Patients with a normal temporomandibular joint can develop myofascial pain syndrome (formerly known as myofascial pain and dysfunction syndrome [MPDS or MFPDS]). Muscle tension, weariness, or (rarely) spasm of the masticatory muscles produce it. Symptoms include pain and soreness in and around the masticatory tissues, as well as discomfort and tenderness referred to other parts of the head and neck, and aberrant jaw motion. The diagnosis is done primarily on the patient’s medical history and physical examination. Analgesics, muscle relaxation, alteration of parafunctional behavior (such as teeth clenching and grinding), and the use of dental appliances are frequently successful.
The most frequent ailment affecting the temporomandibular area is TMD. It affects more women than men, with a bimodal age distribution in the early 20s and around menopause.
Parafunctional activity such as bruxism (teeth clenching or grinding) can produce both discomfort and trigger points (which induce referred pain) in the afflicted muscle. Bruxism is divided into two types: sleep and awake bruxism, each with its own set of etiologies.
The muscles of mastication are not the only ones affected by myofascial pain syndrome. It can affect any muscle in the body, but the neck, shoulders, and back are the most usually affected.
Myofascial Pain Syndrome Symptoms and Signs
Pain and tenderness of the masticatory muscles, as well as pain and limiting of jaw excursion, are common symptoms. Both sleep bruxism and sleep-disordered breathing (such as obstructive sleep apnea and upper airway resistance syndrome) are linked to a headache that is worse when you first get up and gradually improves throughout the day. Giant cell arteritis must be recognized from such pain. If parafunctional activity persists throughout the day, awake symptoms such as jaw muscle fatigue, jaw pain, and headaches frequently intensify.
When the mouth opens, the jaw deviates, but not as dramatically or at the same time as it does with internal temporomandibular joint derangement. The examiner can extend the affected muscles by gently pressing on the bottom anterior teeth, allowing the patient to open their mouth further 1 to 3 mm beyond their unaided maximum opening.
Diagnosis of Myofascial Pain Syndrome
- Clinical evaluation
- Sometimes polysomnography
A simple test may be helpful in determining the diagnosis: On each side, 2 or 3 tongue blades are put between the backmost molars, and the patient is urged to softly seal their mouth (1, 2). The diversion that is created in the joint region may help to alleviate the symptoms. X-rays are usually ineffective unless they are used to rule out arthritis. The erythrocyte sedimentation rate (ESR) is measured if giant cell arteritis is suspected.
If sleep-disordered breathing is suspected, polysomnography should be performed.
Treatment of Myofascial Pain Syndrome
- Mild analgesics
- Oral appliances
- Anxiolytics or cyclobenzaprine may be used at bedtime for a short period of time.
- Trigger point injections, as well as other forms of physical and behavioral therapy
A dentist’s oral appliance can prevent teeth from contacting each other, reducing the damage caused by bruxism. Many sports goods stores and drugstores provide over-the-counter heat-moldable (boil and bite) mouthguards; however, these devices should only be used for limited periods of time and as diagnostic tools. Oral appliances should ideally be constructed, fitted, and adjusted by a dentist because they may induce unintended tooth movement or a paradoxical increase in muscle activity.
For acute exacerbations and short relief of symptoms, low dosages of benzodiazepine taken at bedtime are often beneficial. Cyclobenzaprine may help you relax your muscles. Anxiolytics and muscle relaxants should be taken with caution in patients with concomitant sleep disorders, such as sleep apnea because they can aggravate these problems. Individually or in combination, mild analgesics such as nonsteroidal anti-inflammatory medications (NSAIDs) or acetaminophen are recommended. Opioids should not be utilized because the illness is chronic, save in the case of abrupt exacerbations. Antidepressant medication can be helpful in some situations of persistent pain when taken under medical care.
When awake, the patient must learn to stop parafunctional activity (e.g., jaw clenching, teeth grinding). Chewing gum and hard-to-chew foods should be avoided. Some individuals benefit from physical therapy, relaxation biofeedback, and counseling.
Trigger point injections, transcutaneous electric nerve stimulation (TENS), and “spray and stretch,” which involves stretching the jaw open after the skin around the painful area has been cooled with ice or sprayed with a skin refrigerant like ethyl chloride. Muscle spasms can be effectively treated with botulinum toxin.
Even if untreated, most individuals experience a reduction or complete cessation of major symptoms within 6 to 12 months.
Points to Remember
- Temporomandibular pain is more commonly caused by myofascial pain syndrome than by temporomandibular joint dysfunction.
- Parafunctional behavior can cause masticatory muscular tension, weariness, and (rarely) spasm (eg, bruxism).
- Masticatory muscle discomfort and tenderness, uncomfortable jaw excursion limitation, and headache are common in patients.