Vitamin D and Temporomandibular Disorders: What Do We Know So Far?

Vitamin D Levels and Temporomandibular Disorders: A Bidirectional Two-Sample Mendelian Randomization Analysis

Objective

Growing researches explore vitamin D's role in temporomandibular disorders (TMDs), but the link between vitamin D and TMDs remains debated. To clarify the causal relationship, we conducted a Mendelian randomization (MR) analysis using data from genome-wide association studies (GWAS).

Subjects and Methods

The GWAS dataset of vitamin D (GWAS ID: ukb-d-30890_irnt; sample size: 329247) was obtained from the IEU Open GWAS project. And that of TMDs (GWAS ID: finn-b-TEMPORO; sample size: 134280), initiated on August 25th, 2017 and publicly released on December 18th, 2023, was extracted from the FinnGen dataset, whose cases were diagnosed based on the revised International Classification of Diseases, 10th Edition (ICD-10) code K07.6. Both datasets were obtained from the European population. According to three assumptions of MR analysis, a bi-directional MR analysis was performed to measure the causal relationship, with Inverse variance weighted (IVW) as the primary method and MR Egger and Weighted median as supplement. Moreover, diverse sensitivity analyses, including Cochran's Q test, MR Egger intercept, Mendelian randomized polymorphism RESidual Sum and Outlier (MR-PRESSO), and leave-one-out analysis, were used to verify the stability of the findings.

Results

The MR analysis supported causal effects of vitamin D levels on TMDs risks within the European population using IVW method [odds ratio = 1.316; 95% confidence interval = 1.086 to 1.595; P = 0.005], supported by MR Egger and Weighted median. While there was no indication that TMDs have a direct impact on vitamin D levels [β: -0.00738, standard error = 0.00665; P = 0.568].

Conclusion

The study revealed that within the European population higher levels of vitamin D led to higher risks of developing temporomandibular disorders, but found no obvious evidence that TMDs are causally associated with vitamin D. The conclusion should be cautiously interpreted, given the selection bias of TMDs patients sample.

Nutritional Strategies for Chronic Craniofacial Pain and Temporomandibular Disorders: Current Clinical and Preclinical Insights

This narrative review provides an overview of current knowledge on the impact of nutritional strategies on chronic craniofacial pain associated with temporomandibular disorders (TMDs). Individuals experiencing painful TMDs alter their dietary habits, avoiding certain foods, possibly due to chewing difficulties, which might lead to nutrient deficiencies. Our literature investigation revealed that the causal links between nutritional changes and craniofacial pain remain unclear. However, clinical and preclinical studies suggest that nutraceuticals, including vitamins, minerals, polyphenols, omega-3 fatty acids, isoprenoids, carotenoids, lectins, polysaccharides, glucosamines, and palmitoylethanolamides, could have beneficial effects on managing TMDs. This is described in 12 clinical and 38 preclinical articles since 2000. Clinical articles discussed the roles of vitamins, minerals, glucosamine, and palmitoylethanolamides. The other nutraceuticals were assessed solely in preclinical studies, using TMD models, mostly craniofacial inflammatory rodents, with 36 of the 38 articles published since 2013. Our investigation indicates that current evidence is insufficient to assess the efficacy of these nutraceuticals. However, the existing data suggest potential for therapeutic intervention in TMDs. Further support from longitudinal and randomized controlled studies and well-designed preclinical investigations is necessary to evaluate the efficacy of each nutraceutical intervention and understand their underlying mechanisms in TMDs.

Therapeutic challenges in temporomandibular disorders

Background and aims

This study aimed at evaluating the etiology and treatment challenges of temporomandibular disorders (TMDs).

Methods

160 subjects with TMDs, 38 males (23.8%) and 122 females (76.3%) were studied. A personalized coefficient was designated, which included the resolution of the main symptom, correction of secondary symptoms, patient collaboration (emotional parameter), treatment duration, and cost.

Results

The most frequent cause for consultation was muscle impairment (42.5%), or limitation of mouth opening, followed by joint impairment (23.1%). Muscle pain was noticed, particularly in the masseter (57.5%) and lateral pterygoid muscles (51.9%). Tooth pain or gingival retraction was frequently associated with tooth wear (48.1%) and dental abfraction (31.3%). Remote symptomatology was dominated by otologic symptomatology. Iatrogenic etiology was highest (69.4%), followed by untreated missing teeth (66.9%). Treatment options included muscle relaxation, occlusal balancing (equilibration), kinesitherapy, medication, and swallowing re-education. Most patients benefited from four to seven different types of therapy, which resulted in a higher cost and a longer and more uncomfortable treatment. The primary symptom was relieved in 82.3% of cases, with recurrence occurring in 15.7%.

Conclusion

The treatment of temporomandibular joint dysfunction is time-consuming, demanding, and intricate. Most patients required four to seven different types of therapy, which increased the expense, treatment duration, and suffering.

Systemic Factors in Temporomandibular Disorder Pain

The science of temporomandibular disorder (TMD) pain and its management has gone through significant changes during the last several decades. The authors strongly feel that the effect of systemic factors influencing TMD pain has been largely overlooked and poorly accounted for, even in established pain-management programs and protocols. The hope is that this article will act as a wake-up call for the pain management community to consider the importance of adequate knowledge of the systemic factors that affect the experience of TMD pain by the patient.

Temporomandibular Joint Disorders and the Eating Experience

Temporomandibular joint disorder (TMD) is a chronic disorder that significantly affects oral function. It can affect appetite and the mechanical components involved with eating, including mandibular opening, biting, chewing, and even swallowing. Thus, dietary intake and, subsequently, nutrition status are affected. The functional challenges presented by the disorder affect eating-related quality of life and can affect food choices and diet quality and composition. This article addresses disorder-related factors affecting the eating experience of adults with TMDs and approaches to diet management.

Vitamin D3 Metabolism and Its Role in Temporomandibular Joint Osteoarthritis and Autoimmune Thyroid Diseases

The aim of this review was to present the metabolism of vitamin D3, as well as to discuss the role of vitamin D3 in bone metabolism, temporomandibular joint osteoarthritis (TMJ OA), and autoimmune thyroid diseases (AITD) on the basis of the literature. Vitamin D3 plays a significant role in human health, as it affects the calcium-phosphate balance and regulates the bone metabolism. Calcitriol impresses the pleiotropic effect on human biology and metabolism. Its modulative function upon the immune system is based on the reduction of Th1 cell activity and increased immunotolerance. Vitamin D3 deficiency may lead to an imbalance in the relationship between Th1/Th17 and Th2, Th17/Th reg, and is considered by some authors as one of the possible backgrounds of autoimmune thyroid diseases (AITD), e.g., Hashimoto's thyroiditis or Graves' disease. Moreover, vitamin D3, through its direct and indirect influence on bones and joints, may also play an important role in the development and progression of degenerative joint diseases, including temporomandibular joint osteoarthritis. Further randomized, double blind studies are needed to unequivocally confirm the relationship between vitamin D3 and abovementioned diseases and to answer the question concerning whether vitamin D3 supplementation may be used in the prevention and/or treatment of either AITD or OA diseases.

The Prevalence and Predicting Factors of Temporomandibular Disorders in COVID-19 Infection: A Cross-Sectional Study

Introduction

During the pandemic of coronavirus disease 2019 (COVID-19), an increase in temporomandibular disorders (TMDs) was noticed in infected patients. In the present study, we aimed to assess the prevalence of TMDs during COVID-19 infection and to evaluate associated factors.

Methods

An observational cross-sectional online survey was conducted in April and May 2021 in order to estimate the prevalence of TMDs in participants who were previously infected with COVID-19. A multivariable logistic regression model was carried out to explore predicting factors of TMDs during COVID-19 infection.

Results

In total, the prevalence of TMDs during the COVID-19 infection period among participants was 41.9%. High fever episodes (adjusted odds ratio {aOR}: 3.25), gastro-esophageal reflux (aOR: 2.56), and toothache (aOR: 3.83) during COVID-19 illness were found to be positive predictors of TMDs, while vitamin D deficiency was found to be a negative predictor (aOR: 0.28).

Conclusion

Our study has highlighted a relatively high prevalence of TMDs in COVID-19-infected patients that may conclude TMDs as a possible COVID-19 symptom. Further studies are warranted to confirm the association between TMDs and COVID-19 infection and thereupon include TMDs among the known symptoms of COVID-19.

Effectiveness of Vitamin D along with Splint therapy in the Vit D deficient patients with Temporomandibular disorder-A Randomized, double-blind, placebo-controlled clinical trial

Aim

The purpose of this study is to comparatively evaluate the Vitamin D supplementation and stabilization splint therapy in patients exhibiting temporomandibular disorders (TMD).

Settings and Design

The study design was double-blinded, parallel-group, randomized and placebo-controlled trial conducted in patients with low Vitamin D and TMDs, which were allocated to two groups, Study group S + D (Stabilization splint with Vitamin D supplementation) and Control Group S (Stabilization Splint with placebo drug).

Subjects and Methods

Thirty-six participants of 18-45 years of age gap with Vitamin D deficiency and TMD were included in the study. Preoperative values of Vitamin D levels in ng/ml, comfort mouth opening (CMO) in mm, maximum mouth opening (MMO) in mm, temporomandibular joint (TMJ) tenderness (grading 0-3), Visual analog scale score (VAS Score 0-10 cm), and total energy (TE) integral values of both left and right TMJ's in Hertz (Hz) were recorded using joint vibration analysis All the values of CMO, MMO, TMJ Tenderness and VAS were recorded at each follow-up at 1^st week, 1^st month, 2^nd month, and 3^rd month, respectively. Postoperative Vitamin D levels and TE of both TMJs were recorded at end of 3 months.

Statistical Analysis Used

For intergroup comparison, Mann-Whitney U-test and Pearson Chi-square tests were done. For Intragroup comparison, Wilcoxon signed rank test was used for comparison.

Results

In Intergroup comparison, a significant difference was seen in CMO, VAS score and MMO (P < 0.05) but not among mean values of TE of right and left TMJ, and Vitamin D levels (P < 0.05). In both groups, there were significant statistical variations in CMO, VAS score, MMO, and TE integral before and after treatment in the right and left TMJs (P < 0.05).

Conclusions

The study concludes centric stabilization splint helps in improving symptoms of TMD patients and Vitamin D supplementation provided faster relief in those cases.