Utilization and Accuracy of Dental Age Estimation Methods and Development of Tooth Maturity Reference Values in a Kenyan Population

Abstract

A person’s age is often verified through legal documents. However, in Kenya, a third of children aged less than 5 years have no birth certificates while 9% of adults lack identification documents. Therefore, age has to be estimated through dental development among other methods. The main objective of the study was to determine the utilization and accuracy of dental age estimation methods and to develop tooth maturity reference values in a Kenyan population. The study design was cross-sectional while the study population included persons seeking dental and age estimation services at eight level 5 health facilities over a 5-year period. Additionally, data was collected from a select population whose sample size was determined as 320 using Cochran formula. A questionnaire was used to capture information such as sources of referral and methods used to assess age. Dental panoramic radiographs of 3-23 years old were also reviewed to test the accuracy of 6 age assessment methods and to determine tooth maturity reference values. The radiographs were collected from two University Dental Hospitals. Data collected from questionnaires were analysed to show the mean age of attendance, number of referrals from different institutions and methods used to assess age. Radiographs were reviewed to show mean dental age according to different methods and the mean chronological age of attaining various tooth maturity levels. The data were analysed using the Statistical Packages for Social Sciences (SPSS) for windows, V 26 (SPSS Inc., Chicago, IL, USA). Descriptive statistics included frequency, mean, range and standard deviation. While inferential statistics to compare means comprised of 95% confidence interval, paired-samples t-test, independent-samples t-test, one-way ANOVA and Chi square test for comparing proportions. Results were presented in tables and figures. For ethical approval, proposal was submitted to Kenyatta National Hospital/University of Nairobi (KNH/UON)-Ethics and Research Committee (ERC) under approval number P104/02/2019 and later to National Commission for Science, Technology & Innovation for research permit. Authorisation was also sought and granted from hospitals to conduct the study by accessing patients and their details. Data from dental registers showed that only 12,738(5.73%) of all dental patients sought age assessment services. Data analysed from a sample of 316 patients revealed that more children (248, 78.5%) than adults (68, 21.5%) (Χ2(7)=39.883, p=0.000) sought age assessment services. Majority (267,84.49%) were referred by the court of law. A combination of non-medical and medical methods was randomly applied to assess age. There was significant use of panoramic radiographs to assess age (210,66.5%) (Χ2(7)=164.991, p=0.000). Among the methods tested for accuracy, the Cameriere method had the lowest mean deviation from the actual age -0.03±1.22 years, p=.542 followed by Willems method (0.05±1.16 years, p=.165). The Demirjian and Haavikko methods followed with significant deviation. Tooth maturity tables were created which showed mean age of achieving various tooth formational stages as well as modal stage of teeth maturity for each one-year age group. Girls were only significantly ahead of boys in the maturity of canines. In conclusion, about 6% of dental patients sought age assessment services within the 5-year period. The service was mostly sought for by children. The main source of referral was the Court of law. A combination of non-medical and medical methods was randomly applied to assess age. Willems and Cameriere methods performed the best in estimating age, hence, they are suitable for the local population. The tooth maturity data can be used as a new tool to monitor growth, assess age and to develop new methods of estimating age. There is need for the Ministry of Health to create a national guideline so as to ensure standardized provision of quality age assessment services. Collaboration with Judiciary is highly recommended.