title: Volume measurement of crowns in mandibular primary central incisors by micro-computed tomography.
abstract: OBJECTIVE
  To determine sex differences in the tissue proportions of crowns of mandibular primary central incisors in Chinese children and to quantify the volume of crown components in three dimensions using micro-computed tomography (micro-CT).
  
  
  METHODS
  The specimens used in this study were 41 mandibular first deciduous incisor teeth with intact crowns (21 males and 20 females) obtained from patients between 5-6 years of age. Each specimen was scanned using micro-CT at a resolution of 0.05 mm and 3D-rendered images were created. The volume of each component of the crown was measured and examined for differences in different sex and ages.
  
  
  RESULTS
  The pulp chamber volume decreased with age and the volume ratio of the pulp chamber to the whole crown was significantly smaller in 6-year-olds than in 5-year-olds (p < 0.05).
  
  
  CONCLUSIONS
  Males had significantly larger tooth crown volumes and dentin volumes than females did (p < 0.001), while the volume of enamel showed no sexual dimorphism.
authors.affiliation: Ninth People's Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, PR China.
authors.forename: Jin-Lan
authors.initials: JL
authors.lastname: Ma
authors.forename: Si-Zhen
authors.initials: SZ
authors.lastname: Shi
authors.forename: Y
authors.initials: Y
authors.lastname: Ide
authors.forename: H
authors.initials: H
authors.lastname: Saka
authors.forename: S
authors.initials: S
authors.lastname: Matsunaga
authors.forename: H
authors.initials: H
authors.lastname: Agematsu
mesh_terms: D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007180:Incisor / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D008297:Male; D008334:Mandible / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed / Q000379:methods*