Search Results (1,669)

Ceramic dental implants, particularly one-piece zirconia, offer a biocompatible and aesthetic alternative to titanium, with high strength and improved oral hygiene. By eliminating the implant–abutment micro-gap, they reduce bacterial accumulation because of their low plaque affinity and enhance stability. However, challenges remain, including alignment precision, limited retrievability, and sensitivity to mechanical stress. Misalignment can affect occlusal and functional outcomes, and zirconia’s rigidity complicates crown removal and modification. This case report explores the use of PEEK (polyether ether ketone) primary telescopic crowns to overcome these limitations, improving force distribution, enabling minor adjustments, and enhancing prosthetic retrievability in full-mouth zirconia restorations. A 62-year-old male patient seeking a fixed solution to replace removable dentures received 16 one-piece zirconia implants (eight per jaw). PEEK telescopic crowns were used over implant abutment copings, finalized with aesthetic zirconia bridges. The report details surgical and prosthetic procedures, along with a brief literature review on zirconia implants and PEEK applications. PEEK integration in telescopic prosthetic designs marks a notable advancement in prosthodontics. Its shock-absorbing, biocompatible, and stress-modulating properties make it valuable for implant-supported and hybrid restorations. As digital workflows advance, PEEK-based telescopic restorations may increasingly replace traditional metal-based solutions, improving long-term clinical outcomes. Further clinical research on a larger sample is needed. Full article

This paper describes the status of developing Josephson arbitrary waveform synthesizer (JAWS) chips at NIM (National Institute of Metrology, China). To obtain high junction integration density and fewer data input channels, the chip employs an on-chip Wilkinson power divider and inside/outside dc blocks, enabling both arrays to be driven by a single pulse-generator channel. In addition, the tapered coplanar waveguide structure is used to ensure the microwave uniformity of the long-junction array. Each array consisted of 4000 double-stack Nb/Nb_xSi_1−x/Nb junctions, and 16,000 junctions are integrated in the chip in total. The JAWS chip demonstrates good performance, capable of synthesizing a 300 mV root mean square (rms) voltage with exceptionally low harmonic distortion. Dc and ac voltage-current characteristics measurements indicate that the junctions are with a critical current of 2.5 mA, and a normal-state resistance of 4.5 mΩ per junction. Contact aligners are manually operated to fabricate the chips, and process errors in the fabrication are estimated in this paper. Full article

Brown tumors (BTs) are rare osteolytic lesions that typically occur in association with primary or secondary hyperparathyroidism (PHP and SHP). Excessive secretion of parathyroid hormone induces increased bone resorption, resulting in lesions characterized by fibrosis, vascularization, and hemosiderin deposition. The most common sites include the jaws, ribs, pelvis, and long bones. Clinical manifestations may involve pain, swelling, or pathological fractures. We present the case of a mandibular BT in a 48-year-old female with chronic renal failure and secondary hyperparathyroidism. The patient exhibited progressive mandibular swelling with radiological features resembling an aggressive odontogenic or malignant lesion. Laboratory analysis confirmed markedly elevated parathyroid hormone levels, while scintigraphy demonstrated increased focal uptake in the mandible and ribs. Histopathological evaluation revealed multinucleated giant cells within a fibrous stroma, consistent with BT. Despite initiation of systemic endocrine therapy, the lesion continued to enlarge, necessitating complete surgical excision of the mandibular mass. This case underscores the diagnostic dilemmas of mandibular BT, which may closely mimic aggressive jaw pathologies. Importantly, while many BTs regress after systemic management of hyperparathyroidism, this case illustrates that surgical excision may be unavoidable in patients with unstable systemic status or progressive local disease. Comprehensive clinical, radiological, laboratory, and histopathological evaluation remains essential to ensure timely diagnosis and appropriate treatment. Full article

Background/Objective: Postural stability and motor coordination require precise regulation of agonist and antagonist muscle activities. Jaw clenching modulates neuromuscular control during static and reactive postural tasks. However, its effects on dynamic voluntary movement remain unclear. This pilot study aimed to investigate the effects of jaw clenching on muscle activity and kinematics during repetitive single-leg sit-to-stand task performance. Methods: Eleven healthy adults (age: 21.2 ± 0.4 years; 6 males and 5 females; height: 167.9 ± 9.6 cm; body weight: 59.7 ± 8.1 kg) performed repetitive single-leg sit-to-stand tasks for 30 s under jaw-clenching and control conditions. Electromyography (EMG) signals from eight muscles and kinematic data from 16 inertial measurement unit sensors were analyzed, focusing on the seat-off phase. Results: Jaw clenching resulted in a significantly lower success rate than the control condition (success rate: 0.96 ± 0.13 vs. 0.78 ± 0.29, p = 0.047). Under the jaw clenching condition, failed trials exhibited higher medial gastrocnemius and masseter EMG activity (p < 0.001), lower erector spinae longus EMG activity (p < 0.001), and altered kinematics, including increased trunk yaw and roll angles (p < 0.001). Jaw clenching increased the coactivation of the gastrocnemius and tibialis anterior muscles (p < 0.001), disrupting the reciprocal muscle patterns critical for task performance. Conclusions: These findings suggest that jaw clenching may reduce task performance by altering neuromuscular coordination during dynamic postural tasks. Full article

This meta-review evaluated the possibility of more specified recommendations in antibiotic treatment through a narrowed focus on facial trauma. The aim was to analyze the effect of different regimens of antibiotic in treatment of skeletal trauma to the face. The knowledge mapping was based on existing systematic reviews (SRs) on trials specified in a PICO: Participants (P): Adults and children, diagnosed with fractures to the facial skeleton. Interventions (I): Antibiotic intervention. Comparator (C): Placebo, no antibiotics. Outcomes (O): Postoperative infection, pain, re-operation, other complications, healing deficiencies, (Oral) Health related Quality of Life, removal of osteosynthesis, adverse reactions. The literature search in PubMed, The Cochrane Library, and Web of Science according to PRISMA resulted in 1487 records. A COVIDENCE selection process resulted in 29 articles retrieved and read in full text revealing 10 articles eligible for evaluated according to ROBIS. Three SRs were considered to have low risk of bias and constituted the final evidence evaluation. The meta-review of these SRs did not provide sufficient support for prolonged antibiotic treatment after surgical intervention of midfacial fractures in comparison with antibiotics only the first day postoperatively. No support for antibiotic treatment for conservatively managed fractures alone was found. This review is limited by a relatively low number of included SRs. However, tendencies in outcomes suggests a restricted duration of antibiotics in treatment of facial fractures. Full article

Bruxism, defined as a repetitive jaw-muscle activity characterized by clenching or grinding of teeth and/or by bracing or thrusting of the mandible, is a prevalent behavior affecting up to 22% of adults worldwide. While traditionally viewed as a disorder, current understanding recognizes bruxism as a behavior that may have both positive and negative consequences. Objective assessment methods for evaluating the effectiveness of interventions in symptomatic patients remain limited. This article presents the first longitudinal study using myotonometry to quantify changes in masseter muscle following botulinum toxin type A (BoNT-A) treatment in patients with symptoms of bruxism. In total, 57 patients were recruited and their masseter muscle tone, stiffness, elasticity, relaxation time, and creep parameters were measured. Measurements were performed at baseline, 3 weeks, and 3 months post-injection during both rest and maximum voluntary contraction. BoNT-A treatment produced significant improvements in all biomechanical parameters, with the greatest effects observed in patients with the highest baseline muscle values. The objective biomechanical changes correlated with the duration of BoNT-A’s therapeutic effects. These findings establish myotonometry as a valuable tool for objective assessment of masticatory muscle function and demonstrate that BoNT-A produces measurable, long-lasting biomechanical changes in masseter muscle parameters, supporting its possible clinical application in this challenging condition. Full article

Background: Central giant cell granuloma of the jaw is a benign but potentially aggressive lesion that can cause pain, facial deformity, tooth loss, and jaw destruction. Many treatment methods are described in the literature, but the less invasive ones are associated with a higher recurrence rate. For several decades, extensive bone resection procedures have been the most effective treatment to date. This study aimed to evaluate a minimally invasive treatment protocol combining multiple weekly intralesional steroid injections with surgical removal of residual tumor tissue and chemical cauterization using Carnoy’s solution. Methods: Thirteen patients with histologically confirmed central giant cell granulomas of the jaws were treated according to the protocol, including weekly triamcinolone injections and, when necessary, fenestration of the cortical bone to access residual lesions. Patients were monitored clinically and radiologically over six years, with reconstruction of bone defects using autogenous grafts and platelet-rich fibrin. Results: The treatment effectively reduced tumor size, restored cortical bone, and allowed preservation of jaw structure. Only one recurrence was observed, and complications were minor and transient. The protocol was equally effective for both aggressive and non-aggressive lesions, regardless of patient age or comorbidities. Conclusions: These findings suggest that combining pharmacological and surgical approaches with chemical cauterization provides a safe, effective, and tissue-preserving strategy for managing central giant cell granulomas, minimizing recurrence while reducing surgical morbidity. Full article

The AGC kinases constitute a large and ancient gene superfamily with origins that coincided with the appearance of multicellularity. Three AGC kinase families—protein kinase A (PKA), protein kinase G (PKG), and protein kinase C (PKC)—mediate the actions of neuropeptide hormones, biogenic amines, and other ligands on various physiological processes in metazoans. Metazoans express two PKG types. Jawed vertebrates express three PKA catalytic (C) subunits, four regulatory (R) subunits, and twelve PKCs, organized into conventional, novel delta-like, novel epsilon-like, atypical, and protein kinase N (PKN) subfamilies. By contrast, invertebrate PKA and PKC sequences are not well characterized. Consequently, limited database resources can result in misidentification or mischaracterization of proteins and can lead to misinterpretation of experimental data. A broad phylogenetic and sequence analysis of CrusTome transcriptome and GenBank databases was used to characterize 640 PKA-C sequences, 1122 PKA-R sequences, and 1844 PKC sequences distributed among the Annelida, Arthropoda, Chordata, Cnidaria, Nematoda, Mollusca, Echinodermata, Porifera, Platyhelminthes, and Tardigrada. Phylogenetic analysis and multiple sequence alignments revealed conservation of certain PKA-C, PKA-R and PKC isoforms across metazoans, as well as diversification of additional taxon-specific isoforms. Decapods expressed four PKA-C isoforms, designated PKA-C₁, -C_D1, -C_GLY1, and -C_GLY2; five PKA-R isoforms, designated PKA-RI₁, -RI_D1, -RII_GLY, and -RII_D1; and five PKC isoforms, designated PKN_D1-3, conventional cPKC_D1, novel nPKC_D1δ and nPKC_D1ε, and atypical aPKC_D1. PKA-C_GLY1, -C_GLY2, and -RII_GLY had glycine-rich N-terminal sequences that were unique to crustaceans. These data suggest lineage-specific diversification that retained the core catalytic function of each kinase, while regions outside of the kinase domain may provide specialized regulatory mechanisms and/or spatiotemporal subcellular localization in invertebrate tissues. Full article

Macellicephaloides Uschakov, 1955 (Annelida: Polynoidae) is a genus of deep-sea polychaetes characterized by a specialized pharynx bearing two pairs of jaws (with the dorsal pair fused) and three pairs of lateral papillae, the middle pair of which is greatly elongated, and remarkable adaptability to diverse deep-sea habitats. Most species in this genus inhabit abyssal depths (>7200 m), with high diversity in western Pacific trenches, while a few occur in relatively shallow habitats such as deep-sea seamounts and hydrothermal vents. This paper presents a new species, Macellicephaloides lingshuiensis sp. nov., found in deep-sea cold seeps in the South China Sea, representing the shallowest distribution record for the genus to date and the first record from cold seep environments. The classification and phylogeny of Macellicephaloides and related genera have long been the subject of debate. A previous study suggested that Macellicephaloides is nested within the Macellicephala clade, but our analyses—based on 13 mitochondrial protein-coding genes, 12S, 16S, 18S, 28S rRNA, and ITS1-ITS2 sequences—tentatively indicate that these two genera form independent evolutionary clades. Additionally, our phylogeny indicates a close evolutionary relationship between deep-sea Macellicephaloides and cave-dwelling polynoids (e.g., Gesiella), highlighting ecological connections between deep-sea and cave habitats. These conclusions are supported by morphological comparisons and genetic distance analyses. Although the subfamily Macellicephalinae is recovered as a monophyletic group, intergeneric phylogenetic relationships within it remain unresolved, highlighting the need for additional data from more species and genera. We amend the generic diagnosis of Macellicephaloides and provide an identification key to all valid species in the genus. This study clarifies the taxonomy and phylogeny of Macellicephaloides and related taxa, emphasizing the importance of continued sampling in understudied deep-sea habitats to enhance our understanding of their biodiversity. Full article

This study aimed to analyse young consumers’ behaviour in Poland toward the consumption of plant-based beverages as milk alternatives. The sensory analysis included oat, buckwheat, cashew, almond, soy, pea, rice, coconut, hazelnut, and macadamia nut beverages and their mixtures. Quantitative analysis of sensory desirability and sensory profiling were employed to evaluate plant-based beverages. The study was conducted among young people (aged 18–35) who declared a vegan or omnivorous diet. It was found that the most frequently consumed beverages included oat and soy beverages, both among vegan and traditional (omnivorous) young groups. A significantly lower frequency of plant-based beverage consumption was confirmed in the group of people with an omnivorous diet. The taste characteristics in plant-based beverages are a key factor in driving sensory desirability among young consumers. Analysis of the influence of respondents’ declared diet and gender revealed no significant differences in the desirability of the taste of the plant-based beverages. The consumers rated the coconut, pea, macadamia, oat, and rice–coconut beverages as the most desirable in terms of taste. The lowest taste desirability was confirmed for the soy drink despite its high reported consumption. The importance of this study focused on the local market development in vegan food, as well as its potential due to further consumer expectations. Full article

Targeting the problem of lack of theoretical model for wear calculation of key actuators in the knotter, a tripping mechanism of knotter based on the principle of elastic deformation was designed. A rigid–flexible coupling dynamic analysis model of the tripping mechanism was established based on the modal stress method, and the contact force time history curves and dynamic stress results between the groove cam and the ball roller, as well as between the knotter jaw and the tripping plate slot, were simulated. Based on MSC, Marc MENTAT, a finite element wear calculation model of the tripping mechanism, was constructed. Through 600 simulations equivalent to 6000 working cycles, the wear cloud maps of the tripping plate and the large gear groove cam were obtained, and the key wear areas and expansion trends were analyzed. The rapid wear tests were conducted by using a self-made knotter fatigue wear test bench, which showed that the maximum deviation between the measured value and the simulated value of the contact pair wear was less than 10%. This verified that the proposed wear model for the tripping mechanism can be used for calculating the contact pair wear of the mechanism, providing a reference for the heat treatment process of the surface hardness of the parts. Full article

Computer-assisted surgery (CAS) and virtual surgical planning (VSP) have transformed jaw reconstruction, allowing immediate insertion of dental implants during surgery for better rehabilitation of occlusal function. However, traditional planning for optimal location and angulation of dental implants and fibula relies on experience and can be time-consuming. This study aimed to propose a function-driven workflow and develop an automatic computer program for optimal positioning of simultaneous dental implants and fibula segments. A customized computer program was developed using MATLAB. Computed tomography (CT) of the lower limbs of ninety-one Southern Chinese individuals was retrieved and cross-sections of three-dimensional (3D) fibula models were comprehensively investigated for implant installation. Our research proves that the accuracy of the program in identifying the anatomical orientation of the fibula was 92%. The ideal location, angulation and length of implant could be automatically generated based on any selected implant diameter, with a surgical feasibility of 94%. To the best of our knowledge, this is the first study to develop and validate a customized automatic computer program for osseointegrated implant design in fibula flap surgery. This program can be incorporated into the current workflow of CAS to further the development of reliable and efficient surgical planning for function-driven jaw reconstruction. Full article

Background: Orthognathic surgery aims to align the jaws with the facial skeleton and correct dental occlusion. This paper introduces the concept of planning the maxillomandibular complex (MMC) as a whole, utilizing a t-forming set of landmarks: the maxillary central incisor, the chin, and the occlusal plane. Methods: The background, hypothesis, and rationale of the new T concept are explained. A case of a 28-year-old male with skeletal class III malocclusion and an open bite was used to illustrate the application of the T concept in step-by-step surgical planning. The planning encompasses four phases: Phase One involves correcting frontal deformity and various asymmetries, Phase Two involves correcting chin anterior–posterior deformity, Phase Three involves correcting anterior–posterior and vertical MMC position, and Phase Four involves correcting MMC rotation. Results: The T concept provided a structured approach to plan MMC as a whole and integrate all structures into harmony. Conclusions: The T concept provides a logical approach to MMC positioning in orthognathic surgery, addressing functional and aesthetic concerns. It acts as a checkpoint to verify MMC position, helping surgeons achieve better results and avoid compensatory procedures. Full article

Background/Objectives: The purpose of the study is to determine and compare the accuracy and efficiency of two dynamic navigation systems (DNS)—Navident (ClaroNav, Canada) and X-Guide (Nobel Biocare, Switzerland)—vs. a free-hand (FH) approach in performing endodontic microsurgery (EMS) on human cadavers. Methods: a total of 119 roots of six cadavers were randomly divided into three groups (Navident/X-Guide/FH). The cadavers’ jaws were scanned pre-operatively with computed tomography. The DICOM data were uploaded and digitally managed with software interfaces for registration, calibration, and virtual planning of EMS. Osteotomy was performed under DNS control and using a dental operating microscope (FH control group). Post-operative scans were taken with same settings as preoperative. Accuracy was then determined by comparing pre- and post-scans of coronal and apical linear, angular deviation, angle, length, and depth of apical resection. Efficiency was determined by measuring the procedural time of osteotomy, apicectomy, retro-cavity preparation, the volume of substance, and cortical bone loss, as well as iatrogenic complications. Outcomes were also evaluated in relation to different operators’ skill levels. Descriptive statistics and inferential analyses were conducted using R software (4.2.1). Results: DNS demonstrated better efficiency in osteotomy and apicectomy, second only to FH in substance and cortical bone loss. Both DNS approaches had similar accuracy. Experts were faster and more accurate than non-experts in FH, apart from resection angle, length and depth, and retro-cavity preparation time, for which comparison was not statistically significant. The Navident and X-guide groups had similar trends in increasing efficiency and accuracy of EMS. All complications in the FH group were performed by non-experts. The X-guide group demonstrated fewer complications than the Navident group. Conclusions: Both DNS appear beneficial for EMS in terms of accuracy and efficacy in comparison with FH, also demonstrating the decreasing gap of skill expertise between experts and novice operators. Through convenient use X-guide diminishes the level of iatrogenic complications compared to Navident. Full article

Background/Objective: In the context of global aging, maintaining daily habits such as adequate nutrition and regular exercise are essential to achieve healthy aging. Therefore, the preservation of swallowing and physical functions is fundamental. Jaw-opening force, an important swallowing function, is linked to physical function. Daily health behaviors are shaped by decision-making biases, which influence decision-making. Individuals with high procrastination tendencies may be less likely to engage in health-promoting behaviors, potentially leading to functional decline. While such tendencies are associated with general health behaviors, little is known about their associations with swallowing and physical functions among older adults. The objective of this study was to examine the associations between decision-making biases and swallowing and physical functions in community-dwelling older adults. Methods: A questionnaire survey was conducted to collect basic information and assess decision-making biases. The jaw-opening force (swallowing function) and grip strength (physical function) were measured. Associations of decision-making biases with jaw-opening force and grip strength were examined using multivariable linear regression analysis. We further conducted sex-stratified sensitivity analyses. Results: This cross-sectional study targeted 107 community-dwelling older adults. There was a significant negative association between procrastination tendency and jaw-opening force (B = −0.715, p = 0.005), and grip strength (B = −1.552, p = 0.003), indicating that individuals with a propensity for procrastination had lower jaw-opening force and grip strength. Conclusions: Procrastination tendency may be used as an indicator to detect swallowing and physical functions. Moreover, incorporating this modifiable factor to promote behavior change may prevent functional decline. The study results highlight the significance of considering individuals’ decision-making biases—particularly procrastination tendency—in clinical settings. Full article