儿童从6岁开始换牙,在其后的6~7年时间是乳牙恒牙混合牙列阶段,直到15岁左右,这一时期称为替牙期。这是人一生中生长发育最活跃最关键的阶段,也是儿童颌骨和牙弓发育成长的重要时期,是口颌及颅面形态的主要形成和功能完善期;也是龋病、牙龈炎患病的高峰时期,而且此期是儿童大脑发育和性格形成的主要时期。颜面形象的美与丑常常会 Children from the age of 6 began to change teeth, followed by 6 to 7 years of primary teeth mixed dentition stage, until the age of 15, this period is called the period of dentition. This is the life and growth of the most active and most critical stage, but also children’s jaw and dental arch growth and development of an important period of oral and craniofacial morphology is the main form and function of the perfect period; also dental caries, gingivitis Peak period, and this period is the main period of development and character formation of children’s brain. Beauty and ugliness of the face image often