Objectives: to determine salivary electrolyte concentration of oral potentially malignant disorders (OPMD) and oral squamous cell carcinoma (OSCC) patients. A related systematic review was performed.
Methods: Observational study. Unstimulated saliva from 18 patients with OSCC, 18 with OPMD, and 18 without oral lesions was collected. A biochemical analysis was performed to evaluate the salivary concentrations of potassium (K), phosphorus (P), sodium (Na), calcium (Ca), magnesium (Mg), zinc (Zn), copper (Cu), and iron (Fe). Kruskal-Wallis test was performed, and p < 0.05 was interpreted as statistically significant. The literature search for the systematic review retrieved 9 studies that associated salivary electrolyte levels with presence and progression of OSCC.
Results: A highly significant increase was found in the salivary Mg levels in the OPMD group (5.41 µg/mL) in comparison with the OSCC (3.71µg/mL) and control group (3.51 µg/mL) (p = 0.041). No differences were observed in other salivary levels elements. The results of the systematic review revealed that one article indicated a decrease, and three papers reported an increase in salivary Na levels in patients with OPMD and OSCC. Two articles indicated a decrease in salivary K levels in OSCC, and the other two reported high Mg levels in OPMD and OSCC.
Conclusion: High salivary Mg levels can be a potential biomarker indicating the presence of OPMD, however, the evidence is still contradictory and more studies are required.
Keywords: Electrolytes; Precancerous Condition; Saliva; trace elements.