Search results
Results from the WOW.Com Content Network
In humans, the mandible, or lower jaw, is connected to the temporal bone of the skull via the temporomandibular joint. This is an extremely complex joint which permits movement in all planes. The muscles of mastication originate on the skull and insert into the mandible, thereby allowing for jaw movements during contraction.
A concerted effort of the lateral pterygoid muscles helps in lowering the mandible and opening the jaw. Unilateral action of a lateral pterygoid muscle causes contralateral excursion (a form of mastication), usually performed in concert with the medial pterygoids. [citation needed] When they work independently, they can move the mandible side ...
The levator labii superioris alaeque nasi muscle (occasionally shortened alaeque nasi muscle) is, translated from Latin, the "lifter of both the upper lip and of the wing of the nose". The muscle is attached to the upper frontal process of the maxilla and inserts into the skin of the lateral part of the nostril and upper lip. [1]
The lateral pterygoid plate of the sphenoid (or lateral lamina of pterygoid process) is broad, thin, and everted and forms the lateral part of a horseshoe like process that extends from the inferior aspect of the sphenoid bone, and serves as the origin of the lateral pterygoid muscle, which functions in allowing the mandible to move in a lateral and medial direction, or from side-to-side.
The geniohyoid is a paired short muscle that arises from the inferior mental spine, on the back of the mandibular symphysis, and runs backward and slightly downward, to be inserted into the anterior surface of the body of the hyoid bone. [2]: 346 It lies in contact with its fellow of the opposite side. It thus belongs to the suprahyoid muscles.
The action of the muscle during bilateral contraction of the entire muscle is to elevate the mandible, raising the lower jaw. Elevation of the mandible occurs during the closing of the jaws. The masseter parallels the medial pterygoid muscle, but it is stronger and superficial fibres can cause protrusion.
This also supplies the tensor tympani muscle and the tensor veli palatini muscle. The medial pterygoid nerve is a main trunk from the mandibular nerve, before the division of the trigeminal nerve - this is unlike the lateral pterygoid muscle, and all other muscles of mastication which are supplied by the anterior division of the mandibular nerve.
The mylohyoid muscle originates from the anterior (front) part of the mylohyoid line. [1] Rarely, the mylohyoid muscle may originate partially from other surfaces of the mandible. [ 2 ] The posterior (back) part of this line, near the alveolar margin , gives attachment to a small part of the superior pharyngeal constrictor muscle , and to the ...