The structure and composition of temporary deciduous teeth, commonly known as “baby teeth,” are different in children with cerebral palsy, compared with healthy kids, a study has found.

The study, “The effect of cerebral palsy on neonatal line thickness and enamel components,” was published in the journal Archives of Oral Biology.

Teeth are made up of different layers that gradually deposit and calcify on top of each other during development. The outer layer of the teeth, called enamel, is partially formed at birth and continues to calcify after birth.

The neonatal line is a visual indicator characterized by a change in dimension and orientation of enamel deposition that marks the transition between the enamel formed before and after birth.

“The neonatal line is present in the deciduous teeth that begin calcification in weeks 14–18.5 of pregnancy and in the first permanent molars that begin calcification prior to birth,” the researchers said.

Previous studies have reported that children with cerebral palsy (CP), a neurological disorder caused by brain lesions that occur during fetal development or infancy, have a series of developmental defects in the enamel of their deciduous teeth.

In this study, a group of researchers from the Barzilai Medical University Center (Israel) set out to examine the structure and mineral composition of the prenatal and post-natal enamel of deciduous teeth in children with CP.

The investigators analyzed a total of 58 deciduous teeth that had been extracted or naturally exfoliated: 29 teeth from children with CP and 29 pair-matched teeth from healthy children (controls).

All teeth were cut and polished. Teeth sections were examined using a light microscope and a scanning electron microscope. The researchers then measured the width of the neonatal line and the levels of different minerals (e.g. calcium, phosphorus, magnesium) present in the teeth enamel before and after birth.

The neonatal line was visible in 25 teeth (13 from children with CP and 12 from healthy children). On average, the neonatal line in the deciduous teeth of the children with CP was 5.69 μm in width, which was significantly thinner than the width of 9.25 μm found in the teeth of the healthy children.

“The narrower neonatal lines in children with cerebral  palsy may possibly be explained by a shorter duration of labor, as in cesarean delivery. However, the teeth from the CP group examined were collected during a period of several years and the data regarding the method of delivery was not available at the time that the research was done,” the researchers noted.

In both groups, the levels (measured as ion content, wt%) of magnesium and sodium found in prenatal enamel were significantly higher compared to levels found in post-natal enamel. Prenatal magnesium levels were 0.27 wt% in children with CP and 0.22 in controls, versus a 0.19 post-natal magnesium level in both groups. Prenatal sodium levels were 1.02 (versus 0.81 postnatal) in children with CP, and 0.85 (versus 0.77 postnatal) in controls.

However, in the prenatal enamel of children with CP, the levels of magnesium (0.27 wt%) and sodium (1.02) were found to be significantly higher compared to the levels found in the prenatal enamel of healthy children, which were 0.22 for magnesium and 0.85 for sodium.

The higher concentration of magnesium in the enamel that developed before birth in children with CP “may have resulted from a high concentration of magnesium in the mothers’ blood during pregnancy, which in turn might have resulted from their antenatal exposure to magnesium sulfate [a neuroprotective agent sometimes given to pregnant women],” the investigators wrote.

“However, despite this exposure to magnesium, children were still born with cerebral palsy,” they added.