Differences between direct (anthropometric) and indirect (cephalometric) measurements of the skull

This study sought to determine the relative reliability of indirect cephalometric measurements and direct anthropometric ones taken in norma frontalis of 25 dry adult human skulls. Six of the 11 linear projective measurements were singular and located in the orbital, middle, and lower parts of the face, with two from each part. Two of the five paired measurements were taken in the orbital region on both sides, and the other three were taken in the middle to lower face between the midpoint of the facial axis and the landmarks lateral to it. Both sin,gular and paired cephalometric distances were significantly shorter than the anthropometric distances. Mean numerical differences were much greater in paired measurements than in singular ones. The differences between these two sets of findings are a result of the uneven position of the landmarks used for measurement, located, as they are, on different planes of the face. These differences are undetectable by two-dimensional cephalograms. From the *Center for Craniofacial Care and Research, The Hospital for Sick Children, and the Division of Plastic Surgery, University of Toronto; Division of Orthodontics, The Hospital for Sick Children, and the University of Toronto Faculty of Dentistry; and Department of Research Design and Biostatistics, Sunnybrook Hospital and Women's Health Sciences Center, Toronto, Ontario, Canada. Address correspondence to Dr Farkas, The Hospital for Sick Children, Center for Craniofacial Care and Research, 555 University Avenue, Toronto, Ontario, Canada M5G 1X8; E-mail: Ifarkas@interlog.com.