Hall Judith G
Department of Medical Genetics, UBC and Children's and Women's Health Centre of British Columbia, Vancouver, British Columbia, Canada.
J Craniofac Surg. 2010 Sep;21(5):1336-8. doi: 10.1097/SCS.0b013e3181ebcd4f.
After the craniofacial structures have completed embryologic development, movement of facial muscles begins. Paraxial mesoderm of the first (mastication) and second pharyngeal (facial expression) arches gives rise to the muscles of the craniofacial area. Muscles derived from the third and fourth pharyngeal arches are involved in swallowing and vocalization. For the human newborn face to have a normal morphologic appearance, contractions of these muscles must occur to stimulate forward growth of bone, cartilage growth, and facial muscle bulk. Facial muscles begin to contract between 6 and 8 weeks of embryonic development and can be observed on prenatal ultrasound by 9 weeks after fertilization. Lack of craniofacial muscle contractions may lead to ocular hypertelorism, flat zygoma and midface, high bridge of the nose, depressed tip of the nose, small and open mouth, trismus, microretrognathia, small tongue, and abnormal palate (high arch, bifid uvula, submucous cleft, and cleft palate).
颅面结构完成胚胎发育后，面部肌肉开始运动。第一（咀嚼）和第二咽弓（面部表情）的轴旁中胚层产生颅面部的肌肉。源自第三和第四咽弓的肌肉参与吞咽和发声。为了使人类新生儿面部具有正常的形态外观，这些肌肉必须收缩以刺激骨骼向前生长、软骨生长和面部肌肉体积增加。面部肌肉在胚胎发育的6至8周开始收缩，受精后9周可通过产前超声观察到。颅面肌肉缺乏收缩可能导致眼距增宽、颧骨和中面部扁平、鼻梁高、鼻尖凹陷、小嘴且张开、牙关紧闭、小下颌后缩、小舌以及腭异常（高拱、悬雍垂裂、黏膜下腭裂和腭裂）。
