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The Journal of Comparative Neurology Apr 2024Cellular-level anatomical data from early fetal brain are sparse yet critical to the understanding of neurodevelopmental disorders. We characterize the organization of...
Cellular-level anatomical data from early fetal brain are sparse yet critical to the understanding of neurodevelopmental disorders. We characterize the organization of the human cerebral cortex between 13 and 15 gestational weeks using high-resolution whole-brain histological data sets complimented with multimodal imaging. We observed the heretofore underrecognized, reproducible presence of infolds on the mesial surface of the cerebral hemispheres. Of note at this stage, when most of the cerebrum is occupied by lateral ventricles and the corpus callosum is incompletely developed, we postulate that these mesial infolds represent the primordial stage of cingulate, callosal, and calcarine sulci, features of mesial cortical development. Our observations are based on the multimodal approach and further include histological three-dimensional reconstruction that highlights the importance of the plane of sectioning. We describe the laminar organization of the developing cortical mantle, including these infolds from the marginal to ventricular zone, with Nissl, hematoxylin and eosin, and glial fibrillary acidic protein (GFAP) immunohistochemistry. Despite the absence of major sulci on the dorsal surface, the boundaries among the orbital, frontal, parietal, and occipital cortex were very well demarcated, primarily by the cytoarchitecture differences in the organization of the subplate (SP) and intermediate zone (IZ) in these locations. The parietal region has the thickest cortical plate (CP), SP, and IZ, whereas the orbital region shows the thinnest CP and reveals an extra cell-sparse layer above the bilaminar SP. The subcortical structures show intensely GFAP-immunolabeled soma, absent in the cerebral mantle. Our findings establish a normative neurodevelopment baseline at the early stage.
Topics: Humans; Brain; Cerebral Cortex; Corpus Callosum; Neurons; Head
PubMed: 38591638
DOI: 10.1002/cne.25612 -
Seminars in Pediatric Neurology Sep 2014There is increasing evidence documenting activation of inflammatory processes in focal epilepsies. This review article summarizes current data regarding immune mediated... (Review)
Review
There is increasing evidence documenting activation of inflammatory processes in focal epilepsies. This review article summarizes current data regarding immune mediated inflammatory processes in patients with symptomatic partial epilepsies such as mesial temporal sclerosis, focal cortical dysplasia, and Rasmussen's encephalitis. We have also reviewed several neuronal surface antibody-associated syndromes, which have been recently described with focal seizures as an important part of clinical presentation, such as antibody-associated limbic encephalitis and N-methyl-D-aspartic acid receptor antibody syndrome. An autoimmune mechanism may be one pathogenic factor in some symptomatic epilepsies acting as a triggering event in the process leading to the development of epilepsy.
Topics: Animals; Autoantibodies; Autoimmune Diseases; Cytokines; Encephalitis; Epilepsies, Partial; Humans; Nerve Tissue Proteins
PubMed: 25510942
DOI: 10.1016/j.spen.2014.08.002 -
Clinical and Experimental Dental... Dec 2019The aim of this study was to determine the influence of short base lengths and supplemental grooves on surface area and rotational resistance in a simulated-maxillary...
OBJECTIVES
The aim of this study was to determine the influence of short base lengths and supplemental grooves on surface area and rotational resistance in a simulated-maxillary premolar.
MATERIALS AND METHODS
Trigonometric calculations were done to determine the total surface area with and without supplemental grooves. Additional computations were done to determine the maximum wall angle needed to resist rotation displacement in a premolar-sized model. Wall heights of 3.0, 4.0, and 5.0 mm were used in the surface area and rotational axis computations. The rotational axis was located on the lingual restoration margin to produce a buccal-to-lingual rotational displacement.
RESULTS
Total surface area decreased with increasing four-wall taper levels from 2° to 18° and decreasing preparation heights from 5 to 3 mm. Significant surface area improvements were found with the supplemental use of mesial and distal axial grooves compared with the same condition without grooves in all taper levels and preparation height categories. Resistance to rotational displacement was determined to occur at only at very low levels of opposing wall taper angles. The use of supplemental grooves on mesial and distal axial walls significantly improved both total surface area and rotational resistance.
CONCLUSIONS
The vertical wall taper angles, preparation heights, and supplemental grooves play a role in resistance form and restoration stability.
Topics: Bicuspid; Dental Prosthesis Design; Dental Prosthesis Retention; Humans; Maxilla; Models, Theoretical; Rotation; Surface Properties; Tooth Preparation, Prosthodontic
PubMed: 31890300
DOI: 10.1002/cre2.229 -
Journal of Fish Biology Oct 2022Teeth are an integral component of feeding ecology, with a clear link between tooth morphology and diet, as without suitable dentition prey cannot be captured nor broken...
Teeth are an integral component of feeding ecology, with a clear link between tooth morphology and diet, as without suitable dentition prey cannot be captured nor broken down for consumption. Bull sharks, Carcharhinus leucas, undergo an ontogenetic niche shift from freshwater to marine habitats, which raises the question: does tooth morphology change with ontogeny? Tooth shape, surface area and thickness were measured using both morphometrics and elliptic Fourier analysis to determine if morphology varied with position in the jaw and if there was an ontogenetic change concordant with this niche shift. Significant ontogenetic differences in tooth morphology as a function of position in the jaw and shark total length were found, with upper and lower jaws of bull sharks presenting two different tooth morphologies. Tooth shape and thickness fell into two groupings, anterior and posterior, in both the upper and lower jaws. Tooth surface area, however, indicated three groupings, mesial, intermediate and distal, in both the upper and lower jaws. While tooth morphology changed significantly with size, showing an inflection at sharks of 135 cm total length, each morphological aspect retained the same tooth groupings throughout. These ontogenetic differences in tooth morphologies reflect tooth strength, prey handling and heterodonty.
Topics: Animals; Ecosystem; Jaw; Sharks; Tooth; Diet
PubMed: 35848707
DOI: 10.1111/jfb.15170 -
Compendium of Continuing Education in... Mar 2019The use of silver diamine fluoride (SDF) for management of dental caries has gained considerable attention due to recent regulatory clearance in the United States. The... (Review)
Review
The use of silver diamine fluoride (SDF) for management of dental caries has gained considerable attention due to recent regulatory clearance in the United States. The primary focus of policies, presentations, and publications has been the arrest of caries lesions (cavities) because of the material's unique ability to non-invasively achieve this elusive and clinically important goal. However, SDF also has proven efficacy in prevention, ie, decreasing the incidence of new caries lesions. Analysis of nine clinical trials in children shows that SDF prevented 61% of new lesions compared to controls. To prevent one new caries lesion, clinicians need to treat four primary teeth (one patient) or 12.1 permanent molars (three patients) with SDF. The preventive effect appears to be immediate and maintains at the same fraction over time. Direct comparisons of SDF applied once per year with alternative treatments show that SDF is more effective than other topical fluorides placed two to four times per year and more cost-effective than dental sealants. Enamel lesions may be even more responsive than cavitated dentin lesions. Annual application of SDF to high-risk surfaces (eg, mesial surfaces of permanent first molars where the distal surface of the second primary molar is carious) in patients with any risk of new caries lesions appears to be the most cost-effective approach available to prevent dental caries. SDF is an underutilized evidence-based preventive agent for dental caries.
Topics: Child; Cost-Benefit Analysis; Dental Caries; Fluorides, Topical; History, 20th Century; Humans; Quaternary Ammonium Compounds; Silver Compounds
PubMed: 30829497
DOI: No ID Found -
Frontiers in Veterinary Science 2021Cheek teeth (second through fourth premolars and first through third molars) diastema is a common and painful equine disorder caused by the absence of effective tight...
BACKGROUND
Cheek teeth (second through fourth premolars and first through third molars) diastema is a common and painful equine disorder caused by the absence of effective tight interdental contact between these teeth. Limited objective information is available on the angulation of equine cheek teeth that control dental drift or on mesial or distal equine cheek teeth drift that should normally prevent this disorder.
OBJECTIVES
To measure the angulation of the mesial and distal cheek teeth in horses of different ages, quantify age-related cheek teeth mesial and distal dental drift, and measure the cheek teeth row length in horses of different ages.
STUDY DESIGN
Retrospective review of computed tomographic images of equine heads.
METHODS
Case details and CT images from clinical equine cases that had undergone standing CT head examination were collated.Three sets of measurements were acquired from each head. "Head size" calculated as the distance between the caudal aspect of the orbit and the caudal aspect of the naso-incisive notch was used to standardize measurements in different sized heads. The length of the cheek teeth rows measured from the mesial aspect of the Triadan 06 occlusal surface to the distal aspect of the Triadan 11 occlusal surface. The rostro-caudal (antero-posterior) position and angulation of the mandibular and maxillary Triadan 06 and 11 teeth were measured in relation to reference lines drawn on CT images.
RESULTS
Significant mesial drift occurred in the maxillary and mandibular Triadan 11s. Despite their distal angulation, the upper and lower Triadan 06s also drifted mesially. The mean angulation of Triadan 06 and 11 mandibular teeth (17.8 and 26.2°, respectively) was almost double that of maxillary teeth (9.2 and 13.3°, respectively) with both Triadan 11s having greater angulation than the 06s. Cheek teeth angulation only significantly decreased in the mandibular 06s. Cheek teeth arcade lengths decreased with age, but these decreases were not significant.
MAIN LIMITATIONS
Limitations include the relatively small sample size.
CONCLUSIONS
In the population of horses used for this study, age related mesial drift occurred in both Triadan 06 and 11s, and the angulation of these teeth did not decrease with age in most arcades.
PubMed: 35242831
DOI: 10.3389/fvets.2021.804061 -
BMC Oral Health May 2022To evaluate the effect of amalgam contamination, different surface treatments, and adhesive protocols on dentin microleakage to bulk-fill composite resin material.
BACKGROUND
To evaluate the effect of amalgam contamination, different surface treatments, and adhesive protocols on dentin microleakage to bulk-fill composite resin material.
METHODS
Forty teeth were fixed in (polyvinyl siloxane) PVS molds, and the Class II cavities were placed on mesial and distal aspects. Thirty teeth were restored by amalgam and thermocycled to 10,000 cycles (5 and 55 °C, 30-s dwell time). The rest were restored with Filtek one Bulk Fill composite without amalgam predecessor. Samples were divided into: G1 (dentin pretreated with 2% chlorhexidine gluconate), G2 (0.5 mm of dentin was removed), G3 (no surface modification), and G4 (control, where composite was bonded to sound dentin without amalgam predecessor.). Single Bond Universal Adhesive system was used to bond the composite material, by using the etch-and-rinse protocol in the mesial cavity preparation and self-etch protocol in the distal. Specimens underwent thermocycling for 5000 cycles, then embedded in silver nitrate and sectioned for stereomicroscope examination. Descriptive statistics, Mann-Whitney U test, and Kruskal-Wallis test were used to analyze the results at p < 0.05.
RESULTS
The highest microleakage score values (4.00) were found in the G2, and G4 in etch-and-rinse protocol. While the lowest scores were found in G2 when using self-etching protocol (1.5). Lower microleakage values were associated with the chlorhexidine treatment group for both adhesive protocols. No significant differences were found between amalgam contaminated and non-contaminated groups.
CONCLUSIONS
Amalgam contamination did not affect microleakage. Self-etching adhesive protocol significantly reduced microleakage for all groups irrespective of the surface treatment. Chlorhexidine pretreatment improved microleakage for both adhesive protocols but had no significant effect.
Topics: Chlorhexidine; Composite Resins; Dental Cavity Preparation; Dental Cements; Dental Leakage; Dental Restoration, Permanent; Dentin; Dentin-Bonding Agents; Humans; Materials Testing; Resin Cements
PubMed: 35585533
DOI: 10.1186/s12903-022-02214-1 -
The Journal of Contemporary Dental... Jan 2022To evaluate the buccal, lingual, mesial, and distal crestal bone around implant using CBCT analysis having buccal crestal bone width of 1 mm after placement of implant...
AIM
To evaluate the buccal, lingual, mesial, and distal crestal bone around implant using CBCT analysis having buccal crestal bone width of 1 mm after placement of implant and after 3 months of loading.
MATERIALS AND METHODS
Twenty-five patients between 18 and 60 years of age with adequate bone width and height were selected for this study with single or multiple missing teeth. Surgical stent was fabricated for all of them by using self-cure acrylic resin for selection of implant according to the availability of bone, and gutta-percha was used as radio-opaque marker to locate the implant site. After proper analysis, in the first stage surgery, implants were placed. After 3 months to this, the second stage surgery was performed followed by elastomeric impression for porcelain fused to metal prosthesis fabrication. The buccal, lingual, mesial, and distal bone width and height were evaluated by using cone-beam computed tomography (CBCT). CBCT was standardized in terms of FOV (field of vision), slice thickness, and interval. After 3 months of loading, CBCT was taken to evaluate the alteration in the crestal bone around implants. Pre- and post-loading, crestal bone on four locations was measured by using CBCT software.
RESULTS
There is significant bone loss at all the locations, buccal, lingual, mesial, and distal, at the time of placement and after 3 months of loading of implant ( <0.05). The mean difference of 0.840, 0.933, 0.840, and 0.380 at buccal, lingual, mesial, and distal locations, respectively, shows statistically significant difference in pre- and post-values of mean bone loss at buccal, lingual, mesial, and distal positions. Pre-loading bone loss was maximum in the distal surface, while post-loading bone loss was maximum in the buccal surface.
CONCLUSION
From this study, it is concluded that although crestal bone loss was higher before implant placement, there was significant alteration in crestal bone even after loading of implant.
CLINICAL SIGNIFICANCE
It is widely accepted that the bone loss around the implant crest module is multidisciplinary in nature. Long-term preservation of the crestal bone is a paramount for successfully functioning of dental implants. Preserving crestal bone will help in dissipating the functional load. With proper treatment planning by the practitioner, this technical contribution to the crestal bone loss can be minimized and long-term survival of dental implants can be achieved.
Topics: Cone-Beam Computed Tomography; Dental Implants; Gutta-Percha; Humans; Tongue; Tooth Loss
PubMed: 35656662
DOI: No ID Found -
Hua Xi Kou Qiang Yi Xue Za Zhi = Huaxi... Jan 2022This study aimed to investigate the quality of single crown digital models, enhance communication between clinicians and technicians, and improve the quality of...
OBJECTIVES
This study aimed to investigate the quality of single crown digital models, enhance communication between clinicians and technicians, and improve the quality of restorations to further reduce remake rate.
METHODS
A total of 1 312 single crown digital models (180 anterior teeth, 294 premolars, and 838 molars) were randomly selected from a large commercial dental factory. The digital models were evaluated by three investigators with the same working experience with the same intraoral scanning system (CEREC). CEREC SW 4.4 was used in capturing the images of single crown preparations, and prepCheck 3.1 was used in evaluating the quality of single crown digital models.
RESULTS
Approximately 6.55%, 0.08%, 81.17%, 19.59%, and 22.48% of 1 312 single crown digital models did not meet the standards of the undercut, surface quality, margin quality, buccal-lingual taper, and mesiodistal taper, respectively. Moreover, 23.25%, 28.51%, 28.43%, and 28.35% of the investigated single crown digital models did not meet the standards of the buccal inclination taper, lingual inclination taper, mesial inclination taper, and distal inclination taper, respectively. The quality of anterior teeth, premolars, molars at the margin quality, buccal-lingual taper, mesiodistal taper, buccal inclination taper, lingual inclination taper, mesial inclination taper, and distal inclination taper significantly varied in the evaluation results (<0.01).
CONCLUSIONS
In addition to the undercut and surface quality met the standard, the overall situation of the quality of the single crown digital preparation model was poor, and the quality of the preparation needs to be improved urgently.
PubMed: 38596993
DOI: 10.7518/hxkq.2022.01.008 -
Clinical Oral Investigations Mar 2018To evaluate the predictive power of the morphology of the distal surface on 1st and mesial surface on 2nd primary molar teeth on caries development in young children.
OBJECTIVE
To evaluate the predictive power of the morphology of the distal surface on 1st and mesial surface on 2nd primary molar teeth on caries development in young children.
SAMPLE AND METHODS
Out of 101 3-to 4-year-old children from an on-going study, 62 children, for whom parents' informed consent was given, participated. Upper and lower molar teeth of one randomly selected side received a 2-day temporarily separation. Bitewing radiographs and silicone impressions of interproximal area (IPA) were obtained. One-year procedures were repeated in 52 children (84%). The morphology of the distal surfaces of the first molar teeth and the mesial surfaces on the second molar teeth (n=208) was scored from the occlusal aspect on images from the baseline resin models resulting in four IPA variants: concave-concave; concave-convex; convex-concave, and convex-convex. Approximal caries on the surface in question was radiographically assessed as absent/present.
RESULTS
Of the 52 children examined at follow-up, 31 children (60%) had 1-4 concave surfaces. In total 53 (25%) of the 208 surfaces were concave. A total of 22 children (43%) had 1-4 approximal lesions adding up to 59 lesions. Multiple logistic regression analyses disclosed that gender, surface morphology on one of the approximal surfaces (focus-surface), and adjacent-surface morphology were significantly related to caries development (p values ≤ 0.03). The odds ratio for developing caries in the focus-surface/adjacent-surface in the four IPA variants were convex-convex, 1.0; convex-concave, 5.5 (CI 2.0-14.7); concave-convex, 12.9 (CI 4.1-40.3); and concave-concave, 15.7 (CI 5.1-48.3).
CONCLUSION
Morphology of approximal surfaces in primary molar teeth, in particular both surfaces being concave, significantly influences the risk of developing caries.
CLINICAL RELEVANCE
The concave morphology of approximal surfaces can predict future caries lesions supporting specific home-care and in-office preventive strategies.
Topics: Child, Preschool; Colombia; Dental Caries; Female; Humans; Male; Models, Dental; Molar; Oral Hygiene; Prevalence; Radiography, Bitewing; Risk Factors; Tooth, Deciduous
PubMed: 28735465
DOI: 10.1007/s00784-017-2174-3