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Dentistry Journal Apr 2024By correctly repositioning teeth, orthodontic therapy improves both the function and appearance of an occlusion. The relationship between teeth and the tissues that... (Review)
Review
By correctly repositioning teeth, orthodontic therapy improves both the function and appearance of an occlusion. The relationship between teeth and the tissues that surround and support them significantly influences these alterations. With ever more adults seeking orthodontic care, orthodontists are increasingly seeing patients with periodontal issues. Concerns about the patient's appearance, such as uneven gingival margins or functional issues caused by inflammatory periodontal diseases, should be accounted for when designing orthodontic treatment plans. Furthermore, orthodontics may increase the chances of saving and recovering a degraded dentition in cases of severe periodontitis. Today, general dentists, dontists, and orthodontists play integrative roles that enable them to achieve the best possible results for their patients. This review will improve the results of interdisciplinary treatments and increase cooperation between dental specialists by drawing attention to the essential connection between orthodontics and periodontics in regular clinical practice.
PubMed: 38668024
DOI: 10.3390/dj12040112 -
Cells Apr 2024Ischemic stroke is a major cerebrovascular disease with high morbidity and mortality rates; however, effective treatments for ischemic stroke-related neurological...
Human-Induced Pluripotent Stem Cell-Derived Neural Progenitor Cells Showed Neuronal Differentiation, Neurite Extension, and Formation of Synaptic Structures in Rodent Ischemic Stroke Brains.
Ischemic stroke is a major cerebrovascular disease with high morbidity and mortality rates; however, effective treatments for ischemic stroke-related neurological dysfunction have yet to be developed. In this study, we generated neural progenitor cells from human leukocyte antigen major loci gene-homozygous-induced pluripotent stem cells (hiPSC-NPCs) and evaluated their therapeutic effects against ischemic stroke. hiPSC-NPCs were intracerebrally transplanted into rat ischemic brains produced by transient middle cerebral artery occlusion at either the subacute or acute stage, and their in vivo survival, differentiation, and efficacy for functional improvement in neurological dysfunction were evaluated. hiPSC-NPCs were histologically identified in host brain tissues and showed neuronal differentiation into vGLUT-positive glutamatergic neurons, extended neurites into both the ipsilateral infarct and contralateral healthy hemispheres, and synaptic structures formed 12 weeks after both acute and subacute stage transplantation. They also improved neurological function when transplanted at the subacute stage with γ-secretase inhibitor pretreatment. However, their effects were modest and not significant and showed a possible risk of cells remaining in their undifferentiated and immature status in acute-stage transplantation. These results suggest that hiPSC-NPCs show cell replacement effects in ischemic stroke-damaged neural tissues, but their efficacy is insufficient for neurological functional improvement after acute or subacute transplantation. Further optimization of cell preparation methods and the timing of transplantation is required to balance the efficacy and safety of hiPSC-NPC transplantation.
Topics: Induced Pluripotent Stem Cells; Humans; Animals; Neural Stem Cells; Cell Differentiation; Ischemic Stroke; Rats; Synapses; Male; Neurites; Brain; Brain Ischemia; Neurons; Rats, Sprague-Dawley; Stroke
PubMed: 38667286
DOI: 10.3390/cells13080671 -
Materials Today. Bio Jun 2024Periodontal ligament (PDL) cells play a crucial role in maintaining periodontal integrity and function by providing cell sources for ligament regeneration. While...
Periodontal ligament (PDL) cells play a crucial role in maintaining periodontal integrity and function by providing cell sources for ligament regeneration. While biophysical stimulation is known to regulate cell behaviors and functions, its impact on epigenetics of PDL cells has not yet been elucidated. Here, we aimed to investigate the cytoskeletal changes, epigenetic modifications, and lineage commitment of PDL cells following the application of stretch stimuli to PDL. PDL cells were subjected to stretching (0.1 Hz, 10 %). Subsequently, changes in focal adhesion, tubulin, and histone modification were observed. The survival ability in inflammatory conditions was also evaluated. Furthermore, using a rat hypo-occlusion model, we verified whether these phenomena are observed . Stretched PDL cells showed maximal histone 3 acetylation (H3Ace) at 2 h, aligning perpendicularly to the stretch direction. RNA sequencing revealed stretching altered gene sets related to mechanotransduction, histone modification, reactive oxygen species (ROS) metabolism, and differentiation. We further found that anchorage, cell elongation, and actin/microtubule acetylation were highly upregulated with mechanosensitive chromatin remodelers such as H3Ace and histone H3 trimethyl lysine 9 (H3K9me3) adopting euchromatin status. Inhibitor studies showed mechanotransduction-mediated chromatin modification alters PDL cells behaviors. Stretched PDL cells displayed enhanced survival against bacterial toxin (C12-HSL) or ROS (HO) attack. Furthermore, cyclic stretch priming enhanced the osteoclast and osteoblast differentiation potential of PDL cells, as evidenced by upregulation of lineage-specific genes. , PDL cells from normally loaded teeth displayed an elongated morphology and higher levels of H3Ace compared to PDL cells with hypo-occlusion, where mechanical stimulus is removed. Overall, these data strongly link external physical forces to subsequent mechanotransduction and epigenetic changes, impacting gene expression and multiple cellular behaviors, providing important implications in cell biology and tissue regeneration.
PubMed: 38654935
DOI: 10.1016/j.mtbio.2024.101050 -
Computer Methods and Programs in... Jun 2024Advanced cases of head and neck cancer involving the mandible often require surgical removal of diseased sections and subsequent replacement with donor bone. During the...
STATEMENT OF PROBLEM
Advanced cases of head and neck cancer involving the mandible often require surgical removal of diseased sections and subsequent replacement with donor bone. During the procedure, the surgeon must make decisions regarding which bones or tissues to resect. This requires balancing tradeoffs related to issues such as surgical access and post-operative function; however, the latter is often difficult to predict, especially given that long-term functionality also depends on the impact of post-operative rehabilitation programs.
PURPOSE
To assist in surgical decision-making, we present an approach for estimating the effects of reconstruction on key aspects of post-operative mandible function.
MATERIAL AND METHODS
We develop dynamic biomechanical models of the reconstructed mandible considering different defect types and validate them using literature data. We use these models to estimate the degree of functionality that might be achieved following post-operative rehabilitation.
RESULTS
We find significant potential for restoring mandibular functionality, even in cases involving large defects. This entails an average trajectory error below 2 mm, bite force comparable to a healthy individual, improved condyle mobility, and a muscle activation change capped at a maximum of 20%.
CONCLUSION
These results suggest significant potential for adaptability in the masticatory system and improved post-operative rehabilitation, leading to greater restoration of jaw function.
Topics: Humans; Mastication; Mandibular Reconstruction; Mandible; Computer Simulation; Biomechanical Phenomena; Bite Force
PubMed: 38640839
DOI: 10.1016/j.cmpb.2024.108174 -
Cureus Mar 2024This case report explores how the presence of an adjacent implant influenced the restoration of a tooth with pulpitis in a gastro-esophageal reflux disease (GERD)...
This case report explores how the presence of an adjacent implant influenced the restoration of a tooth with pulpitis in a gastro-esophageal reflux disease (GERD) patient. A patient with GERD requires a tooth-colored crown not only for aesthetics but also to address potential galvanic concerns arising from an adjacent implant. GERD, a condition causing non-cavity erosion, weakens tooth structure over time, presenting significant challenges in treatment. It resulted in bite relapse and insufficient occlusal clarity over time. A comprehensive treatment approach was needed to restore both function and appearance. This involved managing galvanism using non-metallic materials to ensure optimal occlusal clarity, as well as meticulously reinforcing and restoring tooth structure. Monoblock post-fused crowns were chosen for their superior durability, stability, and comfort. The ceramic layering not only effectively prevented galvanic issues by insulating the tooth structure but also significantly improved the natural appearance of teeth, thereby promoting long-term oral health and successfully managing complex dental concerns. The dental team successfully restored the damaged tooth by considering specific factors that influenced the treatment plan, including achieving optimal aesthetic outcomes.
PubMed: 38638723
DOI: 10.7759/cureus.56482 -
Nature Communications Apr 2024Functional trade-offs can affect patterns of morphological and ecological evolution as well as the magnitude of morphological changes through evolutionary time. Using...
Functional trade-offs can affect patterns of morphological and ecological evolution as well as the magnitude of morphological changes through evolutionary time. Using morpho-functional landscape modelling on the cranium of 132 carnivore species, we focused on the macroevolutionary effects of the trade-off between bite force and bite velocity. Here, we show that rates of evolution in form (morphology) are decoupled from rates of evolution in function. Further, we found theoretical morphologies optimising for velocity to be more diverse, while a much smaller phenotypic space was occupied by shapes optimising force. This pattern of differential representation of different functions in theoretical morphological space was highly correlated with patterns of actual morphological disparity. We hypothesise that many-to-one mapping of cranium shape on function may prevent the detection of direct relationships between form and function. As comparatively only few morphologies optimise bite force, species optimising this function may be less abundant because they are less likely to evolve. This, in turn, may explain why certain clades are less variable than others. Given the ubiquity of functional trade-offs in biological systems, these patterns may be general and may help to explain the unevenness of morphological and functional diversity across the tree of life.
Topics: Biological Evolution; Skull; Bite Force; Phylogeny
PubMed: 38627430
DOI: 10.1038/s41467-024-47620-x -
Case Reports in Dentistry 2024A 26-year-old woman had a masticatory dysfunction, straight profile, retrognathic maxilla and mandible, and Angle's class I with a tendency to class III malocclusion on...
A 26-year-old woman had a masticatory dysfunction, straight profile, retrognathic maxilla and mandible, and Angle's class I with a tendency to class III malocclusion on both sides, with bilateral posterior crossbites and a 4 mm anterior open bite. Orthognathic surgery and orthodontic camouflage with and without tooth extraction were considered as treatment options. The patient's preferred method of treatment was orthodontic camouflage without extraction. The transpalatal arch had been placed for the bilateral molars' derotation. After 3 months, the upper segmented fixed appliance was implanted to address the posterior crossbites in the premolar's region. One mini-implant was inserted into the anterior palatum after the transpalatal arch was removed, and a supporting device was attached to the first permanent molars to give indirect skeletal stability. Orthodontic treatment's active phase lasted 23 months, and all treatment objectives were achieved during that time: the desired facial profile, adequate occlusion, appropriate overbite, and overjet.
PubMed: 38623492
DOI: 10.1155/2024/7768109 -
Cureus Mar 2024Introduction Dentin hypersensitivity (DH) is the most common problem encountered by clinicians. It can be managed either by blocking neural activities or by occluding...
Introduction Dentin hypersensitivity (DH) is the most common problem encountered by clinicians. It can be managed either by blocking neural activities or by occluding tubules. Ozonated oil facilitates the simple passage of desensitizing agents into dentinal tubules. Aim This study aimed to evaluate the effect of ozonated oil on dentinal tubule occlusion before and after the application of desensitizing toothpaste. Materials and methods The study was carried out in Kalinga Institute of Dental Sciences, KIIT (Deemed to be University), Bhubaneswar, India. The sample size of the study was 80. The first group contained specimens for control. The second group comprised specimens treated with ozonated oil. The third group comprised specimens being treated with a desensitizing agent. The fourth group contained specimens treated with both the desensitizing agent and ozonated oil. The specimens then received an acid challenge. The specimens were observed under a scanning electron microscope (SEM) before any therapy, after the application of the therapeutic agents and after the 37.5% ortho-phosphoric acid challenge. Results Inferential statistics to compare between the groups was calculated using one-way analysis of variance (ANOVA) statistics. Post-hoc Tukey's honestly significant difference (HSD) was performed to compare the groups. The mean scores of the partial tubular occlusion of Group 1, Group 2, Group 3 and Group 4 before the acid challenge were 0.035, 0.691, 0.564 and 0.368, respectively. The maximum score was obtained in the case of Group 2, which was statistically significant. The mean scores for partial tubule occlusion after the acid challenge for Group 1, Group 2, Group 3 and Group 4 were 0.055, 0.531, 0.733 and 0.142, respectively. There was evidence of maximum partial tubule occlusion after the acid treatment in the case of Group 3. The mean scores of Group 1, Group 2, Group 3 and Group 4 before the acid challenge were 0.019, 0.309, 0.442 and 0.609, respectively. The maximum score was obtained in the case of Group 4, implying a greater number of total tubular occlusions before the acid challenge. The mean scores of the total tubular occlusions after the acid challenge for Group 1, Group 2, Group 3 and Group 4 were 0.047, 0.465, 0.272 and 0.890, respectively. There was evidence of maximum tubule occlusion in the case of Group 4, which was statistically significant. Conclusion Overall, the application of a desensitizing toothpaste with ozonated oil holds promise as a potentially more effective treatment approach for DH. Further research and clinical studies may be needed to fully validate its efficacy and safety in dental practice.
PubMed: 38618378
DOI: 10.7759/cureus.56131 -
Journal of Dental Sciences Apr 2024This scoping review investigated the evidence on the three-dimensional analysis of a posed smile in adults to discover any research gaps in this research area.... (Review)
Review
This scoping review investigated the evidence on the three-dimensional analysis of a posed smile in adults to discover any research gaps in this research area. Electronic searches of articles written in English were performed using the four databases of Embase, PubMed, Springer, and Web of Science with publications from 2010 to 2023. Reference lists were also manually searched to identify additional studies. The results showed that 13 cross-sectional descriptive studies from Asia, Europe, North and South America met our inclusion criteria. Studies mainly focused on linear and angle measurement for resting and smiling faces and landmark movement from resting to smiling. Most studies conducted analysis of smiles stratified by sex, ethnicity, smile type, dental occlusion, skeletal pattern, and age. Two studies compared smiling with the resting position and one study compared the attractive smiling group with the ordinary group. Our scoping review revealed the insufficiency of some measurement methods, such as those employing area, volume, and soft tissue thickness. Furthermore, few studies were conducted in Asian populations, and comparisons of various smile types, overjet types, horizontal skeletal patterns, and comparisons of smiles between people with untreated normal occlusion and those who had been orthodontically treated were lacking.
PubMed: 38618097
DOI: 10.1016/j.jds.2023.10.021 -
Journal of the Indian Society of... Jan 2024Early childhood caries is a major public health issue in India. The primary reason for poor oral health in children is a lack of awareness about the role of primary...
Early childhood caries is a major public health issue in India. The primary reason for poor oral health in children is a lack of awareness about the role of primary teeth and the importance of an early dental visit for infants and toddlers. The primary objectives of an early dental visit are to analyze the child's risk level, provide guidance to parents regarding proper oral hygiene measures, review dietary and eating habits, provide information regarding the infectivity of dental caries, review the risks of traumatic injuries and discuss factors which affect the development of occlusion. Through this paper, we are proposing an "Age One" policy that recognizes dentists, physicians, allied health professionals, community health-care workers, and nongovernmental organizations to work toward a child's overall health as partners to achieve this goal. The expectation is that this policy will provide guidance to childcare centers, pediatric dentists, other health-care professionals, and legislators regarding oral health activities and the promotion of oral health in infants. The purpose of the policy is to lay the foundation for a lifetime of preventive education and dental care, to help ensure optimal oral health beginning in childhood and continuing through the life course.
Topics: Child, Preschool; Infant; Child; Humans; Oral Health; Dental Caries; Educational Status; Dentists; Policy
PubMed: 38616420
DOI: 10.4103/jisppd.jisppd_538_23