The chewing muscles are called so because they are involved in the complex process of mechanical grinding of food. They also provide movement of the lower jaw. Due to this, a person can close and open his mouth, talk, yawn, etc. The chewing muscles are fixed on the bones in the same way as others. They are fixed at both ends. The movable part of the muscles is fixed on the lower jaw. The fixed one is fixed on the bones of the skull. All the muscles involved in chewing food and moving the lower jaw have a normal structure. They have a muscular part. It can contract and move the lower jaw.
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There are much fewer chewing muscles than, for example, facial muscles. There are only 4 first ones. However, they perform the most important functions, including ensuring the preservation of the "corner of youth". These include muscles:
- Temporal.
- Chewable.
- Lateral and medial pterygoids.
All these elements form a single structure. When shortened or deformedone of them is subject to change and the rest.
Lateral pterygoid muscle: photo, brief description
It has two heads. They are separated by their own connective sheath (fascia). The lateral pterygoid muscle originates from the bone at the base of the skull. In this case, the beams depart from different points. The narrower (upper) protrudes from the infratemporal region of the greater wing in the sphenoid bone, as well as from the infratemporal crest. A wider (lower) beam comes out from the side. It originates from the pterygoid lateral plate in the sphenoid bone. The fibers unite when they reach the anchor point.
Lateral pterygoid muscle: functions
It should be said that this element of musculature has various connections with other facial structures. If the lateral pterygoid muscle begins to function poorly or is deformed, this may affect the activity of other systems. Dysfunction of this element can cause the development of a variety of symptoms and disorders, up to hearing loss. The lateral pterygoid muscle provides jaw extension. This is achieved by simultaneous contraction of the beams on the right and left. If the lateral pterygoid muscle is involved only on one side, the jaw moves in the opposite direction. For example, when the right beam is shortened, it moves to the left, and vice versa.
Medial element
This muscle is presented in the shape of a quadrangle. She isacts as the most important element of the mandibular ligament. The muscle is located on the inner surface of the bone, opposite the masticatory, in the same direction as it. In some cases, their bundles are connected. The element is fixed with the help of thick processes. There are two in total. The larger one is attached to the pterygoid lateral part in the sphenoid bone, the smaller one is attached to the pyramidal process in the palatine part and the tubercle on the upper jaw. At the bottom, the muscle is also fixed at two points. Between the processes, many important structures are formed. Among them are nerves, alveolar, maxillary vessels. The medial element, as well as the lateral pterygoid muscle, provides movement of the lower jaw. When contracting on both sides, the bone moves forward and upward, on the one hand - to the side.
Chewable
This muscle is located on top of the pterygoid (medial and lateral). She is quite strong because she trains more often than others while chewing. Its contours are quite well felt, especially when it is in a reduced state. The muscle is fixed on the zygomatic arch. It has a rather complex structure. Muscle fibers are divided into deep and superficial parts. The latter departs from the middle and anterior sections of the zygomatic arch. The deep part is attached a little further. It departs from the rear and middle sections of the arc. The surface element extends backwards and downwards at an angle. At the same time, it covers the part located deep.
Temple element
This muscle moves away immediately fromthree bones. The temporal element occupies almost 1/3 of the surface of the skull. In its shape, the muscle resembles a fan. The fibers go down and pass into a fairly powerful tendon. It is fixed on the coronoid process of the lower jaw. This muscle provides biting movements. In addition, she delays the lower jaw, advanced forward, and also raises it to close with the upper. The temporal jaw does not have a pronounced relief. However, she is directly involved in the formation of "sunken temples". With weight loss or frequent nervous stress, the muscle takes on a thinner and flatter shape. The temporal line and zygomatic arch at the same time acquire relief. It is in this case that the face looks emaciated. With dysfunction or spasm, it is very difficult to detect changes in it.
