What are Pterygoids?
The pterygoid muscles are two of the four muscles of mastication, located in the infratemporal fossa of the skull. These muscles are: lateral pterygoid and medial pterygoid. The primary function of the pterygoid muscles is to produce movements of the mandible at the temporomandibular joint.
What do the lateral pterygoid muscles do?
The Lateral pterygoid muscle is active during mastication and during mandibular movements such as protrusion (forward movement of the mandible), abduction (depression of the mandible), mediotrusion (movement of the mandibular condyle towards the midline), and particularly during speaking, singing, and clenching.
What is the function of medial pterygoid muscle?
The function of medial pterygoid, while contracting bilaterally, it produces elevation and protrusion of the mandible, while unilaterally contracted, it produces contralateral excursion (Neumann, 2010; Okeson, 2013). It pulls the ramus of the mandible medially and shifting the mandible toward to the contralateral side.
What is the lateral pterygoid action?
The primary function of the lateral pterygoid muscle is to pull the head of the condyle out of the mandibular fossa along the articular eminence to protrude the mandible. At the beginning of this action it is assisted by the digastric, mylohyoid and geniohyoid muscles.
What is Ramus of mandible?
The rami are two vertical processes located on either side of the body; they join the body at the angle of the mandible. At the superior aspect of each ramus, the coronoid and condylar processes articulate with the temporal bone to create the temporomandibular joint which permits mobility.
What is the Infratemporal fossa?
The infratemporal fossa is a complex space of the face that lies posterolateral to the maxillary sinus and many important nerves and vessels traverse it. It lies below the skull base, between the pharyngeal sidewall and ramus of the mandible.
What is a pterygoid process?
Definition of pterygoid process : a process extending downward from each side of the sphenoid bone in humans and other mammals.
What is medial pterygoid plate?
The medial pterygoid plate (or medial pterygoid lamina) of the sphenoid bone is a horse-shoe shaped process that arises from its underside. The anterior margin of the plate articulates with the posterior border of the vertical part of the palatine bone. In many animals it is a separate bone called the pterygoid bone.
How do you test for medial pterygoid?
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 happens when the lateral pterygoid contracts?
Lateral pterygoid is a two-headed, fan-shaped muscle located in the infratemporal fossa of the skull. Lateral pterygoid contributes to this function by protruding and depressing the mandible when contracting bilaterally, and by rotating the mandible when contracting unilaterally. …
What is the Ramus?
Definition of ramus : a projecting part, elongated process, or branch: such as. a : the posterior more or less vertical part on each side of the lower jaw that articulates with the skull.