Dental Age Estimation: A Test of the Reliability of Correctly Identifying a Subject Over 18 Years of Age Using the Gold Standard of Chronological Age as the Comparator

This study was designed to test the reliability of using the third molars to demarcate between child and adult status. A total of 2000 dental panoramic tomographs were used for assessment of the calculated age using the 8‐stage system of tooth development and applied to all four third molars. The LL8 was also assessed using this 8‐stage system. For each tooth development stage, the Normal distribution and percentile summary data were estimated. The calculated dental age compared with the chronological age was statistically significantly different (p < 0.001) for both females and males giving underestimates of the true age. Comparison of single tooth dental age and chronological age was only slightly different. The most important finding is that the assignment to above or below the 18‐year threshold, in the age range 17 years to 19 years, could be wrong on up to 50% of occasions.     

Global Clusters in Municipal E-Governance: A Longitudinal Study

This research focuses on the trends in municipal e-governance among large municipalities based on a worldwide survey in 2011. The study replicates previous surveys conducted every other year since 2003 and the longitudinal assessment analyzes specific features of municipal websites. This paper examines these longitudinal trends in terms of four different clusters: 1) digitally mature cities, 2) digitally moderate cities, 3) digitally minimal cities, and 4) digitally marginal cities, and identifies the best practices among them. There were significant changes in the top ranking cities, with Seoul, Toronto, Madrid, Prague, and Hong Kong representing the highest level in e-governance.     

Expressing Uncertainty in Dental Age Estimation: A Comparison between Two Methods of Calculating the “Average” Standard Deviation

The expression of uncertainty is defined by the standard deviation and is usually expressed in multiples of the standard deviation (±1sd, ±2sd, and ±3sd). The objective was to use weighting of the sd calculation by the number or count of subjects for each tooth development stage. A comparison shows the difference between the range of uncertainty using the unweighted sd and the weighted sd. The range of uncertainty related to Dental Age Estimation is statistically significantly greater (p < 0.001) for the weighted sd compared to the unweighted sd. It is concluded that the number of subjects for each Tooth Development Stage in the Reference Data set should be included in the calculation for a single Dental Age Estimation using the Simple Average Method when presenting the uncertainty associated with the point estimate of the “mean” for Dental Age Estimation of a single subject of unknown age.     

Dental Age Estimation: Pattern Recognition of Root Canal Widths of Mandibular Molars. A Novel Mandibular Maturity Marker at the 18‐Year Threshold

The final stage of third molar development is used to assign a subject to above the 18‐year threshold. Some subjects exhibiting this final stage are less than 18 years. Radiographs from 1000 females and 1000 males age 16.00–25.99 years were examined. Each half‐year age band comprised 50 females and 50 males. Three categories of root canal widths (RCW) of the LL6, LL7, and LL8 [FDI 36, 37, and 38] were defined. Reproducibility was achieved by re‐assessing the same subjects 12 months apart. For females, the minimum value for RCW‐A was 16.33 years, RCW‐B 17.23 years, and RCW‐C 18.45 years. For males, the minimum values were RCW‐A 17.16 years, RCW‐B 18.29 years, and RCW‐C 18.16 years. The presence of RCW‐C in a female, and the presence of RCW‐B or RCW‐C in a male is compelling evidence that the subject is above the 18‐year threshold.