Myofascial Pain Dysfunction
Symptoms and Signs
Symptoms include pain and tenderness of the masticatory muscles and often pain and limitation of jaw excursion. Both nocturnal bruxism and sleep-disordered breathing (such as obstructive sleep apnea and upper airway resistance syndrome) can lead to headache that is more severe on awakening and gradually subsides during the day. Such pain must be distinguished from giant cell arteritis. Daytime symptoms, including jaw muscle fatigue, jaw pain, and headaches, may worsen if bruxing continues throughout the day.
The jaw deviates when the mouth opens but usually not as suddenly or always at the same point of opening as it does with internal temporomandibular joint derangement. Exerting gentle pressure, the examiner can open the patient’s mouth another 1 to 3 mm beyond unaided maximum opening.
Diagnosis
• Clinical evaluation
• Sometimes polysomnography
A simple test may aid the diagnosis: two or three tongue blades are placed between the rear molars on each side, and the patient is asked to close the mouth gently. The distraction produced in the joint space may ease the symptoms. X-rays usually do not help except to rule out arthritis. If giant cell arteritis is suspected, ESR is measured.
Polysomnography should be done if sleep-disordered breathing is suspected.
Treatment
• Mild analgesics
• Splint or mouth guard
• An anxiolytic at bedtime can be considered
• Physical therapy modalities may be considered