title: [Radiographic study of the development of the permanent teeth].
abstract: OBJECTIVE
  To study the development of permanent teeth by radiographic methods.
  
  
  METHODS
  The permanent teeth development of children ranging from 4-17 years was evaluated from 1709 panoramic radiographs by the Nolla's method. Each tooth was graded from 0 to 10 stage. The average developmental stage for girls and boys were calculated.
  
  
  RESULTS
  The average developmental stage and development curves for girls and boys were obtained respectively. For the completion of crown and root development, girls are more advanced than boys by an average of 0.3 and 0.6 years.
  
  
  CONCLUSIONS
  Girls are ahead of boys for the development of the permanent teeth. The norms of the maturation of permanent teeth can be used to evaluated the development of the individual teeth.
authors.affiliation: Department of Oral Radiology, Peking University School of Stomatology, Beijing 100081, China.
authors.forename: Y
authors.initials: Y
authors.lastname: Zhao
authors.forename: Z
authors.initials: Z
authors.lastname: Zou
authors.forename: X
authors.initials: X
authors.lastname: Chu
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D008297:Male; D011862:Radiography, Panoramic; D012737:Sex Factors; D014070:Tooth / Q000000981:diagnostic imaging* / Q000254:growth & development