Srinivasan Shruti, Murthy Prashanth Sadashiva, Deshmukh Seema, Shamsundar N M
Department of Pedodontics and Preventive Dentistry, JSS Dental College and Hospital, JSS University, Mysore, Karnataka, India.
Department of Anatomy, JSS Medical College, JSS University, Mysore, Karnataka, India.
J Indian Soc Pedod Prev Dent. 2017 Jul-Sep;35(3):249-253. doi: 10.4103/JISPPD.JISPPD_112_17.
The prominent striae of retzius corresponding to the occurrence of live birth is known as the neonatal line (NNL). The very presence of this line indicates the exposure of the infant to the stressful event of birth.
The study was aimed at locating the NNL in the developing primary teeth of the neonate and associating the presence of NNL to the occurrence of live birth.
The donated bodies of the neonates were taken, and a surgical incision was made along the crest of the alveolar ridge in the maxillary anterior region, enabling the careful removal of the tooth germs from within the jaw segment. The maxillary central incisor tooth germs were embedded in acrylic and viewed under the stereomicroscope, polarized microscope, and scanning electron microscope (SEM).
This being a pilot observational study, no statistical analysis methods were employed.
The NNL was best visualized under polarized microscopy and was clearly appreciated in the control samples and faintly seen in the 10-day-old neonate. No evidence of the line was present in the tooth germ of the stillborn child.
The very presence of the NNL indicates that the infant was alive during the stressful process of birth. This can be used as substantial evidence in infanticide cases brought before the law.
与活产发生相对应的芮氏线显著条纹被称为新生儿线（NNL）。这条线的存在表明婴儿经历了分娩这一应激事件。
本研究旨在确定新生儿发育中的乳牙中的新生儿线位置，并将新生儿线的存在与活产的发生联系起来。
获取新生儿的捐赠尸体，在上颌前部牙槽嵴顶沿其做外科切口，以便从颌骨段内小心取出牙胚。将上颌中切牙牙胚嵌入丙烯酸树脂中，在体视显微镜、偏光显微镜和扫描电子显微镜（SEM）下观察。
由于这是一项初步观察性研究，未采用统计分析方法。
在偏光显微镜下，新生儿线最清晰可见，在对照样本中清晰可辨，在10日龄新生儿中隐约可见。死产儿的牙胚中未发现该线的迹象。
新生儿线的存在表明婴儿在分娩这一应激过程中是存活的。这可作为提交法庭的杀婴案件的重要证据。
