Rao A K, Sarkar S
Dept. of Pedodontics & Preventive Dentistry, Dr. R. Ahmed Dental College, Calcutta.
J Indian Soc Pedod Prev Dent. 1999 Mar;17(1):29-32.
When the normal physiological process of deciduous tooth exfoliation and eruption of its successor is disrupted, a series of changes are observed in the dental arches. The aim of the study was to evaluate the amount of changes in arch length after the premature loss of deciduous molars. The sample consisted of 82 children, 53 without premature loss and 29 with premature loss of either deciduous first or second molar or both, unilaterally. A reduction in arch length was observed both in the maxilla and mandible at the molar region and an increase in arch length at the canine region in the mandible. Reduction in arch length was due to mesial migration of the molar and the increase in arch length was due to the distal migration of canine. It was seen that arch length reduction was more in maxilla as compared to the mandible and that distal drifting of canine was observed only in the mandible.
当乳牙脱落及其后继恒牙萌出的正常生理过程受到干扰时，牙弓会出现一系列变化。本研究的目的是评估乳牙磨牙过早缺失后牙弓长度的变化量。样本包括82名儿童，其中53名没有过早缺失，29名单侧乳牙第一或第二磨牙或两者过早缺失。在上颌和下颌的磨牙区域均观察到牙弓长度减小，在下颌尖牙区域牙弓长度增加。牙弓长度减小是由于磨牙近中移动，而牙弓长度增加是由于尖牙远中移动。可以看出，上颌的牙弓长度减小比下颌更明显，并且仅在下颌观察到尖牙远中漂移。
