Nyström Marjatta Elina, Ranta Helena Meri, Peltola Jaakko Sakari, Kataja Jorma Matti
Department of Orthodontics, Institute of Dentistry, University of Helsinki, Finland.
Acta Odontol Scand. 2007 Feb;65(1):36-43. doi: 10.1080/00016350600965900.
The aim was to provide radiographic data on postnatal development of the 8 mandibular teeth to serve as reference norms in clinical dentistry, forensic dentistry, anthropology, and research.
Developmental stages of teeth were assessed from a total of 2795 radiographs, mostly panoramic, of 1970 Finns (966 M and 1004 F) from birth to age 25. The grading was based on Demirjian's 8 mineralization stages and the crypt stage.
Timing of development in individual mandibular teeth is presented in two ways: as age at attainment of each developmental stage and as age of subjects in a developmental stage. Initiation of mineralization was visible in 1st molars at 0.20 years, in central incisors at 0.22 years, lateral incisors at 0.37 years, and canines at 0.56 years of age. Timing was usually earlier in girls than in boys. Differences were greatest in canines, where females were advanced by 1.74 years at the closure of the apex. Root development in 3rd molars showed an opposite trend, where apical closure was 1.19 years earlier in men. In 3rd molars, age at apical closure in females was 21.50 years, among the highest reported. In general, the early developmental stages had the shortest duration and the last stages the longest.
Timing of postnatal development of individual mandibular teeth in Finns resembled developmental schedules reported for other Caucasian population groups. Any differences were mostly small and inconsequential.
旨在提供8颗下颌牙齿出生后发育的影像学数据，作为临床牙科、法医牙科、人类学及研究领域的参考标准。
从1970名芬兰人（966名男性和1004名女性）出生至25岁期间拍摄的总共2795张X线片（大多为全景片）中评估牙齿的发育阶段。分级基于德米尔坚的8个矿化阶段和牙囊阶段。
个体下颌牙齿的发育时间以两种方式呈现：达到各发育阶段时的年龄以及处于某发育阶段的受试者年龄。矿化开始在第一磨牙为0.20岁，中切牙为0.22岁，侧切牙为0.37岁，尖牙为0.56岁。发育时间通常女孩比男孩早。差异在尖牙中最大，女性在根尖闭合时比男性提前1.74岁。第三磨牙的牙根发育呈现相反趋势，男性根尖闭合时间比女性早1.19岁。在第三磨牙中，女性根尖闭合年龄为21.50岁，是所报道的最高年龄之一。总体而言，早期发育阶段持续时间最短，最后阶段持续时间最长。
芬兰人个体下颌牙齿出生后发育时间与其他高加索人群组报道的发育时间表相似。任何差异大多较小且无关紧要。
