Myogenous temporomandibular disorders and salivary markers of oxidative stress-A cross-sectional study

Piano level laser therapy versus epidermal growth factor injection for painful myogenic temporomandibular disorder (a randomized clinical trial)

OBJECTIVE

The aim of this clinical trial was to evaluate the effectiveness of Piano level laser therapy using Nd-YAG laser and intramuscular EGF injection in pain alleviation, function, and quality of life improvement in patients suffering from myogenic TMD.

MATERIALS AND METHODS

A randomized clinical trial was performed on 29 patients suffering from chronic painful myogenic TMD based on diagnostic criteria for temporomandibular disorders. Group I (n = 13patients) was treated using 1064 nm Nd-YAG Laser (4 sessions once/week). Group II (n = 14 patients) was treated by intramuscular injection of EGF. Pain using numerical rating score, pain free opening and unassisted maximum opening were measured at baseline, 7,14,21 days, 1 and 3 months. Quality of life using OHIP-14 was assessed at baseline, 1 and 3 months.

RESULTS

Results showed that there was a significant pain reduction (P < 0.000) and increase in pain free opening (P < 0.0001) in both test groups. However, only group I showed a significant increase in maximum opening (P = 0.007). Quality of life significantly improved in both groups (P = 0.0001). There was no significant difference between the two treatments in pain scores, pain free opening, maximum opening nor quality of life.

CONCLUSION

Both treatment modalities offered effective and cost-effective non- to minimally invasive treatment options for myogenic TMD with no side effects.

CLINICAL RELEVANCE

Myogenic TMD forms a public health issue and is a common musculoskeletal problem causing pain and disability. The proposal of effective, non-invasive, and affordable treatment options can help solve this issue.

Oxidative imbalance as a co-player in jaw functional limitations and biopsychosocial profile in patients with temporomandibular disorder-myofascial pain with referral

Introduction

Temporomandibular disorders have a multifactorial etiology including biological, biomechanical, neuromuscular, and biopsychosocial factors. Current research on temporomandibular disorders focuses on identifying clinically relevant biomarkers thus creating a new way of thinking about this dysfunction. The aim of the study was to determine the relationship between salivary/blood concentrations of oxidative/nitrosative stress biomarkers and biopsychosocial findings in patients with temporomandibular disorder-myofascial pain with referral.

Methods

The sample enrolled a total of 26 individuals with temporomandibular myofascial pain with referral (twenty women, six men). The procedure included clinical examination according to the Diagnostic Criteria for Temporomandibular Disorders, saliva and blood collection. Biochemical analysis concerned, among others, the content of reduced glutathione, uric acid, total antioxidant capacity, advanced glycation end products, malondialdehyde, total lipid hydroperoxides, kynurenine, N-formylkynurenine, and peroxynitrite. All determinations were considered with respect to the Patient Health Questionnaire-4 (PHQ-4), Patient Health Questionnaire-9 (PHQ-9), Patient Health Questionnaire-15 (PHQ-15), Generalized Anxiety Disorder-7 (GAD-7), Jaw Functional Limitation Scale-20 (JFLS-20), Perceived Stress Scale-10 (PSS-10), and Beck Depression Inventory (BDI).

Results and discussion

The average age of participants was 24.2 ± 1.23. High content of kynurenine and N-formylkynurenine in plasma was related to intensified psychological distress (PHQ-4) and anxiety (GAD-7). Low concentration of plasma malondialdehyde and total lipid hydroperoxides was linked with severe somatization (PHQ-15) and stress (PSS-10), respectively. Reduced levels of non-enzymatic antioxidants were associated with greater jaw functional mobility restrictions as well as limited mastication and communication factor with respect to JFLS-20. These findings indicate that oxidative stress biomarkers are significantly related to the biopsychosocial profile in patients with temporomandibular disorder.

The relationship between oxidative stress markers and temporomandibular disorders: A systematic review and meta-analysis

Background

Oxidative stress has a role in many pathologic conditions, including oral diseases and temporomandibular joint disorders (TMDs) pathophysiology. This study compared the selected oxidative biomarkers' levels in TMD patients and healthy controls in a systematic review and meta-analysis.

Materials and Methods

Medline/PubMed, Scopus, Web of Science, Google Scholar, and Embase were systematically searched for English articles up to October 2022 using MeSH and free keywords. Joanna Briggs Institute checklist was used to assess the risk of bias. Differences between biomarker levels in TMD patients were compared to the control group.

Results

Ten case-control studies were included based on inclusion and exclusion criteria with a total of 659 patients: 314 with TMD and 345 healthy controls. The studies investigated 15 markers, including total oxidant status (TOS), total antioxidant status, and malondialdehyde (MDA). There was a significant difference in the salivary MDA of patients with TMD in comparison with healthy people; standard mean difference = 3.22 (95% confidence interval [CI]: 0.28-6.16); I 2 = 96.0%). The Antioxidant status in serum was significantly lower in patients with TMD in comparison with healthy people; weighted mean difference = -0.52 (95% CI: -0.90 to -0.14; I 2 = 97.0%). The result of TOS was inconclusive.

Conclusion

Salivary MDA and serum total antioxidative status measurements may be used as a biomarker for diagnosing TMD. Due to the lack of sufficient evidence, it is not possible to express a definite relation between the amount and type of marker and TMD diagnosis, which suggests that more case-control studies with larger sample sizes are required.

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.

Association between oxidative stress and chronic orofacial pain and potential druggable targets: Evidence from a Mendelian randomization study

BACKGROUND

Oxidative stress indicators affect chronic orofacial pain (COFP), but how to reduce these effects is uncertain.

OBJECTIVES

11 oxidative stress biomarkers were collected as exposures, while four forms of COFP were chosen as outcomes for Mendelian randomization (MR) study.

METHODS

The effect estimates between oxidative stress and COFP were calculated using inverse variance-weighted MR (IVW-MR). Then, functional mapping and annotation (FUMA) was utilized in order to carry out SNP-based functional enrichment analyses. In addition, the IVW-MR method was applied to combine effect estimates when using genetic variants associated with oxidative stress biomarkers as an instrument for exploring potential druggable targets.

RESULTS

The results indicated that oxidative stress biomarkers (causal OR of uric acid (UA), 0.998 for myofascial pain, 95% CI 0.996-1.000, p < .05; and OR of glutathione transferase (GST), 1.002 for dentoalveolar pain, 95% CI 1.000-1.003, p < .05) were significantly linked with the probability of COFP. Functional analysis also demonstrated that UA and myofascial pain genes were prominent in nitrogen and uracil metabolism, while GST and dentoalveolar pain genes were enriched in glutathione metabolism. Also, the study provided evidence that solute carrier family 2 member 9 (SLC2A9) and glutathione S-transferase alpha 2 (GSTA2) cause discomfort in the myofascial pain (OR = 1.003, 95% CI 1.000-1.006; p < .05) and dentoalveolar region (OR = 1.001, 95% CI 1.000-1.002; p < .05), respectively.

CONCLUSIONS

In conclusion, this MR study indicates that genetically predicted myofascial pain was significantly associated with decreased UA and dentoalveolar pain was significantly associated with increased GST level. SLC2A9 inhibitor and GSTA2 inhibitor were novel chronic orofacial pain therapies and biomarkers, but clinical trials are called to examine if these oxidative biomarkers have the protective effect against orofacial pain, and further research are needed to explore the underlying mechanisms.

Associations of tissue damage induced inflammatory plasticity in masseter muscle with the resolution of chronic myalgia

Gene plasticity during myogenous temporomandibular disorder (TMDM) development is largely unknown. TMDM could be modeled by intramuscular inflammation or tissue damage. To model inflammation induced TMDM we injected complete Freund's adjuvant (CFA) into masseter muscle (MM). To model tissue damage induced TMDM we injected extracellular matrix degrading collagenase type 2 (Col). CFA and Col produced distinct myalgia development trajectories. We performed bulk RNA-seq of MM to generate gene plasticity time course. CFA initiated TMDM (1d post-injection) was mainly linked to chemo-tacticity of monocytes and neutrophils. At CFA-induced hypersensitivity post-resolution (5d post-injection), tissue repair processes were pronounced, while inflammation was absent. Col (0.2U) produced acute hypersensitivity linked to tissue repair without inflammatory processes. Col (10U) generated prolonged hypersensitivity with inflammatory processes dominating initiation phase (1d). Pre-resolution phase (6d) was accompanied with acceleration of expressions for tissue repair and pro-inflammatory genes. Flow cytometry showed that immune processes in MM was associated with accumulations of macrophages, natural killer, dendritic and T-cells, further confirming our RNA-seq findings. Altogether, CFA and Col treatments induced different immune processes in MM. Importantly, TMDM resolution was preceded with muscle cell and extracellular matrix repairs, an elevation in immune system gene expressions and distinct immune cell accumulations in MM.

Involvement of Oxidative Stress and Nutrition in the Anatomy of Orofacial Pain

Pain is a very important problem of our existence, and the attempt to understand it is one the oldest challenges in the history of medicine. In this review, we summarize what has been known about pain, its pathophysiology, and neuronal transmission. We focus on orofacial pain and its classification and features, knowing that is sometimes purely subjective and not well defined. We consider the physiology of orofacial pain, evaluating the findings on the main neurotransmitters; in particular, we describe the roles of glutamate as approximately 30-80% of total peripheric neurons associated with the trigeminal ganglia are glutamatergic. Moreover, we describe the important role of oxidative stress and its association with inflammation in the etiogenesis and modulation of pain in orofacial regions. We also explore the warning and protective function of orofacial pain and the possible action of antioxidant molecules, such as melatonin, and the potential influence of nutrition and diet on its pathophysiology. Hopefully, this will provide a solid background for future studies that would allow better treatment of noxious stimuli and for opening new avenues in the management of pain.

Immune-enhancing activity of polysaccharides and flavonoids derived from Phellinus igniarius YASH1

Introduction: Phellinus igniarius (P. igniarius) (Sanghuang) is a widely used traditional Chinese medicine fungus, and its natural products have great potential for clinical application in immune enhancement. This study aimed to explore the immune-enhancing activity and underlying mechanisms of the polysaccharides and flavonoids derived from Phellinus igniarius (P. igniarius) and to provide a theoretical and experimental basis for the development of novel drugs. Methods: Wild P. igniarius YASH1 from the Loess Plateau in Yan'an region was collected, and polysaccharides and total flavonoids were extracted, isolated and identified from mycelium and sporophore. In vitro antioxidant activity was detected through the scavenging activity of hydroxyl radicals and total antioxidant capacity. Cell Counting Kit-8 and trypan blue detection kit were used to detect the effect of extract polysaccharides and flavonoids on the proliferation and phagocytosis ability of immune cells. To assess the effect of the drugs on cytokine secretion by immune cells and immune recovery in immunocompromised mice, the expression of interleukin (IL)-2, IL-6, interferon (IFN)-γ, and tumor necrosis factor (TNF)-α were examined at the cellular and animal levels. The species composition, abundance of gut microbiota and the altered content of short-chain fatty acids in the feces were analyzed to elucidate the possible mechanisms of drugs by 16S ribosomal RNA (rRNA) amplifiers sequencing and liquid chromatography-tandem mass spectrometry (LC-MS/MS). Results: Both polysaccharides and flavonoids derived from mycelium or sporophore had antioxidant activity and may stimulate the expression and secretion of IL-2, IL-6, and IFN-γ in immune cells while inhibiting TNF-α expression and secretion and increasing IL-2, IL-6, and IFN- γ expression levels in mice. Furthermore, polysaccharides and flavonoids from mycelium and sporophore showed different effects on the metabolic response of intestinal short-chain fatty acids (SCFAs) in mice, and the use of these drugs remarkably changed the species composition and abundance of intestinal flora in mice. Discussion: Polysaccharides and flavonoids from P. igniarius YASH1 mycelium and sporophore have in vitro antioxidant activity, and they affect the promotion of cell proliferation, stimulation of IL-2, IL-6, and IFN-γ secretion, and inhibition of TNF-α expression in immune cells. Polysaccharides and flavonoids from P. igniarius YASH1 may enhance immunity in immunocompromised mice and remarkably affect the intestinal flora and content of SCFAs.

Myofascial Temporomandibular Disorders at a Turning Point: Pragmatic or Evidence-Based Management?

Unvalidated theories have been proposed for the etiopathogenesis of masticatory myofascial temporomandibular disorders (mTMD). Modalities such as cone-beam computed tomography/computed tomography and MRI contributes little to the diagnosis of mTMD. Diagnosing mTMD is based on the recognition of "familiar pain" presentation in the masticatory myofascial tissue. This assessment tool contributes little our understanding of the underlying disease process. Thus, management of mTMD is empirical and arbitrary. Exploring emerging technologies to identify biomarkers and objectively assess myofascial tissue physiology in disease and health may be key in moving the diagnosis of mTMD from the pragmatic paradigm to an evidence-based paradigm.

A Retrospective Clinical Trial Regarding Oral Rehabilitation Diagnosis Strategies Based on Stomatognathic System Pathology

INTRODUCTION

Orofacial pain is a common occurrence in daily dental practice; it is frequently attributed to temporomandibular dysfunction, one of its major causes, followed by pathology of the salivary glands, without avoiding interference at the level of the pain pathways caused by complications of periodontal pathology. The main objective of this study is to identify an important cause of pain in the oral-maxillofacial territory by quantifying the changes at the salivary glandular level using stereological methods. The secondary objective of the present research is to identify the implications of periodontal changes as a consequence of salivary quantitative and qualitative changes, quantified using periodontal indices, on the balance of the temporomandibular joint, dysfunction of it being an important cause of facial pain and having a profound impact on the complex oral rehabilitation algorithm of each clinical case, a condition evaluated with the analysis of the results of the Souleroy questionnaire.

MATERIAL AND METHODS

In a retrospective study, we evaluated the clinical results obtained after applying complex rehabilitation treatment to 35 subjects, 20 women and 15 men with salivary and TMJ dysfunctions, selected between 2020 and 2021 from the Clinic of Maxillofacial Surgery, Iasi.

RESULTS AND DISCUSSION

The most common symptoms of temporomandibular disorders (TMDs) that were identified through the Souleroy questionnaire were pain and different types of damage to the masticatory muscles. The most significant changes in elders are reported in the case of serous cells, which reduced their percentage volume from 46.7% to 37.4%.

CONCLUSION

As regards stereological analysis in conjunction with histological images, there were significant changes in diameters, perimeters, and longitudinal axes in the adult patients as opposed to the elderly patients, which were also influenced by the type of pathology at this level. The scores recorded on the diagnostic Souleroy scale indicated a large number of patients with low efficiency and maximum stress levels: 20.0% in level 1, 25.7% in level 2, and 25.7% in level 3.

Identification of crucial salivary proteins/genes and pathways involved in pathogenesis of temporomandibular disorders

Temporomandibular disorder (TMD) is a collective term for a group of conditions that lead to impairment of the function of the temporomandibular joint. The proteins/genes and signaling pathways associated with TMD are still poorly understood. The aim of this study was to identify key differentially expressed salivary proteins/genes (DEGs) associated with TMD progression using LC-MS/MS coupled with a bioinformatics approach. The protein–protein interaction network was obtained from the STRING database and the hub genes were identified using Cytoscape including cytoHubba and MCODE plug-ins. In addition, enrichment of gene ontology functions and the Reactome signaling pathway was performed. A total of 140 proteins/genes were differentially expressed. From cluster analysis, a set of 20 hub genes were significantly modulated: ALB, APOA1, B2M, C3, CAT, CLU, CTSD, ENO1, GSN, HBB, HP, HSPA8, LTF, LYZ, MMP9, S100A9, SERPINA1, TF, TPI1, and TXN. Two enriched signaling pathways, glycolysis and gluconeogenesis, and tryptophan signaling pathway involving the hub genes CAT, ENO1, and TPI1 have been identified. The rest of the hub genes were mainly enriched in the innate immune system and antimicrobial peptides signaling pathways. In summary, hub DEGs and the signaling pathways identified here have elucidated the molecular mechanisms of TMD pathogenesis.

Altered Plasma Proteins in Myogenous Temporomandibular Disorders

The aims of this study were (1) to compare the levels and interactions of several plasma proteins in patients with myogenous temporomandibular disorders (TMDM) compared to healthy and pain-free controls, (2) to compare the levels and interactions in two TMDM subgroups, myalgia (MYA) and myofascial pain (MFP), and (3) to explore associations between the proteins and clinical data. Thirty-nine patients with TMDM (MFP, n = 25, MYA, n = 14), diagnosed according to the diagnostic criteria for TMD (DC/TMD), aged 38 years, and sex-matched pain-free controls completed an extended DC/TMD Axis II questionnaire and the plasma concentration of 87 biomarkers were analyzed. Nine proteins separated TMDM from controls (p = 0.0174) and 12 proteins separated MYA from MFP (p = 0.019). Pain duration, characteristic pain intensity, pain catastrophizing, perceived stress, and insomnia severity were significantly associated with protein markers (p < 0.001 to p < 0.022). In conclusion, several plasma proteins were upregulated in TMDM and either upregulated or downregulated in MYA compared to MFP. Some proteins in TMDM were associated with pain variables, sleep disturbance, and emotional function. These results show that systemic differences in protein expression exist in patients with TMDM and that altered levels of specific plasma proteins are associated with different clinical variables.

Preclinical models of deep craniofacial nociception and temporomandibular disorder pain

Chronic pain in temporomandibular disorder (TMD) is a common health problem. Cumulating evidence indicates that the etiology of TMD pain is complex with multifactorial experience that could hamper the developments of treatments. Preclinical research is a resource to understand the mechanism for TMD pain, whereas limitations are present as a disease-specific model. It is difficult to incorporate multiple risk factors associated with the etiology that could increase pain responses into a single animal. This article introduces several rodent models which are often employed in the preclinical studies and discusses their validities for TMD pain after the elucidations of the neural mechanisms based on the clinical reports. First, rodent models were classified into two groups with or without inflammation in the deep craniofacial tissues. Next, the characteristics of each model and the procedures to identify deep craniofacial pain were discussed. Emphasis was directed on the findings of the effects of chronic psychological stress, a major risk factor for chronic pain, on the deep craniofacial nociception. Preclinical models have provided clinically relevant information, which could contribute to better understand the basis for TMD pain, while efforts are still required to bridge the gap between animal and human studies.

Myogenous temporomandibular disorders and salivary markers of oxidative stress-A cross-sectional study

BACKGROUND

The clinical care of chronic pain requires personalised understanding of the mechanisms involved. Temporomandibular disorders (TMD) are the most common chronic orofacial pain conditions, and oxidative stress has been proposed to be implicated in their pathophysiology, especially in arthrogenous TMD. However, few studies have explored oxidative stress in myogenous TMD (TMDM).

OBJECTIVE

The aims of this study were to compare the salivary oxidative stress profiles between individuals with TMDM and healthy controls, and to explore associations of these markers with clinical characteristics.

METHODOLOGY

Saliva samples were collected from 39 individuals with TMDM and 37 age and sex-matched healthy volunteers. Psychological stress levels and clinical characteristics were assessed in all participants. The samples were analysed for total oxidant status (TOS), total antioxidative capacity (TAC) and superoxide dismutase activity (SODa). Comparisons between groups were performed using parametric and non-parametric tests depending on data distribution.

RESULTS

Psychological stress was higher in TMDM compared to controls (P < .001). TAC levels were significantly higher (P < .05) whereas TOS levels were significantly lower (P < .05) in TMDM compared to controls. There were no differences in SODa levels between groups and no correlations were found between clinical characteristics and oxidative stress markers.

CONCLUSION

Individuals with TMDM showed higher levels of antioxidative markers, but lower levels of oxidative markers. These results can be explained in part by chronicity and adaptation to the disease and other factors, such as psychological stress. Longitudinal studies must be conducted to clarify the role of oxidative stress in TMDM.