Table of Contents
What is the function of pterygoid?
The primary function of the pterygoid muscles is to produce movements of the mandible at the temporomandibular joint. Both muscles are innervated by branches of the mandibular division of the trigeminal nerve (CN V3), and receive their blood supply from branches of the maxillary artery.
What are the functions of the two head of the lateral pterygoid muscle?
Lateral pterygoid is a two-headed, fan-shaped muscle located in the infratemporal fossa of the skull. It is one of the four masticatory muscles, along with the medial pterygoid, temporalis and masseter muscles. All these muscles act upon the temporomandibular joint (TMJ) to enable chewing (mastication) and biting.
Which muscle helps to open the jaw?
The masseter muscle provides powerful elevation and protrusion of the mandible by originating from the zygomatic arch and inserting along the angle and lateral surface of the mandible. The temporalis muscle originates from the floor of the temporal fossa and inserts onto the coronoid process of the mandible.
Where do you find the pterygoid muscles?
The medial pterygoid muscle, a major elevator of the jaw is a square-shaped masticatory muscle, located on the medial aspect of the lower jaw bilaterally. It is also known as internal pterygoid muscle.
What does pterygoid mean?
(Entry 1 of 2) : of, relating to, or lying in the region of the inferior part of the sphenoid bone of the vertebrate skull. pterygoid. noun.
What is the medial pterygoid?
Anatomical terms of muscle The medial pterygoid (or internal pterygoid muscle), is a thick, quadrilateral muscle of mastication. The mandibular branch of the fifth cranial nerve, the trigeminal nerve, innervates the medial pterygoid muscle.
How do you massage a pterygoid muscle?
Gently squeeze the muscle between the index finger and the thumb. Start with a gentle pressure, and gradually increase the muscle squeeze as tolerated. Teach the patient to self-squeeze the lateral pterygoid muscle for 1 minute several times per day. Relief of the headache, jaw or facial pain is sometimes immediate.
What is the strongest muscle in the body?
The strongest muscle based on its weight is the masseter. With all muscles of the jaw working together it can close the teeth with a force as great as 55 pounds (25 kilograms) on the incisors or 200 pounds (90.7 kilograms) on the molars. The uterus sits in the lower pelvic region.
How do jaw muscles work?
The jaw muscles move the jaw in a complex three-dimensional manner during jaw movements. There are three jaw-closing muscles (masseter, temporalis, and medial pterygoid) and two jaw-opening muscles (lateral pterygoid and digastric). The basic functional unit of muscle is the motor unit.
How do you test a medial pterygoid muscle?
To palpate from outside the mouth, the head is tilted slightly to access the muscle. Palpation with one finger locates trigger points on the inner surface of the mandible by pressing upward at its angle. Palpation of the mid-belly is performed inside the mouth with the pad of the palpating index finger.
What muscles attach to the medial pterygoid plate?
The pharyngeal aponeurosis is attached to the entire length of the posterior edge of the medial plate, and the constrictor pharyngis superior takes origin from its lower third.
Can you palpate the medial pterygoid muscle?
The medial and lateral pterygoid muscles are difficult to palpate, and therefore, assessment is carried out using intra-oral palpation (see Fig. 2.1).
What is the function of the medial pterygoid muscle?
The contraction of the medial pterygoid elevates the mandible (jaw closure) and moves it forward (protrusion). These movements are reinforced by the muscle sling formed with the masseter. The lateral pterygoid differs from the other three muscles of mastication as it is the only one among them which can open the jaw.
How is the medial pterygoid related to the parotid gland?
Near its insertion, the outer surface of the medial pterygoid muscle is related to the process of the parotid gland . The inner surface of the muscle is in relation to tensor veli palatini, styloglossus and salpingopharyngeus muscles. The latter two muscles separate the medial pterygoid muscle from the superior pharyngeal constrictor.
How is an examination of the medial pterygoid done?
Examination for trigger points in the medial pterygoid is performed both inside and outside the mouth with the patient in a supine position. To palpate from outside the mouth, the head is tilted slightly to access the muscle. Palpation with one finger locates trigger points on the inner surface of the mandible by pressing upward at its angle.
Where does the pterygoid fascia begin and end?
The pterygoid fascia covers the medial and lateral pterygoid muscles. It originates from the lamina lateralis of the pterygoid process and extends to the spina angularis, the petrotympanic fissure and the mandible above the insertion of the pterygoid muscles.