title: Dental emergence among urban Zambian school children: an assessment of the accuracy of three methods in assigning ages.
abstract: In situations where birth records are unavailable and stated ages are unreliable, the emergence of the permanent dentition can serve as an indicator of age. Due to substantial variation in the timing of tooth emergence, a sample (n = 721) of Zambian school children, with known ages, was examined to provide a tooth emergence reference standard for the area. Three methods for assigning ages were utilized and their accuracy assessed. A random test sample was withheld from the original study in order to further evaluate the methods' accuracy. The three methods-1) number of teeth, 2) regression and 3) probit analysis-were applied to Zambian children, and estimates of age were made. Predicted ages were compared to actual ages to determine the percentage of accuracy in three categories-(+/-) .5, +/- 1.0 and +/- 2.0 years- and paired t-tests were conducted. Each of the three methods was then applied to the test sample, and their accuracy was evaluated in the same manner. Methods 1 and 2 were found to provide the higher percentage of correct ages within +/- .5 years, assigning roughly 39% of both male and female children within this increment. This was also the case at the next increment, with methods 1 and 2 assigning a higher percentage (66-76%) of children to the +/- 1.0 year category, while the accuracy of method 3 was quite a bit lower. The results for the test sample were very similar to those of the main sample. The overall accuracy of methods 1 and 2 was very similar in both the main and test samples, while method 3 had lower accuracy and t-tests indicated significant differences. Therefore, due to ease of application in the field setting, method 1, mean age per number of teeth emerged, is the method of choice.
authors.affiliation: University of Arizona, Tucson 85721, USA. RHONDA.CPC@mhs.unc.edu
authors.forename: R M
authors.initials: RM
authors.lastname: Gillett
mesh_terms: D000293:Adolescent; D000366:Age Determination by Teeth / Q000379:methods*; D000367:Age Factors; D002648:Child; D016001:Confidence Intervals; D019229:Dentition, Permanent; D005260:Female; D006801:Humans; D008297:Male; D011237:Predictive Value of Tests; D012044:Regression Analysis; D012727:Sex Characteristics; D014078:Tooth Eruption; D014505:Urban Population; D015024:Zambia