Contents lists available at ScienceDirect Archives of Oral Biology journal homepage: www.elsevier.com/locate/archoralbio The effect of cerebral palsy on neonatal line thickness and enamel components Fanny Hershkovitz, Leibovitz Shirley, Ornit Cohen, Uri Zilberman ⁎ Pediatric Dental Clinic, Barzilai Medical University Center, Ashkelon, Israel ARTICLE INFO Keywords: Cerebral palsy Neo-natal line Enamel Ion contents Magnesium ABSTRACT Objective: The aim of the study was to compare the neonatal line width as well as the composition of the pre- natal and post-natal enamel in deciduous teeth of children with cerebral palsy (CP) to deciduous teeth of healthy children. Design: 58 extracted or normally exfoliated deciduous teeth were collected for the study, 29 teeth from children with cerebral palsy and 29 pair matched teeth from healthy children who served as controls. The teeth were cut along the bucco-lingual/palatal axis and polished up to a thickness of 50–100 microns. The sections were ex- amined using a light microscope and scanning electron microscope (SEM). The neonatal line was identified in 25 teeth and measured in width and the enamel concentrations of calcium, phosphorus, silicon, magnesium, so- dium, oxygen, and carbon were measured in the pre-natal and post-natal enamel using ESD program. Results: The neonatal line was significantly narrower in the deciduous teeth collected from children with cer- ebral palsy. In both groups, the concentration of magnesium and sodium in the pre-natal enamel was sig- nificantly higher than in the post-natal enamel. Magnesium and sodium levels were significantly higher in pre- natal enamel in the CP group compared to the pre-natal enamel of the control group. Conclusions: The neonatal line was narrower in the deciduous teeth collected from children with cerebral palsy than in those collected from healthy children. Children with cerebral palsy have a higher concentration of magnesium and sodium in the enamel that developed before birth. 1. Introduction Matrix secretion and calcification of the hard tooth tissues, enamel, dentin and cementum is carried out in the form of layers. At birth, the primary tooth germs are not complete and the enamel is only partially formed and calcified. A physiological disturbance in the cellular activity of the ameloblasts at birth causes an accentuated incremental line known as the neonatal line. A neonatal line is an optical phenomenon caused by a change in the dimension, direction, and degree of calcifi- cation of the enamel prisms that is caused by biological stress in the sudden transition from intra-uterine to extra-uterine life (Sabel et al., 2008). The neonatal line represents the enamel created during the birth process and separates between the pre-natal and the post-natal enamel. Whittaker and Richards (1978) described the line as a 0.2 μm dis- turbance in the prism, with a post-natal diffuse zone/ area of 15–16 μm where the enamel crystals are less compressed, so the width of the line is about 16 μm. A similar hypomineralization line can also be shown in the dentin, but the calcification nature and inability to repair the enamel make the enamel neonatal line to be clear and reliable more than in the dentin, but it cannot be detected in all deciduous teeth (Janardhanan, Umadethan, Biniraj, Kumar, & Rakesh, 2011). The neonatal line is present in the deciduous teeth that begin cal- cification in weeks 14–18.5 of pregnancy and in the first permanent molars that begin calcification prior to birth (Janardhanan et al., 2011). It begins at the enamel- dentinal junction (EDJ) in the gingival third of the deciduous teeth and continues to the enamel surface in the centrals and canines and parallel to the cusp tips in molars. This mineralization disorder is caused by changes in the nutrition and environment of the newborn during birth (Zanolli, Bondioli, Manni, Rossi, & Macchiarelli, 2011). Several studies have dealt with the effect of birth, vaginal or caesarean section, on the width of the neonatal line and the relationship between birth length and neonatal line expression (Eli, Sarnat, & Talmi, 1989; Zanolli et al., 2011). Cerebral Palsy (CP) is a disability in children characterized by a non-progressive motor disturbance of the central nervous system (Scherzer, 1974). CP is generally caused by common external, time- https://doi.org/10.1016/j.archoralbio.2019.06.001 Received 29 January 2019; Received in revised form 30 May 2019; Accepted 2 June 2019 ⁎ Corresponding author at: Barzilai Medical University Center, 2nd Hahistadrut st, Ashkelon, 7830604, Israel. E-mail address: ori@barzi.health.gov.il (U. Zilberman). Archives of Oral Biology 104 (2019) 119–122 0003-9969/ © 2019 Elsevier Ltd. All rights reserved. T