Search Results (453)

Background/Objectives: The aim of this study is to evaluate pretreatment osseous changes in the temporomandibular joint (TMJ) in orthognathic surgery patients using cone-beam computed tomography (CBCT) and to determine the distribution of the findings according to sagittal skeletal malocclusion groups. Methods: CBCT images of 103 patients (206 condyles) were retrospectively analyzed. Patients were classified as Class I, II, and III based on ANB angles. Condylar morphology was assessed for flattening, sclerosis, erosion, osteophyte formation, and subchondral bone cysts. All evaluations were performed by a single investigator (κ = 0.87). Group differences were analyzed using the chi-square test with Bonferroni correction (p < 0.05). Results: The most frequent alteration was flattening (29.6%), followed by sclerosis (11.2%), erosion (10.7%), osteophyte formation (8.3%), and subchondral bone cysts (4.4%). No significant sex-related differences were found (p > 0.05). A significant difference was observed only in sclerosis (p = 0.049), which was more prevalent in Class I than Class III. Flattening predominated in all groups, while erosion and osteophytes were more common in Class II, and sclerosis was more frequent in Class I. Conclusions: This study demonstrated that condylar flattening was the most common morphological alteration in orthognathic patients across all skeletal malocclusion groups. The higher prevalence of sclerosis in Class I compared with Class III suggests that mandibular positioning may influence adaptive and degenerative remodeling processes of the TMJ. This study emphasizes the importance of CBCT evaluation for detecting osseous changes in TMJ before orthognathic surgery and demonstrates that pre-existing alterations may impact surgical stability and postoperative functional outcomes. Full article

Background: Retinitis pigmentosa (RP) encompasses a group of inherited retinal disorders characterized by progressive degeneration of rod and cone photoreceptors, leading to vision loss. Among RP subtypes, RP11 is linked to mutations in PRPF31, a key spliceosome component, resulting in retinal cell dysfunction. Although PRPF31 is ubiquitously expressed, its mutations predominantly impact retinal cells, leading to the progressive loss of photoreceptors. Despite significant progress, studies have focused on photoreceptor and retinal pigment epithelium dysfunction in late disease stages, leaving early molecular events and the involvement of other retinal cell types unresolved. Moreover, comprehensive single-cell analyses capturing dynamic transcriptional changes across all retinal populations at early and late differentiation stages are still lacking. Methods: Using patient-derived retinal organoids (ROs), this study investigates the impact of PRPF31-RP11 mutation through a series of morphological, functional, molecular, and transcriptomics analyses. Results:. Single-cell RNA sequencing revealed dynamic gene expression related to early Müller glia activation, retinal ganglion cell distress, and progressive photoreceptor degeneration. Findings identify dysregulated molecular pathways associated with phototransduction, oxidative stress, and inflammation. Conclusions: Our results support a specific RO model of RP11 in which PRPF31 mutation recapitulate in vitro key features of RP, while simultaneously eliciting compensatory or modulatory responses in other retinal cell types. Full article

Background: Impaired mucus drainage from the paranasal sinuses is often associated with nasal obstruction and reduced airway function in growing patients. Orthopedic maxillary protraction and expansion techniques can enhance airway dynamics, but their underlying fluid–structure mechanisms remain insufficiently understood. Objective: To validate that the Right Angle Maxillary Protraction Appliance (RAMPA), combined with a semi-rapid maxillary expansion (sRME) intraoral device gHu-1, improves mucus drainage by enhancing nasal airflow through nasal cavity expansion. Methods: The effects of RAMPA therapy were analyzed using computational fluid dynamics (CFD) for single-phase (air) and two-phase (air–mucus) flows within the nasal cavity, employing the unsteady RANS turbulence model. Finite element method (FEM) results from prior studies were synthesized to assess changes in the center and radius of maxillary rotation induced by RAMPA-assisted sRME. A male patient (aged 8 years 7 months to 11 years 7 months) treated with extraoral RAMPA and the intraoral appliance (gHu-1) underwent pre- and post-treatment cone-beam computed tomography (CBCT) and ear, nose, and throat (ENT) evaluation. Results: FEM analysis revealed an increased radius and elevated center of maxillary rotation, producing expansion that was more parallel to the palatal plane. CFD simulations showed that nasal cavity expansion increased airflow velocity and pressure drop, enhancing the suction effect that promotes mucus clearance from the frontal sinus. Clinically, nasal passages widened, paranasal opacities resolved, and occlusal and intermolar widths improved. Conclusions: RAMPA combined with sRME improves nasal airflow and maxillary skeletal expansion, facilitating paranasal mucus clearance and offering a promising adjunctive approach for enhancing upper airway function in growing patients. Full article

Objectives: This study evaluated and compared the sealing ability and elemental composition of a resin-based endodontic sealer (AH Plus) used with three root canal obturation techniques: single cone (SC), lateral compaction (LC), and warm vertical condensation (WVC). The investigation focused on microstructural characteristics, interfacial integrity, and elemental distribution within filled root canals. Material and Methods: Sixty extracted single-root teeth were instrumented using the ProTaper Gold system and randomly assigned to three groups (n = 20) according to the obturation technique. The AH Plus Jet sealer was applied in all cases. Following obturation, samples were subjected to radiographic investigation and analyzed using optical microscopy and scanning electron microscopy (SEM) coupled with energy-dispersive X-ray spectroscopy (EDX) to assess the sealing performance and chemical composition. Results: Radiographic and microscopic assessments indicated that the SC method showed strong gutta-percha adhesion to dentin with a thin cement layer, whereas WVC provided excellent adaptation and penetration of gutta-percha. The LC technique demonstrated good adhesion but displayed occasional structural irregularities. SC has the thicker adhesion layer with uneven distribution regarding coronal, median, and apical, regions ranging from 45 to 80 μm, while WVC ensures a thin and uniform sealing layer of about 35 μm in all regions. SEM and EDX analyses detailed the interfacial microstructure and confirmed the presence of carbon (C), oxygen (O), calcium (Ca), zinc (Zn), barium (Ba), and sulfur (S) across all groups. Conclusions: All three obturation techniques (SC, WVC, LC) achieved effective sealing when combined with the AH Plus sealer. The main difference between the methods consists of the sealer layer thickness and its even distribution regarding gutta-percha cones. Full article

Background: Bronchoscopic thermal ablation has emerged as a minimally invasive therapeutic option for managing pulmonary nodules in patients unsuitable for surgery or radiotherapy. Robotic-assisted bronchoscopy (RAB) offers enhanced stability and precise navigation, potentially improving the safety and accuracy of bronchoscopic ablation. However, clinical data on RAB-guided microwave ablation (MWA) remains limited. Therefore, further evidence is needed to evaluate its feasibility, safety, and early therapeutic performance. Methods: We conducted a single-center retrospective feasibility study of shape-sensing RAB-guided MWA (ssRAB-MWA) for pulmonary nodules between October 2024 and September 2025. Eligible lesions (≤3.0 cm) included both primary lung cancers and metastatic nodules. All procedures were performed under general anesthesia using the ssRAB system integrated with cone-beam CT for intra-procedural confirmation. Technical success, safety outcomes, and short-term efficacy were assessed. Results: Nine patients (with 11 lesions: 3 primary, 8 metastatic) underwent ssRAB-MWA with 100% technical success. The median ablation time per nodule was 10 min (range, 1–26). One patient developed post-ablation pneumonia requiring hospitalization; no pneumothorax, major bleeding, or airway injury occurred. All lesions exhibited a transient increase in size immediately following MWA, followed by gradual reduction or stabilization over time. PET-CT evaluation demonstrated metabolic remission in primary lesions, with one patient achieving pathologic complete response after surgery. Conclusions: ssRAB-MWA appears to be a feasible and safe navigation-guided technique for small pulmonary lesions, offering encouraging early local control in both primary and metastatic lung cancers. This platform may expand the therapeutic spectrum of interventional pulmonology, bridging diagnosis and local therapy. Larger multicenter studies are warranted to validate long-term outcomes. Full article

Background/Objectives: Artificial intelligence (AI) systems may enhance diagnostic accuracy in cone-beam computed tomography (CBCT) analysis. However, most validations focus on isolated tooth-level tasks rather than clinically meaningful full-mouth assessment outcomes. To evaluate the diagnostic accuracy of a commercial AI platform for detecting dental treatment features on CBCT images at both tooth and full-scan levels. Methods: In this retrospective single-center study, 147 CBCT scans (4704 tooth positions) were analyzed. Two experienced readers annotated treatment features (missing teeth, fillings, endodontic treatments, crowns, pontics, orthodontic appliances, implants), and consensus served as the reference. Anonymized datasets were processed by a cloud-based AI system (Diagnocat Inc., San Francisco, CA, USA). Diagnostic metrics—sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and F1-score—were calculated with 95% patient-clustered bootstrap confidence intervals. A “Perfect Agreement” criterion defined full-scan level success as an entirely error-free full-mouth report. Results: Tooth-level AI performance was excellent, with accuracy exceeding 99% for most categories. Sensitivity was highest for missing teeth (99.3%) and endodontic treatments (99.0%). Specificity and NPV exceeded 98.5% and 99.7%, respectively. Full-scan level Perfect Agreement was achieved in 82.3% (95% CI: 76.2–88.4%), with errors concentrated in teeth presenting multiple co-existing findings. Conclusions: The evaluated AI platform demonstrates near-perfect accuracy in detecting isolated dental features but moderate reliability in generating complete full-mouth reports. It functions best as an assistive diagnostic tool, not as an autonomous system. Full article

This review examines the role of differential forms, Pfaffian systems, and hypersurfaces in general relativity. These mathematical constructions provide the essential tools for general relativity, in which the curvature of spacetime—described by the Einstein field equations—is most elegantly formulated using the Cartan calculus of differential forms. Another important subject in this discussion is the notion of conformal geometry, where the relevant invariants of a metric are characterized by Élie Cartan’s normal conformal connection. The previous analysis is then used to develop the null surface formulation (NSF) of general relativity, a radical framework that postulates the structure of light cones rather than the metric itself as the fundamental gravitational variable. Defined by a central Pfaffian system, this formulation allows the entire spacetime geometry to be reconstructed from a single scalar function, Z, whose level surfaces are null. Full article

Neuronal circuits arise as axons and dendrites extend, navigate, and connect to target cells. Axonal growth, in particular, integrates deterministic guidance from substrate mechanics and geometry with stochastic fluctuations generated by signaling, molecular detection, cytoskeletal assembly, and growth cone dynamics. A comprehensive quantitative description of this process remains incomplete. We review stochastic models in which Langevin dynamics and the associated Fokker–Planck equation capture axonal motion and turning under combined biases and noise. Paired with experiments, these models yield key parameters, including effective diffusion (motility) coefficients, speed and angle distributions, mean-square displacement, and mechanical measures of cell–substrate coupling, thereby linking single-cell biophysics and intercellular interactions to collective growth statistics and network formation. We further couple the Fokker–Planck description to a mechanochemical actin–myosin–clutch model and perform a linear stability analysis of the resulting dynamics. Routh–Hurwitz criteria identify regimes of steady extension, damped oscillations, and Hopf bifurcations that generate sustained limit cycles. Together, these results clarify the mechanisms that govern axonal guidance and connectivity and inform the design of engineered substrates and neuroprosthetic scaffolds aimed at enhancing nerve repair and regeneration. Full article

Background: Periodontitis is a common inflammatory disease characterized by progressive loss of alveolar bone. Cone-beam computed tomography (CBCT) can visualize 3D periodontal bone defects, but its interpretation is time-consuming and examiner-dependent. Deep learning may support standardized CBCT assessment if performance and biological relevance are adequately characterized. Methods: We used the publicly available MMDental dataset (403 CBCT volumes from 403 patients) to train a 3D ResNet-18 classifier for binary discrimination between periodontitis and healthy status based on volumetric CBCT scans. Volumes were split by subject into training (n = 282), validation (n = 60), and test (n = 61) sets. Model performance was evaluated using area under the receiver operating characteristic curve (AUROC), area under the precision–recall curve (AUPRC), and calibration metrics with 95% bootstrap confidence intervals. Grad-CAM saliency maps were used to visualize the anatomical regions driving predictions. To explore phenotype-level biological concordance, we analyzed an independent gingival transcriptomic cohort (GSE10334, n ≈ 220 arrays after quality control) and an independent oral microbiome cohort based on 16S rRNA amplicon sequencing, using unsupervised clustering, differential expression/abundance testing, and pathway-level summaries. Results: On the held-out CBCT test set, the model achieved an AUROC of 0.729 (95% CI: 0.599–0.850) and an AUPRC of 0.551 (95% CI: 0.404–0.727). At a high-sensitivity operating point (sensitivity 0.95), specificity was 0.48, yielding an overall accuracy of 0.62. Grad-CAM maps consistently highlighted the alveolar crest and furcation regions in periodontitis cases, in line with expected patterns of bone loss. In the transcriptomic cohort, inferred periodontitis samples showed up-regulation of inflammatory and osteoclast-differentiation pathways and down-regulation of extracellular-matrix and mitochondrial programs. In the microbiome cohort, disease-associated samples displayed a dysbiotic shift with enrichment of classic periodontal pathogens and depletion of health-associated commensals. These omics patterns are consistent with an inflammatory–osteolytic phenotype that conceptually aligns with the CBCT-defined disease class. Conclusions: This study presents a proof-of-concept 3D deep learning model for CBCT-based periodontal disease classification that achieves moderate discriminative performance and anatomically plausible saliency patterns. Independent transcriptomic and microbiome analyses support phenotype-level biological concordance with the imaging-defined disease class, but do not constitute subject-level multimodal validation. Given the modest specificity, single-center imaging source, and inferred labels in the omics cohorts, our findings should be interpreted as exploratory and hypothesis-generating. Larger, multi-center CBCT datasets and prospectively collected paired imaging–omics cohorts are needed before clinical implementation can be considered. Full article

Background/Objectives: The primary objective of this study was to evaluate the accuracy of maxillary repositioning using a two-plate patient-specific osteosynthesis system. The secondary objective was to determine whether accuracy is influenced by the number of maxillary segments. Methods: A retrospective single-centre cohort study was conducted on patients undergoing bimaxillary orthognathic surgery with a maxilla-first two-plate PSO system. Virtual Surgical Planning was performed based on the Cone-Beam Computed Tomography (CBCT) data of the patient, with patient-specific plates being designed and manufactured accordingly. Postoperative CBCT scans (7–10 days post-op) were registered to the preoperative plan, and deviations in translation and rotation between the plan and results were determined. Sub-group analyses were performed on one-, two- and three-segment maxillary osteotomy patient groups. Results: The inclusion criteria were met by 61 patients, of whom 47 were included for analysis (mean age 27.9 ± 9.4 years). Sub-millimetre median translational accuracies were found: anteroposterior 0.7 mm, transverse 0.4 mm, vertical 0.6 mm. The median rotational deviations were ≤1° for yaw and roll, and 1.6° for pitch. Accuracy was consistent across the one-, two-, and three-segment osteotomy groups. Conclusions: The two-plate PSO system is clinically accurate in bimaxillary surgery. There is no significant difference in accuracy between one-piece and segmental osteotomies of the maxilla when using the two-plate system. Full article

Background/Objectives: The objective of this study was to investigate current endodontic practice patterns and the adoption of newer technologies among dentists, endodontic specialists, and postgraduate students in Spain and Latin America. Methods: A cross-sectional survey was conducted using a structured 30-item questionnaire covering demographics, training, technology adoption (NiTi instrumentation, magnification, CBCT, irrigation adjuncts, bioceramic sealers), obturation techniques, irrigant selection, and clinical procedures. The survey was distributed through a professional Instagram account and WhatsApp groups of dentists, specialists, and postgraduate students. Participation was voluntary, anonymous, and restricted to qualified professionals. Data were collected via Google Forms, cleaned, and grouped into Spain, Mexico, Venezuela, Colombia, Southern Cone & Andes (Argentina, Chile, Peru, Ecuador, Bolivia), and other countries. Descriptive statistics were calculated, and intergroup comparisons were performed using Chi-square or Fisher’s exact tests with Bonferroni correction (p < 0.05). Multiple regression analyses were performed. Results: A total of 1358 valid responses were analyzed, distributed as follows: Spain (219), Mexico (353), Venezuela (162), Colombia (108), Southern Cone & Andes (260), and other countries (256). Most respondents (62.8%) had ≤10 years of experience, and 61.2% reported postgraduate training. Loupes (55.4%) were the most frequent magnification system, followed by microscopes (18.6%). Sodium hypochlorite (98.3%) was the irrigant of choice, commonly used with EDTA (83.5%) and, to a lesser extent, chlorhexidine (33.4%). Sonic (83.2%) and ultrasonic (52.9%) activation were frequent. Bioceramic sealers were used by 18.9%, while calcium hydroxide medication was applied by 37.4%. Specialists and master-level clinicians showed greater use of rotary NiTi systems, CBCT, magnification, and bioceramic sealers, whereas general practitioners relied more on manual instrumentation and single-cone obturation. Success was mainly verified by combined clinical and radiographic evaluation (86.7%). Spain demonstrated higher adoption of microscopes, warm vertical compaction, and CBCT. Conclusions: Core practices such as sodium hypochlorite irrigation and rubber dam use were widespread, while advanced technologies and irrigant protocols varied with training level and region. Continuous education remains essential to promote evidence-based practice and reduce disparities in endodontic innovation. Full article

Inconel 625 is widely employed in high-temperature and corrosive environments, where the integrity of welded joints critically influences component performance. This study systematically investigates how laser beam welding (LBW) heat input governs cooling behaviour, microstructure evolution, elemental segregation, and the mechanical performance of Inconel 625 weld joints aiming to become sustainable joints. A single-spot monochromatic non-contact type infrared pyrometer is used to monitor the thermal cycles of the molten weld pool and the cooling rate and melt pool lifetime were determined based on the thermal cycle data. The impact of cooling rate and melt pool lifetime on weld geometry, microstructure, micro-segregation, and mechanical properties were thoroughly investigated. The findings revealed that the fibre laser welding produced sound, defect-free joints across all experimental heat-input conditions and the weld quality was fairly dictated by cooling rate during solidification. Reducing heat input (by using faster laser scan speeds) increased the cooling rate (1.45 × 10³ to 3.65 × 10³ °C/s), resulting in a shortened melt-pool lifetime and altered weld bead geometry from hourglass to truncated-cone profiles. Eventually, the fusion-zone microstructure transitioned from coarse cellular/columnar dendrites at high heat inputs to refined dendrites at low heat inputs. The EDS analysis revealed pronounced Nb and Mo segregation in slowly cooled welds and Laves phase formation due to insufficient time for solute redistribution and γ-Ni matrixes were consistent noted with XRD-observed peaks. The presence of the brittle Laves phase adversely affects the microhardness and tensile strength of the weld joints. Mechanical testing confirmed that decreasing heat input (in faster laser scan speeds) enhanced micro-hardness and tensile strength due to grain refinement and solute entrapment in the γ matrix. The highest joint strength (989.3 ± 10.4 MPa) and elongation (40.3 ± 1.8%) approached those of the work material, and these findings establish processing parameter–structure–property relationships for the LBW of Inconel 625. The co-relation in the present manuscript can be used in the future for process monitoring and for controlling the mechanical properties of laser welding and may provide a practical guidance for optimizing weld quality in advanced industrial applications. Full article

Background/Objectives: The clinical outcome of root canal treatments using calcium silicate-based sealer (CSBS) remains unclear. This study aimed to evaluate the 1-year effect of CSBS in combination with a single-cone obturation technique on periapical lesion (PL) healing evaluated on cone beam computed tomography scans (CBCT) after single-visit root canal retreatment. Methods: This randomized clinical study involved 50 patients with chronic apical periodontitis and previous root canal treatment (ClinicalTrials.gov ID: NCT04072926). The inclusion criteria were previous endodontic treatment, asymptomatic inadequate endodontic treatment, PLs measuring > 5 mm, and percussion and palpation sensitivity. The exclusion criteria were immunocompromised status, pregnancy, periodontally compromised teeth, vertical root fracture, and antibiotic usage in the last month. Single-visit root canal retreatment was performed by the same endodontist. The patients were randomly divided into two groups based on the root canal sealer used: CSBS (BioRoot RCS) and epoxy resin-based sealer (ERBS) (AH Plus). Periapical healing, as the primary outcome measure, was determined according to the reduction in PL volume on CBCT from the preoperative period to the 1-year postoperative period. Results: Pre- and postoperative PL volumes (p > 0.05) were not significantly different between the CSBS and ERBS groups. The success rate (loose criteria) was 82.9% in the ERBS group and 94.7% in CSBS group. Conclusions: Root canal retreatment outcomes of CSBS, including periapical healing, are comparable to those of ERBS at 1 year after the retreatment. Full article

This study focuses on a single-step microwave-assisted carbonization and activation method for biomasses derived from peanut shells and spruce cones. Using phosphoric acid as the activating agent, this process leads to carbon materials with a micro-mesoporous structure, favoring dye adsorption. Elemental and surface analyses confirmed that the physicochemical properties of the obtained carbons are strongly dependent on the biomass’ source. The carbon materials obtained in this way, differing in porous structure and the presence of functional groups on their surfaces, were used for static adsorption of hazardous dye crystal violet from water. The adsorption behavior of both materials fits well with the Langmuir and Freundlich isotherms, indicating a combination of monolayer and heterogeneous surface adsorption, driven primarily by physical interactions. Of these two materials, carbon derived from spruce cones was characterized by better porosity, higher surface functionality, and higher adsorption capacity, demonstrating its potential as a cost-effective and sustainable material for wastewater treatment applications. Full article

Background: Cone-beam computed tomography (CBCT) was used for a 1-year follow-up of a randomized clinical trial to compare a stainless-steel Tornado file system with OneShape and WaveOne rotary systems for biomechanical canal preparation, as indicated by radiolucency sizes of periapical lesions. Methods: Lower molars with necrotic pulps and periapical lesions were randomly divided into three groups (n = 20) according to three rotary file systems. After root canal treatment, clinical and assessment of the CBCT periapical index scores were blindly evaluated at one year using pre- and post-instrumentation CBCT images. Statistical analysis was performed to compare the three systems at a p-value of 0.05. Results: The results revealed a significant decrease in the size of apical radiolucency in each group after one-year follow-up, with no statistically significant difference among the three systems (p > 0.05). Conclusions: CBCT is a valuable biomedical imaging modality for assessing periapical lesion healing. Tornado, WaveOne, and OneShape systems can be used with similar efficacy for root canal preparation in teeth with periapical lesions. Clinical Trial Registration: The study was retrospectively registered with ClinicalTrials.gov (NCT06752837). Date of Registration: 30 December 2024. The CONSORT group has identified it as essential. Full article