牙列拥挤是一种常见的牙颌畸形,其发病率约占牙颌畸形的60～70%。从人类进化过程中发现:咀嚼器官的退化有不平衡现象,即牙槽、颌骨的退化速度快于牙齿,因此造成了牙齿拥挤及其他类型的牙颌畸形。所以毛氏认为:牙量相对大,骨量相对小是牙列拥挤的主要发病机制。从临床实践中常可观察到牙列拥挤的病例,其牙量相对大似乎更为突出。国外资料也显示出牙齿大小与牙列拥挤有关,而且进一步从测量统计学方面研究了牙列拥挤程度与牙齿大小之间的关系。国内把牙量、骨量与牙列拥挤之间联系起来的研究报 Dental crowding is a common dento-mandibular deformity, the incidence of dental deformity accounts for about 60 to 70%. From the evolution of human found that: the degradation of chewing organ imbalance, that is, the alveolus, jaw degeneration faster than the teeth, resulting in crowding and other types of dental deformities. Therefore, Mao believes that: a relatively large amount of teeth, the relatively small amount of bone is the main pathogenesis of crowding. From the clinical practice can often be observed cases of crowded teeth, the relatively large amount of teeth seems to be more prominent. Foreign data also show that the size of the teeth is related to crowding of the dentition, and furthermore, the relationship between the degree of dentition crowding and the size of the teeth is further studied from the measurement statistics. Domestic research on the relationship between tooth quantity, bone mass and dentition crowding