Grevstad H J, Selvig K A
Scand J Dent Res. 1983 Jun;91(3):231-41. doi: 10.1111/j.1600-0722.1983.tb00807.x.
Permanent incisors from fetal New Zealand white rabbits aged 25-30 days in utero and from 1-20 days postnatally were processed for light microscopy. Examination of longitudinal and cross-sections revealed that cementum deposition and fiber attachment first occurred at 27 days in utero. A tooth-to-bone course of principal fibers confined to lateral aspects of the teeth was observed in 29-day fetal incisors, whereas lingually the periodontal ligament remained undeveloped as late as 5 days postnatally. In 20-day postnatal incisors, the development of the functional periodontal ligament was complete as evidenced by the fiber arrangement on all aspects of the root-analogue tooth surface. This study shows that 25-26-day fetal rabbit permanent incisors represent the end of the follicular phase, whereas 27-day fetal to 20-day postnatal teeth demonstrate distinct histologic characteristics of initial, incomplete and complete periodontal fiber attachment.
对子宫内25 - 30天龄以及出生后1 - 20天龄的新西兰白兔胎儿的恒切牙进行处理，用于光学显微镜检查。对纵切面和横切面的检查显示，牙骨质沉积和纤维附着最早在子宫内27天时出现。在29天龄的胎儿切牙中观察到，主纤维束从牙齿延伸至牙槽骨，局限于牙齿的侧面，而舌侧的牙周韧带直到出生后5天仍未发育。在出生后20天龄的切牙中，功能性牙周韧带发育完全，这在牙根模拟牙表面各方面的纤维排列中得到了证实。这项研究表明，25 - 26天龄的胎儿兔恒切牙代表滤泡期的结束，而27天龄的胎儿至出生后20天龄的牙齿则显示出牙周纤维附着初始、不完全和完全阶段的不同组织学特征。
