Buccal and palatal alveolar bone dimensions in the anterior maxilla

DATA AVAILABILITY STATEMENT : The data that support the findings of this study are available on request from the corresponding author. The data are not publicly available due to privacy or ethical restrictions.OBJECTIVE : Anterior maxillary immediate implant placement has become a popular procedure. It has aesthetic and functional risks. A prerequisite for success is sufficient alveolar bone for primary stability. Many cone-beam computed tomography (CBCT) studies have assessed alveolar bone dimensions in the anterior maxilla, with varying results. More accurate information on the alveolar bone dimensions in the anterior maxilla is required. The objective of the present study was to evaluate bone dimensions in the anterior maxilla using micro-CT, a high-resolution imaging tool. MATERIALS AND METHODS : Seventy-two human skulls were scanned using micro-CT at the South African Nuclear Energy Corporation. Specialized software was used for 3-D rendering, segmentation, and visualization of the reconstructed volume data. Axial planes were created over each alveolus/tooth from canine to canine. Buccal and palatal bone dimensions were measured at crestal, 3 mm, 6 mm, and 9 mm levels. RESULTS : Buccal bone rarely exceeded 0.5 mm, consisting of bundle bone only for all investigated teeth at all levels. Up to a third of teeth showed buccal fenestrations. Alveolar bone on the palatal side was thicker than buccal and increased from <1 mm at crestal level up to 3.77 mm, 4.56 mm, and 5.43 mm for centrals, laterals, and canines at the 9 mm level, respectively. CONCLUSIONS : Immediate implants in the anterior maxillae has anatomical risks. Alveolar bone on the buccal aspect is very thin, with fenestrations in certain positions. Therefore, a thorough planning and individual approach are needed to avoid possible complications and achieve stable aesthetic and functional results in the long-term.The Ministry of Education, Science and Technological Development of the Republic of Serbia.http://wileyonlinelibrary.com/journal/cidam2024Oral Pathology and Oral BiologyPeriodontics and Oral MedicineSDG-03:Good heatlh and well-bein

Micro-anatomy of the ear of the southern white rhinoceros (Ceratotherium simum simum)

The white rhinoceros is the largest of the five extant rhinoceros species. The population is declining rapidly because of intense poaching. However, normal anatomical descriptions in this species are lacking. The purpose of this study is to describe the osseous anatomy of the middle and inner ear of the southern white rhinoceros using micro‐focus X‐ray computed tomography imaging. Four temporal bones obtained from two 1‐day old southern white rhinoceros preserved in 10% formalin were scanned. Tri‐dimensional reconstructions were obtained and volumes of the middle ear ossicles and inner ear structures were calculated. Excellent high spatial resolution 3D images were obtained for all samples and virtual models of the auditory ossicles and bony labyrinth were generated. Visualization of the tympanic membrane, middle ear and inner ear structures was possible in all samples. Whereas the stapes and incus had a shape similar to their human or equine counterparts, the malleus showed a unique appearance with a long rostral branch projecting latero‐distally to the manubrium. The cochlea described 2 turns rostro‐laterally around its axis, with a medial direction of rotation. However, identification of the soft tissue structures of the middle ear was sometimes difficult and visualization of the small structures of the membranous labyrinth was not possible using this formalin fixation and alternative techniques should be investigated. Further investigations are needed in order to provide a complete virtual model including both soft and bone tissues of this difficultly accessible region.The DST‐NRFhttps://onlinelibrary.wiley.com/journal/143902642021-11-11hj2021Companion Animal Clinical Studie

Earliest hominin cancer: 1.7-million-year old osteosarcoma from Swartkrans Cave, South Africa

The reported incidence of neoplasia in the extinct human lineage is rare, with only a few confirmed cases of Middle or Later Pleistocene dates reported. It has generally been assumed that premodern incidence of neoplastic disease of any kind is rare and limited to benign conditions, but new fossil evidence suggests otherwise. We here present the earliest identifiable case of malignant neoplastic disease from an early human ancestor dated to 1.8–1.6 million years old. The diagnosis has been made possible only by advances in 3D imaging methods as diagnostic aids. We present a case report based on re-analysis of a hominin metatarsal specimen (SK 7923) from the cave site of Swartkrans in the Cradle of Humankind, South Africa. The expression of malignant osteosarcoma in the Swartkrans specimen indicates that whilst the upsurge in malignancy incidence is correlated with modern lifestyles, there is no reason to suspect that primary bone tumours would have been any less frequent in ancient specimens. Such tumours are not related to lifestyle and often occur in younger individuals. As such, malignancy has a considerable antiquity in the fossil record, as evidenced by this specimen

A geometric morphometric approach to the study of variation of shovel-shaped incisors

Objectives: The scoring and analysis of dental nonmetric traits are predominantly accomplished by using the Arizona State University Dental Anthropology System (ASUDAS), a standard protocol based on strict definitions and three‐dimensional dental plaques. However, visual scoring, even when controlled by strict definitions of features, visual reference, and the experience of the observer, includes an unavoidable part of subjectivity. In this methodological contribution, we propose a new quantitative geometric morphometric approach to quickly and efficiently assess the variation of shoveling in modern human maxillary central incisors (UI1). Materials and methods: We analyzed 87 modern human UI1s by means of virtual imaging and the ASU‐UI1 dental plaque grades using geometric morphometrics by placing semilandmarks on the labial crown aspect. The modern human sample was composed of individuals from Europe, Africa, and Asia and included representatives of all seven grades defined by the ASUDAS method. Results: Our results highlighted some limitations in the use of the current UI1 ASUDAS plaque, indicating that it did not necessarily represent an objective gradient of expression of a nonmetric tooth feature. Rating of shoveling tended to be more prone to intra‐ and interobserver bias for the highest grades. In addition, our analyses suggest that the observers were strongly influenced by the depth of the lingual crown aspect when assessing the shoveling. Discussion: In this context, our results provide a reliable and reproducible framework reinforced by statistical results supporting the fact that open scale numerical measurements can complement the ASUDAS method

Life on a Mesoarchean marine shelf – insights from the world’s oldest known granular iron formation

Abstract: The Nconga Formation of the Mesoarchean (~2.96–2.84 Ga) Mozaan Group of the Pongola Supergroup of southern Africa contains the world’s oldest known granular iron formation. Three dimensional reconstructions of the granules using micro-focus X-ray computed tomography reveal that these granules are microstromatolites coated by magnetite and calcite, and can therefore be classified as oncoids. The reconstructions also show damage to the granule coatings caused by sedimentary transport during formation of the granules and eventual deposition as density currents. The detailed, three dimensional morphology of the granules in conjunction with previously published geochemical and isotope data indicate a biogenic origin for iron precipitation around chert granules on the shallow shelf of one of the oldest supracratonic environments on Earth almost three billion years ago. It broadens our understanding of biologically-mediated iron precipitation during the Archean by illustrating that it took place on the shallow marine shelf coevally with deeper water, below-wave base iron precipitation in micritic iron formations

Performance of the ATLAS electromagnetic calorimeter end-cap module 0

The construction and beam test results of the ATLAS electromagnetic end-cap calorimeter pre-production module 0 are presented. The stochastic term of the energy resolution is between 10% GeV^1/2 and 12.5% GeV^1/2 over the full pseudorapidity range. Position and angular resolutions are found to be in agreement with simulation. A global constant term of 0.6% is obtained in the pseudorapidity range 2.5 eta 3.2 (inner wheel)

Construction, assembly and tests of the ATLAS electromagnetic barrel calorimeter

The construction and assembly of the two half barrels of the ATLAS central electromagnetic calorimeter and their insertion into the barrel cryostat are described. The results of the qualification tests of the calorimeter before installation in the LHC ATLAS pit are given

Production of Xi_c^0 and Xi_b in Z decays and lifetime measurement of Xi_b

The charmed strange baryon Xi_c^0 was searched for in the decay channel Xi_c^0 -> Xi- pi+, and the beauty strange baryon Xi_b in the inclusive channel Xi_b -> Xi- l- anti-nu X, using the 3.5 million hadronic Z events collected by the DELPHI experiment in the years 1992--1995. The Xi- was reconstructed through the decay Xi- -> Lambda pi-, using a constrained fit method for cascade decays. An iterative discriminant analysis was used for the Xi_c^0 and Xi_b selection. The production rates were measured to be f_{Xi_c^0} x BR(Xi_c^0 -> Xi- pi+)= (4.7 +/- 1.4 (stat.) +/- 1.1 (syst.))10^{-4} per hadronic Z decay, and BR(b -> Xi_b) x BR(Xi_b -> Xi- l- X)= (3.0 +/- 1.0 (stat.) +/- 0.3 (syst.))10^{-4} for each lepton species (electron or muon). The lifetime of the Xi_b baryon was measured to be tau_{Xi_b} = 1.45{^{+0.55}_{-0.43}} (stat.) +/- 0.13 (syst.) ps. A combination with the previous DELPHI lifetime measurement gives tau_{Xi_b} = 1.48{^{+0.40}_{-0.31}} (stat.) +/- 0.12 (syst.) ps.Comment: 21 pages, 9 figures, Accepted by Eur. Phys. J.

A micro-CT study of the greater palatine foramen in human skulls

The greater palatine foramen (GPF) is an important anatomical landmark and has substantial clinical relevance in dental surgery. Knowledge of its precise location and dimensions is required for proper planning of surgical procedures involving the posterior maxilla. We used microfocus computed tomography to determine the location and dimensions of the GPF, and any sex and race variations in those measurements, in 77 human skulls scanned at the South African Nuclear Energy Corporation. Specialized software was used for three-dimensional rendering, segmentation, and visualization of the reconstructed volume data. GPF location ranged from adjacent to the first molar to distal of the third molar. The most common GPF location was near the third molar (66.7% of skulls), and the GPF was as close as 6.31 mm (mean distance 12.75 ± 3 mm). The mean GPF dimensions were 5.22 mm on the anteriorposterior axis and 2.81 mm on the lateral-medial axis. We noted no significant differences in relation to race, sex, or age in the sample. The GPF was adjacent or posterior to the third maxillary molar in most skulls.https://www.jstage.jst.go.jp/browse/josnusdam2019AnatomyPeriodontics and Oral Medicin

A geometric morphometric approach to the study of variation of shovel‐shaped incisors

OBJECTIVES : The scoring and analysis of dental nonmetric traits are predominantly accomplished by using the Arizona State University Dental Anthropology System (ASUDAS), a standard protocol based on strict definitions and three‐dimensional dental plaques. However, visual scoring, even when controlled by strict definitions of features, visual reference, and the experience of the observer, includes an unavoidable part of subjectivity. In this methodological contribution, we propose a new quantitative geometric morphometric approach to quickly and efficiently assess the variation of shoveling in modern human maxillary central incisors (UI1). MATERIALS AND METHODS : We analyzed 87 modern human UI1s by means of virtual imaging and the ASU‐UI1 dental plaque grades using geometric morphometrics by placing semilandmarks on the labial crown aspect. The modern human sample was composed of individuals from Europe, Africa, and Asia and included representatives of all seven grades defined by the ASUDAS method. RESULTS : Our results highlighted some limitations in the use of the current UI1 ASUDAS plaque, indicating that it did not necessarily represent an objective gradient of expression of a nonmetric tooth feature. Rating of shoveling tended to be more prone to intra‐ and interobserver bias for the highest grades. In addition, our analyses suggest that the observers were strongly influenced by the depth of the lingual crown aspect when assessing the shoveling. DISCUSSION : In this context, our results provide a reliable and reproducible framework reinforced by statistical results supporting the fact that open scale numerical measurements can complement the ASUDAS method.Supplementary material: Table S1 Supporting Information Table 1. Visual scoring performed by two independent observers (intra‐ and interobserver tests). SSc: Statistical Scoring; VS1T1: Visual scoring Observer 1 Test 1; VS1T2: Visual scoring Observer 1 Test 2; VS2: Visual scoring Observer 2. In some cases, the observers gave an intermediate rating (0_1 meaning a category between ASUDAS references 0 & 1). Table S2: Supporting Information Table 2. Definition of UI1 shoveling grades (Scott et al., 2018; Scott & Irish, 2017; Turner et al., 1991). Table S3: Supporting Information Table 3. Correlations between various measurements obtained from the coordinates of the 7 ASUDAS reference casts. The ASUDAS category values were also compared against these metrics. Table S4: Supporting Information Table 4. Correlations between various measurements obtained from the coordinates of all French samples (both contemporary and medieval). Maximum depth and hollow area are the directly measured metrics based on the non‐Procrustes alignment method. Principal components were obtained from both Procrustes and non‐Procrustes methods. Only PC1 is presented here for simplicity. Shades of color represent the degree of correlation, with darker green corresponding to the highest degrees and white to the lowest degree. Table S5: Supporting Information Table 5. Correlations of rater‐assigned ASUDAS categories with various measurements obtained from the coordinates of all French samples. Figure S1 Supporting Information Figure 1. Principal Component loadings represented as PC shape changes. Results are shown here for non‐Procrustes PCs; the plots for Procrustes PCs are very similar. The axes are same as in Figure 2. The black line, showing the shape for ASUDAS reference cast category 3, indicates the baseline in all figures. The thick colored curve in each figure represents a + 1 unit shift toward the direction of the PC from the baseline. Thin dotted lines join the coordinate of each of the 100 points before and after the shift, thus representing the amount and direction of shift for each point.Toulouse Dental Faculty (PLTRO); Midi‐ Pyrenées Region; Université Toulouse III–Paul Sabatier; CHU de Toulouse; Université de Toulouse; French CNRS; Arizona State Universityhttps://wileyonlinelibrary.com/journal/ajpahj2020Anatom