Effects of different treatments for obstructive sleep apnea on temporomandibular joint: a randomized clinical trial.

BACKGROUND: In recent years, obstructive sleep apnea (OSA) has been increasingly recognized as a significant health concern. No previous studies assessed the effect of recommended treatment modalities of patients with OSA on the temporomandibular joint (TMJ). The current study aimed to evaluate the effect of different treatment modalities of OSA, such as continuous positive airway pressure (CPAP), mandibular advancement device (MAD), and oral myofunctional therapy (OMT) on subjective symptoms, clinical, and radiographic signs of temporomandibular disorders. PATIENTS & METHODS: This hospital-based prospective randomized controlled clinical trial study was approved by the institutional review board and formal patient consent, 39 OSA patients, ranging in age from 19 to 56 after confirmation with full night Polysomnography (PSG) with healthy TMJ confirmed clinically and radiographically with magnetic resonance imaging (MRI) were randomly allocated into three treatment groups. Group 1: 13 patients were managed with CPAP after titration, group 2: 13 patients were managed with digitally fabricated MAD, and group 3: 13 patients were managed with OMT. The following parameters were evaluated before and 3 months after the intervention. Pain using a visual analogue scale (VAS), maximum inter-incisal opening (MIO), lateral movements, and clicking sound of TMJ. MRI was done before and 3 months after the intervention. RESULTS: Out of the 83 patients enrolled, 39 patients completed the treatment. There were no statistically significant differences in lateral jaw movements or clicking, and no significant difference in MRI findings between the three studied groups before and after the intervention. The OMT group showed a statistically significant difference in pain (p = 0.001), and MIO (p = 0.043) where patients experienced mild pain and slight limitation in mouth opening after 3 months of follow-up in comparison to MAD and CPAP groups. CONCLUSION: CPAP and MAD are better for preserving the health of TMJ in the treatment of OSA patients. While OMT showed mild pain and slight limitation of MIO (that is still within the normal range of mouth opening) compared to CPAP and MAD. TRIAL REGISTRATION: The study was listed on www. CLINICALTRIALS: gov with registration number (NCT05510882) on 22/08/2022.

Automatic detection and visualization of temporomandibular joint effusion with deep neural network.

This study investigated the usefulness of deep learning-based automatic detection of temporomandibular joint (TMJ) effusion using magnetic resonance imaging (MRI) in patients with temporomandibular disorder and whether the diagnostic accuracy of the model improved when patients' clinical information was provided in addition to MRI images. The sagittal MR images of 2948 TMJs were collected from 1017 women and 457 men (mean age 37.19 ± 18.64 years). The TMJ effusion diagnostic performances of three convolutional neural networks (scratch, fine-tuning, and freeze schemes) were compared with those of human experts based on areas under the curve (AUCs) and diagnosis accuracies. The fine-tuning model with proton density (PD) images showed acceptable prediction performance (AUC = 0.7895), and the from-scratch (0.6193) and freeze (0.6149) models showed lower performances (p < 0.05). The fine-tuning model had excellent specificity compared to the human experts (87.25% vs. 58.17%). However, the human experts were superior in sensitivity (80.00% vs. 57.43%) (all p < 0.001). In gradient-weighted class activation mapping (Grad-CAM) visualizations, the fine-tuning scheme focused more on effusion than on other structures of the TMJ, and the sparsity was higher than that of the from-scratch scheme (82.40% vs. 49.83%, p < 0.05). The Grad-CAM visualizations agreed with the model learned through important features in the TMJ area, particularly around the articular disc. Two fine-tuning models on PD and T2-weighted images showed that the diagnostic performance did not improve compared with using PD alone (p < 0.05). Diverse AUCs were observed across each group when the patients were divided according to age (0.7083-0.8375) and sex (male:0.7576, female:0.7083). The prediction accuracy of the ensemble model was higher than that of the human experts when all the data were used (74.21% vs. 67.71%, p < 0.05). A deep neural network (DNN) was developed to process multimodal data, including MRI and patient clinical data. Analysis of four age groups with the DNN model showed that the 41-60 age group had the best performance (AUC = 0.8258). The fine-tuning model and DNN were optimal for judging TMJ effusion and may be used to prevent true negative cases and aid in human diagnostic performance. Assistive automated diagnostic methods have the potential to increase clinicians' diagnostic accuracy.

Impact of migraine and fibromyalgia on temporomandibular disorder: A retrospective study on pain, psychological factors and quality of life.

OBJECTIVES: This study assessed the impact of migraine and fibromyalgia (FM) in TMD patients, focusing on pain, anxiety, depression, and quality of life (QoL). Additionally, we investigated how these variables relate to the total number of comorbidities to gain insights into their interactions. METHODS: A retrospective data collection was conducted during January 2016 to December 2022, involving 409 adult TMD patients. TMD patients were categorised into four groups: those without comorbidity (TMD-only) and those with comorbid migraine and/or fibromyalgia (TMD + MG, TMD + FM and TMD + MG + FM). Quantitative variables were compared among them. Linear regression was used to analyse the associations between these variables. RESULTS: Most of study population were women (79%) with a mean age of 44.43 years. TMD + MG patients reported longer pain duration, higher pain scores and greater pain interference compared with TMD-only patients. Similarly, TMD + FM patients had higher pain intensity than patients with TMD only. Both the TMD + MG and TMD + FM groups had higher levels of anxiety, depression, and health impairment compared with patients with TMD only. Patients with all three pain conditions (TMD + MG + FM) experienced the longest pain duration, highest pain intensity, psychological distress, and impaired QoL. The result showed positive associations between pain outcomes, psychological measures, pain's impact on QoL, and the number of comorbidities and a negative association between overall health states and the number of comorbidities. CONCLUSIONS: These findings underscore the importance of considering the presence of comorbidities and addressing physical and psychological aspects in the management of TMD patients.

Clinical benefit of botulinum toxin for treatment of persistent TMD-related myofascial pain: A randomized, placebo-controlled, cross-over trial.

BACKGROUND: Injections of botulinum toxin type A (BoNT-A) have been proposed as an additional treatment modality for patients suffering chronic temporomandibular disorder (TMD)-related myofascial pain (MFP). BoNT-A impairs muscle function, along with its analgesic effect, and a minimal effective dose should be used. The objective of this randomized placebo-controlled crossover study was to evaluate the clinical benefit of a moderate dose (50 U) of BoNT-A. METHODS: Sixty-six subjects were randomized into two groups, one which received BoNT-A first and a second which received a saline solution (SS) first. Follow-ups were performed 2, 11, and 16 weeks after the injections. Diagnostic criteria for temporomandibular disorders (DC/TMD) diagnostic algorithms were used to evaluate characteristic pain intensity (CPI) and pain-related disability based on the Graded Chronic Pain Scale (GCPS). Electromyographic and bite force were also evaluated. RESULTS: The within-group analysis showed a significant improvement in pain intensity and pain-related disability after BoNT-A (p < 0.001, p = 0.005, p = 0.011) and SS (p = 0.003, p = 0.005, p = 0.046) injections up to week 16. The between-group analysis of pain-related variables revealed no differences between groups at any time. Nonetheless, BoNT-A, but not SS, caused a significant decline in muscle performance. The number needed to treat (NNT) regarding a clinically significant pain reduction (≥30%) was 6.3, 57.0, and 19.0 at 2, 11, and 16-week follow-ups favoring BoNT-A. CONCLUSIONS: Injections of 50 U of BoNT-A might improve MFP symptoms, but the specific effect of the drug on pain compared to the placebo is not obvious.

The majority of patients report satisfaction more than 24 years after temporomandibular joint discectomy.

PURPOSE: To retrospectively evaluate long-term outcomes after temporomandibular joint (TMJ) discectomy. METHODS: Included patients (n = 64) had undergone discectomy during 1989-1998 at Umeå University Hospital. A questionnaire was used to evaluate pre- and postoperative symptoms, postoperative complications, general pain, and subjective opinion about the outcome of the surgery. RESULTS: The results are based on responses from 47 patients (40 women/7 men), including 36 (30 women/6 men) who completed the questionnaire and 11 (10 women/1 man) who were contacted by telephone and answered selected questions. Seventeen patients were excluded because of death, a move abroad, declining to participate, or no available patient information. Among the respondents, 41 (87%) were satisfied with the results, five (11%) were unsatisfied, and one (2%) patient did not answer the question. The results showed a significant long-term improvement in locking, clicking/crepitation, and pain when chewing or opening the jaw (p = 0.001). The prevalence of headaches had decreased significantly at follow-up (p = 0.001). Reported impaired jaw-opening capacity showed no significant improvement (p = 0.08). Of the 47 respondents, 19 (40%) had asked for additional treatment after the discectomy, and six of the 19 patients (13%) had undergone more surgery of the joint. CONCLUSION: The results of this retrospective long-term follow-up study indicate that TMJ discectomy has a high success rate, as most patients were satisfied with the postoperative results. Discectomy is thus an effective surgical intervention for patients with disabling TMJ pain and dysfunction when conservative interventions have been unsuccessful.

Association between obstructive sleep apnea and temporomandibular disorders: A meta-analysis.

BACKGROUND: Obstructive sleep apnea (OSA) is a very common condition in patients with temporomandibular disorders (TMD). However, there is little evidence of a connection between them. OBJECTIVE: The aim of this systematic review and meta-analysis is to assess the association between OSA and TMD in adult population. METHODS: Case-control, cross-sectional and cohort studies on the association between TMD and OSA were searched in the EMBASE, LILACS, LIVIVO, PubMed/MEDLINE, Scopus, Web of Science, Google Scholar, Open Grey and Pro Quest databases. TMD should be assessed using Research Diagnostic Criteria (RDC/TMD) or Diagnostic Criteria (DC/TMD) and OSA using polysomnography (PSG) and/or a validated questionnaire. The risk of bias was evaluated using the Joanna Briggs Institute Critical Assessment Checklists; and an association meta-analysis was performed. The effect measure included the odds ratio (OR) in dichotomous variables and a 95% confidence interval (CI). Certainty of evidence was determined by analysing groups using the Grading of Recommendations Assessment, Development and Evaluation (GRADE). RESULTS: Out of the 1024 articles screened, 7 met the inclusion criteria for the qualitative synthesis, and 6 for quantitative analysis. All articles were classified at low risk of bias. A positive association with OSA was found in patients with TMD (OR = 2.61; 95% CI = 2.31, 2.95). A significant association was also found irrespective to the OSA diagnostic methods applied (for studies using PSG + validated questionnaires: OR = 2.74; 95% CI = 2.11, 3.57; for studies using validated questionnaires only: OR = 2.55; 95% CI = 2.22, 2.92). GRADE was moderate. CONCLUSION: Patients with TMD presented a significant association with OSA regardless of the OSA diagnostic method (PSG and/or validated questionnaires). OSA screening should be part of the TMD examination routine. Furthermore, due to the different OSA assessment methods used and the small number of studies included, there is a need to include a larger number of studies using PSG to better elucidate this association.

Deletion of vitamin D receptor exacerbated temporomandibular joint pathological changes under abnormal mechanical stimulation.

AIMS: Temporomandibular disorder can cause degenerative pathological changes by aseptic inflammation in the temporomandibular joint (TMJ). Vitamin D (VD) is known for maintaining calcium homeostasis, and recent studies indicated that VD and the vitamin D receptor (VDR) are important in inflammatory responses. In this study, we explored the anti-inflammatory effect of VD-VDR signaling axis in TMJ pathological degeneration. MAIN METHODS: Mice ablated for Vdr (Vdr-/-res) were fed with a rescue diet to avoid hypocalcemia. With abnormal mechanical stimulation, unilateral anterior crossbite (UAC) induced temporomandibular disorders in mice. Histological staining, immunohistochemistry staining, and micro-CT analysis were performed to evaluate TMJ pathological changes. To identify the mechanisms in the aseptic inflammatory process, in vitro experiments were conducted on wild-type (WT) and Vdr-/- chondrocytes with compressive mechanical stress loading, and the related inflammatory markers were examined. KEY FINDINGS: Vdr-/-res mice did not develop rickets with a high calcium rescue diet. The TMJ cartilage thickness in Vdr-/-res mice was significantly decreased with mechanical stress stimulation compared to WT mice. UAC-induced bone resorption was obvious, and the number of osteoclasts significantly increased in Vdr-/-res mice. The proliferation was inhibited and the gene expression of Il1b, Mmp3, and Mmp13 was significantly increased in Vdr-/- chondrocytes. However, WT chondrocytes showed significantly increased Tnfa gene expression as a response to mechanical stress but not in Vdr-/- chondrocytes. SIGNIFICANCE: VD-VDR is crucial in TMJ pathological changes under abnormal mechanical stimulation. Deletion of Vdr exacerbated inflammatory response excluding TNFα, inhibited chondrocyte proliferation, and promoted bone resorption in TMJ.

Bi-directional two-sample Mendelian randomization identifies causal association of depression with temporomandibular disorders.

BACKGROUND: Depression and anxiety have been suggested to be associated with temporomandibular disorders (TMD) in observational studies. However, the causal association and the direction in the relationship between depression/anxiety and TMD remain unknown. OBJECTIVES: This study investigated the potential causal relationship between depression/anxiety and TMD with two-sample bi-directional Mendelian randomization (MR). METHODS: Summary statistics of depression (N = 500 199), anxiety disorder (N = 17 310) and TMD (N = 195 930) were sourced from large-scale genome-wide association studies (GWAS). The primary Mendelian randomization (MR) estimation employed the inverse-variance weighted meta-analysis (IVW). Additional MR sensitivity methods and multivariate MR (MVMR) were applied to address pleiotropy. RESULTS: IVW results indicated a causal effect of genetically predicted depression on TMD (OR = 1.887, 95% CI = 1.504-2.367, p < .001), which was supported by other sensitivity MR approaches. MVMR results suggested that the negative effect of depression on TMD persisted after conditioning on other potential confounders. The association of anxiety disorder with TMD was not supported by our findings. In the reverse direction, we did not find compelling evidence suggesting the causal effect of TMD on depression and anxiety disorder. CONCLUSIONS: The present study suggests a potential causal association between genetic liability for depression and the risk of TMD. Our MR findings align with prior epidemiological research, underscoring the significance of early detection and prevention of depression in the treatment of TMD.

Analysis of the Effect of Exams on Perceived Stress and Temporomandibular Joint Status in Physiotherapy Students: A Pilot Study.

Background and Objectives: Temporomandibular disorders or dysfunction (TMDs) encompass a range of complex conditions that impact the temporomandibular joint (TMJ), chewing muscles, teeth, and/or their supporting tissues. Stress is one of the most associated factors studied as a TMD predictor. The aim is to figure out the influence of stress on TMJ status and salivary cortisol in university students during and before exams. Materials and Methods: The study was non-experimental, employing a longitudinal, analytical, observational cohort design. The study population consisted of students enrolled in the physiotherapy degree program at the Alfonso X El Sabio University (Madrid, Spain). Data were collected during two distinct academic periods: the first period was characterized by low academic stress and no exams, and the second period coincided with the high academic stress of final course exams. The collected results included sociodemographic data, assessment of TMJ status (Fonseca Index), evaluation of muscle evaluation (masseter, upper trapezius, and sternocleidomastoid) using a MOXY Monitor (muscle oxygenation) and Neurotrac® (surface EMG, sEMG), assessment of perceived stress (PSS-14), and measurement of salivary cortisol (enzyme immunoassay with Elisa). The statistical analysis was conducted with a confidence level of 95% (p ≤ 0.05) and asymptotic or bilateral significance. Results: 70 students were analyzed during two different measurement periods. According to the Fonseca Index, initially, 37.14% of the analyzed students showed mild TMDs, 17.14% moderate TMDs, and 45.72% showed no TMDs. In general terms, stress increased with age and is related to female sex, maximum mouth opening decreased with age, oxygen saturation decreased with age and academic stress, and myoglobin concentration was related to age. Furthermore, muscle contraction decreased during higher academic stress and increased with age. For women, age was a risk factor for suffering from TMDs, and stress worsened the transition from having TMDs to having no TMDs in both sexes. Conclusions: Academic stress influences TMJ status and muscle outcomes such as oxygen saturation, myoglobin concentration, and muscle contraction, although more research is needed.

Comparison of Machine Learning Algorithms Fed with Mobility-Related and Baropodometric Measurements to Identify Temporomandibular Disorders.

Temporomandibular disorders (TMDs) refer to a group of conditions that affect the temporomandibular joint, causing pain and dysfunction in the jaw joint and related muscles. The diagnosis of TMDs typically involves clinical assessment through operator-based physical examination, a self-reported questionnaire and imaging studies. To objectivize the measurement of TMD, this study aims at investigating the feasibility of using machine-learning algorithms fed with data gathered from low-cost and portable instruments to identify the presence of TMD in adult subjects. Through this aim, the experimental protocol involved fifty participants, equally distributed between TMD and healthy subjects, acting as a control group. The diagnosis of TMD was performed by a skilled operator through the typical clinical scale. Participants underwent a baropodometric analysis by using a pressure matrix and the evaluation of the cervical mobility through inertial sensors. Nine machine-learning algorithms belonging to support vector machine, k-nearest neighbours and decision tree algorithms were compared. The k-nearest neighbours algorithm based on cosine distance was found to be the best performing, achieving performances of 0.94, 0.94 and 0.08 for the accuracy, F1-score and G-index, respectively. These findings open the possibility of using such methodology to support the diagnosis of TMDs in clinical environments.

The association of T102C (rs6313) polymorphism in the 5-HT2A receptor gene with temporomandibular disorders and anxiety in a group of Turkish population.

OBJECTIVE: To investigate the relationship between T102C (rs6313) polymorphism in the 5-hydroxytryptamine receptor-2A (5HTR2A) gene and temporomandibular disorder (TMD) and anxiety. METHODS: This observational case-control study included 80 patients and 70 healthy controls. TMD was diagnosed using the criteria for TMD (DC/TMD). Anxiety was assessed with the Beck anxiety scale. A genotyping study of HTRR2A T102C (rs6313) gene polymorphism was performed from genomic DNA isolated from blood. RESULTS: The TMD group had higher anxiety scores than the control group (p < .05). The TMD group was similar to the control group regarding genotype and allele frequencies. However, the polymorphic CC genotype was more common in those with high anxiety (p < .05). CONCLUSION: There was no clear evidence of an association between TMD and the T102C polymorphism in HTR2A and TMD. However, anxiety is closely related to the T102C polymorphism in HTR2A.

Challenged by the jaw - an interview study on patients' experiences of temporomandibular disorders in rheumatic inflammatory diseases.

PURPOSE: Rheumatic inflammatory diseases affecting the temporomandibular joint and the masticatory system (TMD) have been described as painful and limiting. However, the condition is often overlooked in primary care. The objective of this qualitative study was to explore and describe TMD-related experiences and perceptions of persons with rheumatic inflammatory disease, and to put this into a rehabilitation perspective. MATERIALS AND METHODS: Seven participants with rheumatic inflammatory disease and concomitant TMD were interviewed using a semi-structured interview guide. Giorgi's phenomenological method was used for analysis of the material. RESULTS: The general structure of the results after phenomenological reduction indicated that the phenomenon could be described as the process of being challenged by the jaw. Five themes emerged from the analysis; 1. Physical challenges of the jaw and the struggle to retain control, 2. Shame and social challenges, 3. Worrying about the future, frustration, grief, and loss of freedom, 4. Defiance, endurance, and efforts to maintain self-esteem, and 5. Health-care experiences. CONCLUSIONS: TMD in rheumatic inflammatory diseases are complex problems associated with various challenges to the sufferer. An increased awareness of the condition and earlier interventions could reduce both suffering and worsening of the condition.

The connection between the jaw and the rest of the body tends to be neglected.Questions about the jaw should be asked to detect eventual temporomandibular disorder (TMD) at an early stage to prevent worsening of the condition.Patient's experiences of TMD must be considered in the rehabilitation process.Health care providers are important for an earlier, more consistent, and more accessible diagnosis and treatment for this group of people.

Relationship Between Temporomandibular Joint Effusion, Pain, and Jaw Function Limitation: A 2D and 3D Comparative Study.

Purpose: This study aimed to investigate the relationship between temporomandibular joint (TMJ) effusion and TMJ pain, as well as jaw function limitation in patients via two-dimensional (2D) and three-dimensional (3D) magnetic resonance imaging (MRI) evaluation. Patients and Methods: 121 patients diagnosed with temporomandibular disorder (TMD) were included. TMJ effusion was assessed qualitatively using MRI and quantified with 3D Slicer software, then graded accordingly. In addition, a visual analogue scale (VAS) was employed for pain reporting and an 8-item Jaw Functional Limitations Scale (JFLS-8) was utilized to evaluate jaw function limitation. Statistical analyses were performed appropriately for group comparisons and association determination. A probability of p<0.05 was considered statistically significant. Results: 2D qualitative and 3D quantitative strategies were in high agreement for TMJ effusion grades (κ = 0.766). No significant associations were found between joint effusion and TMJ pain, nor with disc displacement and JLFS-8 scores. Moreover, the binary logistic regression analysis showed significant association between sex and the presence of TMJ effusion, exhibiting an Odds Ratio of 5.168 for females (p = 0.008). Conclusion: 2D qualitative evaluation was as effective as 3D quantitative assessment for TMJ effusion diagnosis. No significant associations were found between TMJ effusion and TMJ pain, disc displacement or jaw function limitation. However, it was suggested that female patients suffering from TMD may be at a risk for TMJ effusion. Further prospective research is needed for validation.

Investigating the effect of depression on clinical symptoms of temporomandibular disorder in young stressful men.

OBJECTIVES: The objective of this study was to investigate the relationship of the depression level with temporomandibular disorders (TMDs) in young conscripts as a population with chronic stresses. MATERIAL AND METHODS: A total number of 144 male conscripts with chronic stress and different levels of depression were assigned to four groups according to the Beck's Depression Inventory (BDI). The control group consisted of age-matched male conscripts without chronic stress. The diagnosis of TMD was made according to the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD). Data were analyzed using Mann-Whitney and chi-square tests. RESULTS: The participants with severe depression were significantly more susceptible to have TMD (p = .001) followed by the moderate depression, borderline clinical depression, mild mood disturbance, and control groups. The TMD diagnoses were more prevalent within depression groups compared with the control population (p = .01). CONCLUSIONS: The level of depression is directly associated with the presence of TMD in young men with chronic stress.

Association of night-time sleep and daytime napping with painful temporomandibular disorder.

BACKGROUND: Painful temporomandibular disorder (TMD) is the common cause of chronic oro-facial pain, which may interfere with sleep. Previous studies have documented an association between sleep and TMD. OBJECTIVES: This study aimed to further explore the association of night-time sleep and daytime napping with painful TMD. METHODS: A total of 419 patients (aged 31.88 ± 11.54 years with women forming 85.4%) from a TMD/Orofacial Pain center were enrolled. Patients' sleep conditions were evaluated with the Pittsburgh Sleep Quality Index (PSQI) questionnaire, and information on night-time sleep duration, napping duration and napping frequency was interviewed. TMD was diagnosed according to the Diagnostic Criteria for TMD protocol and stratified into myalgia (muscle pain), arthralgia (joint pain) and combined (muscle and joint pain) subgroups. The severity of TMD was measured with the Fonseca Anamnestic Index (FAI) questionnaire. Restricted cubic spline (RCS) regression models were established to explore relationships between sleep and painful TMD subgroups. RESULTS: Patients with poor sleep quality (PSQI≥6) had higher FAI scores (median 60, p < .001) and higher proportions of painful TMDs. The myalgia subgroup had higher PSQI scores (median 8, p < .001) than the arthralgia subgroup. The RCS models indicated a non-linear relationship between night-time sleep duration and myalgia (p < .001), which was not observed in arthralgia. However, there were no significant findings concerning napping and painful TMD subgroups. CONCLUSION: This study found that the association between sleep and TMD is mainly related to painful TMD conditions, which are associated with night-time sleep duration.

ß2-adrenergic receptor activation decreases the mechanical sensitivity of rat masticatory muscle afferent fibres.

BACKGROUND: Activation of ß2 adrenergic receptors reduces cutaneous mechanical pain thresholds in rats. While ß2 adrenergic receptor activation may contribute to mechanisms that underlie temporomandibular joint pain, its effect on masticatory muscle pain sensitivity is uncertain. OBJECTIVES: The current study sought to determine the extent to which ß adrenergic receptors are expressed by masticatory muscle afferent fibres, and to assess the effect of local activation of these receptors on the mechanical sensitivity of masticatory muscle afferent fibres in rats. METHODS: Trigeminal ganglion neurons that innervate the rat (n = 12) masseter muscle and lower lip were identified by tissue injection of fluorescent dyes and were then stained with antibodies against ß1 or ß2 adrenergic receptors. Extracellular recordings from 60 trigeminal ganglion neurons that innervate the masticatory muscle were undertaken in a second group of anaesthetised rats of both sexes (n = 37) to assess afferent mechanical activation thresholds. Thresholds were assessed before and after injection of the ß adrenergic receptor agonists into masticatory muscle. RESULTS: ß1 and ß2 adrenergic receptor expression was greater in labial skin than in masticatory muscle ganglion neurons (p < .05, one-way ANOVA, Holm-Sidak test). There was a higher expression of ß2 adrenergic receptors in masticatory muscle ganglion neurons in males than in females. The mixed ß agonist isoproterenol increased afferent mechanical activation threshold in male but not female rats (p < .05, Mann-Whitney test). In male rats, salbutamol, a ß2 selective agonist, also increased afferent mechanical activation threshold but hydralazine, a vasodilator, did not (p < .05, Mann-Whitney test). CONCLUSION: Activation of ß2 adrenergic receptors decreases the mechanical sensitivity of masticatory muscle afferent fibres in a sex-related manner.

Comparative effects of post isometric relaxation technique and Bowen's therapy on pain, range of motion and function in patients with temporomandibular joint disorder.

BACKGROUND: The most common cause of mouth and facial pain is a temporomandibular joint disorder, which affects the patient's quality of life and interferes with their ability to perform daily tasks. OBJECTIVE: The purpose was to compare the effects of the Post-Isometric Relaxation Technique and Bowen's Therapy on pain, range of motion and functional activity in patients with temporomandibular joint disorders. METHODS: This study was a randomized clinical trial. A total of 24 participants were randomly allocated into two groups using the lottery method. Baseline treatment was the same (ultrasound and tapping) in both groups. Group 1 (12 participants) was treated with a post-isometric relaxation technique, and Group 2 (12 participants) with Bowen's therapy for two sessions per week (total duration of 4 weeks). Outcome measures were the Numeric Pain Rating Scale, Maximal mouth opening inter-incisal rural and jaw functional limitation scale-20. SPSS version 25 was used for statistical analysis. RESULTS: A significant improvement in pain, range of motions and functional activities in the post-isometric group showed significant results (p < 0.05) as compared to Bowen's group (independent t-test). However, within-group comparison (paired t-test), both groups showed significant results (p < 0.05). CONCLUSION: This study concluded that post-isometric relaxation was more effective in terms of pain, range of motions for mouth opening, lateral deviations and functional activity of temporomandibular joint disorder patients. However, both groups showed clinical results according to minimal clinical difference values. TRIAL REGISTRY NUMBER: The trial is registered under ClinicalTrials.govt with reference no. ID: NCT05392049 registered on 26/05/2022.

Temporomandibular disorders in patients with HIV: a cross-sectional study.

Untreated HIV infection leads to severe immunodeficiency and can be associated with an accelerated aging process and a higher prevalence of frailty. Systemic changes are known to cause greater oral manifestations and decreased orofacial function. However, there is no investigation on Temporomandibular Disorders (TMD) in this population. This study aims to assess the prevalence of TMD in individuals living with HIV/AIDS. This cross-sectional study included HIV patients, with undetectable plasma viral load, under follow-up in the infectious disease's outpatient clinic at the Federal University of Bahia hospital. We recorded socio-demographic data, Fried's frailty criteria, Research Diagnostic Criteria for Temporomandibular Disorder, and Beck's Depression Inventory (BDI) through the application of structured questionnaires and extra-oral examination findings. Data analysis was conducted on SPSS-v18. The sample consisted of 198 patients. The prevalence of TMD was (33.8 %), most affecting females (46.6 %). Difficulty in opening the mouth and parafunctional habits were the main symptoms of the disease, as well as functional limitations. The mean of the BDI score was higher in TMD group than in those without TMD (11.01 ± 8.61 vs. 7.60 ± 7.52 valor de p = 0.004). Logistic regression showed an association between sex (OR=2.305, 95 % CI 1.243‒4.275) and depression (OR = 1.045, 95 % CI 1.005‒1.087) and TMD in HIV patients. The present study observed the prevalence of symptoms associated with TMD as difficulty opening the mouth, muscle fatigue, and joint noises in patients with chronic HIV and associated with depression. Highlights the importance of a broader view of the health of individuals living with HIV.

Orthodontic and orthopedic management of dentofacial deformity from juvenile idiopathic arthritis: a systematic literature review.

BACKGROUND: An update on the knowledge regarding the orthopedic/orthodontic role in treating JIA-related dentofacial deformities is relevant. OBJECTIVES: This systematic review aimed to assess the level of evidence regarding the management of dentofacial deformity from juvenile idiopathic arthritis (JIA) with orthodontics and/or dentofacial orthopedics. SEARCH METHODS: The following databases were searched without time or language restrictions up to 31 January 2024 (Medline, Embase, Cochrane Central Register of Controlled Trials, Scopus, Web of Science, and Latin American and Caribbean Health Sciences Literature). SELECTION CRITERIA: Inclusion criteria were studies dealing with JIA subjects receiving treatment with orthodontic and/or dentofacial orthopedic functional appliances. DATA COLLECTION AND ANALYSIS: After the removal of duplicate studies, data extraction, and risk of bias assessment according to ROBINS-I guidelines were conducted. Data extraction was conducted by two independent authors. RESULTS: The electronic database search identified 397 eligible articles after the removal of duplicates. Following the application of the pre-defined inclusion and exclusion criteria, 11 articles were left for inclusion. Two trials were associated with a severe risk of bias, four trials were at moderate risk of bias, and the other five presented a low risk of bias. Various research groups employed and documented the effects of different types of appliances and methodologies. The study heterogeneity did not allow for meta-analyses. In addition, a lack of uniformity in treatment objectives was observed across the included studies. After treatment with dentofacial orthopedics skeletal improvement was demonstrated in 10 studies, and a decrease in orofacial signs and symptoms was reported in 7 studies. CONCLUSIONS: Across the available literature, there is minor evidence to suggest that dentofacial orthopedics may be beneficial in the management of dentofacial deformities from JIA. There is little evidence to suggest that it can reduce orofacial signs and symptoms in patients with JIA. Based on current evidence, it is not possible to outline clinical recommendations for specific aspects of orthopedic management in growing subjects with JIA-related dentofacial deformity. REGISTRATION: PROSPERO (CRD42023390746).

Temporomandibular joint stress analysis of patients with different mandibular deformities during unilateral molar occlusion.

Mandibular prognathism, retrusion and deviation are common mandibular deformities. They can lead to functional and aesthetic problems due to their important role in the oral system. Different from other occlusions, unilateral molar occlusion often occurs during mastication, which has a deep impact on the functions of temporomandibular joints (TMJs). Therefore, the study of unilateral molar occlusion is of great importance and significance to the daily life of patients with mandibular deformities. A total of 35 individuals were involved in this study, including 11 asymptomatic subjects, 10 patients with mandibular prognathism, 5 patients with mandibular retrusion and 9 patients with mandibular deviation. Finite element (FE) models corresponding to the unilateral molar occlusion were constructed. During unilateral molar occlusion, mandibular deformity increases the pressure on the condyle and articular disc. Compared with mandibular protrusion or retraction, facial asymmetry will significantly increase the stress of TMJ. Chewing on the non-deviated side also will lead to higher stress in the TMJ of patients with mandibular deviation. Therefore, patients with mandibular deviation have the highest risk of temporomandibular disorder (TMD), and it is recommended that patients with mandibular deviation chew bilaterally or with the deviated side.