Blood flow changes of a superficial temporal artery before and after low-level laser irradiation applied to the temporomandibular joint area.

PURPOSE The aim of this study was to evaluate the blood flow changes of a superficial temporal artery before and after low-level laser irradiation was applied to the TMJ area of healthy subjects. METHODS Right TMJ areas of six healthy subjects were irradiated with a CO2 laser. Variation of diameter, blood flow rate, and blood flow volume of the vessel, on both the irradiated side and opposite side, before and after irradiation on the TMJ were evaluated by using a Doppler flowmeter. RESULTS The diameter and blood flow volume of the vessel after irradiation increased significantly compared to that before irradiation. CONCLUSION Low-level laser irradiation applied to the right TMJ area caused an expansion of blood vessels and an increase in blood flow volume. The same result on the contralateral side may be caused by the vasodilator reflex via the hypothalamic thermostat.