[Dynamics of the sagittal cranial base changes during second trimester of normal intrauterine growth and development].
The aim of the present study was an estimation of dynamics of changes in anterior (NS) and posterior (SBa) cranial base lengths, during the second trimester of normal intrauterine growth and development. Material was consisted of 40 fetuses, gestational ages 14th to 23rd week, both sexes, derived from artificial abortions in uncomplicated pregnancies. The investigation was performed on the standardised lateral cephalometric radiographs. Results showed that anterior and posterior cranial base had almost equal rates of growth during the period investigated (approximately 1.8 mm per week). The posterior cranial base demonstrated greater individual variability during growth than the anterior one. Consequently, length of the anterior cranial base (NS) may be used as a confident predictor of the gestational age.