Comparison of chronologic, dental and skeletal ages upon commencing orthodontic treatment during the years 2010-2012 versus 1990-1992

Objectives: The purpose of this study was to investigate whether chronologic, dental and skeletal ages at onset of orthodontic treatment have decreased during the last few decades, as was previously found for age of sexual maturity, and to find out whether correlations exist between these ages.
Methods: The sample used in this retrospective cross-sectional study included 300 adolescents (139 males, 161 females), who began their orthodontic treatment during the years 1990-1992 or 2010-2012 (152 and 148 subjects, respectively). Dental age upon commencing orthodontic treatment was determined by patients’ panoramic radiograph, by the degree of their dentition roots development. Skeletal age was determined by lateral cephalometric radiographs, analyzing cervical vertebral maturation, which is divided into six consecutive developmental stages.
Results: Mean chronologic age was 12.26 ± 1.22 years during 1990-1992, and 12.63 ± 1.64 during 2010-2012 (p=0.028). Mean dental age was 12.27 years ± 1.88 during 1990-1992, and 13.02 ± 2.20 during 2010-2012 (p=0.002). Mean skeletal developmental stage of subjects was 2.68 ± 1.60 during 1990-1992, and 2.99 ± 1.75 during 2010-2012 (p>0.1).
Conclusions: Conclusions: although no significant change of skeletal age upon commencing orthodontic treatment has occurred over the last two decades, both chronologic and dental ages have increased, particularly for females. There is significant correlation between chronologic, dental and skeletal ages for the entire group, particularly for females.