Dental and Skeletal Maturation in North American Children

Objective: This study examines the relationship between the Moorrees method of determining dental development age (using seven teeth), a two-tooth Moorrees derivative and skeletal age. Method: We evaluated archival radiographs of children ranging in age from 2 to 16. (protocol # 1997-0809: Dental Maturation was last approved by UIC IRB # 1 on October 2, 2002 for the period of October 25, 2002 to October 24, 2003). The skeletal age (Greulich W.M. and Pyle S.I. 1959, Radiographic Atlas of Skeletal Development of the Hand and Wrist, 2nd ed, Oxford, Oxford Univ Press) of a group of children was determined using serial radiographs of hands and wrists and compared to dental age (Moorrees C.F.A., Fanning E.A. and Gron A-M. 1963, Consideration of dental development in serial extraction. Angle Orthod. 33: 44-91.) in each child. Additionally a two-tooth Moorrees dental age was calculated using the canine and 1st premolar. Results: The correlation coefficient (r) of the two-tooth development age with the skeletal age was 0.8. Index bones of the hand and wrist were evaluated and the correlation coefficient calculated for both the capitate/hamate and the radius/ulna components. With regard to the dental age for this entire sample r=0.8. Conclusion: The results indicate that the two-tooth variant of Moorrees determination of dental age can be use as an indicator of dental maturation in lieu of the complete seven tooth assessment. The resulting values must be interpreted in light of the highly variable clinical course of dental development. While results of individual assessments agree, the variations in child development should be considered.