Study of the Plasmatic Oxidative Stress Markers in Temporomandibular Joint Disorders

Oxidative stress is considered to have an important role in the pathogenesis of many inflammatory diseases. This investigation sought to determine whether the appliance of etiologic factors for temporomandibular joint disorder is associated with modified values of oxidative stress as measured by biomarkers in plasma. A case-control study design was used to compare oxidative stress biomarkers (malondialdehyde and glutathione) in plasma from Wistar rats with different etiologic factors (biomechanical stress, estrogen hormones and emotional stress), compared to non-temporomandibular joint controls. Etiologic factors were applied in five groups (n=10) of mature female Wistar rats, individually (biomechanical stress, estrogen hormones and emotional stress) in three groups or in combination for two groups (biomechanical stress-emotional stress and biomechanical stress-emotional stress). No factor applied for the control group. Blood samples were taken after 30 and 60 days of experiment. Malondialdehyde and glutathione levels in plasma were evaluated. The most important modifications in malondialdehyde levels were recorded for the fifth group (biomechanical stress-emotional stress) where values increased significantly from 30 to 60 days plasma analysis (p = 0.003). No statistical differences were recorded in glutathione plasmatic levels between control and experimental groups at 30 days analysis. At 60 days, glutathione plasmatic evaluation recorded higher values than control for all experimental groups. Our findings in this rat experimental model, clearly indicate that biomechanical stress, estrogen hormones and emotional stress, have an impact on oxidative stress development and consequently on the functionality of the temporomandibular joint in rats. Moreover combined actions of these factors, increase the oxidative stress phenomena on temporomandibular joint in rats.