Cranial base growth and morphology in second-trimester normal human fetuses and fetuses with cleft lip

Objective: The present radiographic study describes the size and shape of t he cranial base from the sagittal aspect for a sample of 77 second-trimeste r "normal" control fetuses (n = 61) and fetuses (n = 16) exhibiting isolate d, unilateral clefts of the lip (CL), ranging in fertilization age from 10 to 22 weeks. Methods: Fetuses were placed in a cephalostat, and standardized, lateral he ad radiographs were taken. The radiographs were traced, and 15 cephalometri c landmarks were identified and digitized for analysis, Growth curves for c ranial base lengths, angles, and areas were compared between control and CL groups. Also, cranial base triangles were constructed and shape comparison s were made using tensor biometric analysis. Results: No significant differences (p > .05) in regression line slopes wer e noted for any comparisons between the control and CL samples. Tensor biom etric analysis also revealed no significant differences in the shapes of va rious cranial base triangles between the control and CL samples. Conclusion: This report presents second-trimester baseline growth curves fo r various cranial base components in CL human fetal specimens, and these da ta suggest that CL fetuses may also be used as an appropriate control sampl e for prenatal growth comparison studies of cleft lip and palate and cleft palate.