# Estimation of Age in Humans Using Dental Translucency of Permanent Teeh: An Experimental Study
## 3 Results  
The characteristics of the sample are reported in Table S2 of the Supplementary Materials. The sample is mainly composed of females (59.4% of the total sample). Dividing the sample into three age groups, the majority of males were 60 years of age or more, whilst, in females, the youngest and the oldest group are numerically equally represented (\(p=0.041\)). As regards the tooth type, the most represented are the multi-rooted teeth in both sexes (more than two-thirds of the sample). Table 2 reports the mean and standard deviation of the three considered tooth measures (RH, PH, and RHT). Females' teeth have significantly lower RH and RHT. Comparing the two sexes, no differences emerged in the PH, whereas RH and RHT resulted in significantly higher in males in the oldest group and the total sample. On the other hand, all three measures are always significantly different between age classes, with an increasing trend with increasing age, both in the total sample and in each sex separately. The youngest group always has significantly lower measures than the other groups. \begin{table}
\begin{tabular}{l l l l l} \hline
**References** & **Sample Size** & **Tooth Type** & **Population** & **Regression Equations** \\ \hline _Undetermined sex_ & & & & & \\ \hline Bang and Ramm [19] & 978 & Any & Norwegians & \begin{tabular}{l} Equation 1 \$: (RHT \(<\) 9.0 mm): \\ \(\overline{\text{A}=\text{B}_{0}+(\text{B}_{1}\times\text{RHT})}\) + (B\({}_{2}\times\text{RHT}\)) \\ Equation 2 \$: (RHT \(>\) 9.0 mm): \\ \(\overline{\text{A}=\text{B}_{0}+(\text{B}_{1}\times\text{RHT})}\) \\ \end{tabular} \\ \hline [PERSON] et al. [6] & 306 & Single-rooted & French & \begin{tabular}{l} A = 0.18[(PH \(\times\) 100)/RH] + 0.42 \\ [(RHT\({}^{*}\)100)/RH] + 25.53 \\ \end{tabular} \\ \hline [PERSON] et al. [17] & 78 & \begin{tabular}{l} Incisors and \\ premolars \\ \end{tabular} & \begin{tabular}{l} Colombian mestizo \\ population \\ \end{tabular} & \begin{tabular}{l} A = 0.87(RH) + 0.18[(PH \(\times\) 100)/RH] + \\ 0.47[(RHT \(\times\) 100)/RH] + 11.22 \\ \end{tabular} \\ \hline [PERSON] and [PERSON] [20] & 100 & Single-rooted & Peruvians & \begin{tabular}{l} A = 31.71 \(-\) 1.18(RH) + 5.81(PH) + \\ 3.14(RHT) \\ \end{tabular} \\ \hline [PERSON] et al. [11] & 50 & \begin{tabular}{l} Lower central \\ incisors \\ \end{tabular} & Indians & \begin{tabular}{l} A : 22.25 + 77.04(RHT/RH) \({}^{\circ}\) \\ \end{tabular} \\ \hline [PERSON] et al. [21] & 30 & \begin{tabular}{l} Any (not \\ specified) \\ \end{tabular} & Indians & \begin{tabular}{l} A = \(-\) 9.947 + 8.610(RHT) \({}^{\circ}\) \\ \end{tabular} \\ \hline _Males_ & & & & \\ \hline [PERSON] and [PERSON] [8] & 95 & Single rooted & \begin{tabular}{l} [PERSON] collection \\ (Caucasians) \\ \end{tabular} & \begin{tabular}{l} A = 0.16(RH) + 0.29([PH \(\times\) 100]/RH) + \\ 0.39([RHT \(\times\) 100]/RH) + 23.17 \\ \end{tabular} \\ \hline _Females_ & & & & \\ \hline [PERSON] and [PERSON] [8] & 72 & Single rooted & \begin{tabular}{l} [PERSON] collection \\ (Caucasians) \\ \end{tabular} & \
\begin{tabular}{l} A = 1.10(RH) + 0.31([PH \(\times\) 100]/RH) + \\ 0.39([RHT \(\times\) 100]/RH) + 11.82 \\ \end{tabular} \\ \hline \end{tabular}
\begin{tabular}{l l l l l l} \hline  & & & & & \\ \end{tabular}
\end{table} 
Table 1: Equations to estimate age-at-death (A) based on dentin translucency from the literature reported separately for indeterminate sexes, male sex and female sex. Table 3 presents the results of the intra- and inter-operator variability for the three considered tooth measures, and Table S3 reports the ICC values for the sample divided by age class. Again, the results indicate excellent reliability for all the measures in the total sample and for the majority of the measures dividing the sample by age class and by tooth type. The only exceptions are RHT for the youngest and the oldest group and PH for the oldest group, which reported good reliability. Less reliability, in general, resulted in inter-operator variability.