Clinical Relevance of Oxidative Imbalance in Patients with Temporomandibular Disorder-Myofascial Pain with Referral: An Exploratory Case-Control Study.

BACKGROUND: Temporomandibular disorders constitute multifaced systemic impairments capable of compromising overall physiological homeostasis. This study compares oxidative and nitrosative stress biomarkers between patients with temporomandibular myofascial pain with referral and healthy controls. METHODS: We enrolled 44 individuals with temporomandibular myofascial pain with referrals and 44 controls. The procedure involved clinical examination based on the Diagnostic Criteria for Temporomandibular Disorders and saliva collection. Biochemical determination involved advanced glycation end products (AGEs), advanced oxidation protein products (AOPPs), thiobarbituric-acid-reactive substances (TBARS), and total nitric oxide (NO). RESULTS: Median concentrations of TBARS and total NO were significantly elevated in the study group relative to the controls (TBARS: 6.078 vs. 1.486; total NO: 138.6 vs. 23.82), whereas the concentration of AOPPs was significantly lower (151.1 vs. 505.3). Multiple regression revealed that myofascial pain was an independent predictor of the observed differences, even after we adjusted for age and salivary flow rate (TBARS: β = 4.78 [95% CI: 2.020, 7.541], adjp = 0.0018; total NO β = 128.4 [95% CI: 82.70, 174.1] adjp = 0.0004; AOPP β = -755.7 [95% CI: -1228, -283.5] adjp-value = 0.0028. CONCLUSIONS: Myofascial pain with referral is independently associated with oxidative imbalance, highlighting the relevance of TBARS and total NO as promising severity biomarkers. The unexpected decrease in AGE and AOPP levels requires standardized studies to confirm diagnostic utility.