Spectrum of positional deformities - is there a real difference between plagiocephaly and brachycephaly?

Aim This study analyses pathomorphological and physiological head shapes and classifies the pathomorphology in positional plagiocephaly and brachycephaly. Patients and methods 78 infants with a positional plagiocephaly (5.99 months) and 32 infants with a positional brachycephaly (6.53 months) with a Cephalic index > 94% were investigated in this study and compared to a matched control group of 35 infants. The head shapes were analysed by stereophotogrammetry 3D data. Results The cephalic index, the total width, and coronal circumference were the highest values in patients with brachycephaly and the lowest values in the control group. The asymmetry of the head showed that the diagonal difference in brachycephalic patients more than doubled, and in patients with plagiocephaly almost tripled compared to the controls. A significantly higher total volume and vertex height was found for the patients with plagiocephaly and the patients with brachycephaly compared to the controls. Conclusion The cephalic index is a valuable and reliable parameter in order to differentiate positional deformities from unaffected skulls. Pathomorphology of a plagiocephaly is associated with the most severe asymmetry of the head. Plagiocephaly and brachycephaly overlap in several criteria. Therefore it seems justified to speak of a continuum rather than to differentiate between plagiocephaly and brachycephaly.