Vitti M, Basmajian J V
Am J Orthod. 1975 Oct;68(4):412-9. doi: 10.1016/0002-9416(75)90182-7.
The temporalis, masseter, and depressor muscles of fifteen normal children were studied electromyographically to determine their activities during the position of resting tonus, during various movements of the mandible, and during the act of swallowing. Analysis of our results led to the following conclusions: 1. Resting tonus of the mandible does not depend on neuromuscular activity in the three portions of the temporalis, masseter, and depressor muscle group; they were inactive bilaterally. 2. Opening of the jaw either slowly or maximally, and against resistance, is brought about by the contraction of the depressor muscle group. 3. Closing of the jaw quickly is brought about mainly by greater contraction of the masseter muscle, and slightly by contraction of the temporalis. 4. Closing the jaw quickly with occlusal contact of the teeth is effected by the temporalis and masseter muscles. 5. Protraction of the jaw is performed by contraction of the masseter muscles. The depressor muscle group contracts to maintain the slight depression followed by the protraction. 6. Swallowing saliva and water is accompanied by contractions of the depressor muscle group. 7. Incisor chewing of gum and peanuts mainly recruits marked contraction of the masseter muscle. Some slight-to-moderate activity is achieved by the temporalis. The depressor muscle group acts in antagonism with the elevator muscles. 8. Chewing gum on the right and left molar sides and normal mastication are effected by the contraction of the temporal and masseter muscles. The suprahyoid muscle group acts in antagonism with the elevator muscles. 9. Normal children with deciduous teeth have patterns that are similar to those of normal adults.
对15名正常儿童的颞肌、咬肌和降肌进行了肌电图研究，以确定它们在静息张力状态、下颌骨的各种运动以及吞咽动作时的活动情况。对我们的研究结果进行分析后得出以下结论：1. 下颌骨的静息张力并不取决于颞肌、咬肌和降肌组三个部分的神经肌肉活动；双侧均无活动。2. 下颌骨缓慢或最大程度地张开，以及对抗阻力张开，是由降肌组的收缩引起的。3. 快速闭口主要是由咬肌的更强收缩引起的，颞肌的收缩起轻微作用。4. 牙齿咬合时快速闭口是由颞肌和咬肌完成的。5. 下颌前伸是由咬肌收缩完成的。降肌组收缩以维持前伸后的轻微下压。6. 吞咽唾液和水时伴有降肌组的收缩。7. 用门牙咀嚼口香糖和花生主要引起咬肌的明显收缩。颞肌有一些轻微到中度的活动。降肌组与升肌起拮抗作用。8. 在右侧和左侧磨牙侧咀嚼口香糖以及正常咀嚼是由颞肌和咬肌的收缩完成的。舌骨上肌群与升肌起拮抗作用。9. 乳牙期的正常儿童具有与正常成年人相似的模式。
