Varying techniques of measurement coupled with lack of sufficient data have presented great difficulties in the comparison of dental arch dimensions obtained by different workers. Several authors have attempted to delineate the arches. Lavelle et al measured the dental arches of adults from several different ethnic groups and found little difference between the modern British Caucasian, Australian aborigines, and North American Indians. They did, however, see considerable differences between these modern populations and a group of Anglo-Saxons and a group of West Africans
