[Salivary pH and lysozyme during oropharyngeal radiotherapy].

The pH and lysozyme content of the salivas of 34 patients receiving radiotherapy of the upper respiratory digestive tracts for the treatment of cancer were compared to those of 22 healthy subjects matched for age and gender. After irradiation the salivas of the treated patients had a lower mean pH (p less than 0.001). During radiotherapy no statistically significant changes occurred in the pH or lysozyme rate, but at the beginning of treatment there was an inverse correlation (p less than 0.05) between the increased lysozyme content and the lowered pH. The mean salivary pH and lysozyme rate of 12 patients (35%) initially treated by chemotherapy showed no significant differences from controls. However, the saliva of 21 dentate patients had a mean pH and lysozyme content considerably higher (p less than 0.01) than that of patients without teeth. During radiotherapy there was a statistically significant inverse relationship between the pH of the salivas of the dentate and edentulous groups.