Age estimation in small children: reference values based on counts of deciduous teeth in Finns

The eruption of teeth in the mouth is suitable for age estimations during t he period when teeth an actively emerging, in the deciduous dentition phase approximately from the age of 6 months to 2.5 years. Estimations of age ca n be performed simply by counting the number of teeth in the mouth. Reliabi lity of the estimates depends on the reference data available and each popu lation group should preferably have its own standards. In the present study timing of eruption of successive deciduous teeth was studied lonigitudinal ly in 129 Finns. The dates of clinical eruption of deciduous teeth were rec orded by mothers and checked by dentists. In 40 of the 129 children emergen ce ages of at the most the four last teeth were based only on semiannual re gistrations performed by dentists. The main purpose was to provide normal t imetables of tooth eruption in small children in forms that are practical i n estimations of dental age. No sexual dimorphism existed in the timing of clinical eruption of successive deciduous teeth. The mean age corresponding to the presence of one tooth in the mouth was 7.1 months (S.D. = 1.78) and that corresponding to tooth count 19 was 27.8 months (S.D. = 3.99), If the chronological age is known, the presented distributions and means with var iations make it possible to estimate the degree of advancement or delay in a child's dental development. If the age of the child is not known, the mea n and median ages can be used for estimations of chronological age. However , estimations of age should not be based only on tooth counts because of ma rked variation also within this homogeneous group. (C) 2000 Elsevier Scienc e ireland Ltd. All rights reserved.