title: Principal component analysis of intercusp distances on the lower first molars of three human populations.
abstract: The distances between the five main cusps of lower first molars were measured on moiré photographs of casts obtained from Japanese, Dutch and Australian Aboriginal children. Principal component analysis of the intercusp distances, log transformed and standardized so that average tooth size was held constant, revealed three sources of shape variation in cusp topography. All populations were similar for scores on component 1 which was concerned with variations in the position of the hypoconulid. The Dutch had lowest scores on component 2 indicating small buccolingual distances compared with mesiodistal, whereas the Australian Aboriginals had the lowest mean score on component 3, expressing the distances between metaconid, entoconid and hypoconulid.
authors.affiliation: Department of Anatomy, Nihon University School of Dentistry at Matsudo, Chiba, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Sekikawa
authors.forename: E
authors.initials: E
authors.lastname: Kanazawa
authors.forename: T
authors.initials: T
authors.lastname: Ozaki
authors.forename: T
authors.initials: T
authors.lastname: Brown
mesh_terms: D044466:Asian People; D005260:Female; D006801:Humans; D007368:Interferometry; D008297:Male; D008963:Molar / Q000033:anatomy & histology*; D009811:Odontometry / Q000379:methods*; D010780:Photogrammetry; D044465:White People