Third molar eruption in orthopantomograms as a feature for forensic age assessment—a comparison study of different classification systems

Abstract

Evaluation of third molar eruption represents an established method for age assessment of living individuals. Different classification systems are available for the radiological assessment of third molar eruption. The aim of this study was to identify the most accurate and reliable classification system for the mandibular third molar eruption on orthopantomograms (OPG). We compared the method of Olze et al. (2012) with the method of Willmot et al. (2018) and a newly derived classification system using OPGs from 211 individuals aged 15–25 years. The assessments were performed by three experienced examiners. One examiner evaluated all radiographs twice. The correlation between age and stage was investigated and the inter- and intra-rater reliability was estimated for all three methods. Correlation between stage and age was similar between classification systems, although higher in the data from males (Spearman’s rho ranging from 0.568 to 0.583) than from females (0.440 to 0.446). Inter- and intra-rater reliability measures were similar across methods and invariant on sex, with overlapping confidence intervals, although the highest point estimates for both intra- and inter-rater reliability were for the method by Olze et al. with Krippendorf’s alpha values of 0.904 (95% confidence interval 0.854, 0.954) and 0.797 (95% confidence interval 0.744, 0.850). It was concluded that the method of Olze et al. from 2012 is a reliable method for practical application and future studies.

Third Molar Eruption in Dental Panoramic Radiographs as a Feature for Forensic Age Assessment—Presentation of a New Non-Staging Method Based on Measurements

“…However, it is crucial to note that these results for correlation between age and eruption align with the findings reported in the relevant literature. Our group previously reported Spearman's rho values of 0.583 (males) and 0.445 (females) for the Olze et al Method [36].…”

“…In comparison to data from the literature regarding stage-based methods on DPR, the present inter-rater agreement yields significantly better results. Our group explored various stage-based approaches within a cohort of 211 DPRs from individuals aged 15 to 25 years [36]. Their findings favored the method proposed by Olze et al in 2012 as the most suitable.…”

“…For this study, the age range was selected to encompass the eruption of mandibular third molars as comprehensively as possible. In line with the existing literature on the subject, an age range of 15 to 25 years was chosen [36]. Furthermore, the aim was to achieve a balanced distribution between sexes.…”

“…Thus, in these methods, eruption is conceptualized as a categorical variable. Previously, our group demonstrated that among the existing staging classifications, the 2012 classification proposed by Olze et al is particularly well suited for future studies [36].…”

“…Within the forensic science community, there has been a long-standing debate among experts regarding the suitability of methods that rely on the assignment of fixed morphologic stages for age assessment [37]. While numerous studies have substantiated the suitability of individual methods [21,22,24,26,36], others argue that reliance on fixed morphologic stages has inherent limitations and is subjective [37,38]. For example, it has been proposed that when assigning specific developmental stages, intermediate phases may sometimes be neglected, creating the impression of a sudden shift from one stage to a higher one.…”