Maluf G V, Caldas R J, Fregnani E R, Antunes H S, Tobias M A S, da Silva Santos P S. Evaluation of halitosis parameters in patients undergoing head and neck radiotherapy. Oral Dis 2022; DOI: 10.1111/odi.14225. Online ahead of print.

Head and neck radiotherapy may be important in the development of halitosis.

This cross-sectional study considered both irradiated and non-irradiated head and neck cancer patients to assess halitosis parameters and correlation with salivary flow, oral hygiene index, radiation dose and tongue-coating index. Hydrogen sulphide, methyl mercaptan and dimethy sulphide (DMS) levels were measured using a gas chromatograph and sialometry was performed. Thirty-eight patients were allocated to each group. Volatile sulphur compound levels were above the thresholds in both groups. Non-irradiated individuals showed higher levels of hydrogen sulphide and dimethyl sulphide. Patients with asialia had an inexpressive tongue-coating index and increased dimethyl sulphide levels. A decrease in salivary flow rate was followed by a significant increase in volatile sulphur compound levels. Higher doses of radiation to the submandibular salivary glands were associated with higher concentrations of sulphide and methyl mercaptan. Irradiated patients with asialia presented insignificant lingual biofilm. Consequently, lower levels of volatile sulphur compounds were detected in this group. Asialia, a severe radiation-induced hyposalivation, impacted the levels of DMS (extraoral origin).