Attributes of the Oral Cavity as a Site for Basal Body Temperature Measurements

The thermal topography of the oral cavity of 11 women was mapped with thermocouples in early morning waking conditions. A reference thermocouple was placed in the vagina. No significant difference was found in the time required to reach a steady-state oral temperature and in the achieved steady-state temperature difference (T_v-T₀) in the preovulatory and postovulatory phases of the menstrual cycle. Location of the thermocouple in the oral cavity had a significant effect on steady-state temperature differences. After equilibration of oral thermometers, women breathed through their mouths for exactly five minutes. Mouths were closed and a second temperature equilibration phase was recorded. Mouth breathing had a significantly greater effect on the temperature of the anterior sublingual and dorsum of the tongue sites than on the posterior sublingual and buccal trough sites.