口腔一面肌功能的是否正常,影响牙综合体的生长发育和患者牙齿的健康。很多学者认为,“伸舌”是婴儿的正常活动。有的学者观察到胎儿到出生时,舌都较下颌为大,口腔为舌所充满,舌紧贴着硬腭在前部与唇保持接触。在发育过程中,舌骨下降,使舌降低和后移。下颌体的长度随上颌的增加而增加, Oral facial muscle function is normal, affecting the growth and development of dental complex and the patient's teeth health. Many scholars believe that “Tongue” is the normal activities of infants. Some scholars have observed that when the fetus is born, the tongue is larger than the lower jaw, the mouth is filled with the tongue, and the tongue is in close contact with the hard palate in front of the lip. During development, the hyoid bone drops, causing the tongue to lower and to move backward. The length of the mandible increases with the increase of the maxilla,