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.

Identification and classification of pulp calcifications in posterior teeth according to dental condition using digital panoramic radiography and cone beam CT.

OBJECTIVE: To compare digital panoramic radiography (DPR) and cone beam CT (CBCT) in the detection and classification of pulp calcifications in posterior teeth in relation to tooth condition and its location. METHODS: Two hundred and fifty patients with simultaneous DPR and CBCT scans were selected from a dental image bank. For each posterior tooth, its condition was registered (healthy, restored, or decayed). The presence of calcifications was assessed and classified according to location (coronal or radicular) and type (total obliteration, partial obliteration, narrowing, and no calcification). Chi-square and McNemar tests were used to compare DPR and CBCT results, with a significance level of 5%. DPR diagnostic values were calculated using CBCT as reference. RESULTS: Decayed and restored teeth showed a significantly (P < .001) higher prevalence of pulp calcifications than healthy teeth in both imaging exams. There was a significant discrepancy between the imaging modalities in the identification of calcifications (P < .001), especially for radicular calcifications of maxillary teeth (DPR = 55.2%; CBCT = 30.9%). In the case of coronal calcifications, there was a greater discrepancy between CBCT and DPR in the mandibular teeth (10.7%) than in the maxillary teeth (7.7%). Overall, DPR presents higher sensitivity (0.855) than specificity (0.483) for pulp calcifications detection. CONCLUSION: DPR considerably overestimates pulp calcifications in posterior teeth, as compared to CBCT. A higher prevalence of pulp calcifications is related to decayed and restored teeth.

Pulp stones in unerupted teeth: a retrospective analysis using cone-beam computed tomography.

BACKGROUND: A pulp stone is a calcified mass that develops in the dental pulp of any tooth. Despite many studies examining the relationship between pulp stone formation and non-oral factors, the methods used in these studies have been unable to explain the exact role of these factors alone as distinct from probable effects within the oral cavity environment. Considering that totally unerupted (impacted or developing) teeth are unexposed to the oral cavity's environmental and functional conditions, they provide a more suitable material for studying the effects of these non-oral factors on pulp stone formation. This research study aimed to investigate pulp stones in unerupted teeth and the associated factors in a Saudi subpopulation. METHODS: The study included 644 cone-beam computed tomography images, with 496 (50.9%) maxillary and 479 (49.1%) mandibular teeth. Of the investigated patients, 293 (45.5%) were men, and 351 (54.5%) were women. The age range was 15-76 years. A chi-square test was used to investigate the associations between pulp stones and age, gender, and history of systemic disease and chronic medication use. RESULTS: Pulp stones in unerupted teeth were present in 24.2% of the examined dental jaws and 18.6% of the examined teeth. There was no statistically significant relationship between pulp stones and gender (p > 0.05). A significantly greater percentage of pulp stones were found with increasing age (p = 0.000). Additionally, a significantly increased number of pulp stones was observed in patients with systemic diseases and chronic medications (p < 0.05). CONCLUSIONS: The results support the idea that pulp stones can be present in any type of unerupted tooth. This study provides additional evidence of the increased incidence of pulp stones with age, systemic disease, and chronic medications.

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.

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.

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.

Effects of advanced glycation end products on dental pulp calcification.

OBJECTIVE: The main aim of this study was to elucidate the effects of advanced glycation end products (AGEs) on the calcification of cultured rat dental pulp cells (RDPCs) and to investigate the crystallisation ability of glycated collagen. MATERIALS AND METHODS: AGEs were prepared via non-enzymatic glycation of a dish coated with type I collagen using dl-glyceraldehyde. To investigate the effects of AGEs on RDPCs, we performed WST-1 and lactate dehydrogenase assays; alkaline phosphatase, Alizarin Red S and immunohistochemical staining; and real-time quantitative reverse transcription PCR. In addition, we performed crystallisation experiments on glycated collagen. All microstructures were analysed using scanning electron microscopy/energy-dispersive X-ray spectroscopy and transmission electron microscopy/diffraction pattern analysis. RESULTS: AGEs did not affect the proliferation or differentiation of RDPCs, but enhanced the calcification rate and cytotoxicity. No major calcification-related genes or proteins were involved in these calcifications, and glycated collagen was found to exhibit a negative polarity and form calcium phosphate crystals. Cytotoxicity due to drastic changes in the concentration of pericellular ions led to dystrophic calcification, assumed to represent an aspect of diabetic pulp calcifications. CONCLUSION: Glycated collagen-containing AGEs provide a nurturing environment for crystallisation and have a significant effect on the early calcification of RDPCs.

Intra-pulpal connective tissue formation and the advanced carious lesion: Is chondrogenesis and heterotopic ossification a response to pulpal inflammation?

AIMS: (a) The aim of this study was to investigate both the formation of dense connective tissue within the dental pulp, and its association with pulpal inflammation in teeth with advanced carious lesions; and (b) to investigate in vitro whether inflammation affects the expression of markers related to chondrogenesis/osteogenesis in pulp cells. MATERIALS AND METHODS: Radiology and Histology: Forty-six teeth with advanced carious lesions were radiographically investigated for intra-pulpal radiodense structures. Specimens were processed for histology and stained with haematoxylin/eosin and proteoglycan-specific stains. The intra-pulpal connective tissue was scored as pulp stones or ectopic connective tissue. Cell culture: pulpal cells from human third molars (n = 5) were cultured in chondrogenic medium +/- TLR2/4 agonists. Expression of the genes IL6, TLR2/4, SOX9, COL1A1, COL2A1, TGFB1, RUNX2 and ALPL was assessed by qPCR. Proteoglycan content within cultures was assessed spectrophotometrically. RESULTS: Radiodense structures were discovered in about half of all pulps. They were associated with ectopic connective tissue (χ2  = 8.932, p = .004, OR = 6.80, 95% CI: [1.84, 25.19]) and with pulp stones (χ2  = 12.274, df = 1, p < .001, OR = 22.167, 95% CI: [2.57, 200.00]). The morphology of the ectopic tissue resembled cartilage and was associated with inflammatory infiltration of the pulp (χ2  = 10.148, p = .002, OR = 17.77, 95% CI: [2.05, 154.21]). After continuous stimulation of cultured cells with TLR2/4 agonists, the expression of two inflammatory markers increased: IL6 at Days 7 (p = .020) and 14 (p = .008); TLR2 at Days 7 (p = .023) and 14 (p = .009). Similarly, expression of chondrogenic markers decreased: SOX9 at Day 14 (p = .035) and TGFB1 at Day 7 (p = .004), and the osteogenic marker COL1A1 at Day 7 (p = .007). Proteoglycan content did not differ between unstimulated and stimulated cells. CONCLUSIONS: Ectopic connective tissue resembling cartilage can form in teeth affected by advanced carious lesions. This tissue type is radiographically visible and is associated with inflammatory infiltration of the pulp. Although TLR2/4 agonists led to an inflammatory response in cell culture of pulp cells, the effect on the expression of osteogenic/chondrogenic markers was limited, suggesting that immune cells are needed for connective tissue formation in vivo.

Three scleral ossicles in the West African Denticle herring Denticeps clupeoides (Clupeiformes: Denticipitidae).

The eyes of teleostean fishes typically exhibit two ossifications, the anterior and posterior sclerotics, both associated with the scleral cartilage. The West African Denticle herring Denticeps clupeoides has three scleral ossifications, including the typical two associated with the scleral cartilage (anterior and posterior sclerotic) and a third ossification (Di Dario's ossicle), spatially separated from the scleral cartilage and located within the anteromedial wall of the sclera. The medial rectus muscle inserts on the medial surface of Di Dario's ossicle, suggesting that this third sclerotic may play a role in forward rotation of the eye in this surface feeding fish.

Morphological study of the oral denticles of the porbeagle shark Lamna nasus.

Oral denticles of sharks are composed by a crown, dentine covered by a layer of enameloid and pulp cavity, the same structure of the dermal denticles found across the body surface of most elasmobranchs. In addition, oral papillae and taste buds are distributed among denticles within the oropharyngeal cavity, playing a fundamental role for tasting as part of the chemosensory system of fishes. Scanning electron microscopy (SEM) has been employed as an important tool for the study of dermal denticles and other structures, as well as histology and more recently computed tomography (CT) scan analysis. Herein, the authors used two methods for the study of the morphology of the oropharyngeal cavity of Lamna nasus (Lamniformes), an oceanic and pelagic shark: SEM and CT scan. The general morphology of oral denticles studied herein is related to abrasion strength as they are diamond-shaped, lack lateral cusps and have less pronounced ridges. In addition, smooth ridges and broad rounded denticles could be related to prevent abrasion during food consumption and manipulation. Oral papillae had a round shape and were observed only under SEM. The densities of papillae were estimated in 100 per cm2 , whereas denticles were 1760 and 1230 cm2 over the dorsal and ventral regions, respectively. The high numbers of denticles are inversely proportional to papillae density; denticles seem to restrict papillae distribution. Regarding the differences between methodologies, under SEM, only the crown was visualized, as well the papillae, allowing the estimation of size and density of both structures. Nonetheless, under CT scan, the whole components of denticles were clearly visualized: different views of the crown, peduncle, basal plate, and pulp cavity. On the contrary, oral papillae were not visualized under CT due to the tissue preparation. Furthermore, both methods are complementary and were important to extract as much information as possible from denticles and papillae.

Molecular and phenotypic characterization of two cryptic species of the predatory genus Mononchoides Rahm, 1928 (Rhabditida: Diplogastridae) and their congeneric affinities.

Based on morphometric, morphological and molecular characterization using partial small subunit 18S ribosomal DNA (rDNA) and the D2/D3 domain of large subunit 28S rDNA, we described a new species Mononchoides kanzakii collected from manure, and the known species Mononchoides composticola Steel, Moens, Scholaert, Boshoff, Houthoofd and Bert, 2011, isolated from the dung beetle Oniticellus cinctus (Fabricius, 1775). Phylogenetic trees based on the evolutionary model (GTR + I + G) were inferred by Bayesian inference algorithms. Mononchoides kanzakii sp. n. is characterized by 28-32 longitudinal ridges, discontinuous at level of stoma; amphidial apertures inconspicuous; metastegostom armed with thorn-shaped dorsal tooth; a flattened, claw-like right subventral tooth, and left subventral denticulate ridge with 12-14 fine denticles delimited by a group of five denticles in females vs. triangular, flattened right subventral tooth, 5-8 prominent denticles at left subventral sector in males; cloacal lips with a distinct rim; and gubernaculum with cuticularized, proximal and distal extensions of equal length, each constituting half of the length of the wider part of gubernaculum.

Nestin and dental pulp stones - a case report-driven hypothesis.

The dental pulp stem cells (DPSCs) are mesenchymal stem/stromal cells (MSCs) with multilineage potential of differentiation. Different studies investigated dental pulp stones (PS), the calcified masses in the dental pulp, in regard to their prevalence, topography and structure. The etiology of PS is still unclear and, to our knowledge, the DPSCs were not attributed yet specific roles in PS formation. We report here an immunohistochemical study of a PS-embedding dental pulp from an impacted third mandibular molar of an adult patient, in which we used antibodies against CD34, Ki67, glial fibrillary acidic protein (GFAP), α-smooth muscle actin (α-SMA) and nestin. While endothelial cells expressed CD34 and pericytes or vascular smooth muscle cells expressed α-SMA, DPSCs and the osteoblasts coating the PS were exclusively labeled with nestin antibody. Stromal networks of nestin-expressing DPSCs were regarded as in situ providers of osteogenic progenitors involved in PS formation. Further experimental studies, with larger lots of tissue samples, as well as extended panels of markers, are needed in order to elucidate the DPSC hypothesis in the PS etiology.

ASSOCIATION OF PULP CALCIFICATIONS AND CARDIOVASCULAR DISEASE: A SYSTEMATIC REVIEW AND META-ANALYSIS.

INTRODUCTION: This systematic review and meta-analysis was performed to evaluate the association between pulp calcifications (PC) and cardiovascular disease (CVD). METHOD: Five databases (PubMed, Scopus, Embase, Web of Science and ProQuest) were searched to identify articles. Quality assessment of the selected articles was done using Joanna Briggs Institute critical appraisal tool and the inter-examiner agreement was calculated using the Cohen-Kappa test. The random-effects maximum likelihood model was used to evaluate the association between the conditions. Trim-and-fill funnel plot was used to evaluate the presence of publication bias. The level of evidence was evaluated using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) tool. RESULTS: A total of 2487 articles were identified from the initial search. Ten articles were included in this review of which 7 were cross-sectional and 3 were case-control studies. Eight articles had a low risk of bias (RoB), one article each had a moderate and high RoB. Inter-examiner reliability score was 0.8592. Seven articles reported a statistically significant positive association between CVD patients and PC. Two articles reported a non-significant positive association and one article reported no association between the same. A significant difference was observed in favor of CVD patients to possess more PC in comparison to non-CVD patients with an OR of 4.30 (95% confidence interval (CI): 2.19, 8.46; p = .000). Asymmetry in the Trim-and-fill funnel Plot suggested the presence of publication bias. GRADE analysis demonstrated low certainty of the evidence for the overall sample. CONCLUSION: There exists a low level of evidence to show that CVD patients are more prone to have PC in comparison to non-CVD patients.

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.

Analysis on the predictive value of different variables in pulp stones appearance frequency and its pulpal response to cold stimuli.

This study evaluated the presence of pulp stones in a Seville population, correlating their presence and size with state of the crown and pulp response to cold stimuli, encompassing variables such as age, gender, location (arch and teeth group). The study included 1090 teeth corresponding to 146 patients. Each patient underwent a visual examination, periapical radiographs and sensibility tests. The SPSS 25 software (SSPS, Chicago, USA) was used to carry out the statistical analysis, doing logistic regression to compare variables and Chi-square with a significance level p < 0.001. Of 1090 teeth studied, 524 were molars and 566 premolars. Of the molars, 316 showed calcifications and of the 566 premolars only 6 showed pulp stones (p < 0.001). Due to the low prevalence of premolar pulp calcifications, our study included only molars. These calcifications were significantly more common in women than in men (71.5% vs. 28.5%) and in people over 40 years. Significant differences were identified between the state of the crown and the pulp response with the presence of pulp stones, although size did not influence this association. The set of independent variables has a statistically significant effect on the criterion variable (χ2 = 260.25, p < 0.001). There was a significant association between the state of the crown and the type of pulp response with the presence of pulp stones, but not with the size of the calcification. In conclusion, the highest probability to find pulpal calcification was observed in women over 40 years old in upper molars, and though the pulpal reaction of teeth with pulpal calcification varies, frequently there is an immediate response to a cold stimulus. There is no correlation between the size of pulp stones and the condition of the crown, just as the sensitivity of the pulp did not correlate with the size of pulp stones.

Prevalence of pulp stones in an Iranian subpopulation: an assessment using cone beam computed tomography.

Undetected pulp stones can complicate root canal treatment. Knowledge about the prevalence of this anomaly in specific populations can improve endodontic treatment outcomes. The objective of this study was to use cone beam computed tomography (CBCT) to assess the prevalence of pulp stones in an Iranian subpopulation. In this descriptive, analytical, cross-sectional study, the CBCT scans of 150 (75 female and 75 male) patients aged 15 to 70 years were retrieved from the 2017 to 2018 archives of an Iranian university. A total of 4200 teeth were evaluated for the presence of pulp stones by a senior dental student under the supervision of an experienced oral and maxillofacial radiologist. The panoramic radiographic views were evaluated first, and then each tooth was evaluated on sagittal, coronal, axial, cross-sectional, and multiplanar views with 0.5-mm slice thickness. Data regarding the presence of pulp stones as well as the effects of age, sex, tooth type, and jaw on the presence of pulp stones were analyzed using independent t and chi-square tests. Of 4200 teeth, 571 had pulp stones, yielding prevalence rates of 13.6% in the studied teeth and 76.0% in the study population. The prevalence of pulp stones was higher in female patients, the mandible, anterior teeth, and the mandibular left quadrant. The mandibular left central incisor (tooth 24) had the highest (38.7%) and the maxillary left second premolar (tooth 13) had the lowest (1.3%) prevalence of pulp stones. The high prevalence of pulp stones in this study population suggests that dentists should consider the possible presence of pulp stones when planning endodontic treatment for Iranian patients.

The Pulp Stones: Morphological Analysis in Scanning Electron Microscopy and Spectroscopic Chemical Quantification.

Background and objectives: Pulp stones are hard tissue structures formed in the pulp of permanent and deciduous teeth. Few studies have evaluated their morphology and chemical composition. However, their formation, composition, configuration and role played in overall health status are still unclear. Clinically, they may be symptomatic; technically, they impede access during endodontic therapy, increasing the risk of treatment errors. Thus, this study aimed to morphologically analyze pulp stones and present their chemical quantification, identifying their main chemical elements. It also correlates the results with their possible induction mechanisms. Materials and Methods: Seven pulp nodules were collected from molar teeth needing endodontic treatment. The morphology of the stones was analyzed by scanning electron microscopy (SEM), and their chemical composition was determined by X-ray dispersive energy spectroscopy (EDX). Results: These structures varied considerably in shape, size and topography. The site of the stones in the pulp cavity was the factor that most affected the morphology. The majority of the stones found in the pulp chambers presented nodular morphology, while those in the root canals presented a diffuse shape, resembling root canal anatomy. The topography of the nodules showed heterogeneous relief, revealing smooth and compact areas contrasting with the rugged and porous ones. The chemical composition varied depending on the location of the nodule in the pulp cavity and the relief of the analyzed area. Radicular stones presented considerably lower calcium and phosphorus content than coronary nodules. Conclusions: The high cellularity rate of the coronal pulp predisposes this region to nodular mineralizations around injured cells. The presence of larger caliber vascular bundles and higher collagen fiber content in radicular pulp determines a diffuse morphological pattern in this region. Understanding the morphology and chemical composition of the pulp stones allows future translational pathways towards the prevention or treatment of such conditions.

Radiographic Assessment of Occurrence of Pulp Stones in Molars of Selected Adult Nepalese Populations at Tertiary Care Center.

Background Pulp stones or "denticles" are a frequent finding in coronal and radicular pulp of primary and permanent dentition. These discrete calcified bodies can be seen in a healthy, diseased and sometimes even in an unerupted tooth. These calcifications are mostly present in molars as free, attached or embedded to dentine of pulp chamber or root canals. Objective To determine the occurrence of pulp stones in molars of selected adult Nepalese population using radiographs and assess the association of its occurrence gender and arch wise. Method A descriptive cross-sectional study was performed using orthopantomogram of total 380 patients (190 male and 190 females) of age group ranging from 16-30 years by convenience sampling. Data were collected through the examination of both hard and soft copies of radiographs under magnification. Pulp stones were scored as present or absent and their association with gender and dental arch were recorded. Descriptive statistics and chi square test was performed to see the prevalence and to compare the occurrence of pulp stone respectively. Result Out of 380 radiographic samples, pulp stones were present in 41.05% of the samples. The occurrence of pulp stones were found to be higher in females than in males, although the difference was not statistically significant (p=0.060).The total number of teeth with pulp stones was 238 and 61 in maxillary and mandibular arches respectively, with statistically significant difference (p<0.001). Conclusion The overall occurrence of pulp stone was found to be 41.05%. It was observed more in females (45.78%) than in males (37%) and more frequently located in maxillary molars (29.2%) than in mandibular molars (8.2%).

Dental Manifestations of Ehlers-Danlos Syndromes: A Systematic Review.

Ehlers-Danlos syndromes (EDS) are a group of inherited connective tissue disorders characterized by joint hypermobility, skin hyperextensibility, and variable tissue fragility. However, there are limited published data on the dental manifestations of EDS. This review systematically assessed the spectrum of published dental anomalies in various types of EDS. Twenty-four individual case reports/series and 3 longer case-control studies, reporting on a total of 84 individuals with a clinical diagnosis of EDS, were included in the data analysis. The main dental features listed in classical EDS were pulp calcification and localized root hypoplasia. Common dental abnormalities observed in vascular EDS were pulp shape modifications (52.2%), exceeding root length (34.8%), and molar root fusion (47.8%). Dentinogenesis imperfecta is a consistent finding in osteogenesis imperfecta/EDS overlap syndrome. Data on dental manifestations in other types of EDS are both rare and generally inconclusive.

Morphological and Histochemical Characterization of the Dermal Plates of Pleco (Hypostomus plecostomus).

Studying the dermal skeleton in fish is valuable for phylogenetic specification. The current study describes the detailed structure of the plecostomus dermal skeleton, including its morphogenesis and distribution in the skin. The denticles have a crown and a basal part and are embedded in bony depressions, to which they are attached by denticle ligaments. During denticle morphogenesis, denticle papillae formed from denticle precursor cells align in two cellular layers: an outer ameloblast precursor layer and an inner odontoblast precursor layer. The ameloblast precursors and odontoblast precursors differentiate and secrete enamel and dentine, respectively. We used different histochemical techniques, including Crossmon's trichrome staining, Weigert-Van Gieson staining, periodic acid-Schiff (PAS) staining, combined Alcian blue (AB; pH 2.5)/PAS staining, Weigert-Van Gieson staining, Mallory trichrome staining, and AB staining to distinguish the dentine and denticle ligaments. We used acridine orange to detect lysosome activity during denticle eruption. Transmission electron microscopy was used to detect the denticle ultrastructure, and scanning electron microscopy was used to detect the topographic distributions of different types of dermal tissues in different anatomical regions.