It is a common disease of the facial joint. The exact cause of a person's TMJ disorder is often difficult to determine, it may be due to a combination of factors, such as genetics, arthritis or jaw injury. The ordinary symptoms include pain in the temporomandibular joint (TMJ), disability of mouth opening (locking of the joint, making it difficult to open or close your mouth), and sounds of the joint. The pain occurs in palpation or during mastication. These discomforts affect the daily lives of patients. Photobiomodulation therapy has a pain relief effect on treatments of the TMJ pain.