A histological study of the chronology of initial mineralization in the human deciduous dentition.

Accurate dating of initial mineralization in the dentition was derived from fetuses aged according to the maternal history, assessment of gestational age by obstetricians, paediatricians and pathologists, histological evaluation of their cerebellar and renal development, and accurate measurements of crown-rump length, skull circumference, brain and body weight. Serial sections of the jaws of 121 fetuses ranging from 10 to 26 weeks post-menstrual age first showed mineralized dentine in the deciduous central incisor at 15-19 weeks, in the lateral incisor at 16-21 weeks, in the canine at 19-22 weeks, in the deciduous first molar at 16-19 weeks and in the second molar at 20-22 weeks. These age ranges differ from those for initial mineralization common in textbooks, particularly for the molars.