2004 Volume 15 Issue 2 Pages 67-72
This study evaluated thermographic changes of facial temperature before and after irradiation of CO2 laser to the temporomandibular joint (TMJ) area of 15 healthy subjects (male: 8, female: 7, age: 26.1+/-5.43y.) with no history of orofacial disorders including temporomandibular disorder. The right TMJ area was irradiated by applying the CO2 laser for 10 minutes. The irradiation conditions were a continuous wave with 1.0 W output, at a distance of 10cm from the skin and an ellipse form was drawn around the TMJ area. Five thermograms were taken for each subjects (irradiated side before irradiation, after 5min. and 10min. of irradiation, opposite side before irradiation, after 10 min. of irradiation). The average temperature of the 15 subjects was 34.9±0.86°C before irradiation, 36.7±1.04°C at 5min. of irradiation, and 36.5±0.93°C at 10min. of irradiation. A significant difference was found between before and at 5min. of irradiation, and between before and at 10min. of irradiation. The temperature at 5min. of irradiation was higher than that at 10min. of irradiation. The temperature of the opposite side was 34.9±0.86° before irradiation, and 35.4±0.58° at 10 min. of irradiation. A significant difference was also found between before and at 10min. of irradiation. On the thermogram, the warmed area (up to more than 1°C) of the irradiated side was found not only in the TMJ area, but also in the temporal, forehead, and eyelid regions.
From these results, it was found that the low-level laser irradiation increased the facial temperature not only of the irradiated side, but also of the opposite side. It was thought that these phenomena were caused by the increasing of blood flow and a physiological reaction via central nerve system.