대신장비율로 본 한국인태아천골의 발육상

Abstract

The indices were determined by measuring 15 items in 365 fetal sacra and the following conclusions have been drawn. 1). The growth rates of the sacrum and the sacral arc are a little higher than that of the stature and it corresponds with the result in the fetal pelvis. 2). The growth rate of the greatest height of the sacral arc is much higher than that of the stature and it means the rapid formation of the curvature. 3). The growth rate of the sagittal diameter of the sacral canal is much higher and that of the transverse diameter is a little higher than that of the stature and it means the change of the form of the entrance of the sacral canal from flat anteroposteriorly to oval transversely. 4). The growth rates of the length of the auricular surface, the transverse diameter of the sacral base and the breadth between the lst sacral foramina are a little higher than that of the stature and those of the breadth of the auricular surface, the sagittal diameter of the sacral base and the thickness of the 1st sacral vertebra are still higher than those of the formers and it means the change of the form of the sacrum from strong flat to weak anteroposteriorly . OS). No differences are found in all of the indices between both sexes.