Keinan David, Smith Patricia, Zilberman Uri
Laboratory of Bioanthropology and Ancient DNA, Hadassah School of Dental Medicine, Hebrew University, POB 12272, Jerusalem 91120, Israel.
Arch Oral Biol. 2006 Oct;51(10):836-43. doi: 10.1016/j.archoralbio.2006.04.003. Epub 2006 Jun 6.
This study was designed to test the hypothesis that prenatal growth insults leave permanent signs in the developing primary teeth that can be identified in later life. To test this hypothesis we examined exfoliated and extracted lower second primary molars of children with Down syndrome (DS) and cerebral palsy (CP). Teeth of children with no adverse medical history were used as a control group. Informed consent of parents and children was obtained in all cases. On each tooth two thin sections were cut, one bisecting the mesial cusps and one bisecting the distal cusps. Using a light microscope, the width of prenatal enamel and postnatal enamel was measured on each section at standardized locations from the dentin-enamel junction (DEJ) with the neonatal line used to distinguish between prenatal and postnatal enamel. Chemical analysis of each section was carried out using an energy dispersive spectrophotometer (ESR). The Ca/P ratios of enamel and dentin for each cusp were calculated and intercusp and intergroup differences analysed using non-parametric statistical tests. The results showed that significantly less enamel was laid down prenatally in DS and CP teeth than in the control group and that the enamel of the mesial cusps in these groups was less highly mineralised than that of the controls. The results also showed that in DS teeth growth and mineralisation of all cusps was affected. Based on these findings we propose that analysis of exfoliated deciduous teeth in developmentally challenged children may help in identifying the onset and severity of growth insults in utero and its impact on later development.
产前生长损伤会在发育中的乳牙上留下永久性痕迹，这些痕迹在日后的生活中可以被识别出来。为了验证这一假设，我们检查了唐氏综合征（DS）和脑瘫（CP）患儿脱落及拔除的下颌第二乳磨牙。无不良病史儿童的牙齿用作对照组。所有病例均获得了家长和儿童的知情同意。在每颗牙齿上切取两片薄片，一片将近中牙尖平分，另一片将远中牙尖平分。使用光学显微镜，在每个切片上从牙本质-釉质界（DEJ）的标准化位置测量产前釉质和产后釉质的宽度，以新生线区分产前和产后釉质。使用能量色散光谱仪（ESR）对每个切片进行化学分析。计算每个牙尖的釉质和牙本质的钙磷比，并使用非参数统计检验分析牙尖间和组间差异。结果表明，与对照组相比，DS和CP患儿的牙齿产前形成的釉质明显较少，且这些组近中牙尖的釉质矿化程度低于对照组。结果还表明，DS患儿所有牙尖的生长和矿化均受到影响。基于这些发现，我们认为对发育障碍儿童脱落乳牙的分析可能有助于识别子宫内生长损伤的发生和严重程度及其对后期发育的影响。
