The neonatal line is a particular band of incremental growth lines seen in

histologic Histology, also known as microscopic anatomy or microanatomy, is the branch of biology which studies the microscopic anatomy of biological tissues. Histology is the microscopic counterpart to gross anatomy, which looks at larger structures vis ...

sections of both enamel and dentin of primary teeth. It belongs to a series of a growth lines in

tooth enamel Tooth enamel is one of the four major tissues that make up the tooth in humans and many other animals, including some species of fish. It makes up the normally visible part of the tooth, covering the crown. The other major tissues are denti ...

known as the

Striae of Retzius The striae of Retzius are incremental growth lines or bands seen in tooth enamel. They represent the incremental pattern of enamel, the successive apposition of different layers of enamel during crown formation. There are 3 types of incremental ...

denoting the prolonged rest period of enamel formation that occurs at the time of birth. The neonatal line is darker and larger than the rest of the striae of retzius. The neonatal line is the demarcation between the enamel formation before birth and after birth i.e., prenatal and postnatal enamel respectively. It is caused by the different physiologic changes at birth and is used to identify enamel formation before and after birth. The position of the neonatal line differs from tooth to tooth

Formation

The formation of the neonatal line is caused by changes in the direction and degree of tooth mineralization caused by the biological stress from passing into extra uterine life. Specific factors underlying its formation and width still remain unclear.

Forensic Dentistry

forensic Forensic science, also known as criminalistics, is the application of science to criminal and civil laws, mainly—on the criminal side—during criminal investigation, as governed by the legal standards of admissible evidence and crimin ...

dentistry, the neonatal line can be used to distinguish matters such as if a child died before or after birth and approximately how long a child lived after birth. The neonatal line can be used as a marker for the exact period of survival of an infant through the measurement of the amount of postnatal hard tissue formation and examination of the thickness of the neonatal line.

References

{{Reflist Histology Dental enamel Tooth development