A locked jaw, or trismus, is the inability to fully open the mouth. This condition can be unsettling, limiting normal activities like eating, speaking, or yawning. While often distressing, a locked jaw is frequently manageable, resulting from various factors affecting the jaw muscles or temporomandibular joint.
Immediate Steps for Relief
Gentle techniques can help alleviate a locked jaw. Apply heat or cold to the affected area. A warm, moist washcloth or heating pad for 10-15 minutes can relax jaw muscles, while a cold pack reduces inflammation and discomfort, especially after initial injury.
Gentle jaw exercises are beneficial, but proceed slowly and stop if pain increases. Slowly open and close the mouth within a comfortable range, or gently move the jaw side to side. Another exercise involves placing the tongue on the roof of the mouth and slowly opening the jaw as wide as possible without discomfort.
Over-the-counter pain relievers, such as ibuprofen or acetaminophen, can help manage pain and reduce inflammation. A soft food diet reduces strain on jaw muscles and the temporomandibular joint. Examples include yogurt, mashed potatoes, soups, and smoothies.
Common Reasons for a Locked Jaw
A locked jaw often results from issues within the temporomandibular joint (TMJ) or the surrounding muscles. Temporomandibular joint disorders (TMD) are a frequent cause, particularly when the disc within the joint displaces. This displacement can prevent the jaw from moving smoothly, leading to a “locking” sensation.
Muscle spasms also commonly cause a locked jaw. Stress, teeth clenching, or grinding (often during sleep) can trigger these spasms. This overworks masticatory muscles, causing them to tighten and restrict jaw movement.
Injury or trauma to the jaw can also result in locking. This includes direct blows to the face or conditions like a dislocated jaw, where the condyle of the mandible moves out of its normal position in the temporal bone. Dental procedures, especially those requiring the mouth to be open for extended periods, may sometimes lead to temporary jaw locking due to muscle fatigue or inflammation.
When to Seek Medical Attention
While many locked jaw instances resolve with self-care, some signs require professional medical evaluation. Consult a healthcare provider if jaw locking persists for more than a few hours or a full day, or if it recurs frequently. Severe pain unresponsive to over-the-counter relievers also needs medical attention.
Inability to eat or drink due to a locked jaw can cause dehydration or nutritional deficiencies, requiring prompt medical intervention. Seek immediate medical help if the locked jaw is accompanied by fever, swelling, redness around the jaw, or difficulty breathing. Any jaw locking after a significant injury or trauma also needs assessment.
Professional Medical Treatments
When a locked jaw requires professional intervention, a healthcare provider will perform a physical examination of the jaw and surrounding muscles. Imaging tests like X-rays, CT scans, or MRI scans may also be used to visualize the temporomandibular joint and detect structural issues.
Prescription medications manage symptoms and address specific causes. Muscle relaxants alleviate severe muscle spasms, while stronger anti-inflammatory drugs reduce pain and swelling. Physical therapy restores normal jaw function through exercises that improve range of motion and strengthen jaw muscles.
Oral appliances, such as splints or mouthguards, are used for TMJ disorders or teeth grinding. These devices reposition the jaw, reduce joint strain, and prevent teeth clenching. In some cases, steroid injections directly into the joint or surrounding muscles provide pain relief and reduce inflammation. Surgery is considered only in rare, severe cases where other treatments fail, such as complex disc displacements or severe joint degeneration.