Dental Age Estimation of a Southern Nevada Hispanic Non-Adult Population Employing the London Atlas to Evaluate Archival Orthodontic Cone Beam Computed Tomography (CBCT) Images
Creators: name: Buchanan, Haley 
Publisher: name: University of Nevada, Las Vegas
Year: 2019

description: Age estimation is of societal importance for legal, forensic, and clinical reasons. The London Atlas of Human Tooth Development and Eruption, hereafter referred to as the London Atlas, was introduced as an improved method for determining dental age estimation. The London Atlas was developed from panoramic images of 528 living British Caucasian and Bangladeshi males and females aged 2 to 24 years and panoramic images of 176 archival human skeletal remains, aged 32 in utero to 2 years old, from two specimen collections (AlQahtani, Hector, & Liversidge, 2010). Further investigation is warranted to determine validity of the atlas's use in determining age estimation in specific ethnic subpopulations. Therefore, this project applied the use of the London Atlas to a Southern Nevada subadult Hispanic population to determine the validity of this technique as an instrument for age determination in this subpopulation. Additionally, since the London Atlas was developed using single plane, sagittal panoramic images, this study employed archival CBCT images of the chosen subpopulation (n=250, age range 8.5- 20.7 years) to analyze tooth development stages from coronal, transverse, and sagittal projections to determine if CBCT technology can improve age estimation accuracy.
Estimated age (EA) was compared to true chronological age (TCA) and calculated chronological age (CCA). The latter represents the age ranges used by the London Atlas (AlQahtani et al., 2010). Data collected was analyzed using the following statistical analyses:
- paired t-test with a threshold of statistical significance set at p< 0.05 to evaluate age estimation accuracy,
- mean difference and absolute mean difference to calculate and evaluate bias and range of accuracy, respectively, and
- independent sample t-test to identify differences in age estimation accuracy between males and females.
A statistically significant bias of 0.30 years was found (p< 0.001), indicating a tendency to overestimate age in this population. The absolute mean difference was 1.0 years, indicating a range of accuracy of one year using the London Atlas. There was not a statistically significant difference of age estimation accuracy between males and females (p= 0.408). Results from this research indicated that mean difference and range of accuracy were not significantly improved compared to the AlQahtani research (mean difference= -0.1 years; absolute mean difference= 0.64 years) and other research analyzing the London Atlas (AlQahtani, Hector, & Liversidge, 2014; Alshihri, Kruger, & Tennant, 2015; Pavlovi?, Palmela Pereira, & Vargas de Sousa Santos, 2017; Baylis & Bassed, 2017; McCloe, Marion, da Fonseca, Colvard, & AlQahtani, 2018; Ghafari, Ghodousi, & Poordavar, 2018). Therefore, CBCT imaging for a Southern Nevada Hispanic male and female subadult population evaluated with the London Atlas does not significantly improve age estimation compared to panoramic images. Further research should be conducted to evaluate if an age estimation atlas developed from CBCT images instead of panoramic images would improve age estimation accuracy in other specific ethnic subpopulations.