In a sample of 73 Norwegian medieval skulls with ideal, occlusion measurements were taken directly on the dental arches and on lateral cephalograms. The configuration of the lower face and the position of the incisors were different from modern Norwegian adults. Consequently the material could be used to verify a linear relationship between the position of the lower incisors and some guiding variables. The principles of a guiding multiple linear equation as used in the Bergen cephalometric analysis was confirmed. Further, it was shown that the group of guiding variables related to the position of the lower incisors could be extended by introducing dental arch dimensions.