Variations in oral temperature.

This study investigated the temperature of healthy oral mucosa and underlying bone. Using a fine thermocouple and digital thermometer, four groups of temperatures were measured: (i) adjacent to unerupted third molars before and after surgical removal (n = 51); (ii) at the same site in patients not undergoing surgery (n = 30); and (iii) at the buccal incisor mucosa (n = 30). In each group sublingual temperatures were measured in order to calculate the temperature differential between measurement site and sublingual temperature to compensate for variations between sites and individuals. In the final group (iv) (n = 10) sublingual temperature was recorded in a closed mouth. Mean alveolar bone temperature was 5 degrees C cooler than overlying mucosa, and mean post-operative mucosal temperature was some 2.5 degrees C cooler than before operation (t = 2.32, P < 0.001). Sublingual temperature, in a closed mouth, remained relatively constant. In an open mouth, in both anterior and posterior regions, there were statistically significant decreases in sublingual temperature and in mucosal temperature differentials. Significant differences were also found between temperature differentials calculated using sublingual temperature measured at baseline and after 10 min. This indicates that sublingual temperature should be measured just prior to measuring a mucosal site.