Regional size differences in four commonly used cephalometric atlases: the Ann Arbor, Cleveland (Bolton), London (UK), and Philadelphia atlases compared

Abstract Authors– Dibbets JMH, Nolte K Objective– To explore regional influence on size in roentgenocephalometric atlases. Design– Comparisons of the size of 10 linear distances in four atlases from geographically different regions, i.e. Ann Arbor Michigan, Cleveland Ohio, Philadelphia Pennsylvania and London, UK. Distances compared– anterior cranial base length (S–N), posterior cranial base length (S–Ba), total face height (N–Me), upper face height (N–ANS), lower face height (ANS–Me), mandibular diagonal (Ar–Gn), corpus length (Go–Pg), ramus height (Ar–Go), maxillary length (SNP–SNA), posterior face height (S–Go). Results– Correction for enlargement appeared to be a necessity before distances could be compared. After correction for enlargement, the anterior cranial base was longest in Ann Arbor, lower face height smallest in Cleveland (Bolton standards) and the maxilla was shortest in Philadelphia. Conclusion– Regional size variance in cephalometric data cannot be ignored.