Biochemical Aspects of the Pathogenesis of Temporomandibular Joint Disorders

Minireview on the Connections between the Neuropsychiatric and Dental Disorders: Current Perspectives and the Possible Relevance of Oxidative Stress and Other Factors

Although the connections between neuropsychiatric and dental disorders attracted the attention of some research groups for more than 50 years now, there is a general opinion in the literature that it remains a clearly understudied and underrated topic, with many unknowns and a multitude of challenges for the specialists working in both these areas of research. In this way, considering the previous experience of our groups in these individual matters which are combined here, we are summarizing in this minireport the current status of knowledge on the connections between neuropsychiatric and dental manifestations, as well as some general ideas on how oxidative stress, pain, music therapy or even irritable bowel syndrome-related manifestations could be relevant in this current context and summarize some current approaches in this matter.

Photobiomodulation and Stem Cell Therapy for Temporomandibular Joint Disc Disorders

Background: Temporomandibular disorder (TMD) refers to a group of disorders affecting the temporomandibular joint (TMJ) and its related muscles. The two commonly used treatment modalities for TMD are occlusal splint therapy and relaxation therapy. Neither comprises definitive treatment. Objective: The objective of this review was to report updated information on photobiomodulation and stem cells, as an alternative treatment for the degenerative TMJ disc as a part of TMJ disorders. Materials and methods: With only a few research studies reported till date, this review also proposes the mechanism of laser irradiation on inflammatory mediators to treat TMD. Results: Photobiomodulation of stem cells with and without scaffolds could be used indirectly or directly as modulation of degenerative changes of the TMJ disc. Conclusions: The need for a distinct shift of the research margin in this field of dentistry is evident, specifically regarding the application of photobiomodulation and stem cells for tissue engineering of the TMJ disc.

Intra-articular oxidative state correlated with the pathogenesis of disorders of the temporomandibular joint

We investigated the redox state of albumin in the synovial fluid from patients with temporomandibular joint (TMJ) disorders (TMD) to evaluate the relation between the cause of the TMD and the number of types of oxygen in synovial fluid. The albumin was fractionated into three components, human mercaptalbumin (HMA, reduced form) and two types human non-mercaptalbumin (HNA, oxidized form), by high-performance liquid chromatography (HPLC). The 63 patients were divided into three groups radiologically, and the ratios of the redox state of the synovial fluid in each group were compared. The fraction of HNA was significantly higher in patients with advanced disease than in patients with early disease. This indicates that the TMJ is affected by intra-articlular oxidative stress, and the severity of TMD correlates closely with the number of oxidative factors. Oxidative stress was thought to be responsible for the genesis of TMD.