As you chew on a tasty piece of steak or bite into a big, juicy apple, it's doubtful you're conscious of your lateral pterygoid muscle, also called the external pterygoid muscle. But when it isn't working properly, it suddenly becomes front and center. As one of the four muscles of mastication (chewing), it helps you eat, talk and move your lower jaw. Learning about this muscle may be especially helpful if you are ever diagnosed with a temporomandibular joint (TMJ) disorder.
Anatomy of the External Pterygoid Muscle
Whether you refer to this muscle as the lateral or external pterygoid, it is a small, thick muscle found on both sides of the skull, just below the temples. According to the Loyola University Medical Education Network, it has two heads that originate from sections of the sphenoid bone in the skull. Both heads attach to the mandibular condyle, where the lower jawbone and the TMJ meet.
A paper in the Journal of Manual & Manipulative Therapy explains that this muscle has the primary responsibility of opening the mouth, and it is the strongest muscle involved in moving the jaw side to side and forward and back so that you can grind and chew food.
Trigger Points and TMJ Complications
Just think about how many times a day you open your mouth to talk or chew food. It's no wonder the lateral pterygoid is considered one of the hardest working muscles of mastication. According to a review published in the Journal of Bodywork & Movement Therapies, it can develop a trigger point, which is similar to a knot you may get in your neck when you sleep in an odd position. This trigger point can lead to discomfort and pain in the TMJ. In fact, the review notes that the lateral pterygoid is closely related to the TMJ and plays a key role TMJ dysfunction.
If you've ever had discomfort when chewing or soreness in your jaw muscles when you wake in the morning, you are not alone. The National Institute of Dental and Craniofacial Research estimates that more than 10 million Americans experience some type of TMJ disorder. These complications can arise from arthritis, which can destroy the cartilage that cushions the joint, or from trauma to the face or head area that damages or displaces the joint. According to the textbook Functional Occlusion in Restorative Dentistry and Prosthodontics, 45 percent of patients with TMJ problems also have jaw muscle disorders, and the lateral pterygoid is one of the muscles that may be involved. However, TMJ conditions are complex, and sometimes it's difficult to determine the precise cause of the issue.
Treatment for TMJ Problems
The good news is that a TMJ problem may go away on its own, according to the Mayo Clinic. If the pain and discomfort persist, your doctor or dentist may make the following recommendations to help ease your symptoms:
- Eat soft foods and avoid chewing gum.
- Apply ice packs or heat packs to your face.
- Take prescription or over-the-counter pain relief medications.
- Wear a mouth guard.
- Practice muscle relaxation exercises to reduce stress and lessen tension in your jaw muscles.
- Try physical therapy.
While you can't stop chewing or talking just to limit the strain put on your lateral pterygoid, keep in mind that this muscle can be overworked, just like any other muscle in your body. If you have an ache or pain in your jaw that hasn't gone away within a week or two, see your dentist for a clinical evaluation. If they feel it's a TMJ issue, they can offer treatment options or refer you to a specialist who is experienced in treating TMJ disorders.