关键词: 乳牙列, 牙龄, Demirjian法

Abstract: Objective To explore the rule of the dental development during deciduous dentition and to evaluate the applicability of Demirjian's method for dental age estimation on children during deciduous dentition,aged 4 to 6. Methods Through cluster sampling from kindergartens in Shenzhen,75 children aged 4-year-old (40 boys,35 girls) were chosen.The serial dental pantomograms,taken at ages 4,5 and 6 years old,were used for dental age assessment according to the Demirjian's method.The differences between dental age and chronological age were compared using paired t-test. Results Through 3-year growth,the second molar,the second premolar premolar,the first premolar premolar were at the stage of dental crown development,while the first molar,the canine,the lateral incisor and the central incisor at the stage of dental root formation.In terms of relative growth,female subjects exhibited an more mature teeth development than male subjects between 4 and 6 years old.A significant difference was found between chronological age and dental age. Conclusion Demirjian's method need to be modified to be used in dental age assessment on children during deciduous dentition.

Key words: deciduous dentition, dental age, Demirjian&apos, s method