Prenatal sagittal growth of the osseous components of the human palate.

The human osseous palate consists of the palatine processes of the maxillary bone anterior to the transverse palatine suture and the horizontal processes of the palatine bone posterior to the suture. The purpose of the present study was to analyze the sagittal growth of these different bone components bordering the transverse palatine suture. The material comprised radiographs of cranial midsagittal tissue blocks from 44 human fetal specimens obtained by legally approved abortions. Gestational age (GA) ranged from 10 to 26 weeks and crown-rump lengths (CRLs) from 50 to 240 mm. The lengths of the maxillary and palatine components of the hard palate were measured with a digital caliper on 3x-enlarged projections of the radiographs. A significant increase in the lengths of both palatal components occurred during the period investigated. Regression analysis on GA showed a linear course of the growth curve in the period studied and gave indirect evidence of a curvilinear shape in the period preceeding the one studied. Growth rates for the palatal dimensions were found to be proportional to that of CRL. The increase in total length resulted predominantly from an increase in the anteroposterior dimension of the maxillary component.