDC4 inhibition.
CONCLUSIONS: SDC4 inhibition significantly ameliorates condylar cartilage degeneration, which was mediated, at least partly, through P38 and ERK1/2 signalling. Inhibition of SDC4 may be of great value for the treatment of TMJOA.

BACKGROUND: Poor reporting quality and spin in randomized controlled trial (RCT) abstracts can lead to misinterpretation and distorted interpretation of results.
OBJECTIVE: This methodological study aimed to assess the reporting quality and spin among RCT abstracts on splint therapy for temporomandibular disorders (TMD) and explore the association between spin and potentially related factors.
METHODS: The authors searched PubMed for RCTs on splint therapy for TMD. The reporting quality of each abstract was assessed using the original 16-item CONSORT for abstracts checklist. The authors evaluated the presence and characteristics of spin only in abstracts with nonsignificant primary outcomes according to pre-determined spin strategies. Logistic regression analyses were performed to identify factors associated with the presence of spin.
RESULTS: A total of 148 abstracts were included in the reporting quality evaluation. The mean overall CONSORT score (OCS) was 5.86 (score range: 0-16). Only interventions, objectives and conclusions were adequately reported. Of the 61 RCT abstracts included for spin analysis, spin was identified in 38 abstracts (62.3%), among which 32 abstracts (52.3%) had spin in the Results section and 21 (34.4%) had spin in the Conclusions section. A significantly lower presence of spin was found in studies with exact p-value reporting (OR: 0.170; 95% CI: 0.032-0.887; p = .036) and a two-arm comparison design (OR: 11.777; 95% CI: 2.171-63.877; p = .004).
CONCLUSIONS: The reporting quality of RCT abstracts on splint therapy for TMD is suboptimal and the prevalence of spin is high. More awareness and joint efforts are needed to improve reporting quality and minimize spin.