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Muscle lifting the lower jaw (posterior group)
05-09-2009
Chewing muscles (m. masseter) starts from the bottom edge and the inner surface of the zygomatic arch, the anterior slope of the articular tubercle of temporal bone, temporal fascia. It is attached to the chewing surface of the outer branches of lumpy jaw below the notch. From the lower jaw muscle bundles directed upward, forward and outward. Masticatory muscle raises the lower jaw, its surface layer makes the jaw forward, with unilateral reduction - it shifts downward.
Temporalis muscle (m.temporalis) has fan-shaped form and consists of 3 layers: superficial, medium and deep. It starts from the inner layer of the temporal fascia in the temporal line, temporal bone, the temporal surface of the large wing and infratemporal crest of the sphenoid bone, parietal, frontal scales, the temporal surface of zygomatic bone. Hangs onto the top and the outer surface of the coronoid process, the branches of the mandible in its cutting and oblique lines, the inner surface of the branches of the mandible. From the lower jaw muscle bundles directed upward, outward and somewhat backward. The front and middle beams lift the lower jaw, rear - an advanced jaw pulled back.
Medial muscle webbed (m.pterygoideus medialis) is rectangular in shape. It starts from the walls of the holes pterygium pterygium sprouts sphenoid bone, the outer surface of the pyramidal sprouts palatine bone. Hangs onto pterygium tuberosity on the inner surface of the angle of the mandible (symmetrically with chewing muscle). From the lower jaw muscle bundles directed upwards, inwards and anteriorly at an angle of 37-48 °. At the bilateral muscle contraction raises the lower jaw and brings it forward, with one-sided - moves the lower jaw to the opposite side and upwards.
Lateral webbed muscle (m.pterygoideus lateralis) has a triangular shape and lies in the infratemporal fossa. It starts with two heads (upper and lower). Upper head originates from the infratemporal surface and infratemporal crest of a large wing of sphenoid bone and the tendon of the deep layer of temporalis muscle. Lower head departs from the outer surface of the pterygium sprouts sphenoid bone. The upper head is attached to the articular bag and fibroplate temporomandibular joint, the lower head - to pterygium fossa condylar sprouts mandible. From the lower jaw muscle fibers are directed forward and inward. At the bilateral muscle contraction raises the lower jaw forward, with one-sided - shifts in the opposite direction [SS Mikhailov, 1973].
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