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. Chewing muscles are fixed on the bones in the same way as others. They are fixed at two ends. The moving area of ββthe muscles is fixed on the lower jaw. Fixed fixed on the bones of the skull. All muscles involved in chewing food and lower jaw movement have a normal structure. The muscular part is present in them. It can contract and set the lower jaw in motion.
Kinds
There are much fewer masticatory muscles than, for example, mimic ones. The first is only 4. However, they perform the most important functions, including ensuring the preservation of the "corner of youth." These include muscles:
- Temporal.
- Chewing.
- Lateral and medial pterygoid.
All these elements form a single design. When shortening or deforming one of them, the others undergo changes.
Lateral pterygoid muscle: photo, short description
There are two heads in it. They are separated by their own connective membrane (fascia). The lateral pterygoid muscle starts from the bone at the base of the skull. In this case, the beams depart from different points. The narrower (upper) protrudes from the temporal region of the large wing in the sphenoid bone, as well as from the temporal crest. A wider (lower) beam emerges from the side. It starts from the pterygoid lateral plate in the sphenoid bone. Fibers are combined upon reaching the point of fixation.
Lateral pterygoid muscle: functions
It should be said that this muscle element has various connections with other facial structures. If the lateral pterygoid muscle begins to function poorly or undergoes deformities, 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 extension of the jaw. This is achieved by simultaneously reducing 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 reduced, it moves to the left, and vice versa.
Medial element
This muscle is presented in the shape of a quadrangle. She acts as the most important element of the mandibular ligament. The muscle is located on the inner surface of the bone, opposite the chewing bone, in the same direction. In some cases, their bundles are connected. The element is fixed with the help of thick processes. There are two of them. The larger one is attached to the pterygoid lateral part in the sphenoid bone, the smaller one - in the pyramidal process in the palatine part and the tuber 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 the movement of the lower jaw. When contracting on both sides, the bone moves forward and upward, on the one hand - to the side.
Chewing element
This muscle is located on top of the pterygoid (medial and lateral). It is strong enough, because it trains more often than others during chewing. Her contours are reasonably well felt, especially when she 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 front sections of the zygomatic arch. The deep part attaches a little further. She moves away from the back and middle sections of the arc. The surface element at an angle extends back and down. At the same time, it covers the part located deeply.
Temporal element
This muscle departs immediately from the three 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, it pulls the lower jaw forward and also lifts it to close with the upper. The temporal jaw is not distinguished by a pronounced relief. However, she is directly involved in the formation of "hollow temples." With weight loss or frequent nerve stress, the muscle takes on a thinner and flatter shape. The temporal line and the zygomatic arch acquire relief. It is in this case that the face looks exhausted. With dysfunction or spasm, it is very difficult to detect changes in it.