Deciduous neonatal line: width is associated with duration of delivery

Embryonal tooth enamel development starts in about the 10th week of pregnancy. In a circadian rhythm, appositional layers of organic enamel matrix are formed. Mineralization of the matrix, where hydroxyapatite units form alongside, wavely running enamel prisms, is initiated soon after matrix secretion giving mature enamel an ‘onion-liké appearance [1]. At birth, a particularly well discernible layer, called neonatal line (NNL), is formed. NNL was first named in 1936 by Schour [2] who described it as”a distinctive incremental line in the enamel and a corresponding incremental line in the dentin”.
Source: Forensic Science International - Category: Forensic Medicine Authors: Source Type: research