title: Mandibular permanent first molar and incisor width as predictor of mandibular canine and premolar width.
abstract: BACKGROUND
  Estimating the mesiodistal widths of unerupted permanent canines and premolars is an essential aspect of mixed dentition analysis. Several methods are used to predict tooth width. The best methods demonstrate high values of correlation and determination coefficients. In this study, we aimed to determine a linear regression equation that would predict the sum of the mesiodistal widths of mandibular permanent canines and premolars based on the sum of the widths of the 4 mandibular permanent incisors and first permanent molars.
  
  
  METHODS
  The sample consisted of 500 dental casts, obtained from white Brazilian patients (250 male, 250 female; average ages, 13.8 and 14.4 years, respectively). Mesiodistal tooth widths were measured with an electronic digital caliper. Intraclass correlation coefficients were used to determine measurement consistencies. Paired and unpaired Student t tests were used to determine right/left side and sex differences, respectively. A paired Student t test was also used to compare the predicted and actual sums of the mandibular permanent canines and premolars.
  
  
  RESULTS
  We found high values of correlation (r) and determination (r2) coefficients, varying from r = 0.795 to r = 0.81, and r2 = 0.599 to r2 = 0.656. These values are among the highest described in the literature for nonradiographic prediction methods. On average, there was no difference between predicted and actual widths of the mandibular permanent canines and premolars, and the standard errors of estimation were 1.49 mm for males, 1.36 mm for females, and 1.44 mm for the total sample (considering right and left sides of the mandibular arch together).
  
  
  CONCLUSIONS
  The proposed method showed good accuracy and was easy to use, but it must be tested in other populations.
authors.affiliation: Department of Orthodontics, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil. camiloaquino@ig.com.br
authors.forename: Camilo Aquino
authors.initials: CA
authors.lastname: Melgaço
authors.forename: Mônica Tirre
authors.initials: MT
authors.lastname: de Sousa Araújo
authors.forename: Antônio Carlos
authors.initials: AC
authors.lastname: de Oliveira Ruellas
mesh_terms: D000293:Adolescent; D003818:Dentition, Mixed; D005260:Female; D005544:Forecasting; D006801:Humans; D016014:Linear Models; D008297:Male; D008334:Mandible; D009811:Odontometry / Q000379:methods*; D012727:Sex Characteristics; D019228:Tooth Crown / Q000033:anatomy & histology*; D014097:Tooth, Unerupted