The human body has an estimated 650 named skeletal muscles throughout the body, with just four muscle groups located in the head and neck. Muscles aren’t just responsible for helping you move, but also move food through your digestive system and help your heart pump blood. The muscles in the head and neck help you chew, swallow, make facial expressions, and move your eyes. The muscles in the face are unique because they connect bones to the skin while most other muscles connect strictly to only bone.

closeup of a male's mouth showing a thin beard and large smile

Comparing Arm Movement to Jaw Movement

It’s easy to understand the muscles of the arm. To bend an arm, the triceps and biceps work together to bed. These muscles are known as antagonistic muscles. One set flexes the forearm while the other one extends or opens the forearm. While one muscle works, the other one relaxes. Closing and opening the jaw is similar to bending an arm. To open and close a mouth, chew, swallow, breathe, or talk, all of the muscles in the neck and head must work together in perfect harmony. Although it might sound as simple as arm movement, jaw movement is much more complicated; especially with the intricate movements of the tongue involved.

Mouth Closing Muscles

There are two major antagonistic muscles your face uses to close the jaw: the masseters and the temporalis. Wondering where to locate these muscles? Place your fingers on the sides of your cheeks and then bite down. The movement you feel is the masseters in motion.  Now place your fingers on your temples and then bite down. The motion you feel is the temporalis.

When biting down, the masseter muscles work at the same time which allows your jaw to bite straight down. On the other hand, the temporalis muscle works with other muscles to guide the jaw left or right. Most people actually chew slightly sideways, just like a cow. To chew on the left side, the jaw makes a left to right movement when it closes. To accomplish this, it requires perfect coordination in regards to positioning, opening, and closing muscles. The mouth performs this action thousands and thousands of times per day without much thought.

Opening Muscles

The muscles responsible for opening the jaw are much smaller than the muscles that close the jaw. People who struggle to open their mouths do not have their opening and closing muscles working in harmony. Instead, the muscles are competing with each other, with the closing muscles winning. In some cases, it is actually the temporomandibular joint that prevents the mouth from opening.

The lateral pterygoid is the muscle located on the joint residing in front of the ear canal and is the major opening muscle. When the lateral pterygoid contract, the joint pulls forward and opens the jaw. If you hear a pop or click upon opening the jaw, the lateral pterygoid is involved.

The other muscle in your head is the tensor tympani which is a tiny muscle that resides in the inner ear. It serves the sole purpose of tightening the eardrum when exposed to loud noises. The tensor tympani helps drown out yawning, chewing, and talking sounds so the vibrations don’t make their way to the brain.

So what happens when the muscles don’t work in harmony? One ends up working harder than the other. A common result of disharmony is temporomandibular joint disorder (TMD) which causes painful symptoms like jaw pain, frequent headaches, ear and neck pain, and much more. If you believe your face muscles are working out of harmony, please contact Bite Align to schedule a TMJ evaluation in Fort Atkinson. TMJ treatment can help restore harmony in your face muscles and help you manage painful symptoms. Please call us today at (920) 563-7323 to schedule an appointment with Dr. Stafford.