The prevalence of first-onset temporomandibular disorder in low back pain and associated risk factors: A nationwide population-based cohort study with a 15-year follow-up

Assessment of chronic overlapping pain comorbidities for the management of temporomandibular disorders: Secondary analysis of a randomized clinical trial

BACKGROUND

Chronic painful temporomandibular disorders (TMD) are a functional pain syndrome that embodies a spectrum of clinical manifestations and expresses great complexity through the coexistence of multiple comorbidities.

OBJECTIVE

Evaluate the prevalence of pain comorbidities, explore the correlation between comorbidities, kinesiophobia, catastrophizing, and pain disability at baseline, and determine variables of interest for prediction response to physiotherapy interventions at different follow-up times.

METHODS

This is a secondary analysis of a previously conducted randomized controlled trial (RCT). Outcomes and covariables for this secondary analysis were collected from subjects with chronic TMD (≥3 months), based on the DC/TMD diagnostic criteria, assigned to a multimodal treatment and a second manual therapy control group. The participants underwent follow-up assessment at 7 and 19 weeks. The outcomes (dependent variables) for these analyses were craniofacial pain disability, catastrophizing, and kinesiophobia. However, these outcomes were also used as covariables of interest in addition to comorbidity prevalence and severity at baseline for different analyses. We performed linear regression analyses to determine the association between our outcomes and covariables at baseline and at different follow-ups.

RESULTS

Comorbidity severity explained craniofacial pain disability at baseline, showing a strong correlation (Standardized B: 0.40, p-value: 0.017). Higher comorbidity severity, led to higher craniofacial pain score. Comorbidity severity and baseline catastrophizing predicted a better response to treatment for craniofacial pain improvements at short and long term (R2 .22, p-value : 0.009 and R2 .19, p-value: 0.02 respectively).

CONCLUSION

This study provides insight into the prevention and clinical management of chronic pain related to TMD.

Risk factors for temporomandibular disorders: a systematic review of cohort studies

OBJECTIVE

A systematic review was performed to synthesize and identify risk factors involved in TMD onset.

STUDY DESIGN

Electronic searches were conducted in PubMed, Web of Science, Scopus, Embase, PsyInfo and Lilacs databases, as well as in three gray literature databases (Google Scholar, ProQuest and Open grey). The studies were blindly assessed by two reviewers and selected by a pre-defined eligibility criterion. Risk of bias of included studies was assessed using the Joanna Briggs Institute Critical Appraisal Checklist for Cohort Studies. Grading of Recommendations Assessment, Development and Evaluation (GRADE) was evaluated for most related factors.

RESULTS

Twenty-one cohort studies were included. Significant factors were female gender, symptoms of depression and anxiety, perceived stress, sleep quality, symptoms of obstructive sleep apnea and presence of any comorbidity, such as Irritable Bowel Syndrome, lower back pain, headache frequency, tension-type headache, migraine and mixed headache. Moreover, high estrogen and low testosterone levels in utero, greater pain perception, jaw mobility pain, pain during palpation, orofacial anomalies, as well as extrinsic and intrinsic injuries were also significant.

CONCLUSIONS

Several factors seems to be involved in TMD onset, however, more studies with standardized methodology are necessary to confirm these findings.

Knowledge and awareness about temporomandibular disorder among dentists in India: Questionnaire study and review

AIM

Temporomandibular disorders (TMD) comprise ailments involving the jaw joint (temporomandibular joint) and its associated anatomical structures. The complexity involved in TMD is primarily due to its broad spectrum of conditions, clinical signs and symptoms variability, and multifactorial etiology. Considering the above, the present study was performed to help understand the prevailing knowledge and awareness of TMD among Indian dentists in the context of the new specialty "orofacial pain".

SETTINGS AND DESIGN

Questinnaire study and review.

MATERIALS AND METHODS

The questionnaire was distributed using a web-based portal nationwide among Indian dentists. Dentists were invited to participate, clearly stating that the intent and purpose of the questionnaire was to record the existing knowledge and awareness concerning temporomandibular disorders among Indian dentists. The questionnaire was segregated into three sections: pathogenesis, diagnosis, and management of TMDs. The questions were recorded using a Likert three-point scale (1=agree; 2=disagree; 3=not aware). 310 dentists participated in the survey, among which 105 were general dentists (BDS [Bachelor of Dental Surgery] graduates), and 205 were dentists with specialist training (MDS [Masters of Dental Surgery] graduates).

STATISTICAL ANALYSIS USED

The results obtained from the study participants was used to calculate the percentage and frequency, following which tabulations were made based on graduate type and clinical experience. The values obtained from all three sections were recorded, and the responses were analysed using Pearson's Chi-Square test with statistical significance kept at P < 0.05.

RESULTS

Results of the study disclosed that only 58.1% of general dentists and 46.8% of specialists were confident in handling temporomandibular disorder patients. Splint therapy was the preferred treatment modality for general dentists, whereas dentists with specialist training preferred occlusal rehabilitation.

CONCLUSION

The results of the current survey indicate that Indian dentists lack sufficient training in dental schools on all three sections and face difficulty diagnosing and treating TMDs.

The effects of lumbar stabilization exercises with and without jaw movements in non-specific low back pain (A randomized controlled trial)

Objective

This study aimed to investigate the added effect of jaw clenching on the efficacy of lumbar stabilization exercises to manage chronic non-specific low back pain.

Methods

This randomized controlled trial was conducted at the Sindh Institute of Physical Medicine and Rehabilitation (SIPM&R) Karachi from April 2021 to April 2023. Eighty patients with chronic non-specific low back pain participated in this study. Forty patients each were randomly allocated to the lumbar stability exercise (LSE) group' and the lumbar stability exercise with teeth clenching (LSETC) group. Patients in both groups performed respective exercises twice weekly for 12 weeks. The Numeric Pain Rating Scale (NPRS), Roland Morris Disability Questionnaire (RMDQ), and Pressure Biofeedback Unit (PBU) were used to assess pain, disability, and muscle endurance respectively. Data were collected at the baseline, after six weeks and 12 weeks of intervention. A p-value of <0.05 was considered statistically significant.

Results

Both groups showed statistically significant improvements in pain, disability, and muscle endurance. Upon further stratification, participants aged 20-30 years in the LSETC group showed significantly higher scores than the LSE group for NPRS, RMDQ, and PBU after 12 weeks. Overall, the LSETC group showed relatively higher improvement in mean scores for NPRS, RMDQ, and PBU than the LSE group.

Conclusion

Lumbar stabilization exercises with and without jaw movement are effective for the treatment of chronic non-specific low back pain. The addition of teeth clenching enhanced the effectiveness of lumbar stability exercises, especially in young adults. Trial Registration: Clinicaltrials.gov (NCT04801212), Prospectively registered on March 16, 2021.

Diaphragm dysfunction is found in patients with chronic painful temporomandibular disorder: A case-control study

Aim

To determine whether patients with chronic painful temporomandibular disorder (TMD) had abnormal diaphragm function compared to healthy controls and to explore the correlation between diaphragm contractility, psychological status, and pain characteristics.

Methods

A single-blinded, case-control study was conducted involving 23 chronic painful TMD patients and 22 healthy volunteers. The examination and diagnosis were performed according to the Diagnostic Criteria for Temporomandibular Disorders, and questionnaires were used to evaluate pain, depression, anxiety, and physical symptoms status. B-mode ultrasound was used to measure diaphragm thickness and contractility. The sonographer responsible for measuring the diaphragm was blinded to group membership.

Results

1. Depression, anxiety, and physical symptoms scores were significantly higher in the patients than in the controls (p < 0.05). 2. The Interference Score of pain was significantly correlated with depression and physical symptoms (p < 0.01). 3. Bilateral diaphragm contractility was significantly smaller in the patients than in the controls (right: P = 0.003; left: P = 0.001). 3. There was no correlation between diaphragm contractility on the left and right sides in the patients (r = -0.112, P = 0.611), while there was a positive correlation in the control group (r = 0.638, P = 0.001). 4. No correlation was found between the degree of diaphragm contractility, psychological status, and pain scores.

Conclusions

1. Patients with chronic painful TMD have worse psychological status, including depression, anxiety, and physical symptoms. 2. Patients with chronic painful TMD have a smaller degree of bilateral diaphragm contractility and more significant left-right incongruity, which indicated that diaphragm dysfunction may be correlated with chronic painful temporomandibular disorder.

A comprehensive patient-specific prediction model for temporomandibular joint osteoarthritis progression

Temporomandibular joint osteoarthritis (TMJ OA) is a prevalent degenerative disease characterized by chronic pain and impaired jaw function. The complexity of TMJ OA has hindered the development of prognostic tools, posing a significant challenge in timely, patient-specific management. Addressing this gap, our research employs a comprehensive, multidimensional approach to advance TMJ OA prognostication. We conducted a prospective study with 106 subjects, 74 of whom were followed up after 2 to 3 y of conservative treatment. Central to our methodology is the development of an innovative, open-source predictive modeling framework, the Ensemble via Hierarchical Predictions through Nested cross-validation tool (EHPN). This framework synergistically integrates 18 feature selection, statistical, and machine learning methods to yield an accuracy of 0.87, with an area under the ROC curve of 0.72 and an F1 score of 0.82. Our study, beyond technical advancements, emphasizes the global impact of TMJ OA, recognizing its unique demographic occurrence. We highlight key factors influencing TMJ OA progression. Using SHAP analysis, we identified personalized prognostic predictors: lower values of headache, lower back pain, restless sleep, condyle high gray level-GL-run emphasis, articular fossa GL nonuniformity, and long-run low GL emphasis; and higher values of superior joint space, mouth opening, saliva Vascular-endothelium-growth-factor, Matrix-metalloproteinase-7, serum Epithelial-neutrophil-activating-peptide, and age indicate recovery likelihood. Our multidimensional and multimodal EHPN tool enhances clinicians' decision-making, offering a transformative translational infrastructure. The EHPN model stands as a significant contribution to precision medicine, offering a paradigm shift in the management of temporomandibular disorders and potentially influencing broader applications in personalized healthcare.

Statistical Methods and Machine Learning Algorithms for Investigating Metabolic Syndrome in Temporomandibular Disorders: A Nationwide Study

The objective of this study was to analyze the associations between temporomandibular disorders (TMDs) and metabolic syndrome (MetS) components, consequences, and related conditions. This research analyzed data from the Dental, Oral, Medical Epidemiological (DOME) records-based study which integrated comprehensive socio-demographic, medical, and dental databases from a nationwide sample of dental attendees aged 18-50 years at military dental clinics for 1 year. Statistical and machine learning models were performed with TMDs as the dependent variable. The independent variables included age, sex, smoking, each of the MetS components, and consequences and related conditions, including hypertension, hyperlipidemia, diabetes, impaired glucose tolerance (IGT), obesity, cardiac disease, obstructive sleep apnea (OSA), nonalcoholic fatty liver disease (NAFLD), transient ischemic attack (TIA), stroke, deep venous thrombosis (DVT), and anemia. The study included 132,529 subjects, of which 1899 (1.43%) had been diagnosed with TMDs. The following parameters retained a statistically significant positive association with TMDs in the multivariable binary logistic regression analysis: female sex [OR = 2.65 (2.41-2.93)], anemia [OR = 1.69 (1.48-1.93)], and age [OR = 1.07 (1.06-1.08)]. Features importance generated by the XGBoost machine learning algorithm ranked the significance of the features with TMDs (the target variable) as follows: sex was ranked first followed by age (second), anemia (third), hypertension (fourth), and smoking (fifth). Metabolic morbidity and anemia should be included in the systemic evaluation of TMD patients.

Treating Parafunctional Habits for Alleviating Temporomandibular Disorder and Lower Back Pain: A Phase II Clinical Trial

Objectives: Temporomandibular disorders (TMDs) include a series of signs and symptoms in the temporomandibular joints (TMJ) and muscles of mastication, which are associated with or caused by parafunctional habits. Many of these patients also suffer from lumbar pains. This study aimed to evaluate the effectiveness of treating parafunctional habits in alleviating symptoms of TMD and lower back pain. Materials and Methods: This phase II clinical trial was conducted on 136 patients suffering from TMDs and lumbar pain, who consented to participate in this study. They were provided with instructions on how to discontinue their parafunctional habits including clenching and bruxism. The Helkimo and Rolland Morris questionnaires were used to assess TMD and lower back pain, respectively. Data were statistically analyzed using paired Student's t-test, Wilcoxon, Mann-Whitney, and Spearman correlation tests, with the significance level set at P<0.05. Results: The mean severity score of TMD significantly decreased after the intervention. Following treatment of TMD, the mean severity score of lumbar pain decreased from 8 to 2 (P=0.0001). Conclusion: Based on our findings, it appears that the elimination of parafunctional habits improves TMD and lumbar pain.

Temporomandibular Joint Disorder Comorbidities

Comorbidity is a distinct additional condition that either existed or exists during the clinical course of a patient afflicted by the condition/entity in question. The clinician attempting to manage temporomandibular joint disorder (TMD) and TMD pain must realize that recognition and management of the comorbidities are essential to the successful management of the same with optimal pain control. When TMD presents with multiple comorbidities, the task for the clinician becomes more complex. It is the hope of the authors that this condensed version of TMD-associated comorbidities acts as a primer for understanding the significance of the same in pain management.

Evaluation of the effect of vitamin D3 on mandibular condyles in an ovariectomized mouse model: a micro-CT study

BACKGROUND

This study aimed to investigate the effect of ovariectomy and vitamin D3 on bone microstructure; this effect was examined in three regions of interest at one femoral and two mandibular sampling sites bone in an ovariectomized mouse model.

METHODS

Thirty-six week-old female mice were randomly divided into three groups: 10 subjects were given oral cholecalciferol (vitamin D3) daily for 6 weeks after undergoing bilateral ovariectomy (D3 group), while 10 ovariectomized subjects (OVX) and 10 subjects who underwent a sham operation (SHAM) received peanut oil daily during the investigation. After extermination, the left hemimandible and femur were removed and scanned by micro-CT. The bone micromorphology parameters were analyzed and the BMD was calculated.

RESULTS

The bone volume fraction (BV/TV) was significantly lower in the trabecular bone of the mandibular condyle in the OVX group than in the SHAM and D3 groups. Also there was a significant difference between the SHAM and D3 groups. The specific bone surface (BS/BV) was significantly higher in the OVX and D3 groups than in the SHAM group. Trabecular thickness (Tb.Th) was significantly higher in the SHAM group, and the trabecular bone pattern factor (Tb.Pf) was significantly higher in the OVX group than in the other two groups. Bone mineral density (BMD) of the femur and the mandible was significantly lower in the OVX group than in the SHAM and D3 groups.

CONCLUSIONS

Our results show that ovariectomy causes a significantly weaker bone microstructure in the mandibular condyle, where the protective effect of vitamin D3 resulted in a partial resorption.