Radiographic evaluation of teeth with pulp stones and pulp canal obliteration: characteristics, and associations with dental parameters.

The study aimed to radiographically assess the characteristics of pulp stones (PS) and pulp canal obliteration (PCO) in teeth and examined their associations with various dental parameters such as caries, restorations, periodontal status, and age. This cross-sectional observational study was conducted at the Faculty of Dentistry, King Abdulaziz University between September 2022, and May 2023, involved 101 patients exhibiting 402 teeth with PS or PCO. Data were collected from periapical and bitewing radiographs, and analyzed by two calibrated dentists. Multiple dental parameters were assessed, including caries level, presence and level of restorations, periodontal condition, and age of the patient. The study population consisted of 62 females and 39 males, with an age range of 18-65 years. Inter- and intra-examiner reliability were high (Kappa = 0.88 and 0.98 respectively). PS were more commonly found in molars (81.2%), while PCO were presented in only 115 teeth (23%). Age significantly affected the type of calcification (p < 0.001), with PS more common in the 20-30 age group and PCO more common in individuals over 40. Presence of caries was significantly associated with the type of calcification (p = 0.013), but restoration was not. The majority of teeth with PS (76%) or PCO (93%) had healthy periodontium. Around 40% of teeth with PCO showed signs of periapical changes, a finding significantly different from those with PS (p < 0.001). Pulp calcifications were significantly associated with various dental parameters, including caries presence, age, and periodontal status. The findings provide crucial insights into the epidemiology and aetiology of pulp calcifications.

Glycation promotes pulp calcification in Type 2 diabetes rat model.

OBJECTIVES: Intrapulpal calcifications can occur in the dental pulp of patients with diabetes. We focused on the association between ectopic calcifications in the dental pulp and advanced glycation end products (AGEs) in Spontaneously Diabetic Torii (SDT)-fatty rats, an obese type 2 diabetic rat model, to determine the mechanism of calcification with pulp stone in the dental pulp. MATERIALS AND METHODS: Pathologic calcification in the dental pulp of SDT-fatty rats was observed using electron microscopy and immunohistochemical analysis. Moreover, mechanical analysis of periapical region of molar tooth against occlusal force was performed. RESULTS: In SDT-fatty rats, pathogenic pulpal calcifications occurred during blood glucose elevation after 6 weeks, and granular calcification was observed in the dental pulp after 11 weeks. Pentosidine, a major AGE, and the receptor for AGEs were strongly expressed in the dental pulp of SDT-fatty rats. S100A8, TNF-α, and IL-6 also showed positive response in the dental pulp of the SDT-fatty rat, which indicated pulpal inflammation. Blood flow disorder and hypoxic dental pulp cells were also observed. In silico simulation, strain from occlusal force concentrates on the root apex. CONCLUSIONS: Glycation makes blood vessels fragile, and occlusal forces damage the vessels mechanically. These are factors for intrapulpal calcification of diabetes.

Morphology of pulpal mineralizations: A scoping review.

OBJECTIVE: The aim of this scoping review was to summarize and discuss the morphological features and associated factors of pulpal mineralizations (PMs) as described within the literature. DATA: The study protocol was registered on the Open Science Framework platform and is available at the following link: https://osf.io/hfqwe. This scoping review was developed according to the PRISMA-ScR guidelines. SOURCES: A literature search of four electronic databases was performed in SCOPUS, MEDLINE (PubMed), EMBASE and Word of Science, with the last search on May 29, 2023. Study selection was completed by two reviewers independently. Data was extracted regarding study characteristics, types, and features of PM and associated factors. STUDY SELECTION: Of 1016 studies initially identified ten which qualified were included in this scoping review. Systemic and local factors that result in pulpal insult can contribute to the development of PMs. Three forms of PM have been reported, pulp stones, diffuse mineralizations, and mineralized ectopic connective tissue, with discrete and diffuse mineralization being the two clinically relevant forms. The different forms of PMs exhibit dissimilar morphological features. CONCLUSION: Pulpal mineralizations exist in two clinically relevant forms: diffuse and discrete mineralizations and are likely associated with a pulpal insult. CLINICAL SIGNIFICANCE: Understanding the morphology of dental pulp mineralization is the first step to expanding the knowledge of pulp mineralization and could result in improved diagnosis of endodontic pathosis.

Early diagnosis of aortic calcification through dental X-ray examination for dental pulp stones.

Vascular calcification, an ectopic calcification exacerbated by aging and renal dysfunction, is closely associated with cardiovascular disease. However, early detection indicators are limited. This study focused on dental pulp stones, ectopic calcifications found in oral tissues that are easily identifiable on dental radiographs. Our investigation explored the frequency and timing of these calcifications in different locations and their relationship to aortic calcification. In cadavers, we examined the association between the frequency of dental pulp stones and aortic calcification, revealing a significant association. Notably, dental pulp stones appeared prior to aortic calcification. Using a rat model of hyperphosphatemia, we confirmed that dental pulp stones formed earlier than calcification in the aortic arch. Interestingly, there were very few instances of aortic calcification without dental pulp stones. Additionally, we conducted cell culture experiments with vascular smooth muscle cells (SMCs) and dental pulp cells (DPCs) to explore the regulatory mechanism underlying high phosphate-mediated calcification. We found that DPCs produced calcification deposits more rapidly and exhibited a stronger augmentation of osteoblast differentiation markers compared with SMCs. In conclusion, the observation of dental pulp stones through X-ray examination during dental checkups could be a valuable method for early diagnosis of aortic calcification risk.

Looking for future biological control agents: the comparative function of the deutosternal groove in mesostigmatid mites.

The physics of fluid laminar flow through an idealised deutosternum assembly is used for the first time to review predatory feeding designs over 72 different-sized example species from 16 mesostigmatid families in order to inform the finding of new biological control agents. Gnathosomal data are digitised from published sources. Relevant gnathosomal macro- and micro-features are compared and contrasted in detail which may subtly impact the control of channel- or 'pipe'-based transport of prey liquids around various gnathosomal locations. Relative deutosternal groove width on the mesostigmatid subcapitulum is important but appears unrelated to the closing velocity ratio of the moveable digit. Big mites are adapted for handling large and watery prey. The repeated regular distance between deutosternal transverse ridges ('Querleisten') supports the idea of them enabling a regular fluctuating bulging or pulsing droplet-based fluid wave 'sticking' and 'slipping' along the groove. Phytoseiids are an outlier functional group with a low deutosternal pipe flow per body size designed for slot-like microchannel transport in low volume fluid threads arising from daintily nibbling nearby prey klinorhynchidly. Deutosternal groove denticles are orientated topographically in order to synergise flow and possible mixing of coxal gland-derived droplets and circumcapitular reservoir fluids across the venter of the gnathosomal base back via the hypostome to the prey being masticated by the chelicerae. As well as working with the tritosternum to mechanically clean the deutosternum, denticles may suppress fluid drag. Shallow grooves may support edge-crawling viscous flow. Lateral features may facilitate handling unusual amounts of fluid arising from opportunistic feeding on atypical prey. Various conjectures for confirmatory follow-up are highlighted. Suggestions as to how to triage non-uropodoid species as candidate plant pest control agents are included.

The prevalence of pulp stones in a Turkish paediatric cohort from the Isparta district: an 8-year retrospective radiographic study.

PURPOSE: To evaluate the prevalence of pulp stones in a Turkish paediatric cohort from the Isparta district using panoramic radiographs. METHODS: Panoramic radiographs of 19,857 children and adolescents between the ages of 9 and 18 years were retrospectively analysed to determine the prevalence and distribution of pulp stones. Teeth with pulp stones were classified in terms of dentition, location, dental status and complete or incomplete root formation. Statistical analysis was carried out by applying Chi­square and Mann-Whitney U. Univariate logistic regression analysis was applied to determine the factors affecting pulp stone status. Differences were considered as significant when p < 0.05. RESULTS: Out of a total of 19,857 patients, pulp stones were identified in 6.5%. Among the 548,415 teeth examined, 0.96% had pulp stones. The incidence of pulp stones in girls (7.4%) was higher than in boys (5.7%) (p < 0.001). The prevalence of pulp stones increased with age and was significantly higher in molar teeth. A significant difference existed in the incidence of pulp stones according to the jaws (p < 0.001). In both jaws, no statistically significant difference was observed in terms of teeth with pulp stones being on the right and left (p = 0.834). Of molars with pulp stones, 91.8% had completed root formation. The majority of patients (37.7%) had pulp stones in four teeth. CONCLUSION: Knowing the incidence of pulp stones in paediatric patients by dentists, endodontists, and paediatric dentists will help prevent complications that may occur during applications by facilitating the determination of appropriate methods, especially during endodontic procedures.

Three-dimensional analysis for detection of pulp stones in a Saudi population using cone beam computed tomography.

PURPOSE: To assess the prevalence and distribution of pulp stones in a Saudi population. METHODS: A cone beam computed tomography (CBCT) analysis of 150 upper and 150 lower dental arches was performed. The relationships between pulp stones and age, sex, tooth type, dental arch, orthodontic treatment, caries, and restoration were statistically examined (P < 0.05). RESULTS: A total of 295 dental arches (98.3%) had at least one pulp stone, and the prevalence was higher in the maxillary teeth (56.2%) than in the mandibular teeth (48.1%) (P = 0.0003). Men were more likely to have pulp stones than women (P = 0.011 for the maxilla, P < 0.0001 for the mandible). Furthermore, age and orthodontic treatment had no significant effects on the incidence of pulp stones (P > 0.05). A higher occurrence of pulp stones was observed in the first molars (>91%), and in carious and restored teeth when compared to intact teeth (P < 0.05). CONCLUSION: Pulp stones were more prevalent in the upper dental arches, first molars, and carious and restored teeth, as well as in the male population, and were not associated with age or orthodontic treatment.

Relationships in Shark Skin: Mechanical and Morphological Properties Vary between Sexes and among Species.

Shark skin is a composite of mineralized dermal denticles embedded in an internal collagen fiber network and is sexually dimorphic. Female shark skin is thicker, has greater denticle density and denticle overlap compared to male shark skin, and denticle morphology differs between sexes. The skin behaves with mechanical anisotropy, extending farther when tested along the longitudinal (anteroposterior) axis but increasing in stiffness along the hoop (dorsoventral or circumferential) axis. As a result, shark skin has been hypothesized to function as an exotendon. This study aims to quantify sex differences in the mechanical properties and morphology of shark skin. We tested skin from two immature male and two immature female sharks from three species (bonnethead shark, Sphyrna tiburo; bull shark, Carcharhinus leucas; silky shark, Carcharhinus falciformis) along two orientations (longitudinal and hoop) in uniaxial tension with an Instron E1000 at a 2 mm s-1 strain rate. We found that male shark skin was significantly tougher than female skin, although females had significantly greater skin thickness compared to males. We found skin in the hoop direction was significantly stiffer than the longitudinal direction across sexes and species, while skin in the longitudinal direction was significantly more extensible than in the hoop direction. We found that shark skin mechanical behavior was impacted by sex, species, and direction, and related to morphological features of the skin.

The investigation of WNT6 and WNT10A single nucleotide polymorphisms as potential biomarkers for dental pulp calcification in orthodontic patients.

The aim of this study is to evaluate if single nucleotide polymorphisms (SNPs) in WNT6 and WNT10A are associated with the risk of dental pulp calcification in orthodontic patients. This cross-sectional study followed the "Strengthening the Reporting of Genetic Association Studies" (STREGA) guidelines. Panoramic radiographs (pre- and post-orthodontic treatment) and genomic DNA from 132 orthodontic patients were studied. Dental pulp calcification (pulp stones and/or pulp space narrowing) was recorded in upper and lower first molars. The SNPs in WNT6 and WNT10A (rs7349332, rs3806557, rs10177996, and rs6754599) were assessed through genotyping analysis using DNA extracted from buccal epithelial cells. The association between pulp calcification and SNPs were analyzed using allelic and genotypic distributions and haplotype frequencies (p<0.05). Prevalence of dental pulp calcification was 42.4% in the 490 studied molars. In the genotypic analysis, the SNPs in WNT10A showed a statistically significant value for molar calcification (p = 0.027 for rs1017799), upper molar calcification (p = 0.040 for rs1017799) (recessive model), and molar calcification (p = 0.046 for rs3806557) (recessive model). In the allelic distribution, the allele C of the SNP rs10177996 in WNT10A was associated with molar calcifications (p = 0.042) and with upper first molar calcification (p = 0.035). Nine combinations of haplotypes showed statistically significant value (p<0.05). The findings of this study indicates that SNPs in WNT10A and WNT6 are associated with dental pulp calcification in molars after orthodontic treatment and may be considered as biomarkers for dental pulp calcification.

Effects of Orthodontic Treatment on Pulp Stone Formation: A Retrospective Study.

Objective: This retrospective study was aimed at determining the incidence of dental pulp stone formation during fixed orthodontic treatment. Materials and Methods: A total of 100 patients who received fixed orthodontic treatment were included in this study. Pre- and posttreatment panoramic radiographs of the patients were examined to identify pulp stones. The data were analyzed using McNemar's and Pearson's chi-square tests to investigate the correlations between having a dental pulp stone and gender, age, treatment type, and duration. Results: Dental pulp stones were detected in 17% of patients on pretreatment panoramic radiographs and 35% of patients on posttreatment panoramic radiographs. The incidence of pulp stones sharply increased in the pre- and posttreatment radiographs (38%) (P < 0.001). In addition, there were associations between age, treatment duration, and the incidence of pulp stones (P < 0.05). Nevertheless, no associations were found between treatment type, gender, and the presence of pulp stones. Dental pulp stones were most frequently observed in first molars (62%), followed by second molars (36%). Conclusion: Fixed orthodontic treatment may trigger pulp irritation and calcification, resulting in the formation of pulp stones. Although pulp stones have no serious consequences, an orthodontist must consider the probability of pulp stone formation because it can cause difficulties in endodontic treatment.

Association between the prevalence of pulp stones and calcified atherosclerotic plaques: a systematic review and meta-analysis.

OBJECTIVE: To evaluate the association between the prevalence of pulp stones (PS) in permanent teeth and calcified atherosclerotic plaques (CAP). METHODS: An electronic search was performed in 10 databases to locate observational studies that investigated the association between PS in permanent teeth and CAP, published until March 2022. Two reviewers performed the search, selection and extraction of data from eligible studies. The individual risk of bias of eligible studies was assessed using the JBI Critical Appraisal Tools. The meta-analysis was conducted using fixed and random effects and odds ratio (OR) as an effect measure with a 95% confidence interval (CI). The heterogeneity between the studies was quantified using the I² test. The certainty of evidence was evaluated using the GRADE approach. RESULTS: The electronic search resulted in 2968 records, of which only 7 studies were considered eligible. The total sample consisted of 3770 participants from 5 countries. All studies showed biases of confounding factors and exposure assessment. Based on six studies and with very low certainty of evidence, the meta-analysis showed that patients with PS were more likely to also have CAP in carotid or coronary arteries (OR: 1.70; 95% CI: 1.21; 2.38, I² = 0%). CONCLUSIONS: Limited evidence suggests that there is a positive association between the prevalence of PS in permanent teeth detected using panoramic radiography and CAP in the coronary or carotid arteries.

Dental image enhancement network for early diagnosis of oral dental disease.

Intelligent robotics and expert system applications in dentistry suffer from identification and detection problems due to the non-uniform brightness and low contrast in the captured images. Moreover, during the diagnostic process, exposure of sensitive facial parts to ionizing radiations (e.g., X-Rays) has several disadvantages and provides a limited angle for the view of vision. Capturing high-quality medical images with advanced digital devices is challenging, and processing these images distorts the contrast and visual quality. It curtails the performance of potential intelligent and expert systems and disincentives the early diagnosis of oral and dental diseases. The traditional enhancement methods are designed for specific conditions, and network-based methods rely on large-scale datasets with limited adaptability towards varying conditions. This paper proposed a novel and adaptive dental image enhancement strategy based on a small dataset and proposed a paired branch Denticle-Edification network (Ded-Net). The input dental images are decomposed into reflection and illumination in a multilayer Denticle network (De-Net). The subsequent enhancement operations are performed to remove the hidden degradation of reflection and illumination. The adaptive illumination consistency is maintained through the Edification network (Ed-Net). The network is regularized following the decomposition congruity of the input data and provides user-specific freedom of adaptability towards desired contrast levels. The experimental results demonstrate that the proposed method improves visibility and contrast and preserves the edges and boundaries of the low-contrast input images. It proves that the proposed method is suitable for intelligent and expert system applications for future dental imaging.

Teeth outside the mouth: The evolution and development of shark denticles.

Vertebrate skin appendages are incredibly diverse. This diversity, which includes structures such as scales, feathers, and hair, likely evolved from a shared anatomical placode, suggesting broad conservation of the early development of these organs. Some of the earliest known skin appendages are dentine and enamel-rich tooth-like structures, collectively known as odontodes. These appendages evolved over 450 million years ago. Elasmobranchs (sharks, skates, and rays) have retained these ancient skin appendages in the form of both dermal denticles (scales) and oral teeth. Despite our knowledge of denticle function in adult sharks, our understanding of their development and morphogenesis is less advanced. Even though denticles in sharks appear structurally similar to oral teeth, there has been limited data directly comparing the molecular development of these distinct elements. Here, we chart the development of denticles in the embryonic small-spotted catshark (Scyliorhinus canicula) and characterize the expression of conserved genes known to mediate dental development. We find that shark denticle development shares a vast gene expression signature with developing teeth. However, denticles have restricted regenerative potential, as they lack a sox2+ stem cell niche associated with the maintenance of a dental lamina, an essential requirement for continuous tooth replacement. We compare developing denticles to other skin appendages, including both sensory skin appendages and avian feathers. This reveals that denticles are not only tooth-like in structure, but that they also share an ancient developmental gene set that is likely common to all epidermal appendages.

Endodontia guiada: tecnologia aplicada na resolução de tratamentos de canais calcificados / Guided endodontics: technology applied in the resolution of treatments of calcified canals / Endodoncia guiada: tecnología aplicada en la resolución de tratamientos de conductos calcificados

As calcificações pulpares provocam alterações morfológicas no interior dos canais radiculares que dificultam o tratamento endodôntico. Para solucionar essa dificuldade, a ferramenta Endoguide ou Endodontia Guiada foi desenvolvida para a resolução de casos complexos. Esta pesquisa objetivou descrever as aplicações da ferramenta Endoguide no tratamento de canais calcificados na endodontia. Todas as buscas foram realizadas por um único pesquisador na base de dados PubMed/MEDLINE e busca manual utilizando os descritores "Endodontics", "Digital", "Cone beam", "Guided". Foram considerados elegíveis os artigos publicados entre 2010 e 2022 e excluídos os estudos cuja publicação não foi obtida na íntegra e ainda aqueles em que os resultados não apresentaram embasamento teórico e prático suficientes para que pudessem ser incluídos no trabalho. Após as buscas, foram encontrados 47 artigos, selecionados inicialmente pelo título e resumos, excluindo as duplicatas. Ao final, a leitura completa e coleta de dados foi realizada em 6 artigos. As informações relevantes dos artigos selecionados foram transcritas em forma de quadro para sumarizar os achados. A endodontia guiada pode ser uma excelente alternativa para tratamentos de casos complexos, necessitando um investimento financeiro mínimo no consultório, pois os equipamentos de captura de imagem, planejamento virtual e de guias podem ser realizados em laboratórios capacitados. Assim, concluímos que o emprego da Endoguide como ferramenta no tratamento de canais calcificados se mostrou bem-sucedido e sua utilização não requer um conhecimento amplo, podendo ser usada por profissionais menos experientes.

Pulp calcifications cause morphological changes inside the root canals that make endodontic treatment difficult. To solve this difficulty, the tool Endoguide or Guided Endodontics was developed to solve complex cases. This research aimed to describe the applications of the Endoguide tool in the treatment of calcified root canals in endodontics. All searches were performed by a single researcher in the PubMed/MEDLINE database and manual search using the descriptors "Endodontics", "Digital", "Cone beam", "Guided". Articles published between 2010 and 2022 were considered eligible, and studies whose publication was not obtained in full text were excluded, as well as those in which the results did not have sufficient theoretical and practical basis for them to be included in the study. After the searches, 47 articles were found, initially selected by title and abstract, excluding duplicates. In the end, the complete reading and data collection was performed with 6 articles. Relevant information from the selected articles was transcribed for a table to summarize the findings. Guided endodontics can be an excellent alternative for treating complex cases, requiring minimal financial investment in the office, as image capture equipment, virtual planning and guides can be performed in trained laboratories. Thus, we conclude that the use of Endoguide as a tool in the treatment of calcified canals proved to be successful and its use does not require extensive knowledge and can be used by less experienced professionals.

Las calcificaciones pulpares provocan cambios morfológicos en el interior de los conductos radiculares que dificultan el tratamiento endodóntico. Para solventar esta dificultad se desarrolló la herramienta Endoguide o Endodoncia Guiada para resolver casos complejos. El objetivo de esta investigación fue describir las aplicaciones de la herramienta Endoguide en el tratamiento de conductos radiculares calcificados en endodoncia. Todas las búsquedas fueron realizadas por un único investigador en la base de datos PubMed/MEDLINE y búsqueda manual utilizando los descriptores "Endodontics", "Digital", "Cone beam", "Guided". Se consideraron elegibles los artículos publicados entre 2010 y 2022, y se excluyeron los estudios cuya publicación no se obtuvo a texto completo, así como aquellos en los que los resultados no tenían suficiente base teórica y práctica para ser incluidos en el estudio. Tras las búsquedas, se encontraron 47 artículos, seleccionados inicialmente por título y resumen, excluyendo los duplicados. Al final, se realizó la lectura completa y la recogida de datos con 6 artículos. La información relevante de los artículos seleccionados se transcribió para elaborar una tabla que resumiera los hallazgos. La endodoncia guiada puede ser una excelente alternativa para el tratamiento de casos complejos, requiriendo una mínima inversión financiera en el consultorio, ya que los equipos de captura de imágenes, la planificación virtual y las guías pueden realizarse en laboratorios capacitados. Así, concluimos que el uso de la Endoguía como herramienta en el tratamiento de conductos calcificados demostró ser exitoso y su uso no requiere de grandes conocimientos y puede ser utilizado por profesionales menos experimentados.

Characterization of pulp calcifications and changes in their composition after treatments with citric acid and ethylenediaminetetraacetic acid solutions.

The ectopic calcifications of non-mineralized tissues can occur in several forms throughout life, such as pulpal calcification. The presence of pulp stones is a challenge in endodontic treatment because they partially or fully obliterate the pulp chamber hindering access to root canals and their subsequent shaping. This study aimed to determine their crystallographic properties and evaluate the capacity of citric acid (CA) and ethylenediaminetetraacetic acid (EDTA) to promote the demineralization of pulp calcifications. The samples were obtained from patients with indications of endodontic treatment, and the radiographic examination was suggestive of pulp stone in at least one permanent tooth. The samples were isolated and analyzed by scanning electron microscopy/energy-dispersive x-ray spectroscopy (SEM/EDX). The Fourier Transform by high resolution-transmission electron microscopy, Raman microscopy, and X-ray diffraction (XRD) were used to identify the mineral phase and crystallographic characteristics. To evaluate the effect of CA and EDTA on the crystallinity of calcifications, they were submerged into these two individual solutions and the changes were assessed in situ by Raman spectroscopy. The SEM images obtained from calcifications demonstrated irregular morphologies. EDX of sample surfaces shows a high presence of oxygen, carbon, calcium, and phosphorous, however, other elements such as sodium, magnesium, nitrogen, chlorine, potassium, sulfur, and zinc were identified in less quantity. According to Raman, XRD, and high-resolution transmission electron microscopy, the predominant mineral phase identified in the pulpal calcification was a poor crystallinity apatite. According to in situ analyses, the effect of CA and EDTA was observed on the signals of PO4 3- and CH2 groups corresponding to inorganic and organic components. The changes with CA were evident at 7 min while the effect of EDTA was observed until 15 min of treatment. All results indicate that pulp stones have a heterogeneous composition principally composed of apatite with low crystallinity. The solubility of these pathological minerals is adequate using solutions such as EDTA or CA; however, the effectivity depends on the mineralization grade of calcifications, time, and concentration of exposition to this chemical.

Detection of pulpal calcifications on bite-wing radiographs using deep learning.

OBJECTIVES: Pulpal calcifications are discrete hard calcified masses of varying sizes in the dental pulp cavity. This study is aimed at measuring the performance of the YOLOv4 deep learning algorithm to automatically determine whether there is calcification in the pulp chambers in bite-wing radiographs. MATERIALS AND METHODS: In this study, 2000 bite-wing radiographs were collected from the faculty database. The oral radiologists labeled the pulp chambers on the radiographs as "Present" and "Absent" according to whether there was calcification. The data were randomly divided into 80% training, 10% validation, and 10% testing. The weight file for pulpal calcification was obtained by training the YOLOv4 algorithm with the transfer learning method. Using the weights obtained, pulp chambers and calcifications were automatically detected on the test radiographs that the algorithm had never seen. Two oral radiologists evaluated the test results, and performance criteria were calculated. RESULTS: The results obtained on the test data were evaluated in two stages: detection of pulp chambers and detection of pulpal calcification. The detection performance of pulp chambers was as follows: recall 86.98%, precision 98.94%, F1-score 91.60%, and accuracy 86.18%. Pulpal calcification "Absent" and "Present" detection performance was as follows: recall 86.39%, precision 85.23%, specificity 97.94%, F1-score 85.49%, and accuracy 96.54%. CONCLUSION: The YOLOv4 algorithm trained with bite-wing radiographs detected pulp chambers and calcification with high success rates. CLINICAL RELEVANCE: Automatic detection of pulpal calcifications with deep learning will be used in clinical practice as a decision support system with high accuracy rates in diagnosing dentists.

Chitin contributes to the formation of a feeding structure in a predatory nematode.

Some nematode predators and parasites form teeth-like denticles that are histologically different from vertebrate teeth, but their biochemical composition remains elusive. Here, we show a role of chitin in the formation of teeth-like denticles in Pristionchus pacificus, a model system for studying predation and feeding structure plasticity. Pristionchus forms two alternative mouth morphs with one tooth or two teeth, respectively. The P. pacificus genome encodes two chitin synthases, with the highly conserved chs-2 gene being composed of 60 exons forming at least four isoforms. Generating CRISPR-Cas9-based gene knockouts, we found that Ppa-chs-2 mutations that eliminate the chitin-synthase domain are lethal. However, mutations in the C terminus result in viable but teethless worms, with severe malformation of the mouth. Similarly, treatment with the chitin-synthase inhibitor Nikkomycin Z also results in teethless animals. Teethless worms can feed on various bacterial food sources but are incapable of predation. High-resolution transcriptomics revealed that Ppa-chs-2 expression is controlled by the sulfatase-encoding developmental switch Ppa-eud-1. This study indicates a key role of chitin in the formation of teeth-like denticles and the complex feeding apparatus in nematodes.

Nativus gen. nov., a new huntsman spider genus from South America (Araneae: Sparassidae: Heteropodinae).

In this paper, the new genus, Nativus gen. nov. is proposed to include the type species, Nativus tupana sp. nov. () from Brazil and nine new species: N. carare sp. nov. (), N. hazzii sp. nov. (), N. janai sp. nov. (), N. nocaima sp. nov. (), N. tawu sp. nov. () and N. yurupari sp. nov. () from Colombia, N. juruti sp. nov. () and N. mariua sp. nov. () from Brazil, and N. napo sp. nov. () from Peru. The genus is placed in the subfamily Heteropodinae due to the presence of intermarginal denticles on the chelicerae, a long-toothed female palpal claw, two recurved eye rows with median eyes smaller than laterals, and only one lateral spine on each side of metatarsi III, as well as a ventral branch on the RTA (vRTA) in the male palp. Within Heteropodinae, it seems to be more closely related to Guadana Rheims and Sparianthina Banks due to the presence of intermarginal denticles along the entire cheliceral groove and a dorsal tegular apophysis (DTA) in the male palp. All species are described and illustrated. An identification key and distribution maps are provided for all species of the genus.

A new genus of japygids (Diplura: Japygidae) in mid-Cretaceous amber from northern Myanmar.

Diplura is a cryptic and edaphic group of hexapod animals characterized by the presence of filiform or pincer-like cerci located at the end of the abdomen. As one of the early diverging lineages of Hexapoda, diplurans play a crucial role in unraveling the origin of the hyperdiverse insects. The fossil record of diplurans, however, is exceptionally limited due to their delicate bodies and habitat requirements. Here we report the discovery of a new japygid, Cretojapyx huangi gen. et sp. nov., entombed in mid-Cretaceous Kachin amber (northern Myanmar). This specimen exhibits distinctive features, including the well-developed carinae on abdominal segment X and cerci, left cercus lacking a prominent tooth and denticles, and right cercus with a postmedian tooth followed by uniseriate round denticles. Our finding provides a unique opportunity to gain valuable insights into the evolutionary history of this ancient lineage and deepen our understanding of terrestrial ecosystems during the Mesozoic.

Some Gleanings on the Origin, Etiology, Nature and Development of Pulp Stones - 100-year Perspective.

Quite often in today's contemporary literature, phrases, or statements such as, or similar to the following, are often seen at the beginning of published manuscript, 'despite several microscopic and histochemical studies, the exact cause…is largely unknown…or is elusive…or has not been fully characterized.' Often these types of statements are used as a justification or a rationale for the published paper that follows. However, when looking carefully at the purported issue or issues at hand, there usually is an historical trail to follow that requires a passionate inquisitiveness, an intellectual persistence, and a monumental determination to find the truth…but even what is discovered in this relentless pursuit may not necessarily represent the truth that may remain elusive. Hence, this historical exposé will focus on a specific issue about a little tissue that most contemporary authors have passed off as a mysterious, unknown entity - the Pulp Stone/Nodule. From 1969 to 2021, there have been over 100 publications or more that have addressed pulp stones purely from an epidemiological or management standpoint, with minimal to no effort to identify their true source or etiology, which may be locked in the vaults of antiquity. However, our forefathers had a pretty good handle on these entities as this historical perspective will address.