Related Experiment Video
Updated: Aug 15, 2026

Culturing and Measuring Fetal and Newborn Murine Long Bones
Published on: April 26, 2019
Relative growth of the human fetal skull in width, length and height
1University Dental Hospital, Manchester, U.K.
Abstract:
Linear measurements of the width, length and height of the face and cranium were made on 60 fetuses of 49-212 mm crown-rump length. Absolute growth rate was derived from the slope of the regression line of dimensional length against time. There was a high correlation between absolute growth rate and mean dimensional length (r = 0.995; p less than 0.001). The relative growth rate was calculated by dividing the absolute growth rate by the mean dimensional length. Change in shape was measured by the relative increase or decrease in dimensional length once the outlines were normalized to an equal area to eliminate the effect of size. Change of shape correlated highly with relative growth rate (r = 0.95; p less than 0.001). Relative growth rates provide a reliable indication of change in shape, unlike absolute growth rates, which are mainly influenced by size. Measurement of relative growth rates showed an increase in cranial length greater than height greater than width and facial length greater than width greater than height.
More Related Videos
Related Concept Videos
Nature and Nurture
Bone Formation by Intramembranous Ossification
The process begins when mesenchymal cells in the embryonic skeleton gather together and differentiate into osteogenic cells, which then develop into...
Overview of the Skull
The cranial vault surrounds and protects the brain and houses the middle and inner ear structures. This cavity is bounded superiorly by the rounded top of the skull, which...
Cranial Bones: Superior and Posterior View
The frontal bone is the single bone that forms the forehead. At its anterior midline, between the eyebrows, there is a slight depression called the glabella. The frontal bone also forms the supraorbital margin of the orbit. Near the middle of this margin is the supraorbital foramen, the opening that provides passage for a sensory nerve to the forehead. The frontal bone is thickened just above each supraorbital margin,...
Cranial Bones: Lateral View
The temporal bone forms the lower lateral side of the skull. The temporal bone is subdivided into several regions. The flattened upper portion is the squamous portion of the temporal bone. Below this area and projecting anteriorly is the zygomatic process of the temporal bone, which forms the posterior portion of the zygomatic arch. Posteriorly is the mastoid portion of the temporal bone. Projecting...
Changes in the Appendicular Skeleton with Age
Initially, the limb buds consist of a core of mesenchyme covered by a layer of ectoderm. The ectoderm at the end of the limb bud thickens to form a narrow crest called the apical ectodermal ridge. This ridge stimulates the underlying...

