The effect of cryotherapy on oral mucosa: a study in healthy volunteers

Oral cryotherapy causes local vasoconstriction, which reduces blood flow and reduces the cytotoxic damage to the oral mucosa, has been shown to reduce oral mucositis after intense cytostatic treatment. The main object of this study was to investigate the effect of oral cryotherapy on the temperature in the oral mucosa, the level of proinflammatory cytokine interleukin-6 (IL-6) in saliva and the effect on blood pressure in healthy volunteers, before and after 1 h of cooling the oral cavity with crushed ice. Twelve healthy volunteers [mean age 32.4 (SD 13.2) (20-56) years] were treated with oral cryotherapy in the form of crushed ice. Temperature measurements were performed in the oral mucosa using infrared thermograph following a flowchart protocol. Blood pressure (BP) was measured with a sphygmomanometer. Saliva was analysed for inflammatory cytokine IL-6, using an enzyme-linked immunosorbent assay (ELISA). All participants fulfilled the cooling session. The temperature in the oral cavity decreased significantly (mean 12.9 °C, p < .002). The systolic BP was marginally but significantly higher after cooling (~5 mmHg, p = .019). We could not detect any differences in cytokine IL-6 levels before and after oral cooling. We conclude that cryotherapy during 1 h lowers the mucosal temperature as much as ~12.9 °C, which explains the significant protective effect against mucosal damage by cytostatic drugs. The cooling caused no increase in IL-6 levels. Systemic blood pressure was marginally increased.