title: Variations of crown dimensions of permanent dentitions in a selected population of Nigerian children.
abstract: BACKGROUND
  Race, gender, genetic/ environmental factors contribute to tooth variations which could be in size or shape. However, little has been reported on dimensional variations in permanent dentitions among Nigerians.
  
  
  OBJECTIVE
  To investigate the pattern of variability of mesiodistal and buccolingual tooth dimensions of permanent dentition in Nigerians.
  
  
  METHODS
  Mesiodistal (MD) and buccolingual (BL) tooth dimensions were obtained from teeth on dental stone models of selected 400 healthy adolescents aged 12-15 years using an electronic digital caliper. The descriptive statistics and the variability (determined from the Coefficient of Variation; SD/mean x100) were obtained using SPSS version 13.
  
  
  RESULTS
  The mean tooth dimensions were larger in the males than in the females in all tooth types except in mean MD tooth dimension of maxillary second premolars which was larger in the females though not significant (p = 0.70). The coefficient of variation (CV) in the mean MD and BL dimensions ranged from 5.02 in the mandibula rfirst molars to 7.68 in the maxillary lateral incisors and from 5.38 to 11.07 in the maxillary first molars and the mandibular central incisors respectively. The least variable teeth in MD dimensions were the maxillary first molars in males (CV = 4.94) and mandibular first molars in females (CV = 4.88), while the highest variability was seen in the maxillary second premolars in females (CV = 10.46). In BL dimension the maxillary first molars were the least variable in both genders (CV = 5.22 in males, CV = 5.24 females) while the maxillary lateral incisors of males had the highest variability(CV = 11.90).
  
  
  CONCLUSIONS
  The pattern of variation showed that the later-forming teeth in each tooth class showed more variability than the mesial members. The mesiodistal tooth dimensions were less variable than the buccolingual tooth dimensions.
authors.affiliation: Department of Child Dental Health, Faculty of Dentistry, College of Medicine, University of Lagos, Lagos, Nigeria. odegwabobo@yahoo.com
authors.forename: J O
authors.initials: JO
authors.lastname: Eigbobo
authors.forename: E O
authors.initials: EO
authors.lastname: Sote
authors.forename: F A
authors.initials: FA
authors.lastname: Oredugba
mesh_terms: D000293:Adolescent; D044383:Black People; D002648:Child; D019229:Dentition, Permanent; D005260:Female; D006801:Humans; D008297:Male; D009549:Nigeria; D009811:Odontometry / Q000706:statistics & numerical data; D012016:Reference Values; D012737:Sex Factors; D019228:Tooth Crown / Q000033:anatomy & histology*