Horse Teeth Research Articles

Characterisation of equine odontoclastic tooth resorption and hypercementosis: A comparative study using microCT and radiography in age-matched controls.

Equine odontoclastic tooth resorption and hypercementosis (EOTRH) is a painful disorder primarily affecting the incisor teeth of horses over 15 years of age. Clinical signs of the disease include prehension problems, halitosis and in severe cases weight loss. The disease predominately affects the reserve crown and presents as a loss of dental tissue and excessive build-up of cementum. To determine the radiographic scores of horses with EOTRH and age-matched controls and to increase understanding of EOTRH using microCT to compare teeth from horses with EOTRH and age-matched controls. In vivo and ex vivo studies. This study used radiography (in vivo) and microcomputed tomography (microCT) (ex vivo) to help understand and help characterise the imaging changes that occur in EOTRH. For radiography, 87 patients were assessed using a radiographic scoring system for EOTRH. The microCT study was undertaken on 20 extracted cadaver incisor teeth which were scanned and segmented to measure the different dental tissues. These were assessed using a descriptive analysis (surface roughening, tooth resorption, root blunting and pulp cavity). Radiographic scoring demonstrated that 03s were more severely affected than 01s in EOTRH. Total radiographic score and age had a weak positive correlation. Following microCT, we identified that EOTRH teeth had a lower pulp and enamel volume and therefore significantly higher pulp and enamel ratios relative to the whole tooth volume, compared with control teeth. Cementum and dentine volumes were more variable in EOTRH teeth. Thus, their ratios relative to the whole tooth volume were not different to control teeth. The number of horses was relatively small. Results suggest differing degrees of tooth resorption and hypercementosis, in different affected teeth potentially indicating multiple phenotypes of the disease. We provide further evidence of the presence of subclinical EOTRH imaging changes in some teeth.

Oscar Fraas – Pionier der urgeschichtlichen Forschung Zentral-europas und neue Erkenntnisse zu den Funden der Ausgrabung 1870/71 im Hohle Fels bei Schelklingen

Oscar Fraas was one of the first natural scientists to establish the existence of Ice Age humans. From November 1854 until 1894, he held various positions in the Royal Natural History Cabinet in Stuttgart. As early as the 1860s, he conducted a series of experiments to explain and understand how traces and scratches on Ice Age bone fragments were made. His work is among the first attempts in the world to use Stone Age tools. These were often spontaneous field experiments whose results he did not verify or whose variables are no longer evident today. At the time, however, Fraas’ work was far ahead of most of his colleagues. Overall, Fraas described several attempts to fragment bones and dissect animals using bear mandibles. The following article provides an overview of the experiments carried out by Fraas. In addition, we will present for the first time the perforated horse teeth and bone retouchers from the first archaeological excavation in Hohle Fels in 1870/71 directed by Fraas, which are curated in the collection of the State Museum of Natural History Stuttgart. A new radiocarbon date establishes that Fraas reached at least as deep as the Gravettian layers during his excavation at Hohle Fels.

Horse Teeth Shed Light on Seasonality in Scythian Mound Burials in Southern Russia

ABSTRACT The Scythian archaeological culture is a component of the Scythian-Siberian community of equestrian nomadic pastoralists located in the northern Black Sea region and Ciscaucasia. This paper explores whether the Scythians were present in the central Pre-Caucasus all year round or only during a part of the year and were migrating seasonally. Since Scythian settlements are not known in this region, a possible clue may come from determining the season of the year in which the Scythians buried their deceased tribesmen and performed memorial events. In this paper, we determine the seasonality of the burials and memorial events at the mound burial ground Novozavedennoye-III (southern Russia), dated to 430–300 b.c., by applying cementum increment analysis to horse teeth. This analysis has shown that the studied horses died during May–October. This result indicates that the Scythians were present in the central Pre-Caucasus foothills during some part of the warm season.

Genetic and Molecular Characterization of Maize Landraces from Central China

Maize productivity in the central belt plays a significant role in the food security of China. With good adaptability and disease resistance, landrace germplasm is important for maize improvement. A total of 246 landrace accessions were collected from the maize belts in central China and genotyped with the SLAF-seq (Specific-Locus Amplified Fragment Sequencing) method, and 144,650 SNPs were obtained for each accession. The results showed that the landrace accessions could be divided into three major groups. In the cluster results, Group I included 64 accessions, which mainly belonged to the landrace of White horse teeth; Group II had 71 accessions, which mainly belonged to the lantern red landraces; the rest of the 116 accessions were clustered as Group III, including a variety of types landraces and seven indicator inbred lines. In the results of structure and multidimensional scaling, the accessions’ attribution differed with the clusters, the main reason for which is the attribution change in intermediate germplasms. Linkage disequilibrium decay distance was 0.98 kb, which was much lower than that of temperate and tropical maize inbred lines, indicated the much higher genetic diversity of landrace germplasms. The results can help us select suitable landrace germplasms and speed up the process of inbred line development and maize improvement.

Ecology of large ungulates in the northeastern Iberian Peninsula during the Upper Palaeolithic through stable isotopes and tooth wear analysis

The northeastern Iberian Peninsula acted as a refuge zone during the Late Pleistocene where the persistence of terrestrial ecosystems could provide hunter-gatherers with large prey, mainly horse (Equus ferus) and red deer (Cervus elaphus). Isotopic (δ13C, δ18O, δ15N) and dental wear (mesowear and microwear) analyses have been applied on the remains of both species from the archaeological sites of Arbreda and Bora Gran at Serinyà (Girona), where evidence of human occupation from the Mousterian to the Magdalenian has been attested. The incremental enamel analysis on horse teeth revealed seasonal variation in carbonate δ18O but no detectable change in carbonate δ13C values, reflecting a rather stable diet and habitat over the year. Nevertheless, higher inter-individual than intra-individual contrast in carbonate δ13C indicate different environmental conditions from one individual to another for each stratigraphic unit. In red deer teeth, seasonal signals in enamel carbonate δ13C and δ18O demonstrated mirrored trends. Further, red deer show higher δ13C values than those of horses, both in enamel carbonate and bone collagen, as well as higher variability in mesowear and microwear scores, reflecting a mixed-feeding habit. Despite a strong grazing signal in mesowear and microwear, the lower δ13C values for horses suggest a higher dependence on relatively more humid habitats than red deer, which likely foraged in dryer environments with xeric plants during winter. These differences in ecological partitioning are particularly well illustrated in distinct collagen δ13C and δ15N values during the harsh climatic conditions of the Final Gravettian coeval to the GS-3 or Last Glacial Maximum. The capacity of red deer to adapt to fluctuating environmental conditions contrasts with the niche persistence of horse allowed by the availability of mosaic habitat.

Using horse teeth to shape stone tools: an experimental approach to characterise use-wear traces

Horse tooth retouchers have been identified in several Middle and Upper Palaeolithic sites. They have been typically characterised as ‘soft’ hammers and/or grouped into the category of ‘bone retouchers’ at a technical level. Bone and teeth have different chemical compositions; teeth are denser and heavier than bone, and consequently, their technological features should not be considered homologous. In this work, we experimentally tested the effectiveness of horse teeth as retouchers. To perform this study, we used 41 modern horse teeth to shape flakes of various raw materials by applying different techniques. The resulting use-wear traces were analysed using high-resolution methods and then characterised. The results allowed us to identify the effectiveness of hypsodont teeth in knapping a wide range of tools and to evaluate the influence of 1) the raw materials, 2) the retouching techniques and 3) the gestures of the different knappers on the morphology of the use-wear marks. This work sheds light on the purpose of using teeth as tools by both Neanderthal and early modern human populations as well as understanding how these human species used them. The study leads us to consider tooth retouchers as important elements of the chaîne opératoire in lithic manufacture. Our goal is to highlight the importance of these types of experimental studies to create analogies and infer past processes.

基于离散元法的包衣玉米种子堆积过程颗粒运动研究

The rolling friction coefficient was a fundamental parameter for particle modeling, but it was challenging to quantify for unevenly shaped corn seeds. If the rolling friction coefficients of corn with different guiding seeds and different shapes were not believed to be significantly different, direct simulation in EDEM would produce simulation distortion. This paper began by selecting three models with a relatively high proportion from five corn samples with various shapes (such as horse-tooth shape, spherical shape, oblate shape, and irregular shape, etc.) and modeling them according to the actual seeds. Due to the large disparity between seed models with different shapes, the study adopted the method of combining physical experiment and discrete element simulation, took the rolling friction coefficient as the independent variable and the angle of repose in the simulation test as the target value, and calibrated the rolling friction of various shapes of corn seed particles separately. Coated corn seeds' rolling friction coefficients were accurately predicted (0.0047 for horse tooth, 0.0058 for pyramid, and 0.049 for spherical shape). During the validation test, the calibrated simulation parameters were entered into EDEM for simulation, and the distribution of seeds on the seed platter was compared between the actual test and the simulation test. The results demonstrated that the difference in the sizes of key features was less than 5.60 percent, and the population boundary in the seed platter after calibration was closer to the actual situation, which improved the accuracy of the simulation.

Seasonal climate variations during Marine Isotope Stages 3 and 2 inferred from high‐resolution oxygen isotope ratios in horse tooth enamel from Lower Austria

ABSTRACTWe present sequential oxygen isotope records (δ18Ophosphate vs. VSMOW) of horse tooth enamel phosphate of six individuals from two adjacent Palaeolithic sites in Lower Austria. Three molars from the site Krems‐Wachtberg date to 33–31k cal a bp, and three molars from Kammern‐Grubgraben to 24–20k cal a bp. All teeth show seasonal isotope variations, which are used to reconstruct the annual oxygen isotope composition of drinking water (δ18Odw) and palaeotemperatures. Measured δ18Ophosphate values ranged from 8.6 to 13.0‰ and from 10.8 to 13.9‰ at Krems‐Wachtberg and Kammern‐Grubgraben, respectively. An inverse modelling approach was used to reconstruct summer and winter temperatures after a correction for glacial oceanic source water δ18O. Reconstructed annual δ18Odw was −16.4 ± 1.5‰ at Krems‐Wachtberg and −15.3 ± 1.4‰ at Kammern‐Grubgraben, resulting in annual temperatures of −5.7 ± 3.1 and −3.5 ± 2.9°C, respectively. Summer and winter temperatures reconstructed from individual teeth exhibit high seasonal variations with moderate summer temperatures and extremely low winter temperatures typical for a polar tundra climate. Isotopic differences between individuals are attributed to interannual climate variability or to different drinking water sources. Our reconstructed temperatures are, overall, consistent with previously reported values from European horse teeth, when taking regional differences into account.

ESR/U-series dating of palaeontological remains from the Neanderthal site of Mutzig-Rain (Alsace, France)

The Middle Paleolithic site of Mutzig-Rain, discovered in 1992, has been studied through several pits (called M1 to M15) and excavation area since 2009, evidencing several localities and delivering more than 5000 lithic artifacts and 12,000 well preserved paleontological remains. The main excavation M2 sequence corresponds to a collapsed rock shelter, containing several levels of Middle Paleolithic occupation. The faunal assemblage of the main archaeological levels (l.7a to 7c) from this sequence includes woolly mammoth, reindeer, horse, bison and woolly rhinoceros, reflecting both cold climate and a steppe context for the whole sequence, while microfauna from the lower levels (l.7d and l.10) indicate the occasional presence of forests that could correspond to a cooler climate. In 1995, U-series analyses on bones from M8 were attempted but the obtained results did not follow the sample stratigraphic order. Later, an OSL dating study has placed the M2 archaeological sequence as coeval to the onset of the Weichselian glacial stage (MIS5d-5a), between 100 and 80 ka.The good preservation of the abundant faunal remains at Mutzig-Rain has allowed their use for ESR/U-series dating studies and the results obtained on Mutzig horse teeth are given in the present paper. A first set of analyses of teeth carried out from the M2 excavation provided ages around 106-96 ka for levels M2 l.7, in agreement with the OSL data, despite quite systematic evidence of U-leaching from the dental tissues and the consequent use of the Accelerating Uptake (AU) model for the age calculation. A second set of analyses on teeth from the M2 and M8 localities confirms this uranium leaching trend, placing the deposition of these levels ca 133 -122 ka.Taking the whole set of ESR/U-series ages, which are slightly older than the OSL dates, would suggest that the stratigraphic sequence was deposited between ca 130 ka (M8 l. 6 and M2 l.10) and ca 100 ka (M2 l.7), i.e. on a time range covering the Eemian Interglacial (MIS5e) and the subsequent Early Weichselian Glacial stage (MIS5d-5a). However, as the faunal record indicates a cool climate and an open steppe-like environment for the whole archaeological sequence, the ESR/U-series dating to the Eemian Interglacial in the Mutzig-Rain sequence seems unlikely. In order to check the quality of the paleodosimetric reconstruction of the ESR/U-series analyses, an additional isochron study was performed for the two levels for which several teeth were analyzed: M2 l.7 (n = 4) and M8 l.6 (n = 3). This isochron study validates the proposed reconstruction and confirms the Early Weichselian age of these two levels. These results confirm the chronology established previously with OSL and places Mutzig-Rain as a reference site for the understanding of the Neanderthal Middle Palaeolithic occupation in Eastern France.

Performance Optimization of a Spoon Precision Seed Metering Device Based on a Maize Seed Assembly Model and Discrete Element Method

To improve the sowing performance of the spoon wheel maize seeding machinery, in this paper, two varieties of maize seed are selected as examples. The maize spoon precision seed metering device, a core component of the spoon wheel seeding machinery, is used as the research object. The maize seed assembly model is first established based on the maize seed assembly modeling method. Its validity is verified by the sowing experiment and corresponding DEM simulation under the different revolving speeds of the seed metering wheel. Secondly, the performance of the spoon precision seed metering device is optimized by integrating the maize seed assembly model and multivariate nonlinear regression method. Therefore, the number of sub-spheres of the horse tooth, spherical cone, and spheroid maize seed model are 10–14, 18, and 6, respectively. The results show that the performance of the seed metering device improved when the revolving speed of the seed metering wheel, handing angle, and seed spoon radius are 25 r/min, 40°, and 7 mm, respectively. There is good agreement between the expected results and experimental ones with relative errors of less than 5%, and the optimized seed metering device facilitates the process of seed guiding and seed delivery during the sowing process.

New Materials on the Morphology of the Teeth of the Three-Toed Horse (Hipparion houfenense) from the Pliocene of Western Transbaikalia (Russia).

This article is devoted to the morphological features of the teeth of the three-toed horse (Hipparion houfenense) from the Early Pliocene of Western Transbaikalia (Russia). It contains a number of diagnostic features that are unique to this taxon and distinguish it from other Hipparion species, which allows us to speak about their true diversity at the final stage of their existence in the northeast of Inner Asia.

NEW MATERIALS ON THE MORPHOLOGY OF THE TEETH OF THE THREE-TOED HORSE (<i>HIPPARION HOUFENENSE</i>) FROM THE PLIOCENE OF WESTERN TRANSBAIKALIA (RUSSIA)

This article is devoted to the morphological features of the teeth of the three-toed horse (Hipparion houfenense) from the Early Pliocene of Western Transbaikalia (Russia). It contains a number of diagnostic features that are unique to this taxon and distinguish it from other hipparion species, which allows us to speak about their true diversity at the final stage of their existence in the northeast of Inner Asia.

FRP bar-reinforced ultra-high-performance concrete plates with a grouting sleeve connection: Development and flexural behavior

Fiber reinforced polymer (FRP) bars have been proposed for use in ultra-high performance concrete (UHPC) as the reinforcement to mitigate/avoid the post-peak strain softening of UHPC under tension and to reduce the fiber dosage used in UHPC. The so-formed FRP-reinforced UHPC plates could be adopted for both structural strengthening and constructing novel structural elements. In this paper, a novel connection based on FRP bars and steel grouting sleeves has been developed for prefabrication construction of FRP bar-reinforced UHPC structures. Flexural tests were conducted to gain understandings of the effects of the connection mode (the staggered connection and the horse tooth connection) and reinforcing fiber type (polyethylene (PE) fibers and steel fibers) in the UHPC on the flexural behavior of connected FRP bar-reinforced-UHPC composite plates. The test results revealed that the proposed connection system is reliable since the composite plates always failed outside the connection zone, and most of the crack opening displacements at the interface of the connection are smaller than 0.2 mm at ultimate. The connection mode and the fiber type had little influence on the first cracking load and the initial bending stiffness of the FRP bar-reinforced UHPC plates, while the horse tooth connection led to a better ductility of the composites plates than the staggered connection mode. At given tolerable deflection of 1/200 span (about 5 mm), the longitudinal strains developed in the CFRP bars were about 2000 με for all specimens.

Isolation and cultivation as well as in situ identification of MSCs from equine dental pulp and periodontal ligament.

The lifelong eruption places a great demand on the dental pulp and periodontal ligament (PDL) of horse teeth. Cells within the pulp and PDL seem to play a key role during this remodeling. In this study, we isolated and cultivated MSCs (medicinal signaling cells) from dental pulp, PDL and retrobulbar fat of four horses. Subsequently, we analyzed them by flow cytometry and immunohistochemistry to determine and compare their characteristics. In addition, we localized these cells within the tissue structure via immunohistochemistry of histological sections. For these analyses, several surface markers were applied. The described method illustrates a feasible approach to isolate and cultivate MSCs from equine dental pulp and PDL. In the flow cytometry a vast majority of cultivated cells were positive for CD90 and CD40 and negative for CD11a/18, CD45, CD105 and MHCII suggesting that these cells feature characteristics of MSCs. Immunohistochemistry of histological pulp and PDL sections showed the localization of CD90 positive cells especially in the perivascular region and the subodontoblastic layer. Our findings indicate that the isolation and cultivation of MSCs from equine dental pulp and PDL is feasible although an elaborate and complicated harvesting protocol is required. MSCs isolated from dental pulp and PDL are regarded as candidates for new therapeutical approaches in equine dental medicine like regeneration of periodontal lesions, enhancement of periodontal re-attachment after dental replantation and stimulation of pulp-obliteration and apexification in combination with endodontic therapies.

Micro computed tomography and histological examination of a pathological lesion (healed fracture) in a horse tooth from the medieval site of Crkveno Brdo, Serbia

AbstractThis paper aims to provide insight into the etiology and differential diagnosis of a rare severe pathological lesion in an isolated equine tooth from the medieval site of Crkveno Brdo. The site is located in the southern part of the Carpathian Basin, that is, in the northern part of present‐day Serbia near Senta, some 9 km south‐west of the town center in the vicinity of the village of Gornji Breg. The specimen presented in this study comes from the cultural layer dated to the period between the 14th and the 15th centuries. A healed oblique fracture was present in the right upper second premolar (106) of a horse (Equus caballus) 7–10 years of age. The specimen was subjected to an interdisciplinary approach, including identification of species and tooth type, and assessment of age at death, employing microcomputed tomography (microCT), and histopathology to differentially diagnose the pathological condition. The obtained results were additionally compared with findings in an apparently similar modern case of known etiology.

NEW DATA ON DENTAL MORPHOLOGY OF <i>HIPPARION TCHICOICUM</i> IVANJEV, 1966 FROM WESTERN TRANSBAIKALIA (RUSSIA)

The message is devoted to the morphological features of the teeth of a three-toed horse (Hipparion tchicoicum) from the Pliocene of Western Transbaikalia (Russia). For the first time, it presents a number of diagnostic signs of the Chicoi hipparion, which are criteria for determining this taxon among other fossils of three-toed horses and their real diversity at the final stage of distribution in Inner Asia.

Microscopic examination of the horse teeth and their surrounding tissues. Part II: Histology of the cheek teeth

Microscopic examination of the horse teeth and their surrounding tissues. Part II: Histology of the cheek teeth

Analysis of the metering performance for typical shape maize seeds using DEM

The irregular shape, varying internal compositions, and uneven distributions of maize seeds can degrade the metering performance of maize seeders. This study investigates the effect of irregular maize on the performance of a high-filling-rate seed metering device using DEM. The results show that the seed population in the seed box formed large and small cycles of seed transport due to the disturbances caused by the three wheels. The increasing angular speed of the three wheels reduced the rate of seed filling in the seed filling regions by gravity and disturbances. In addition, an analysis of the repose angle formed by the dropped seed indicated that the angular speed of the taking seed wheel has a certain effect. The large angular speed reduced the coefficient of variation of the seed drop location. The repose angle of the horse tooth seed was greater than those of the other. Meanwhile, the irregular maize seed can also reduce the coefficient of variation of the seed drop location. A comparison between the simulation and experiment results indicates the number of metering seed were basically the same. Keywords: maize seeds, seed metering performance, DEM, verification DOI: 10.25165/j.ijabe.20231601.6813 Citation: Shi L R, Zhao W Y, Sun W, Yang X P, Wang G P, Xin S L. Analysis of the metering performance for typical shape maize seeds using DEM. Int J Agric & Biol Eng, 2023; 16(1): 26–35.

Microscopic examination of horse teeth and their surrounding tissues – Part I: Overview and histology of the incisors

Microscopic examination of horse teeth and their surrounding tissues – Part I: Overview and histology of the incisors

Clinical, Diagnostic and Histological Findings Involving Cheek Teeth Hypercementosis in Nine Horses.

Hypercementosis is infrequently reported to affect the cheek teeth of horses and presents as mineral deposits either attached (peripheral) or solitary ovoid (nodular) structures in the tooth bearing region. There is overlap between radiological and histological appearance of hypercementosis, cementoma, and equine odontoclastic tooth resorption and hypercementosis (EOTRH). The clinical presentation, imaging features, surgical management, and histological findings of nine horses that presented for dental lesions and associated hypercementosis of cheek teeth are reported. Horses were 4-15 years old and presented for either nasal discharge or facial swelling. Peripheral and nodular mineral structures were identified using radiographs or computed tomography in six and three horses, respectively. Eight of nine cases involved maxillary cheek teeth. Of six cases with peripheral hypercementosis, three had enlargement of the apical cross-sectional area that was greater than the coronal cross-sectional area thus preventing extraction along the normal eruption pathway and necessitating sectioning (two cases) and repulsion. Nodular hypercementosis lesions were extracted in three of the four cases. Post-extraction complications occurred in five cases; four cases required additional procedures. All horses returned to their intended use, ie riding or pasture. Histology of extracted dental and proliferative mineral material revealed hypercementosis characterized by large sheets of eosinophilic matrix with lacunae (usually empty; presumed artifact) and frequent, irregular, basophilic cement lines. All cases had evidence of chronic inflammation, such as caries, chronic fractures and/or pulpitis. The findings of this case series share many features with previous published descriptions of cementoma and with histological findings of hypercementosis lesions of EOTRH. Further investigation into differentiation of these entities is warranted.