Muscle Minute TUESDAY – Meet the Masseter

Wait one second. That little thing is the strongest muscle in the body?! That’s right. Based on its weight, the masseter muscle is the strongest muscle of the body, able to clench the jaw with upwards of 200 pounds of force. Let’s take a deeper dive:

Origin	zygomatic arch
Insertion	mandibular ramus and coronoid process
Action	elevation (closing mouth) and protrusion of mandible
Innervation	mandibular n. (largest division of trigeminal n.)
Antagonists	lateral pterygoid

The Real World Masseter

The masseter rarely gets injured. Since its job is to elevate the mandible, it is one of two muscles, along with the temporalis, that allows you to bite down and chew your food. Unfortunately, if it becomes tight, it can prevent you from opening your mouth wide. You should be able to open your mouth to 40-50 mm (equivalent to four fingers placed vertically between your teeth).

Open and close your mouth. Do you hear a crunching or cracking in this joint? Healthy synovial joints require space between the boney surfaces. If muscles surrounding a joint become tight it can close off this space resulting in uneven joint surfaces and osteoarthritis.

Here’s a quick fix (stretch the masseter): Place your tongue on the roof of your mouth. Open your mouth as wide as you can while keeping your tongue in this position. Repeat 6 times. Every day.

Why does this matter?

Bruxism, grinding of the teeth, is often caused by involuntary contractions of the masseter
Hypertrophy of the masseter may case facial distortion or a squareness of the jaw. Some seek botox injections for cosmetic reasons.
Tightness of the masseter may results in headaches, difficulty chewing or biting and osteoarthritis of the TMJ

Conventional thinking says: (Well, conventional thinking often doesn’t ponder this muscle.)

Real World Thinking says: The masseter muscle is small but mighty and often lies at the root of TMJ, headaches and teeth grinding. Stress may increase activation of this muscle, causing hypertrophy. Before you resort to botox to streamline the profile of your face or get rid of pain, do daily stretching with the simple fix above. It just might make the difference.

Because nobody has time to be in pain.

Until next time…