Relationships between dental calcification stages and skeletal maturity indicators in Thai individuals

The purpose of this study was to investigate the relationship between the stages of calcification of various teeth and skeletal maturity stages among Thai individuals. The study subjects consisted 139 male subjects and 222 female subjects ranging in age from 7 years to 19 years. A total of 361 hand-wrist and panoramic radiographs were obtained and analyzed. The tooth development of the mandibular canines, first and second premolars, and second and third molars were assessed according to the Demirjian's system. Skeletal age and skeletal maturity stages were determined from hand-wrist radiographs by using the method outlined in the atlas of Greulich and Pyle and the Fishman's system, respectively. The Spearman rank order correlation coefficient revealed significant relationships (r = 0.31-0.69, P < .01) between dental calcification stages and skeletal maturity stages. The second premolar was the tooth showing the highest correlation (r = 0.66 in male subjects, r = 0.69 female subjects). The third molar demonstrated the poorest correlation (r = 0.47 in male subjects, r = 0.31 in female subjects). The canine stage F for both sexes (63.2% for female subjects, 54.1% for male subjects) coincided with the MP3 stage. The second molar stage E for female subjects (51.4%) and stage G for male subjects (66.7%) were related to the S stage and the MP(3cap) stage, respectively. This suggests that tooth calcification stages from panoramic radiographs might be clinically useful as a maturity indicator of the pubertal growth period. However, further study is recommended in a larger sample size, and future studies should address development of the canines and second molars.