Our strongest muscle is not located in our shoulders, our legs, or even our back. The masseter, the strongest muscle in the body and one of the most used facial muscles, is located in the jaw. It’s got an important job—it enables us to eat and speak—so the strength of the masseter is of paramount importance. But considering how much we use it in everyday life, strengthening the masseter doesn’t require extra work. In fact, this muscle is easily overworked. As with all muscles, the masseter’s true strength lies in the balance between rest and work. You can avoid the jaw pain, inflamed gums, worn-down teeth, and persistent headaches so commonly attributed to an overworked masseter by learning and practicing some simple relaxation techniques.
The masseter is a small, strong, rectangular muscle located at the hinge of the jaw. It originates at the cheek bone (the zygomatic arch) and ends (inserts) along the back, angled portion of the lower jaw (mandible).
The masseter is responsible for elevating the lower jaw (mandible). Jaw elevation happens when the mouth closes. The masseter elevates, for example, when you bite into an apple.
When you strengthen a muscle, for example, by lifting weights, tiny micro-tears develop in the muscle fibers. When you rest after strengthening, the body sends the necessary nutrients to repair the damage to that muscle, and to stimulate its growth to prevent future damage. It is this process of repairing the micro-tears that strengthens the muscle.
Anytime you close the jaw, the masseter is strengthened. In everyday life, the masseter is strengthened each time you “zipper the lips” during quiet time, chew gum, or talk to a friend. The masseter is not commonly strengthened at the gym. However, when actors and singers warm up, they often practice a series of movements to increase mobility in the mouth and face.
When you stretch a muscle, some of the individual muscle fibers (long, thin muscle cells) are pulled out to their longest length, while other muscle fibers remain contracted. The more muscle fibers that lengthen, the greater the stretch. To increase the number of lengthened muscle fibers requires consistent and repetitive stretching. When all the fibers lengthen fully, the muscle is at its longest and allows for maximum flexibility at the surrounding joints. This flexibility increases your overall range of motion and decreases risk of injury.
Ideally, stretching takes place after movement. Movement increases blood flow to the muscles for a safer stretch. This is often referred to as stretching “warm” muscles. The increased blood flow from movement raises the temperature in the muscle so it is literally warmer. Plus, the blood flow boosts the oxygen supply to the body and causes the muscle fibers to have greater flexibility. So, contrary to what many of us were taught, there is no need to stretch before exercise. When you stretch a “cold” muscle, the muscle fibers are less flexible. So, not only is the stretch limited, the muscle is more susceptible to injury.
Stretching and strengthening have a converse relationship. For example, if the jaw must be closed to strengthen the masseter, then it must be open to stretch it. In everyday life, the masseter stretches when you yawn or drool. Again, the masseter is not commonly stretched at the gym, but that doesn’t mean it’s not important. In yoga, lion pose stretches the masseter.
Muscles support and move the skeleton, making them critically important for the structural health of your body. Muscles are made up of sheets of fibrous tissue that can contract and release. Both ends of a muscle connect to one or more bones via tendons. When a muscle contracts, the bones on either side of the muscle pull toward one another. When a muscle releases or stretches, the bones move away from each other. For example, when you’re walking, your muscles continuously contract and release to keep you moving.
The masseter is vital to everyday actions like talking and chewing, but it is often overused. The chewing (masticatory) system is only designed to function for about the amount of time it takes to eat three meals each day—roughly 45 minutes total. Beyond 45 minutes, damage can occur to the teeth, bones, and muscles in and around the mouth. Overeating, chewing gum and tobacco, grinding teeth (bruxism), and clenching all occur outside of this 45-minute window, contributing to masseter overuse and potential damage. Stretching or relaxing the masseter gives the mouth and jaw a break, and even reduces the body’s stress response!
Try our masseter workout to strengthen, stretch, and optimize this muscle.
The most common masseter injuries include strain, tear, and inflammation in the muscle and/or tendons connecting the muscle to the bones.
Other ailments related to imbalance in the masseter include grinding (bruxism), jaw clenching, headaches, migraines, nerve-based neck pain, muscular neck pain, jaw locking, shoulder pain, back pain, and hip pain.