Repeatability of a morphoscopic sex estimation technique for the mental eminence on micro-focus X-ray computed tomography models

OBJECTIVES : Walker's sex estimation method is based on five morphoscopic features of the human skull. This study aimed at testing the repeatability of one of the five traits, the mental eminence, visually on three-dimensional (3D) models, compared to the traditional, tactile scoring approach on bone. MATERIALS AND METHODS : The sample comprised 105 mandibles from the Pretoria Bone Collection and their respective virtual 3D models, obtained from micro-focus X-ray computed tomography (micro-XCT) scans. Four observers independently scored the bones first, followed by the virtual 3D modality. Intra- and interobserver errors (interOE and intraOE) were performed with Fleiss’ and Cohen's Kappa, respectively. We calculated the intermodality agreement per observer with Wilcoxon Signed-Rank tests. RESULTS : The intraOE was moderate on bone (κ=0.448) and substantial on 3D (κ=0.799), while the Fleiss’ Kappa test for the interOE resulted in slight agreement both on bone (κ=0.163) and 3D (κ=0.169) irrespective of level of experience. All Wilcoxon Signed-Rank test P-values were significant. DISCUSSION AND CONCLUSION : The application of the morphoscopic sex estimation for the mental eminence to micro-XCTs could be a matter of personal affinity as the level of experience did not play a role in the results. The expression of the mental eminence trait being population-specific, the individual's population affinity should be considered when sex is estimated in South African skeletons. It remains unclear whether the slight agreement between observers is due to the unreliability of the trait for sex estimation or whether the modalities are not easily interchangeable.UP Postgraduate Bursary, AESOP Erasmus Mundus program, the University of Pretoria, the National Research Foundation of South Africa, the Bakeng se Afrika funding and Erasmus+ KA2 Capacity Building in Higher Education.https://www.sciencedirect.com/journal/forensic-imaginghj2022Anatom

Dento‐alveolar measurements and histomorphometric parameters of maxillary and mandibular first molars, using micro‐CT

BACKGROUND : Micro‐CT is a high‐resolution, non‐invasive, and non‐destructive imaging technique, currently acknowledged as a gold standard modality for assessing quantitatively and objectively dental morphology and bone microarchitecture parameters. PURPOSE : The aim of this study was to analyze critical dental and periodontal measurements characterizing the mandibular (MandFM) and maxillary (MaxFM) first molar architecture, as well as the corresponding bony socket, using micro‐CT. MATERIALS AND METHODS : Thirty‐eight human dried skulls (22‐76 years) were scanned to enable the virtual analysis of 61 first molars. Depending on the type of measurement, the parameters were recorded on two‐dimensional sections or directly on three‐dimensional models. Tooth morphology was described by four aspects (e.g., tooth width, trunk length, root length, and root span), while the socket architecture was assessed by buccal plate thicknesses and bone density measurements. RESULTS : Minimum, maximum, and mean distances as well as cortical and trabecular bone densities were recorded in MandFM and MaxFM. It is noteworthy that the buccal plate thickness was found to be less than 1 mm in more than 55% of cases in MaxFM, whereas only in 20.8% of cases in MandFM (and even 0% at two sites). A wide range of bone densities was observed and the comparison between MandFM and MaxFM did not show a significant difference. Furthermore, cortical densities were negatively correlated with aging, while trabecular densities were not influenced. CONCLUSIONS : Using micro‐CT, three‐dimensional aspects of the human first molar morphology and microstructural parameters of the surrounding bone were evaluated in the mandible and in the maxilla. These comprehensive measurements and their correlation with aging may be of great importance for the use of immediate implant placement in molar extraction sockets and thus the potential long‐term success of this treatment modality.University of Pretoria Postgraduate Research Support Bursary (CT); National Research Foundation of South Africa (MS)http://wileyonlinelibrary.com/journal/cid2019-08-01hj2018Anatom