title: Morphological analysis of the occlusal surface of maxillary molars in Koreans.
abstract: OBJECTIVE
  To determine the diameter of the crown, total crown area, individual cusp area, and occlusal table area in Korean maxillary permanent molars, as well as dental characteristics relevant to the hypocone reduction trait.
  
  
  METHODS
  Subjects included 121 dental school students in Korea (81 men and 40 women). A digital image analysis system was used for measurements and we relied on visual scoring to assign categories of hypocone expression.
  
  
  RESULTS
  The mean crown dimension was larger in the first molar (M1) than in the second molar (M2). Regarding differences according to gender, the crown diameter, total crown area, and individual cusp area were significantly larger in the men than in the women. The mean occlusal table area ratios were 61% for M1 and 57% for M2, and these ratios increased in proportion to the total crown area. With respect to the hypocone and other features of the maxillary molars, differences between the men and women were more prominent for M1 than for M2. The M2 hypocone tended to be smaller than the M1 hypocone, and hypocone reduction was inversely related to the cusp area of the protocone. The protocone area may be considered a reliable parameter for comparing race and/or gender differences in maxillary molars.
  
  
  CONCLUSIONS
  This study concerning characteristics of the maxillary molar occlusal surface in Koreans provides useful information for comparative studies among human races.
authors.affiliation: Department of Anatomy and Neuroscience, College of Medicine, Eulji University, 77 Gyeryong-ro 771 beon-gil, Jung-Gu, Daejeon 34824, South Korea.
authors.forename: Hong-Il
authors.initials: HI
authors.lastname: Yoo
authors.affiliation: Department of Oral Anatomy, School of Dentistry, Chonnam National University, 77 Yongbong-ro, Buk-gu, Gwangju 500-757, South Korea.
authors.forename: Dong-Wook
authors.initials: DW
authors.lastname: Yang
authors.affiliation: Department of Oral Anatomy, School of Dentistry, Chonnam National University, 77 Yongbong-ro, Buk-gu, Gwangju 500-757, South Korea.
authors.forename: Mi-Yeon
authors.initials: MY
authors.lastname: Lee
authors.affiliation: Department of Oral Anatomy, School of Dentistry, Chonnam National University, 77 Yongbong-ro, Buk-gu, Gwangju 500-757, South Korea.
authors.forename: Min-Seok
authors.initials: MS
authors.lastname: Kim
authors.affiliation: Department of Oral Anatomy, School of Dentistry, Chonnam National University, 77 Yongbong-ro, Buk-gu, Gwangju 500-757, South Korea. Electronic address: ksh@jnu.ac.kr.
authors.forename: Sun-Hun
authors.initials: SH
authors.lastname: Kim
mesh_terms: D000328:Adult; D003735:Dental Casting Technique; D005260:Female; D006801:Humans; D008297:Male; D008437:Maxilla / Q000033:anatomy & histology*; D008963:Molar / Q000033:anatomy & histology*; D009811:Odontometry; D010641:Phenotype; D010781:Photography; D056910:Republic of Korea; D012727:Sex Characteristics; D013499:Surface Properties; D019228:Tooth Crown / Q000033:anatomy & histology*
keywords: Cusps; Dimorphism; Hypocone reduction; Maxillary molars; Races