The temporalis muscle acts primarily as an elevator of the lower jaw. This function is largely created by its front vertical fibers, which are constantly in action and counteract gravity when the mouth is closed. The contraction of the posterior, more horizontal fibers of the muscle creates a retraction of the lower jaw and pulls the jaw back. In addition, the temporalis muscle contributes to grinding movements by moving the lower jaw from side to side. Each of these primary masticatory muscles is paired, with each side of the lower jaw having one of four. The function of the lateral pterygis depends on the degree of its contraction. The bilateral contraction of the lateral pterygoid muscles protrudes and squeezes the lower jaw. A unilateral contraction on a particular side, in conjunction with the ipsilateral medial pterygoid muscle, moves the lower jaw to the opposite side. This makes it possible to alternate lateral movements during chewing. Saliva secretion is mediated by autonomic nerve stimulation. Salivary mucus provides lubrication during chewing and swallowing.

The salivary glands also produce saliva amylase in the mouth, which converts starch and glycogen into maltose and maltotriose. The lingual glands produce lingual lipase (Table 10.7), which converts triglycerides into fatty acids and glycerin. The lateral pterygoid is a short, thick muscle with two heads. The upper and lower head. It originates from the temporal fossa to the lower temporal line of the lateral skull. The temporal muscle fibers converge downwards and form a tendon that exists the temporal fossa, which passes under the zygomatic arch and introduces it into the coronaid process of the lower jaw. 1. What masticatory muscle is involved in opening the jaw? Has.

masseter B. temporalis C. medial pterygoid D. Lateral pterygoid The temporal muscle originates from the temporal fossa – a shallow depression on the lateral surface of the skull. The muscle is covered with a hard fascia that can be surgically removed and used to repair a perforated eardrum (an operation known as myringoplasty). Another common condition is temporomandibular joint dysfunction (TMD). The temporomandibular joint is where the temporal bone and lower jaw meet. DCM has a variety of causes, but symptoms can include pain, clicking when opening the mouth, restriction of movement, headache, and dizziness.

A soft diet may be prescribed because chewing can be difficult or painful. It also carries a risk of malnutrition and neurological deficits. Most masticatory muscles are innervated by the motor branch of the fifth cranial nerve, and the chewing process is controlled by nuclei in the brainstem. Stimulation of specific reticular areas in the taste centers of the brainstem causes rhythmic chewing movements. In addition, stimulation of areas of the hypothalamus, amygdala, and even cerebral cortex near sensory areas for taste and smell can lead to chewing. Chewing usually involves an approach, but not necessarily contact between the posterior teeth. It is possible to prepare a food bolus to swallow without contact with the teeth. The effectiveness of crushing the food bolus is influenced by the contour of the occlusal surfaces. Abrupt bump tendencies may or may not promote chewing efficiency, but increase the lateral load on the teeth. The need for effective chewing (and posterior teeth) has decreased significantly with modern food handling techniques. Therefore, the actual occlusal form provided during restorative procedures appears to have minimal chewing efficiency. The effect on the lateral load of the teeth may be greater, especially if the restored teeth have reduced periodontal and bone support.

In these circumstances, a low cusp height and a shallow pit depth seem to be beneficial in reducing lateral loads. In implant-supported prostheses, the inability to dissipate these lateral forces through damping movements results in high loads on restorative materials and can lead to stresses that manifest as peeling of the plating or significant fractures of the core and frame. The temporalis muscle is a fan-shaped muscle with anterior fibers that have a vertical orientation, the middle fibers have an oblique orientation, and the posterior fibers have a more horizontal orientation. The origin of the temporalis muscle extends from the temporal fossa to the inferior temporal line of the lateral skull. The temporal muscle fibers converge downwards and form a tendon that leaves the temporal fossa, passes under the zygomatic arch and introduces the coronaid process of the lower jaw. The function of the anterior and middle fibers of the temporal muscle is to increase the lower jaw. The posterior fibers of the temporalis muscle serve to retract the lower jaw. [4] The chewing cycle is the path taken by the lower jaw when chewing food. During the opening phase, the lower jaw is pressed, which means that it is open; It is lowered to make room for food intake. During the closing phase, the jaw closes.

This action is mainly carried out by the masseter, temporalis and medial pterygoid muscles. The third phase is the occlusal phase. During this phase, the teeth come into contact with each other and the chewing movement is completed. Then the cycle begins again, with the jaw opening, closing and closing its teeth until the food is chewed enough to swallow. The four main muscles of the auction are all innervated by the anterior trunk of the mandibular nerve, which is the third division of the trigeminal nerve (CN V3). The mandibular nerve (CN V3) is the largest and lowest department of the trigeminal nerve (CN V). The trigeminal nerve (CN V) leaves the skull via the foramen ovale of the largest wing of the sphenoid bone. The mandibular nerve contains both sensory and motor fibers. The mandibular nerve is the only division of the trigeminal nerve that carries the motor fibers. The mandibular nerve (CN V3) divides further when it innervates the four main muscles of the deposit. The temporalis muscle is innervated by the deep temporal branches of the mandibular nerve. The medial pterygoid muscle receives an innervation of the medial pterygoid nerve, a division of the mandibular nerve.

The lateral pterygoid muscle receives its nerve supply from the lateral pterygoid nerves, divisions of the mandibular nerve. The masseter muscle receives nerve input from the masseter nerve, a division of the mandibular nerve. [2] Both heads contain the lower fibers of the lateral pterygoid muscle.