Relation of vitamin D and BsmI variant with temporomandibular diseases in the Turkish population

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.

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.

Genetic association of the BsmI variant of vitamin D receptor gene with risk of morbid obesity

OBJECTIVE

The aim of this study was to evaluate the vitamin D receptor (VDR) BsmI variant in morbidly obese patients compared with healthy normal controls.

METHODS

The study included 103 patients with morbid obesity and 120 healthy individuals serving as normal controls. The DNA samples obtained from blood were genotyped using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique. The gender, age, smoking status, triglycerides, total cholesterol, insulin, mean body mass index, and frequency of allele and genotype of the BsmI variant in the VDR gene in morbidly obese patients were evaluated.

RESULTS

The body mass index of the patients was 47.14 ± 7.19. The VDR B/B, B/b, and b/b genotype frequencies were 27.2% versus 28.3%; 54.4% versus 50%; and 18.4% versus 21.7% in the morbidly obese patients and the control group, respectively. There was no statistically significant difference between patients and control subjects in the genotype and allele distribution of the VDR BsmI variant (p>0.05). Both patients and control genotype frequencies are consistent with Hardy-Weinberg equilibrium.

CONCLUSION

The BsmI variant in the VDR gene may not seem to predispose to morbid obesity in our study population. Further studies with a larger number of subjects are needed to make a more precise evaluation of this relationship.

Nutrient insufficiencies and deficiencies involved in the pathogenesis of bruxism (Review)

Stress has been well-documented to have a significant role in the etiopathogenesis of bruxism. Activation of the hypothalamic-pituitary-adrenal axis (HPA) and subsequent release of corticosteroids lead to increased muscle activity. Neurological studies have demonstrated that chronic stress exposure induces neurodegeneration of important neuronal structures and destabilization of the mesocortical dopaminergic pathway. These disruptions impair the abilities to counteract the overactivity of the HPA axis and disinhibit involuntary muscle activity, while at the same time, there is activation of the amygdala. Recent evidence shows that overactivation of the amygdala under stressful stimuli causes rhythmic jaw muscle activity by over activating the mesencephalic and motor trigeminal nuclei. The present review aimed to discuss the negative effects of certain vitamin and mineral deficiencies, such as vitamin D, magnesium, and omega-3 fatty acids, on the central nervous system. It provides evidence on how such insufficiencies may increase stress sensitivity and neuromuscular excitability and thereby reduce the ability to effectively respond to the overactivation of the sympathetic nervous system, and also how stress can in turn lead to these insufficiencies. Finally, the positive effects of individualized supplementation are discussed in the context of diminishing anxiety and oxidative stress, neuroprotection and in the reversal of neurodegeneration, and also in alleviating/reducing neuromuscular symptoms.

Polymorphism but not methylation status in the vitamin D receptor gene contributes to oral mucositis in children

OBJECTIVE

To investigate the relationship between the polymorphisms rs1544410 (BsmI), rs2228570 (FokI) and rs731236 (TaqI) and DNA methylation status in the VDR gene (vitamin D receptor) with oral mucositis (OM) in oncopaediatric patients treated with methotrexate (MTX®).

METHODS

The population comprised healthy patients with haematological malignancies aged between 5 and 19 years. An evaluation of oral conditions was performed using the Oral Assessment Guide. Demographic, clinical, biochemical and haematological data were obtained from medical records. Genomic DNA from oral mucosal cells was used for the analysis of polymorphisms (n = 102) (PCR-restriction fragment length polymorphism) and DNA methylation (n = 81) (methylation-specific PCR).

RESULTS

Males predominated (57.8%), and the mean age was 10.3 years (±4.7). OM affected 84.3% of patients, of which 53.1% developed severe oral mucositis (SOM). Patients with OM had lower platelet and leukocyte counts (p < 0.05). The G allele of rs1544410 (p = 0.040) and the CT genotype of rs2228570 polymorphisms were associated with SOM (p = 0.038). A partially methylated status in the VDR promoter was found in all patients.

CONCLUSION

OM is associated with lower leukocyte and platelet counts. SOM is associated with the rs1544410 and rs2228570 polymorphisms. The methylation status of the VDR is not associated with inflammation or exposure to MTX®.

Effect of vitamin D receptor gene BsmI polymorphism on hospitalization of SARS-CoV-2 positive patients

Low vitamin D levels and adverse effects have been reported in SARS-COV-2 positive patients. This study examined the effect of the vitamin D receptor gene BsmI polymorphism on SARS-COV-2 positive patients. A total of 80 SARS-COV-2 positive inpatients were included in the study, and 110 healthy individuals were included as a control group. The 25-(OH) vitamin D3, lymphocyte, and activated partial thromboplastin time levels of SARS-COV-2 positive patients were lower than those of the control group. The prothrombin time (PT), international normalized ratio (INR), D-dimer, C-reactive protein (CRP), procalcitonin, and ferritin levels of SARS-COV-2 positive patients were higher than those of the control group. A negative correlation was found between 25-(OH) vitamin D3 levels and white blood cell count, PT, INR, D-dimer, CRP, procalcitonin, and ferritin levels in SARS-COV-2 positive patients. The 25-(OH) vitamin D3 level in individuals with the BB genotype was higher than the 25-(OH) vitamin D3 level in individuals with the Bb and bb genotype. A statistically significant difference was found between the groups in terms of the genotype and allele distributions of BsmI polymorphism. When the genotypes were analyzed in terms of bb versus Bb + BB, a statistically significant difference was found between the groups. However, this finding was not found between the intensive care inpatient subgroup and the other inpatient subgroup. In conclusion, BsmI b allele and bb genotype were associated with hospitalization for SARS-COV-2 infection. This may be because individuals with b allele have low levels of vitamin D.

Association of Serum Vitamin D Level with Temporomandibular Disorder Incidence: A Retrospective, Multi-Center Cohort Study Using Six Hospital Databases

The relationship between serum vitamin D levels and temporomandibular disorders (TMDs) remains unclear. Therefore, this study aimed to investigate the association between serum 25-hydroxyvitamin D (25[OH]D) levels and TMD incidence using large-scale health data. Clinical data from the electronic health records of six secondary or tertiary hospitals in Korea were used to evaluate the relationship between serum 25(OH)D levels and TMD incidence. The data were converted to the Observational Medical Outcomes Partnership Common Data Model. A cohort study was designed using the Cox proportional hazards model to examine the hazard ratio (HR) of TMD development after propensity score matching (PSM). An aggregate meta-analysis of the HR was subsequently performed. After 1:4 PSM, a target group with deficient 25(OH)D levels (<20 ng/mL) (N = 34,560) and comparator group with non-deficient 25(OH)D levels (≥20 ng/mL) (N = 47,359) were pooled from six hospital databases. HR meta-analysis demonstrated a significant association between deficient 25(OH)D levels and TMD incidence (pooled HR: 1.50; 95% confidence interval: 1.07-2.12). In conclusion, deficient 25(OH)D levels were found to be associated with an increased TMD risk. Therefore, vitamin D deficiency is a potential risk factor for TMD development.

The relationship of biochemical factors related to calcium metabolism with temporomandibular disorders

OBJECTIVE

The aim of this study is to investigate the relationship between calcium metabolism-related biochemical factors (alkaline phosphatase, vitamin D, parathyroid hormone (PTH), calcium, phosphorus and magnesium), and temporomandibular joint (TMJ) disk displacement with reduction (DDWR).

MATERIALS AND METHODS

This prospective observational study included patients with temporomandibular disorders (TMDs) (n = 50) and healthy controls (n = 50) of similar age and sex. The diagnosis of TMJ DDWR was made using the diagnostic criteria for temporomandibular joint disorders (DC/TMD). Both groups were compared in terms of serum alkaline phosphatase, 25 (OH) vitamin D, PTH, calcium, magnesium, and phosphorus levels. P<0.005 was accepted as a significant difference.

RESULTS

There was no significant difference between the groups in terms of age, gender, and body mass index (BMI). Calcium levels of patients with TMD were statistically significantly lower than control patients (p<0.05). While there was no significant difference between the two groups in terms of mean VIT D, the number of people with severe Vit D deficiency (<10 ng) in the TMD group was significantly higher than in the control group (p<0.05). There was no statistically significant difference between the groups in terms of serum alkaline phosphatase, magnesium, phosphorus and PTH levels.

CONCLUSION

The differences in serum calcium and vitamin D levels seen in the study indicate that biochemical factors related to calcium metabolism may be associated with TMJ DDWR. These results suggest that calcium and vitamin D deficiency should be evaluated and corrected in patients with TMD.

Role of VEGF I/D variant in suspectibility to odontogenic cyst formation

Odontogenic cysts, are located in the jawbones, filled with fluid surrounded by epithelial lining and fibrous connective tissue. Vascular endothelial growth factor (VEGF) can induce physiological and pathological angiogenesis and is an endothelial cell-specific mitogen. The aim of the present study was to investigate whether any possible association between the VEGF insertion/deletion (I/D) variant and odontogenic cyst in Turkish population. Clinical information and venous blood samples were collected from 62 odontogenic cyst patients and 98 healthy controls. DNA was isolated from peripheral blood leukocytes. Genotyping of the VEGF I/D variant was done by the polymerase chain reaction (PCR) method. There was a statistically differece in terms of VEGF I/D allele frequencies between patients and controls. VEGF I/D variant I allele frequency was more prevalant in patients compared to controls (p = 0.006411, OR: 2.08, 95%Cl: 1.322-3.272). A statistically significant association was observed when the patients were compared with the controls according to D/D + I/D versus I/I genotype (p = 0.0508, OR: 1.925, 95%Cl: 0.872-4.246). The genotype distribution of VEGF I/D was not statistically different between patients and controls (p > 0.05). For the first time, our results provided evidence supporting the odontogenic cyst formation associated with the I/D variant at the promoter region of the VEGF gene in a group of Turkish population. Although it was seen in our study that the I/D variant in the promoter region of the VEGF gene supports odontogenic cyst formation, large-scale studies are needed to elucidate the effect of this variant on odontogenic cysts.

Is the Prevalence of Vitamin D deficiency in Patients with Temporomandibular Disorder Higher than Healthy Control Group?

Purpose

Vitamin D plays an essential role in subchondral bone, cartilage, and periarticular muscle. This study aims to assess the prevalence of vitamin D deficiency in temporomandibular disorder (TMD) patients.

Materials and methods

This is a cross-sectional study. Subjects were assigned into two groups based on having signs and symptoms of TMD: Group 1: subjects had TMD, and group 2 healthy group (control group). The serum level of vitamin D was measured in the two groups. The independent t test was used to compare the serum level of vitamin D between the study and control groups.

Results

One hundred ten subjects were studied into two groups (55 subjects in each group). The mean serum level of vitamin D was 18.13 ± 6.38 ng/mL in the study group and 31.83 ± 7.00 ng/mL in the control group. Analysis of the data demonstrated a significant difference in the mean serum level of vitamin D between the study and control groups (p = 0.001).

Conclusion

It seems the serum level of vitamin D is lower in TMD patients than in the healthy control group.

Temporomandibular Disorders and Vitamin D Deficiency: What Is the Linkage between These Conditions? A Systematic Review

Although a growing body of literature has been emphasizing the role of vitamin D in oral health, there is still a gap of knowledge regarding the correlation between temporomandibular disorders (TMDs) and vitamin D. Therefore, the aim of this systematic review was to assess the linkage between hypovitaminosis D and TMDs to map the current literature in this field. On 10 September 2022, PubMed, Scopus, and Web of Science databases were systematically searched from the date of their inception to identify the studies that had assessed patients with TMDs. The primary outcome assessed in this review was the relationship between hypovitaminosis D and TMDs. Out of the 329 studies identified, 13 studies met the eligibility criteria and were included in the present work. Seven studies assessed the relationship between vitamin D and TMDs, reporting that vitamin D serum levels are lower in patients with TMDs. Our results suggested that vitamin D receptor (VDR) polymorphisms might have a role in TMDs' development. However, the quality assessed underlined that only one study did not present a serious risk of bias. Further good-quality studies are needed to clarify the linkage between vitamin D deficiency and TMDs, but the evidence currently available has suggested potential correlations.

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.

Potential adjunct therapies for the management of temporomandibular disorders: An evidence-based review

OBJECTIVE

The aim was to review the role of adjuvant therapies that may potentially contribute toward the management of temporomandibular disorders (TMD).

METHODS

The addressed focused question was, "Are there any adjuvant therapies that may contribute toward the management of TMD?". Indexed databases were searched up to June 2021. The eligibility criteria were the following: (a) original clinical studies and (b) randomized controlled clinical trials (RCTs).

RESULTS

Adjuvant therapies were comprised of acupuncture, manual therapy, jaw exercises, dietary modifications, botulinum toxin therapy, and photobiomodulation. Short-term follow-up results from each of these RCTs showed beneficial effects in terms of pain reduction and improvements in jaw movement among patients with TMD. There are no long-term follow-up results in this regard.

CONCLUSION

The most effective adjunct treatment for managing TMD remains unknown, primarily due to a lack of sufficient scientific evidence.

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

Background and aims. Vitamin D is synthesized in the skin with the aid of ultraviolet-B radiation, playing a variety of roles in the body. Temporomandibular disorders (TMDs) are a group of pathological conditions involving the temporomandibular joints as well as the masticatory muscles and othersurrounding tissues. In the present narrative review, we investigated the potential role of vitamin D in the etiology of temporomandibular disorders in order todetermine whether the current knowledge supports 25-hidroxyvitamin D (25-OHD) supplementation in temporomandibular disorders associated with insufficient or deficient levels of vitamin D. Methods. A literature research was performed in PubMed, Scopus, Science Direct, and Google Scholar databases, and a total of 10 articles were included for analysis. Results.Among the observational studies published to date, investigating the role for vitamin D in the etiology of TMDs, six of them suggest that there is a connection between the two aspects. In this context, patients suffering from TMD, with deficient levels of vitamin D (<30 ng/mL), are most likely to benefit from supplementation, whereas individuals with vitamin D level >50ng/mL probably have little benefit from supplementation.Conclusion.Vitamin D might be a safe, simple, and potentially beneficial way to prevent TMDs or to reduce pain; however, more randomized and placebo-controlled trials are required before any firm conclusions can be drawn.