Shifts in tooth maturation patterns in non-French Canadian boys.

Aims: This study was designed to evaluate the predictability of dental maturation patterns in non-French Canadian boys using the maturation curves developed by Demirjian & Goldstein [1].

Sample: Archival cephalometric radiographs taken during a longitudinal study (1930-1960) of Caucasian Americans were re-evaluated.

Methods: Maturation of the permanent teeth on the left side of the mandible was determined according to the methods described by Demirjian & Goldstein.

Results: Of the 79 boys studied, 12 (15.2%) started below Demirjian's median and continued as such during the maturation process. Seven (8.9%) started within the second standard deviation above Demirjian's median and continued as such during the maturation process. The remaining 60 boys (75.9%) started below the median of Demirjian's curves at an early age. They matured at a rate that placed them above the median value at the end of the study period. The shift took place before the age of 6 years in 46 (76.6%) cases and between the ages of 6 and 8 years in another nine (15%) cases. In five of the cases which started below Demirjian's median (8.3%) the shift only took place after the age of 9 years.

Conclusion: The shift from below median to above median value was considered an important factor in treatment planning. The data indicate that there is considerable risk for treatment planning prior to the age of 8 years. The risk is highest when the children are less than 6 years of age due to growth prediction uncertainties.