Variation in root length of the permanent maxillary central incisor

Abstract

abstract — A metric study was performed on radiographs of permanent maxillary central incisors of a normal Swedish population of 1,038 children. The normal distribution of the root lengths revealed two extreme groups: 2.4% had short roots, formerly described as Short Root anomaly, most prevalent among girls with a boy:girl ratio of 1:2.6. In the opposite extreme group, i.e., with exceptionally long roots comprising 2.3% of the children, the boys dominate with a boy:girl ratio of 5:1. Clinical evidence suggests that variation in root length is of genetic origin.