乳牙担负着儿童时期咀嚼、辅助发音、促进颌面部及牙列正常发育等功能。从乳牙萌出与脱落的时间计算,每个乳牙在口腔内发生作用时间至少是5年,最多可达11年。而这段时间恰是儿童发育成长的重要阶段,因此乳牙患病或早期失落,不仅直接影响咀嚼功能,并可间接妨碍恒牙的交替和排列,咀嚼肌及颌骨的 Teeth teeth chewing during childhood, supporting pronunciation, to promote maxillofacial and dentition normal development and other functions. From the time of eruption and shedding of the deciduous teeth, each deciduous tooth takes effect in the oral cavity for at least 5 years and up to 11 years. This period of time is just an important stage of child development and growth, so the prevalence or early loss of deciduous teeth, not only directly affect the masticatory function, and can indirectly impede the alternation and arrangement of permanent teeth, masticatory muscles and jaw