Chewing gum is a common habit, often used for breath freshening or concentration. However, this repetitive mechanical action can impact the complex structures of the jaw. This article focuses on the mechanics of the jaw, the health of the temporomandibular joint (TMJ), and the conditions that may result from frequent gum chewing.
How Chewing Affects the Jaw Muscles and Joint
Chewing gum is a form of non-nutritive mastication, meaning it involves the physical act of chewing without the breakdown and swallowing of food. This repetitive, low-resistance activity continuously engages the muscles of mastication, primarily the masseter and temporalis muscles. Unlike eating, where the jaw performs a cycle of crushing and resting, gum chewing subjects the jaw to prolonged, monotonous motion that can lead to muscle fatigue.
The temporomandibular joint (TMJ) connects the jawbone to the skull and functions as a sliding hinge. Within the joint is a cartilaginous articular disc that acts as a shock absorber. Repetitive chewing places continuous mechanical stress on both the jaw muscles and the TMJ structures, including this disc.
When food is chewed, the process is brief, and the consistency changes as the food breaks down, altering the forces applied to the joint. Gum maintains its consistency and requires continuous, sustained effort, which is fundamentally different from a typical meal. This constant strain without the natural breaks provided by swallowing poses a potential risk of overuse and strain on the jaw’s components.
Symptoms of Jaw Strain and Temporomandibular Disorder
Excessive gum chewing can contribute to the development of symptoms associated with Temporomandibular Disorder (TMD). A common sign of strain is pain or tenderness in the jaw joint area, which can extend into the face, neck, or ears. This discomfort is often a direct result of muscle overuse and inflammation caused by the prolonged activity.
Another symptom is joint noise, specifically clicking, popping, or grating sounds when the jaw moves. These noises can indicate an issue with the articular disc within the TMJ, such as displacement or damage. In more advanced cases, the jaw may feel stiff or experience limited movement, making it difficult to fully open or close the mouth.
The continuous activity can also lead to masseter muscle hypertrophy, which is the enlargement of the muscle. This enlargement can cause the jawline to appear wider or more square. The underlying muscle tension associated with hypertrophy can trigger headaches, particularly tension headaches or migraines.
When Gum Chewing Becomes a Risk Factor
The risk posed by gum chewing depends highly on the duration and frequency. For individuals with a healthy, pain-free jaw, occasional gum chewing is unlikely to cause harm. However, regular, prolonged chewing—such as for several hours each day—is strongly associated with a higher risk of developing TMD symptoms.
A pre-existing condition, such as bruxism or teeth grinding, significantly amplifies the risk. Individuals who already grind their teeth have strained jaw muscles, and repetitive gum chewing further stresses the joint and muscles. For anyone diagnosed with TMD or who experiences chronic jaw clicking or pain, chewing gum is generally advised against, as the added stress can worsen existing inflammation or joint dysfunction.
To enjoy gum safely, moderation and self-monitoring are the most effective strategies. Dentists often recommend limiting the total chewing time to no more than 15 to 20 minutes per session. A mindful approach involves paying attention to any signs of fatigue, soreness, or pain; if discomfort begins, the gum should be spit out immediately. Alternating the side of the mouth used for chewing can also help prevent the development of muscle imbalances.