Fol. Biol. 2021, 67, 136-142

Scanning Electron Microscopy and Macroscopic Examination of Prematurely Erupted Teeth in Preterm Infants

Vlasta Merglova1, A. Nemeckova2, L. Hauer1, R. Koberova-Ivancakova3

1Department of Dentistry, Faculty of Medicine in Pilsen, Charles University and University Hospital in Pilsen, Czech Republic
2Institute of Histology and Embryology, Faculty of Medicine in Pilsen, Charles University, Czech Republic
3Department of Dentistry, Faculty of Medicine in Hradec Králové, Charles University and University Hospital in Hradec Kralove, Czech Republic

Received March 2021
Accepted September 2021

Prematurely erupted teeth are rare in fullterm neonates and extremely rare in prematurely delivered infants. The aim of this study was to present macroscopic and scanning electron microscopy (SEM) investigations of prematurely erupted primary teeth of preterm very low birthweight (VLBW) and extremely low birthweight (ELBW) infants. Three preterm VLBW and ELBW infants with prematurely erupted lower incisors were examined. The dental examination assessed the type, location, clinical appearance, and degree of mobility of the prematurely erupted teeth. The structural appearance of enamel and dentin of three extracted and longitudinally sectioned prematurely erupted teeth was investigated with scanning electron microscopy (SEM). Lower incisors were rootless with hypermobility. The surface of enamel of the prematurely erupted primary teeth was hypoplastic and hypomineralized and had a typical “honeycomb” appearance in SEM. The aprismatic type of enamel was visible in some regions. The neonatal line separating the layer of prenatal enamel from postnatal enamel was observed. The enamel prisms were interconnected by interprismatic substances, and cross-striations of prisms were visible. Dentin presented a typical tubular character. The dentinal layer near the enamel dentin junction had Y-shaped branching of dentinal tubules. On the pulpal side, dentin had a globular character. The macroscopic and SEM investigations particularly revealed alterations in enamel, while the dentin of neonatal teeth had a nearly normal appearance.


The study was supported by a grant from the Ministry of Health of the Czech Republic – Conceptual Development of Research Organization (Faculty Hospital in Pilsen – FNPl, 00669806).


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