OBJECTIVE: To compare skeletal maturation of female and male subjects from historic samples to present day subjects by assessing Fishman’s Skeletal Maturity Index (SMI). Present day eating habits and lifestyle have been suggested as factors in accelerating pubertal maturation seen within the last century. Consequently, Body Mass Index (BMI) as well as BMI percentile were evaluated to determine whether it is associated with significant differences in skeletal maturation patterns. METHODS: This pilot study included hand-wrist films from 92 subjects from the Burlington and Forsyth longitudinal growth studies (1959-1970) and 146 patients currently enrolled in the Orthodontic department of the Boston University Henry M. Goldman School of Dental Medicine (BUGSDM). The age of the subjects ranged between 7 and 16 years. SMI stage was determined and BMI and BMI percentile were calculated for each subject. RESULTS: The mean chronologic ages of all the SMI stages were not different in males or females when comparing the historic sample to the present sample except for the mean ages at SMI stage 7 and 11 for females and SMI stage 5 for males. Females in the present sample reached SMI stages 7 and 11 significantly earlier: 11.6 versus 13.3 years for SMI 7 (p<0.001) and 15.6 vs. 16.0 for SMI 11 (p<0.05). Males in the present sample also reached SMI 5 significantly earlier: 12.5 vs 13.8 years (p<0.05). It was also seen that present day females at SMI stage 11 not only matured earlier, but also had significantly higher mean BMI and mean BMI percentile than the females at the same stage in the historic sample. This suggests that BMI may be associated with acceleration of maturation among females at SMI stage 11 (p<0.05). CONCLUSIONS: In both male and female subjects, there are differences between past and present populations at certain SMI stages. This evidence suggests that patterns of skeletal maturation may have changed and BMI may be associated with such changes. The differences in skeletal maturation between the two groups may also be a result of the different distribution of race in each group. In the current study, the historic sample consists of only Caucasian subjects whereas the present sample consists of subjects from many different backgrounds. As a result, effects of racial variations could have additionally played a role in the changes seen in skeletal maturation patterns. Increasing our sample size and controlling for race may help further elucidate these changes and determine if this transition towards earlier maturation is in fact due to increasing BMIs.