Longitudinal changes in cranial base angulation in mandibulofacial dysostosis

Longitudinal measures of cranial base angulation (nasion-sella-basion angle; N-S-Ba) were obtained in 24 patients with mandibulofacial dysostosis (MFD), with records available over time spans ranging from 2 years to 29 years. Initial measurements, obtained at ages ranging from 1 month to 13 years, 6 months, indicated basilar kyphosis (N-S-Ba less than 120 degrees) in five patients. Twenty-one patients showed increasing flexure of the cranial base angle (CBA) over time, eight to such a degree that their initially normal CBAs eventually fell into the kyphotic range. At the time of the final available records (age range 4 years, 0 months to 29 years, 2 months), a total of 54 percent of patients thus fell into the kyphotic range. These results point to the time-dependent nature of the appearance of abnormal CB angulation in some patients. In addition, there was a predominance of males in those patients showing significant change in cranial base angulation over time.