Comparative Evaluation of Continuous and Pulse Mode of Ultrasound Therapy in Myalgia of Maxillofacial Region

Therapeutic ultrasound ranges from 750,000 to 3,300,000 Hz (0.75 to 3.3 MHz). Depending upon the output parameters it may produce effects like increase tissue extensibility, reduction of calcium deposits, reduction of pain \& muscle spasm by altering nerve conduction velocity \& changes in cell membrane permeability along with increased rate of tissue repair \& wound healing.There are two main types of ultrasound therapy: thermal and mechanical. Thermal effect which is a result of continuous mode of US therapy causes transient increase in the flexibility of collagenous structures including ligaments, tendons \& joint capsules, thus leading to decrease in the pain \& muscle spasm, stiffness of the joint \& temporary increase in the blood flow. Pulsed mode of US results in nonthermal effect i.e., micro massage like which lead to segmental analgesia due to decreased central \& peripheral sensitization.