Browsing by Author "Pavan Kumar Dubey"

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A comparative evaluation of masticatory load distribution in different types of prosthesis with varying number of implants: A FEM analysis
(Elsevier B.V., 2024) Roopal Srivastava; Rajesh Bansal; Pavan Kumar Dubey; Deepak Singh
Aim: To identify the optimal number and position of implants to reduce stress concentration on the implant, denture, and attachment system for sustaining an overdenture prosthesis. Materials and methods: By incorporating one to eight indigenous implants with bar-type attachments, eight 3D finite element models of mandibular overdentures were created. All models received a 200 N vertical load, and the biomechanical characteristics of peri-implant bone were assessed. Result: The study observed that with a vertical load of 200 N, the maximum equivalent stress around peri-implant tissue in all models was within the physiological tolerance threshold of bone. The von Mises stress values ranged from 116.18 MPa to 536.7 MPa. Conclusion: The three-implant-supported overdenture model revealed superior peri-implant stress, stability, cost-effectiveness, and hygiene maintenance outcomes. Placing a third implant in the mid-symphysis region may offer a practical solution to reduce rotations in two-implant-supported overdentures. © 2024
Comparison of Psychophysical and Neurophysiological Activities in Complete Denture Wearers and Implant Retained Overdenture Wearers: An In Vivo Study
(Begell House Inc., 2025) Ritu Saneja; Bappaditya Bhattacharjee; Ashish Verma; Romesh Soni; Ankita Anand Singh; Pavan Kumar Dubey; Atul Bhatnagar
The present study aimed to evaluate degree of functional and physiological integration of dental implant used for implant retained overdenture and comparing these adaptive change with conventional complete denture in edentulous participants. The psychophysical method evaluated active tactile sensibility (ATS) threshold of sensory receptors of oral cavity and neurophysiological method assessed neurological changes with help of functional magnetic resonance imaging (fMRI) during mastication in participants of both the groups. Mann-Whitney U test was done to compare ATS threshold and activity of sensory cortex in fMRI before and after implant installation in completely edentulous participants. Statistical result showed significant increase (P < 0.001) in activation of sensory cortex, motor cortex, prefrontal cortex, temporal lobe in participants after wearing implant retained overdenture compared with complete denture. For 200, 100, and 80 μm articulating papers non-significant change found between two test groups. The 40 and 12 μm articulating papers showed statistically significant change in ATS threshold (P < 0.05) between two test groups in 12–14 weeks. ATS threshold decreased more in participants with Implant retained overdenture prosthesis as compared with conventional complete denture prosthesis. Most of the activation was seen in prefrontal cortex and bilateral somato-sensory cortex with implant retained prosthesis compared with conventional complete denture prosthesis. © 2025 by Begell House, Inc.
Genetic Association of ACE2 rs2285666 Polymorphism With COVID-19 Spatial Distribution in India
(Frontiers Media S.A., 2020) Anshika Srivastava; Audditiya Bandopadhyay; Debashurti Das; Rudra Kumar Pandey; Vanya Singh; Nargis Khanam; Nikhil Srivastava; Prajjval Pratap Singh; Pavan Kumar Dubey; Abhishek Pathak; Pranav Gupta; Niraj Rai; Gazi Nurun Nahar Sultana; Gyaneshwer Chaubey
Studies on host-pathogen interaction have identified human ACE2 as a host cell receptor responsible for mediating infection by coronavirus (COVID-19). Subsequent studies have shown striking difference of allele frequency among Europeans and Asians for a polymorphism rs2285666, present in ACE2. It has been revealed that the alternate allele (TT-plus strand or AA-minus strand) of rs2285666 elevate the expression level of this gene upto 50%, hence may play a significant role in SARS-CoV-2 susceptibility. Therefore, we have first looked the phylogenetic structure of rs2285666 derived haplotypes in worldwide populations and compared the spatial frequency of this particular allele with respect to the COVID-19 infection as well as case-fatality rate in India. For the first time, we ascertained a significant positive correlation for alternate allele (T or A) of rs2285666, with the lower infection as well as case-fatality rate among Indian populations. We trust that this information will be useful to understand the role of ACE2 in COVID-19 susceptibility. © Copyright © 2020 Srivastava, Bandopadhyay, Das, Pandey, Singh, Khanam, Srivastava, Singh, Dubey, Pathak, Gupta, Rai, Sultana and Chaubey.
Peri-implant stress distribution assessment of various attachment systems for implant supported overdenture prosthesis by finite element analysis – A systematic review
(Elsevier B.V., 2022) Bappaditya Bhattacharjee; Ritu Saneja; Ankita Singh; Pavan Kumar Dubey; Atul Bhatnagar
Background: Various attachments like ball, bar-clip, magnetic attachments are used in implant supported overdentures. Finite Element Analysis (FEA) a newly innovated technology has been used in dental implantology to evaluate stress distribution patterns. There is little evidence available regarding the stress distribution in peri-implant region for implant supported overdentures. The purpose of the review was to generate scientific evidence on peri-implant stress distribution in FEA model with different types of attachments employed in implant supported overdentures. Materials and methods: Systematic review was conducted as per the Preferred Reporting Items for Systematic Reviews Guidelines and Meta-Analyses statement (PRISMA). A comprehensive search was undertaken by two reviewers from January 2020 to June 2020 with no year limits to published articles. Only in-vitro FEA studies were included. Following electronic databases were searched for published studies- PubMed, Web of Science. Characteristics of the studies tabulated and analysis of articles was done to compare different attachment systems. Results: Locator attachments showed better stress distribution than ball attachment system in all the studies but one. Two studies showed results in favour of ball attachment compared to bar-clip attachment system when stress was evaluated distal to the implants. No significant difference in terms of stress concentration could be generated between ball versus magnetic/equator versus locator attachment system due to less number of studies and conflicting results. Conclusion: Various studies showed different results due to heterogenicity in selected attachment systems and study designs. Locator attachments showed favourable stress distribution around peri-implant bone than other attachments. © 2022 Craniofacial Research Foundation
The peopling of Lakshadweep Archipelago
(Nature Publishing Group, 2019) Mohammed S. Mustak; Niraj Rai; Mohan Rao Naveen; Satya Prakash; S. Justin Carlus; Nagarjuna Pasupuleti; Anshika Srivastava; Prajjval Pratap Singh; Idrees Babu; Pavan Kumar Dubey; Gyaneshwer Chaubey; Kumarasamy Thangaraj
The archipelago of Lakshadweep is considered as a stopover to the maritime route since ancient time. It is not very clear when the human first occupied these islands, however in the long history of the islands, the local legends suggest that Lakshadweep has been ruled by different kingdoms. To have a better understanding of peopling of Lakshadweep, we have analysed 557 individuals from eight major islands for mitochondrial DNA and 166 individuals for Y chromosome markers. We found a strong founder effect for both paternal and maternal lineages. Moreover, we report a close genetic link of Lakshadweep islanders with the Maldives, Sri Lanka and India. Most of the Lakshadweep islands share the haplogroups specific to South Asia and West Eurasia, except Minicoy Island that also shares haplogroups of East Eurasia. The paternal and maternal ancestries of the majority of island populations suggest their arrival from distinct sources. We found that the maternal ancestry was closer to South Indian populations, whereas the paternal ancestry was overwhelmed with the haplogroups, more common in the Maldives and North of India. In conclusion, our first genetic data suggest that the majority of human ancestry in Lakshadweep is largely derived from South Asia with minor influences from East and West Eurasia. © 2019, The Author(s).
Unravelling the distinct strains of Tharu ancestry
(Nature Publishing Group, 2014) Gyaneshwer Chaubey; Manvendra Singh; Federica Crivellaro; Rakesh Tamang; Amrita Nandan; Kamayani Singh; Varun Kumar Sharma; Ajai Kumar Pathak; Anish M. Shah; Vishwas Sharma; Vipin Kumar Singh; Deepa Selvi Rani; Niraj Rai; Alena Kushniarevich; Anne-Mai Ilumäe; Monika Karmin; Anand Phillip; Abhilasha Verma; Erik Prank; Vijay Kumar Singh; Blaise Li; Periyasamy Govindaraj; Akhilesh Kumar Chaubey; Pavan Kumar Dubey; Alla G. Reddy; Kumpati Premkumar; Satti Vishnupriya; Veena Pande; Jüri Parik; Siiri Rootsi; Phillip Endicott; Mait Metspalu; Marta Mirazon Lahr; George Van Driem; Richard Villems; Toomas Kivisild; Lalji Singh; Kumarasamy Thangaraj
The northern region of the Indian subcontinent is a vast landscape interlaced by diverse ecologies, for example, the Gangetic Plain and the Himalayas. A great number of ethnic groups are found there, displaying a multitude of languages and cultures. The Tharu is one of the largest and most linguistically diverse of such groups, scattered across the Tarai region of Nepal and bordering Indian states. Their origins are uncertain. Hypotheses have been advanced postulating shared ancestry with Austroasiatic, or Tibeto-Burman-speaking populations as well as aboriginal roots in the Tarai. Several Tharu groups speak a variety of Indo-Aryan languages, but have traditionally been described by ethnographers as representing East Asian phenotype. Their ancestry and intra-population diversity has previously been tested only for haploid (mitochondrial DNA and Y-chromosome) markers in a small portion of the population. This study presents the first systematic genetic survey of the Tharu from both Nepal and two Indian states of Uttarakhand and Uttar Pradesh, using genome-wide SNPs and haploid markers. We show that the Tharu have dual genetic ancestry as up to one-half of their gene pool is of East Asian origin. Within the South Asian proportion of the Tharu genetic ancestry, we see vestiges of their common origin in the north of the South Asian Subcontinent manifested by mitochondrial DNA haplogroup M43. © 2014 Macmillan Publishers Limited All rights reserved.