正常乳牙列生理间隙变化的纵向研究

A longitudinal study on growth of the interdental space in normal deciduous dentition

目的：探讨正常乳牙列的生理间隙在３ ～５ 岁发育时期内的变化趋势、形成原因和生理意义。方法：采用逐年取研究模型的纵向研究方法，追踪观察４４ 例正常乳牙列儿童在３ ～５ 岁期间的牙列发育状况。并对研究模型生理间隙测量和记录，进行统计分析。结果：在３ ～５ 岁的发育阶段内，灵长类间隙的发生率略有升高；前牙的发育间隙发生率显著升高，而后牙的发育间隙发生率却显著降低。另外上牙列的灵长类间隙量略有增加，下牙列的灵长类间隙量略有减少，前牙的各发育间隙量有显著增加趋势，后牙的各发育间隙量有显著减少趋势。而各生理间隙在此期间内纵向发育变化有９ 种类型，但各间隙的主要显著发育类型不尽一致。结论：儿童乳牙列时期生理间隙的主要变化是一个联系广泛、多因素合力作用的过程，其变化对恒牙列的形成及正中牙合位的建立有一定生理意义。

Aim:To investigate the continuous change of interdental space during the stage of deciduous dentition. Methods: The growth of dentition of 44 children 3～5 years old with normal deciduous dentition was observed continually. Results:During the period of deciduous dentition,the incidence of primary space tended to increase slightly,and the incidence of developmental space of anterior teeth increased remarkably while that of posterior teeth decreased evidently. The mean amount of upper primary space increased slightly and that of lower primary space decreased slightly; while that of anterior teeth increased evidently and that of posterior teeth decreased remarkably.Furthermore the primary and developmental space had their own growth tendency and type respectively. Conclusions: Conclusions: The change of physiological space is caused by the cooperation of the various factors,which plays a role in the formation of permanent dentition and centric occlusion.