title: Forecasting the timing of peak mandibular growth in males by using skeletal age.
abstract: BACKGROUND
  It is generally believed that the orthodontic treatment of a patient with a Class II malocclusion and a small mandible is enhanced by good growth at puberty, so that the timing of peak mandibular growth at puberty becomes of interest.
  
  
  METHODS
  To test the belief that skeletal age, whether early, average, or late, can be used to predict the timing of maximum growth of the mandible, whether early, average, or late, the predictive relationship between skeletal age and peak mandibular growth velocity (PMdV) at puberty was evaluated in 94 boys by using their longitudinal records from 4 to 18 years of age. Skeletal age was determined for each subject at ages 9 through 14 by using the method of Greulich and Pyle.
  
  
  RESULTS
  At age 9, the Greulich and Pyle measurements predicted that 30 of the 94 subjects would have delayed PMdV equal to or exceeding 1 SD (of the mean age for PMdV), and 10 would have advanced PMdV equal to or exceeding 1 SD. When the actual age of PMdV was determined retrospectively from plots of annual mandibular growth increments, it was found that only 4 of the 30 in the delayed group had actually experienced delays in PMdV, and only 2 of the 10 in the advanced group had experienced accelerated PMdV.
  
  
  CONCLUSIONS
  Skeletal age is not a reliable predictor of the timing of PMdV.
authors.affiliation: University of Western Ontario, London, Ontario, Canada. whunter@uwo.ca
authors.forename: W Stuart
authors.initials: WS
authors.lastname: Hunter
authors.forename: Sheldon
authors.initials: S
authors.lastname: Baumrind
authors.forename: Frank
authors.initials: F
authors.lastname: Popovich
authors.forename: Gertrud
authors.initials: G
authors.lastname: Jorgensen
mesh_terms: D000293:Adolescent; D000365:Age Determination by Skeleton; D016009:Chi-Square Distribution; D002648:Child; D002675:Child, Preschool; D005544:Forecasting; D050276:Hand Bones / Q000000981:diagnostic imaging; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008312:Malocclusion, Angle Class II / Q000628:therapy*; D008334:Mandible / Q000000981:diagnostic imaging / Q000254:growth & development*; D011336:Probability; D011627:Puberty / Q000502:physiology*; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012737:Sex Factors; D013997:Time Factors