It is possible to strain the muscles that control jaw movement, a common issue known as a masticatory muscle strain. These muscles are subject to injury from overuse, sudden trauma, or chronic tension. The pain originates from the muscle tissue itself, rather than the temporomandibular joint (TMJ) that connects the jawbone to the skull. This muscular discomfort is a frequent cause of facial pain and reduced jaw function, often mistakenly attributed to joint-related issues.
The Specific Muscles Involved
The primary muscles responsible for chewing and jaw movement are known as the muscles of mastication. These muscles work in pairs on both sides of the face, enabling the jaw to close, open, and move side-to-side. The largest is the Masseter, the thick, rectangular muscle felt on the side of the cheek near the back of the jaw. The Temporalis muscle, a fan-shaped muscle located in the temple region, is a main force for closing the jaw and pulling it backward.
Two other pairs of muscles, the Pterygoids—medial and lateral—are deeper and play a complex role in jaw movement. The medial Pterygoid assists in closing the jaw, while the lateral Pterygoid is involved in opening the mouth, moving the jaw forward, and facilitating side-to-side motion. A strain involves microscopic tears in the muscle fibers of one or more of these four groups, leading to inflammation, pain, and restricted movement.
Common Triggers and Causes of Jaw Muscle Strain
One of the most frequent causes of jaw muscle strain is chronic teeth clenching or grinding, a condition known as bruxism. This habit, which may be stress-related or occur during sleep, causes the jaw muscles to work intensely for prolonged periods without rest. This overuse leads to muscle fatigue, tightness, and strain in the Masseter and Temporalis muscles. Excessive use during waking hours, such as habitually chewing gum or constantly biting on objects, can also place strain on the muscle fibers.
Strains can also result from a single traumatic event or excessive force applied to the jaw. This includes direct trauma, like a blow to the face, or biting down suddenly on unexpectedly hard food. Prolonged wide opening of the mouth can also overstretch the muscles. This commonly occurs during lengthy dental procedures, intubation for surgery, or an unusually wide yawn, resulting in tearing and strain.
Recognizing the Signs of a Strain
A strained jaw muscle presents with localized tenderness or a dull ache in the affected muscle, such as the cheek or temple area, which intensifies with movement. This discomfort is often described as stiffness, especially noticeable when waking up after a night of grinding or clenching. Pain upon chewing, talking, or yawning indicates that the muscle tissue is inflamed and strained.
Another frequent symptom is difficulty or an inability to fully open the mouth, a condition medically termed trismus. The muscle guarding and tightness limits the range of motion. Pain can also be referred to other areas, manifesting as a headache, earache, or pain radiating into the neck. Unlike a joint problem, which might involve clicking or locking, a muscle strain primarily involves palpable soreness and tightness.
Immediate Steps for Relief and Recovery
The immediate approach to a jaw muscle strain focuses on resting the affected muscles to allow the strained fibers to heal. This involves adopting a soft diet that requires minimal chewing, avoiding tough, crunchy, or chewy foods like raw vegetables, nuts, or gum.
Relief Measures
- Apply a cold pack to the painful area for 10 to 15 minutes to reduce inflammation and acute pain, particularly in the first 24 to 48 hours.
- Use moist heat for 5 to 10 minutes, three to four times a day, to relax tight muscles and increase blood flow for recovery.
- Use over-the-counter nonsteroidal anti-inflammatory drugs (NSAIDs) like ibuprofen to manage pain and reduce muscular inflammation.
- Perform gentle self-massage of the Masseter and Temporalis muscles using a light circular motion to relieve tension and promote circulation.
- Practice simple, non-painful jaw exercises, such as controlled opening and closing with the tongue touching the roof of the mouth, to maintain mobility.
If the pain persists beyond three to five days, is accompanied by significant swelling, or if the jaw locks, seeking professional medical or dental advice is necessary for a comprehensive evaluation and treatment plan.