Free Radical Damage in Facsimile Synovium: Correlation with Adhesion Formation in Osteoarthritic TMJs

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.

Recent Advancements in Temporomandibular Disorders (TMDs)

TMDs are a group of conditions affecting the joint and or the muscles of mastication.TMDs consist of three main groups of conditions: myofascial pain; disc disorders; TMJ arthritides.The gold standard diagnostic criteria for research involving TMDs are the Research Diagnostic Criteria for TMDs (RDC/TMD). A pragmatic clinically applicable alternative is the Clinical examination protocol for TMDs (CEP-TMD).Signs and symptoms can include: pain in masticatory musculature and or the joint; noises associated with joint movements; locking; headache; otalgia.TMDs' aetiology is multifactorial and biopsychosocial in nature.Reversible conservative management as defined by the American Association of Dental Research is the initial management of choice for all subgroups of TMDs.

Severe bony ankylosis of the temporomandibular joint on one side and contralateral adhesion: A case report

Bony fusion between the mandibular condyle and skull base involves temporomandibular joint (TMJ) bony ankylosis. This condition might originate from trauma, infection, or systemic disease. TMJ adhesion can develop after synovial damage. Both TMJ ankylosis and adhesion lead to functional impairment and pain. Here, we present a case of a 50-year-old female who had bony ankylosis of the right TMJ and adhesion of the left TMJ. She had otitis media in the right ear. A large mass in the right TMJ was observed on computed tomograph. Magnetic resonance image showed a large fused bone mass with normal bone marrow in the right TMJ and flattening of the condyle with a thin disk in the left TMJ. Gap arthroplasty with temporal fascia was performed on the right TMJ, and discectomy, high condylectomy, and coronoidectomy were performed on the left TMJ. During a 2-year follow-up after surgery, the patient had no recurrence.

Genetic polymorphisms in folate pathway enzymes, DRD4 and GSTM1 are related to temporomandibular disorder

Background

Temporomandibular disorder (TMD) is a multifactorial syndrome related to a critical period of human life. TMD has been associated with psychological dysfunctions, oxidative state and sexual dimorphism with coincidental occurrence along the pubertal development. In this work we study the association between TMD and genetic polymorphisms of folate metabolism, neurotransmission, oxidative and hormonal metabolism. Folate metabolism, which depends on genes variations and diet, is directly involved in genetic and epigenetic variations that can influence the changes of last growing period of development in human and the appearance of the TMD.

Methods

A case-control study was designed to evaluate the impact of genetic polymorphisms above described on TMD. A total of 229 individuals (69% women) were included at the study; 86 were patients with TMD and 143 were healthy control subjects. Subjects underwent to a clinical examination following the guidelines by the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD). Genotyping of 20 Single Nucleotide Polymorphisms (SNPs), divided in two groups, was performed by multiplex minisequencing preceded by multiplex PCR. Other seven genetic polymorphisms different from SNPs (deletions, insertions, tandem repeat, null genotype) were achieved by a multiplex-PCR. A chi-square test was performed to determine the differences in genotype and allelic frequencies between TMD patients and healthy subjects. To estimate TMD risk, in those polymorphisms that shown significant differences, odds ratio (OR) with a 95% of confidence interval were calculated.

Results

Six of the polymorphisms showed statistical associations with TMD. Four of them are related to enzymes of folates metabolism: Allele G of Serine Hydoxymethyltransferase 1 (SHMT1) rs1979277 (OR = 3.99; 95%CI 1.72, 9.25; p = 0.002), allele G of SHMT1 rs638416 (OR = 2.80; 95%CI 1.51, 5.21; p = 0.013), allele T of Methylentetrahydrofolate Dehydrogenase (MTHFD) rs2236225 (OR = 3.09; 95%CI 1.27, 7.50; p = 0.016) and allele A of Methionine Synthase Reductase (MTRR) rs1801394 (OR = 2.35; 95CI 1.10, 5.00; p = 0.037). An inflammatory oxidative stress enzyme, Gluthatione S-Tranferase Mu-1(GSTM1), null allele (OR = 2.21; 95%CI 1.24, 4.36; p = 0.030) and a neurotransmission receptor, Dopamine Receptor D4 (DRD4), long allele of 48 bp-repeat (OR = 3.62; 95%CI 0.76, 17.26; p = 0.161).

Conclusions

Some genetic polymorphisms related to folates metabolism, inflammatory oxidative stress, and neurotransmission responses to pain, has been significantly associated to TMD syndrome

Temporomandibular joint pain and synovial fluid analysis: a review of the literature

The pathophysiology of temporomandibular joint pain is not well understood. A significant amount of research has been conducted to evaluate synovial fluid in these patients and in healthy controls. Qualitative and quantitative analyses of the synovial fluid have shown a significant difference between these groups. A multitude of inflammatory mediators and degradation products have been identified. The concentration of these products has been shown to correlate with several clinical parameters including pain, chronicity, severity of degenerative change, and response to treatment. A common inflammatory pathway would appear to be involved in most patients. At the present time, synovial fluid analysis does not have the sensitivity or specificity to allow specific diagnoses and targeted treatment. Continued research with the specific aim of establishing more appropriate therapeutic modalities based on the biochemical pathways is warranted.