Part 3: Lateral and Medial Pterygoid Muscles
At Best Speech Therapy, PLLC, we frequently work with people who complain of pain or discomfort of the jaw. There are a lot of reasons for orofacial pain such as Trigeminal Neuralgia, clenching, grinding, TMJ disorder (TMD), and more. The most common reason for facial pain is due to a muscle imbalance; many times this muscle pain is a result of bruxism or excessive clenching and grinding.
In this series of blogs, I discuss how the jaw muscles and the function of this muscles contribute to pain. We discussed how the masseter muscle can become imbalanced from teeth together postures, bruxism, and more in Part 1. In Part 2, we discussed how the temporalis muscle can become imbalanced from holding your mouth open during extended periods of time, such as mouth breathing or sleeping with your mouth open. In Part 4, we will focus on how jaw work (chewing) is crucial for mouth, airway development and cognitive performance.
The pterygoid muscles are located just below the shallow depression of the temporal bone and deep to the ramus of the mandible. The primary role of these muscles are to move the mandible at the temporomandibular joint, or TMJ region.
The Lateral Ptyergoid muscle, characterized by a superior belly and an inferior belly, is responsible for the following functions of the mouth:
works hand in hand with the medial ptyergoid muscle for chewing and grinding foods.
jaw stability for open mouth grading
Smoothes out movements for sucking and chewing
Helps with diagonal movements required for rotary chewing
Inferior belly: contracts for jaw opening
Superior belly: contracts for mouth closure; may influence the condyle and disc
The Medial Pterygoid muscle, characterized by a deep head and a superficial head, is responsible for the following functions of the mouth:
works hand in hand with the lateral pterygoid muscle for chewing and grinding foods.
elevates and closes the mouth
stabilizes the jaw
helps to bring the jaw forward
assists with jaw grading for food intake movements such as sucking, biting, spoon, fork, cup, or straw
Assists with lip closure
Helps the masseter muscle
Just like the masseter muscle and the temporalis muscle, The jaw branch of the CN V, also known as the Trigeminal Nerve, innervates the ptyergoids. Hence, some pain is neurological and will require a referral to neurologist.
Now that you have a little background regarding the pterygoid muscles, let's get back to that jaw pain...
Signs that you may have an orofacial myofunctional disorder characterized of a jaw symptoms:
Do I have asymmetrical jaw opening and closure?
Do I find my jaw moving or unstable when I open my mouth to obtain food and drinks from a cup, straw, fork, etc?
Do I find myself chewing at the front of mouth?
Do I chew rapidly and find myself swallowing chunks of food?
Do I swallow foods that are not completely chewed?
Do I find one side weaker than other when I'm biting my food?
Do I prefer to suck my food in place of chewing my food?
Do my teeth touch when my lips are closed?
When the mouth is open or the jaw is protruded, or moved forward, for an extended pierod of time; the muscles are in constant tension. This constant tension may result in pain, especially when touched.
In part 4, we will discuss chewing and mastication and how chewing linked with trigeminal nerve pathways play a role in cognitive improvement.
Our orofacial myologists and speech pathologists collaborate with your medical, dental, and whole body professionals to improve functional mouth movements by targeting muscle imbalances.
We strive to improve your quality of life by assessing your jaw, lips, tongue movements and the functions of breathing, chewing/swallowing, and speaking.
Email info@Bestspeechtherapy.com to schedule your Orofacial Myofunctional evaluation today!
Gatto, K. K. (2016). Understanding the orofacial complex: The Evolution of Dysfunction. Outskirts Press.
Mason, R. M., et al. (2020). The importance of the freeway space in orofacial myofunctional therapy. International Journal of Orofacial Myology and Myofunctional Therapy,46(1), 37-47.
Saccomanno, S., & Paskay, L. C. (2020). New trends in myofunctional therapy: Occlusion, muscles and posture. Edi-Ermes.