面部肌肉與表情 Part 2 - 口部群組

FACIAL MUSCLES ORAL GROUP ORBICULARIS ORIS ORAL SPHINCTER This complex muscle surrounds the oral orifice and forms the greater part of the lips. It has extrinsic and intrinsic portions. The major extrinsic or superficial portion is composed of interlacing fibers of the muscles, which converge around the mouth for their insertion into the lips. The intrinsic portion consists of fibers running between the skin and mucous membrane of the lips, and incisives lips. Because of its complex nature, orbicularis oris is capable of producing wide variety of movements of lips, closes lips, protrudes lips, pursing, twisting, motiolus. It is a dense, compact, mobile fibromuscular mass situated about 1.25 cm lateral to the angle of the mouth. It is formed due to interlacing fibers of five muscles, which converge toward the angle of the mouth. These muscles are levator anguli oris, zygomaticus major, boxinator, depressor anguli oris, and rhizorius. Major part of extrinsic muscle fibers of orbicularis oris is derived from motiolus. It can be easily palpated by using opposed thumb and index fingers to compress the skin and mucosa simultaneously. The pulsations of facial artery can be felt just lateral to the motiolus. The inadvertent damage of motiolus during plastic surgery leads to unacceptable facial asymmetry. Paralysis of orbicularis oris The paralysis of one half of orbicularis oris prevents the proper closure of lips on that side. Consequently, the speech is slurred, and the saliva escapes between the lips at the angle of the mouth. Dribbling of saliva from the angle of the mouth. Boxinator Cheek muscle Origin The boxinator arises from the following four sites. Outer surface of the alveolar process of maxilla, opposite three molar teeth. Fibers band that extends from the pterygoid hamulus to maxillary tuberosity. Pterygomaxillary raphe. Pterygomandibular raphe, which extends from the pterygoid hamulus to the mandible behind the third molar tooth. Outer surface of the alveolar process of mandible, opposite three molar teeth. After origin, the fibers run toward the mouth, and fill the gap between the upper and lower jaws. The fibers are arranged into upper, intermediate, and lower groups. Insertion On reaching near the angle of the mouth, upper fibers pass into upper lip, lower fibers into the lower lip, intermediate fibers decusate at mardiolus, and as a result, upper fiber of this group pass into lower lip, and lower fibers pass into the upper lip. Nerve supply Buckle branches of facial nerve. Actions It flattens the cheek against the gum and teeth, and thus prevents the accumulation of food in that vestibule of mouth during mastication. It is responsible for blowing the cheek and expelling the air between the lips from inflated vestibule, as in blowing the trumpet. Hence the name, trumpeteer's muscle. Paralysis of buccinator muscle. If the buccinator muscle is paralyzed as it occurs in facial palsy, the food accumulates in the vestibule of mouth during mastication, and the person cannot blow his cheek. Levator labii superioris aliqui nasi arises from the frontal process of the maxilla, and is inserted into the alla of the nose by one slip, and to the upper lip by another slip. It elevates the upper lip and helps to dilate the nostril. Levator labii superioris aliqui nasi aliqui labi Aliqui nasi 它提高了上脣 大脣部的大腦子 來自大脣骨 並且被插入口角 它提高了口角 向上和向後 低脣部的低脣部 來自前頂的 肚子 並且被插入 下脣 它提高了下脣 向下和稍微向後 低脣部的頂脣 來自前頂的 肚子 並且被插入 口角 它提高了口角 向下和向後 低脣部的低脣部 來自下脣 並且被插入 口角 它提高了口角 並且被插入 下脣 它提高了下脣 它提高了口角 並且被插入 下脣 它提高了口角 並且被插入 下脣