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Mohammad Abdollahi 1 Article
Smokeless tobacco (paan and gutkha) consumption, prevalence, and contribution to oral cancer
Kamal Niaz, Faheem Maqbool, Fazlullah Khan, Haji Bahadar, Fatima Ismail Hassan, Mohammad Abdollahi
Epidemiol Health. 2017;39:e2017009.   Published online March 9, 2017
DOI: https://doi.org/10.4178/epih.e2017009
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AbstractAbstract PDF
Abstract
Smokeless tobacco consumption, which is widespread throughout the world, leads to oral submucous fibrosis (OSMF), which is a long-lasting and devastating condition of the oral cavity with the potential for malignancy. In this review, we mainly focus on the consumption of smokeless tobacco, such as <i>paan</i> and <i>gutkha</i>, and the role of these substances in the induction of OSMF and ultimately oral cancer. The list of articles to be examined was established using citation discovery tools provided by PubMed, Scopus, and Google Scholar. The continuous chewing of <i>paan</i> and swallowing of <i>gutkha</i> trigger progressive fibrosis in submucosal tissue. Generally, OSMF occurs due to multiple risk factors, especially smokeless tobacco and its components, such as betel quid, areca nuts, and slaked lime, which are used in <i>paan</i> and <i>gutkha</i>. The incidence of oral cancer is higher in women than in men in South Asian countries. Human oral epithelium cells experience carcinogenic and genotoxic effects from the slaked lime present in the betel quid, with or without areca nut. Products such as 3-(methylnitrosamino)-proprionitrile, nitrosamines, and nicotine initiate the production of reactive oxygen species in smokeless tobacco, eventually leading to fibroblast, DNA, and RNA damage with carcinogenic effects in the mouth of tobacco consumers. The metabolic activation of nitrosamine in tobacco by cytochrome P450 enzymes may lead to the formation of N-nitrosonornicotine, a major carcinogen, and micronuclei, which are an indicator of genotoxicity. These effects lead to further DNA damage and, eventually, oral cancer.
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  • Understanding dental practitioners' knowledge and practices of smokeless tobacco: South Texas Oral Health Network study
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    Patient Education and Counseling.2025; 130: 108448.     CrossRef
  • Hindi Translation of Oral Health-Related Quality of Life (OHRQoL) Questionnaire and its Validation for Oral Submucous Fibrosis Patients: A Pilot Study
    Amanjot Kaur, Neeti Rustagi, Shruti Khatana, P. G. Gigi, Aparna Ganesan, Pravin Kumar, Kirti Chaudhry
    Journal of Maxillofacial and Oral Surgery.2024; 23(5): 1275.     CrossRef
  • Comparative analysis of two arecoline‐induced oral submucous fibrosis models
    Shijie Tang, Lanxin Jiang, Ying Zhou, Tong Zhou, Yang Peng, Shuting Zhou, Yuan Yue, Xiaoqiang Xia, Jing Li, Qianming Chen, Yuchen Jiang, Xiaodong Feng
    Oral Diseases.2024; 30(6): 3897.     CrossRef
  • Serum and salivary Cu/Zn ratio as a diagnostic biomarker for oral submucosal fibrosis: an analysis of trace metals and LOX gene variants
    Rafia Shah, Feriha Fatima Khidri, Yar Muhammad Waryah, Roohi Nigar, Amber Mahmood, Hina Shaikh, Muhammad Qasim Awan, Ikram Din Ujjan, Ali Muhammad Waryah
    BioMetals.2024; 37(2): 447.     CrossRef
  • Repercussions of Smokeless Tobacco on Buccal Mucosa: A Community Based Observational Study at a Tertiary Care Centre in Western Rajasthan
    Navneet Agarwal, Mohammed Nadeem Shaikh, Anisha Banu, Paridhi Ahuja
    Indian Journal of Otolaryngology and Head & Neck Surgery.2024; 76(2): 1891.     CrossRef
  • Clinical Profile and Prevalence of Oral Mucosal Lesions in Tobacco Users-A Prospective Study from Jammu, India
    Yasir Abbas, Sonika kanotra, Farkhanda Majeed, Areena Anjum, Mehvish Zehra
    Indian Journal of Otolaryngology and Head & Neck Surgery.2024; 76(3): 2373.     CrossRef
  • Oral health related quality of life in head and neck cancer survivors within the first year following treatment: a cross-sectional study in Karachi, Pakistan
    Sana Qamar, Shafquat Rozi, Sobia Sawani, Muhammad Sohail Awan, Shabbir Akhtar, Moghira Iqbaluddin Siddiqui, Syed Akbar Abbas, Shazia Taimoor, Farhan Raza Khan
    Scientific Reports.2024;[Epub]     CrossRef
  • Role of Cell-free DNA as a Non-Invasive Biomarker in the Detection of Head and Neck Squamous Cell Carcinoma
    Swati Singh, Rajeev Goyal, Ashna Gupta, Ritu Singh, Mayank Singh, Parvesh Mehra, Raja Pramanik, Vaishali Suri, Shadan Ali
    Indian Journal of Clinical Biochemistry.2024;[Epub]     CrossRef
  • Effects of Smokeless Tobacco on Oral Health: A Cross-Sectional Study
    Mohammad Arif Khan, Deepti Chandra, Brijendra Singh, Piyush Gowrav, Sanjay Gupta, Tulika Rani Roy
    Cureus.2024;[Epub]     CrossRef
  • Lip, oral and oropharyngeal cancer incidence among Aboriginal and Torres Strait Islander Peoples: First report from Australian population‐based cancer registry, 1999–2018
    S Sethi, X Ju, R Logan, J Hedges, G Garvey, L Jamieson
    Australian Dental Journal.2024; 69(3): 182.     CrossRef
  • Comparative evaluation of GSH, total protein and albumin levels in patients using smokeless tobacco with oral precancerous and cancerous lesions
    Anand Nimbal, Bhagyashri Ahirrao, Aruna Vishwakarma, Prashanth Vishwakarma, Alisha Wani, Asmita Patil
    Medicine International.2024;[Epub]     CrossRef
  • Comparative evaluation of salivary, serum and urinary 8-OHdG in gutka-associated oral submucous fibrosis
    Rajesh K. Prajapati, Jaya Joshi, S Karthikeyan, Muzalda P. S. Inder
    Journal of Oral and Maxillofacial Pathology.2024; 28(1): 37.     CrossRef
  • Clinical Correlation of Types and Forms of Smokeless Forms of Quid (Tobacco and Arecanut) and Occurrence of Oro Mucosal Lesions: A Cross-Sectional Study
    Panchali Kashyap, Tarang Mehta, Chinmay Raval, Pranav V Manek, Kailash Kewalia, Yadavalli Guruprasad, Sugandha Arya
    Journal of Pharmacy and Bioallied Sciences.2024; 16(Suppl 3): S2182.     CrossRef
  • Clinicopathological Characteristics, Prognostic Factors, and Treatment Outcomes of Patients with Oral Tongue Squamous Cell Carcinoma Treated with Glossectomy: A Tertiary Oncology Center Experience
    Hadi A. Al-Hakami, Atheer Ali Al-Talhi, Bassam AlRajhi, Abdulrahman E. Alghamdi, Naif M. Aloufi, Zyad E. Raffah, Mohammad A. Alshareef, Mohammed Al-Garni
    Indian Journal of Otolaryngology and Head & Neck Surgery.2024; 76(5): 3845.     CrossRef
  • Heated tobacco products- well known or well understood? A national cross-sectional study on knowledge, attitudes and usage in Pakistan
    Hammad Atif Irshad, Hamzah Jehanzeb, Sajjan Raja, Umair Saleem, Wamiq Ali Shaikh, Akmal Shahzad, Atiqa Amirali, Nousheen Iqbal, Javaid Ahmed Khan
    BMC Public Health.2024;[Epub]     CrossRef
  • Pattern of Occurrence and Severity of Oral Submucous Fibrosis Among Habitual Gutkha, Areca Nut and Pan Chewers
    Taimoor Ali Khan, Farah Irshad, Faiza Hasan, Kashif Ali Channar, Bushra Arain, Khurram Anwar
    Pakistan Journal of Health Sciences.2024; : 175.     CrossRef
  • Smokeless tobacco and periodontitis: A systematic review with meta‐analysis
    Mir Faeq Ali Quadri, Ahmed M. Kamel, Maryam Nayeem, Tenny John, Anugeetha Thacheril, Gianluca Tartaglia, Santosh Tadakamadla
    Journal of Periodontal Research.2024;[Epub]     CrossRef
  • Cardiovascular Diseases Among Indian Older Adults: A Comprehensive Review
    Bisma Jan, Mohammad Imran Dar, Bharti Choudhary, Parakh Basist, Rahmuddin Khan, Abdulsalam Alhalmi, Youakim Saliba
    Cardiovascular Therapeutics.2024;[Epub]     CrossRef
  • Smokeless tobacco consumption among women of reproductive age: a systematic review and meta-analysis
    Ramaiah Itumalla, Mahalaqua Nazli Khatib, Shilpa Gaidhane, Quazi Syed Zahiruddin, Abhay M Gaidhane, Ahmad Neyazi, Ahmad Farshid Hassam, Prakasini Satapathy, Sarvesh Rustagi, Neelima Kukreti, Bijaya Kumar Padhi
    BMC Public Health.2024;[Epub]     CrossRef
  • Bridging Tradition and Modernity: Embracing the Bipaddled Pectoralis Major Myocutaneous Flap for Challenging Oral Cavity Defects in the Free Flap Era
    Vaishnavi Gattani, Shreya Pawar, Chetan Gupta, Nitin Bhola, Parmarth Sonpal, Palak Agrawal
    Cureus.2024;[Epub]     CrossRef
  • Rural revitalization: Uniting forces for tobacco-free communities
    Logesh Sidhu
    Journal of Family Medicine and Primary Care.2024; 13(8): 3484.     CrossRef
  • Primary Care Clinical Practice Guidelines and Referral Pathways for Oral and Dental Diseases in Pakistan
    Syeda Sehrish Haider, Russell Seth Martins, Rohaid Ali, Nashia Ali Rizvi, Mohsin Ali Mustafa, Salima Saleem Aamdani, Alina Abdul Rehman, Alina Pervez, Sarah Nadeem, Humayun Kaleem Siddiqui, Ali Sadiq, Syed Murtaza Raza Kazmi, Adil H. Haider, Fahad Umer
    Oral.2024; 4(3): 343.     CrossRef
  • Qualitative evaluation of trace elements in commercially packaged forms of tobacco using laser-induced breakdown spectroscopy
    A. Kripa Adlene Edith, Ravikiran Ongole, V. K. Unnikrishnan, U. K. Adarsh
    Scientific Reports.2024;[Epub]     CrossRef
  • Assessment of pharyngeal airway space with MRI In oral submucous fibrosis: A cross-sectional observational study
    Ragavendiran Anandan, Krithika C. Lakshmi, Anuradha Ganesan, Yesoda AniyanK
    Journal of Oral Biology and Craniofacial Research.2024; 14(6): 669.     CrossRef
  • Capsaicin: A review of its pharmacology in gastrointestinal health and disorders
    Rajesh Sandu, Vijayapandi Pandy
    Pharmacological Research - Natural Products.2024; 5: 100103.     CrossRef
  • Oral lesions in patients consuming different types of smokeless tobacco. A literature review.
    Elsy Lorena Jerez, Ashmita Nagrani, Eduardo Arosemena
    Odontología Vital.2024;[Epub]     CrossRef
  • An assessment of oral cancer knowledge, attitudes, and practices among undergraduate students in Malaysian dental schools
    Zheng-Wen Chan, Yi-Fan Phuan, Pei-Yun Ooi, Nuruljannah Nor Azmi, Deepak G.S. Pateel, Hui-Yeng Y. Yap, Shilpa Gunjal
    BMC Oral Health.2023;[Epub]     CrossRef
  • A narrative review of the biopsychosocial and health characteristics of Asian Indians in the United States: Clinical and research implications for neuropsychological functioning
    Preeti Sunderaraman, Farzin Irani, Kamini Krishnan, Jasdeep S. Hundal
    The Clinical Neuropsychologist.2023; 37(5): 911.     CrossRef
  • Decreased functional connectivity in salience network is associated with symptom severity in betel quid‐dependent chewers
    Meiting Ban, Zhongyuan Zhan, Dongcui Wang, Jincheng He, Xueling Zhu, Fulai Yuan
    Addiction Biology.2023;[Epub]     CrossRef
  • A Review of Intervention Strategies for Areca Nut Use Cessation
    Kriti Dhingra, Sonali Jhanjee
    Indian Journal of Psychological Medicine.2023; 45(2): 117.     CrossRef
  • Use of psychoactive substances by goods carriage drivers associated with Kerala, India
    M. S. Siva Prasad, C. V. Priyatha, Jayesh K. Joseph, E. M. Aneesh
    Traffic Injury Prevention.2023; 24(8): 663.     CrossRef
  • Gendered Pattern and Predictors of Tobacco use in India: Evidence from the Second Round of Global adult Tobacco Survey
    Gayatri Nayak, A.K. Kavitha, Nancy Satpathy, Ipsa Mohapatra, Venkatarao Epari, Jugal Kishore, Pratap K. Jena, Parimala Mohanty, Santosh Panda, Chinmay Behera, Ajit Singh
    Indian Journal of Community Medicine.2023; 48(2): 241.     CrossRef
  • A Site-Based Analysis of Relationship Between Clinicopathological Factors and Their Influence on Locoregional Recurrence in Oral Squamous Cell Carcinoma
    Jeyashanth Riju, Amit Jiwan Tirkey, Konduru Vidya, Mansi Agarwal, Malavika Babu, Reshma Kurian, Antony Paulose
    Indian Journal of Surgical Oncology.2023; 14(3): 733.     CrossRef
  • Global, regional, and national burden of oral cancer and its attributable risk factors from 1990 to 2019
    Rongyin Sun, Weijie Dou, Weiliang Liu, Jin Li, Xiangxiang Han, Shunhang Li, Xueqian Wu, Fei Wang, Xin Xu, Jing Li
    Cancer Medicine.2023; 12(12): 13811.     CrossRef
  • Neighborhood Socioeconomic Status and Racial and Ethnic Survival Disparities in Oral Cavity and Laryngeal Cancer
    Yupeng Liu, Lydia Zhong, Sidharth V. Puram, Angela L. Mazul
    Cancer Epidemiology, Biomarkers & Prevention.2023; 32(5): 642.     CrossRef
  • Evaluation of Nicotine Dependence Among Smokeless Tobacco Users Using the Fagerstrom Nicotine Dependence Scale for Smokeless Tobacco
    Hiremath Shaashi uday, Ravikumar Pethagounder Thangavelu, Karthik Rajaram Mohan, Saramma Mathew Fenn, Kumar Appusamy
    Cureus.2023;[Epub]     CrossRef
  • The incidence of oral cavity cancer in Iran: A systematic review and meta‐analysis
    Mohammad Jokar, Negin Namavari, Seyed Alireza Moshiri, Hossein Kargar Jahromi, Vahid Rahmanian
    Cancer Reports.2023;[Epub]     CrossRef
  • Reducing the prevalence of smokeless tobacco in an evolving tobacco landscape
    Filippos T Filippidis
    The Lancet Global Health.2023; 11(6): e817.     CrossRef
  • The global impact of tobacco control policies on smokeless tobacco use: a systematic review
    Aastha Chugh, Monika Arora, Neha Jain, Aishwarya Vidyasagaran, Anne Readshaw, Aziz Sheikh, Jappe Eckhardt, Kamran Siddiqi, Mansi Chopra, Masuma Pervin Mishu, Mona Kanaan, Muhammad Aziz Rahman, Ravi Mehrotra, Rumana Huque, Sarah Forberger, Suranji Dahanaya
    The Lancet Global Health.2023; 11(6): e953.     CrossRef
  • Assessment of pH and Copper Content among Raw and Commercial Areca Nut Products, Contributing Factor towards Oral Submucous Fibrosis
    Sujatha S. Reddy, Rizwana Azmi, Shwetha Shwetha, Pavan T, Ravleen Nagi, Radhaprashanth Radhaprashanth, N Rakesh N Rakesh
    Malaysian Journal of Medicine and Health Sciences.2023; 19(2): 197.     CrossRef
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    Plants.2023; 12(12): 2330.     CrossRef
  • The hidden menace of smokeless tobacco in Pakistan: understanding the risks and possible solutions; a letter to the editor
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    International Journal of Surgery: Global Health.2023;[Epub]     CrossRef
  • Evaluation of Risk Factors in Patients with Head and Neck Cancer: A Case Control Study
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    Amanda Ramos da Cunha, Kelly Compton, Rixing Xu, Rashmi Mishra, Mark Thomas Drangsholt, Jose Leopoldo Ferreira Antunes, Alexander R. Kerr, Alistair R. Acheson, Dan Lu, Lindsey E. Wallace, Jonathan M. Kocarnik, Weijia Fu, Frances E. Dean, Alyssa Pennini, H
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    Cureus.2023;[Epub]     CrossRef
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    Indian Journal of Clinical Biochemistry.2022; 37(2): 178.     CrossRef
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    Australian and New Zealand Journal of Public Health.2022; 46(1): 87.     CrossRef
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    Brazilian Oral Research.2022;[Epub]     CrossRef
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    BMC Public Health.2022;[Epub]     CrossRef
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    Indian Journal of Surgical Oncology.2021; 12(S2): 250.     CrossRef
  • Awake Tracheal Intubation during COVID-19 Pandemic
    Rudranil Nandi, Kruti Bhajikhav, Nandita Gupta, Angshuman Rudra Pal, Neha Desai, Jyotsna Goswami
    Airway.2021; 4(2): 79.     CrossRef
  • Epidemiological Assessment of Oral Cancer Burden in PakistanEpidemiology of oral cancer in Pakistan
    Naila Malkani, Sara Kazmi, Muhammad Usman Rashid
    Cancer Investigation.2021; : 1.     CrossRef
  • Identification & correlation of bacterial diversity in oral cancer and long-term tobacco chewers- A case-control pilot study
    Shriya Sawant, Jinesh Dugad, Deepak Parikh, Sathiyaraj Srinivasan, Harinder Singh
    Journal of Medical Microbiology .2021;[Epub]     CrossRef
  • Perceptions and Practices of General Practitioners towards Oral Cancer and Emerging Risk Factors among Indian Immigrants in Australia: A Qualitative Study
    Nidhi Saraswat, Rona Pillay, Neeta Prabhu, Bronwyn Everett, Ajesh George
    International Journal of Environmental Research and Public Health.2021; 18(21): 11111.     CrossRef
  • Global, regional, and national burden and quality of care index (QCI) of lip and oral cavity cancer: a systematic analysis of the Global Burden of Disease Study 1990–2017
    Ahmad Sofi-Mahmudi, Masoud Masinaei, Erfan Shamsoddin, Marcos Roberto Tovani-Palone, Mohammad-Hossein Heydari, Shervan Shoaee, Erfan Ghasemi, Sina Azadnajafabad, Shahin Roshani, Negar Rezaei, Mohammad-Mahdi Rashidi, Reyhaneh Kalantar Mehrjardi, Amir Ali H
    BMC Oral Health.2021;[Epub]     CrossRef
  • New Scenarios in Pharmacological Treatments of Head and Neck Squamous Cell Carcinomas
    Cristina Porcheri, Thimios A. Mitsiadis
    Cancers.2021; 13(21): 5515.     CrossRef
  • Smokeless tobacco use and reproductive outcomes among women: a systematic review
    A.G. Radhika, Sutapa B. Neogi, Preetha GS, Sumant Swain, Jaswinder Kaur, Jagdish Kaur
    F1000Research.2021; 10: 1171.     CrossRef
  • Nasopharyngeal carcinoma: A new synthesis of literature data (Review)
    Daniela Jicman (Stan), Elena Niculet, Mihaela Lungu, Cristian Onisor, Laura Rebegea, Doinita Vesa, Laura Bezman, Florin Bujoreanu, Mihaela Sarbu, Raul Mihailov, Silvia Fotea, Alin Tatu
    Experimental and Therapeutic Medicine.2021;[Epub]     CrossRef
  • Association of Demographic Details with the Onset of Precancerous Lesions in Bengaluru Population
    Shweta Sharma, Karishma Jain, Dilip N., Puneet Shetty, Chethana T.
    Kristu Jayanti Journal of Core and Applied Biology (KJCAB).2021; : 22.     CrossRef
  • The effect of theory - Based educational intervention on consumption of smokeless tobacco products by merchants’ guilds
    Mohammad Saeed Jadgal, Somayeh Alizadeh, Hadi Alizadeh -Siuki, Saeedeh Sadeghi, Tahmineh Salehian, Moradali Zareipour
    Journal of Education and Health Promotion.2021; 10(1): 428.     CrossRef
  • Colchicine as a Therapeutic Drug in the Management of Oral Submucous Fibrosis - A Randomized Clinical Study
    Somisetty V. M. M. Mounika, Rakesh K. Manne, Natarajan Kannan, Swapna S. Beeraka, Prathi V. Sarath, Kanamarlapudi V. Saikiran
    Journal of Indian Academy of Oral Medicine and Radiology.2021; 33(3): 236.     CrossRef
  • Effect of paan masala on voice parameters
    K. Sandhya, N. Priyanka, C. Chethan
    Journal of Laryngology and Voice.2021; 11(1): 7.     CrossRef
  • Betel Nut (areca) and Smokeless Tobacco Use in Myanmar
    Roger L. Papke, Indraneel Bhattacharyya, Dorothy K. Hatsukami, Ingyin Moe, Sam Glatman
    Substance Use & Misuse.2020; 55(9): 1385.     CrossRef
  • Chemistry, metabolism and pharmacology of carcinogenic alkaloids present in areca nut and factors affecting their concentration
    Alpana K. Gupta, Sonam Tulsyan, Nisha Thakur, Vishwas Sharma, Dhirendra N. Sinha, Ravi Mehrotra
    Regulatory Toxicology and Pharmacology.2020; 110: 104548.     CrossRef
  • Effects of Silver and Gold Nanoparticles Phytosynthesized with Cornus Mas Extract on Oral Dysplastic Human Cells
    Ioana Baldea, Adrian Florea, Diana Olteanu, Simona Clichici, Luminita David, Bianca Moldovan, Mihai Cenariu, Marcela Achim, Ramona Suharoschi, Sorina Danescu, Adriana Vulcu, Gabriela Adriana Filip
    Nanomedicine.2020; 15(1): 55.     CrossRef
  • Significance of 125I radioactive seed implantation on growth differentiation factor and programmed death receptor-1 during treatment of oral cancer
    Gang Xue, Yao Feng, Jia-Bin Li
    World Journal of Clinical Cases.2020; 8(5): 874.     CrossRef
  • Management of early oral cavity squamous cancers
    Abhishek Chatterjee, Sarbani Ghosh Laskar, Devendra Chaukar
    Oral Oncology.2020; 104: 104627.     CrossRef
  • Cancer Prevention in Low-Resource Countries: An Overview of the Opportunity
    Sailaja Kamaraju, Jeffrey Drope, Rengaswamy Sankaranarayanan, Surendra Shastri
    American Society of Clinical Oncology Educational Book.2020; (40): 72.     CrossRef
  • Impact of COVID-19 on the early detection of oral cancer: A special emphasis on high risk populations
    Sadeq Ali AL-Maweri, Esam Halboub, Saman Warnakulasuriya
    Oral Oncology.2020; 106: 104760.     CrossRef
  • Status and strategies for the management of head and neck cancer during COVID‐19 pandemic: Indian scenario
    Anand Gupta, Vipin Arora, Deepa Nair, Nishant Agrawal, Yu‐xiong Su, F Christopher Holsinger, Jason Y K Chan
    Head & Neck.2020; 42(7): 1460.     CrossRef
  • Betel Quid, Health, and Addiction
    Roger L. Papke, Dorothy K. Hatsukami, Thaddeus A. Herzog
    Substance Use & Misuse.2020; 55(9): 1528.     CrossRef
  • Metal-induced oxidative stress: an evidence-based update of advantages and disadvantages
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    Current Opinion in Toxicology.2020; 20-21: 55.     CrossRef
  • A qualitative study of gutka and paan masala use among Bhutanese and Burmese migrants in Georgia
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    PLOS ONE.2020; 15(8): e0237266.     CrossRef
  • Interaction of human oral cancer and the expression of virulence genes of dental pathogenic bacteria
    Mansour Moghimi, Ronak Bakhtiari, Jalil Fallah Mehrabadi, Nagar Jamshidi, Nazanin Jamshidi, Abolghasem Siyadatpanah, Watcharapong Mitsuwan, Veeranoot Nissapatorn
    Microbial Pathogenesis.2020; 149: 104464.     CrossRef
  • Role of Oral Bacteria in the Development of Oral Squamous Cell Carcinoma
    Qinyang Li, Yao Hu, Xuedong Zhou, Shiyu Liu, Qi Han, Lei Cheng
    Cancers.2020; 12(10): 2797.     CrossRef
  • Prevalence of Tobacco Consumption among Men in Amarpur Village, Uttar Pradesh, India, May 2019: A cross-sectional study
    AliJan Nazari, NaveenH Simon, Ajoke Akinola, Muskan Kaushik
    CHRISMED Journal of Health and Research.2020; 7(2): 115.     CrossRef
  • Prenatal Exposure to Gutkha, a Globally Relevant Smokeless Tobacco Product, Induces Hepatic Changes in Adult Mice
    Shannon Doherty Lyons, Jason L. Blum, Carol Hoffman-Budde, Pamela B. Tijerina, M. Isabel Fiel, Daniel J. J. Conklin, Francesca Gany, Joseph A. Odin, Judith T. Zelikoff
    International Journal of Environmental Research and Public Health.2020; 17(21): 7895.     CrossRef
  • Global impact of tobacco control policies on smokeless tobacco use: a systematic review protocol
    Monika Arora, Aastha Chugh, Neha Jain, Masuma Mishu, Melanie Boeckmann, Suranji Dahanayake, Jappe Eckhardt, Sarah Forberger, Rumana Huque, Mona Kanaan, Zohaib Khan, Ravi Mehrotra, Muhammad Aziz Rahman, Anne Readshaw, Aziz Sheikh, Kamran Siddiqi, Aishwarya
    BMJ Open.2020; 10(12): e042860.     CrossRef
  • Effect of Areca Nut on Oral Health: A Review
    M Shirzaiy, F Neshat
    Journal of Research in Dental and Maxillofacial Sciences.2020; 5(3): 1.     CrossRef
  • Patterns of Tobacco Use and its Relation to Oral Precancers and Cancers among Individuals Visiting a Tertiary Hospital in South India
    Ravikiran Ongole, Aarish Khan, Joanna Baptist, Natarajan Srikant, Fatema Lukmani
    The Journal of Contemporary Dental Practice.2020; 21(3): 304.     CrossRef
  • COVID-19 and Its Impact on Tobacco Use – Is India Prepared to Unlock the link?
    Radhakrishnan Jayakrishnan
    European Journal of Medical and Health Sciences.2020;[Epub]     CrossRef
  • Cisplatin Every 3 Weeks Versus Weekly With Definitive Concurrent Radiotherapy for Squamous Cell Carcinoma of the Head and Neck
    Joshua M Bauml, Ravi Vinnakota, Yeun-Hee Anna Park, Susan E Bates, Tito Fojo, Charu Aggarwal, Sewanti Limaye, Nevena Damjanov, Jessica Di Stefano, Christine Ciunci, Eric M Genden, Juan P Wisnivesky, Rocco Ferrandino, Ronac Mamtani, Corey J Langer, Roger B
    JNCI: Journal of the National Cancer Institute.2019; 111(5): 490.     CrossRef
  • Differential expression of salivary S100A7 in oral submucous fibrosis
    Muhammad Arsalan Raffat, Naila Irum Hadi, Mervyn Hosein, Adnan Mustafa Zubairi, Sana Ikram, Zohaib Akram
    The Saudi Dental Journal.2019; 31(1): 39.     CrossRef
  • Grass roots approach to control levels of carcinogenic nitrosamines, NNN and NNK in smokeless tobacco products
    Alpana K. Gupta, Sonam Tulsyan, Mausumi Bharadwaj, Ravi Mehrotra
    Food and Chemical Toxicology.2019; 124: 359.     CrossRef
  • DARK Classics in Chemical Neuroscience: Arecoline
    Andrey D. Volgin, Alim Bashirzade, Tamara G. Amstislavskaya, Oleg A. Yakovlev, Konstantin A. Demin, Ying-Jui Ho, Dongmei Wang, Vadim A. Shevyrin, Dongni Yan, Zhichong Tang, Jingtao Wang, Mengyao Wang, Erik T. Alpyshov, Nazar Serikuly, Edina A. Wappler-Guz
    ACS Chemical Neuroscience.2019; 10(5): 2176.     CrossRef
  • Smokeless Tobacco and Its Adverse Effects on Hematological Parameters: A Cross-Sectional Study
    Anjani Kumar Shukla, Tanya Khaitan, Prashant Gupta, Shantala R. Naik
    Advances in Preventive Medicine.2019; 2019: 1.     CrossRef
  • GC-MS Analysis and Cytotoxicity Evaluation of Shammah (Smokeless Tobacco) Samples of Jazan Region of Saudi Arabia as Promoter of Cancer Cell Proliferation
    Asaad Khalid, Hassan A. Alhazmi, Ashraf N. Abdalla, Waquar Ahsan, Shahnaz Sultana, Mohammed Al Bratty, Sadique A. Javed, Zia ur Rehman
    Journal of Chemistry.2019; 2019: 1.     CrossRef
  • How Each Component of Betel Quid Is Involved in Oral Carcinogenesis: Mutual Interactions and Synergistic Effects with Other Carcinogens—a Review Article
    Shajedul Islam, Malsantha Muthumala, Hirofumi Matsuoka, Osamu Uehara, Yasuhiro Kuramitsu, Itsuo Chiba, Yoshihiro Abiko
    Current Oncology Reports.2019;[Epub]     CrossRef
  • Oral Cavity Cancer in the Indian Subcontinent – Challenges and Opportunities
    N. Mummudi, J.P. Agarwal, S. Chatterjee, I. Mallick, S. Ghosh-Laskar
    Clinical Oncology.2019; 31(8): 520.     CrossRef
  • Chronic Exposure to Chewing Tobacco Induces Metabolic Reprogramming and Cancer Stem Cell-Like Properties in Esophageal Epithelial Cells
    Keshava K. Datta, Shankargouda Patil, Krishna Patel, Niraj Babu, Remya Raja, Vishalakshi Nanjappa, Kiran Kumar Mangalaparthi, Bharti Dhaka, Pavithra Rajagopalan, Sayali Chandrashekhar Deolankar, Ramakrishnan Kannan, Prashant Kumar, T. S. Keshava Prasad, P
    Cells.2019; 8(9): 949.     CrossRef
  • Association of smokeless tobacco with oral cancer: A review of systematic reviews
    Smita Asthana, Parul Vohra, Satyanarayana Labani
    Tobacco Prevention & Cessation.2019;[Epub]     CrossRef
  • Correlation of urinary cotinine with cardiovascular risk factors in pan masala tobacco users
    Sanjeeb Shrestha, Deebya Raj Mishra, Niraj Dhakal, Suresh Bhandari, Sagar Khanal, Madhab Lamsal
    Indian Heart Journal.2019; 71(6): 459.     CrossRef
  • Prevalence of Oral mucosal lesions and their association with Pattern of tobacco use among patients visiting a dental institution
    Swati Verma, Hunny Sharma
    Indian Journal of Dental Research.2019; 30(5): 652.     CrossRef
  • Smokeless tobacco products profile and pictorial warning labels in India: A review
    Fareeda Shaik, Narendra Maddu
    Population Medicine.2019;[Epub]     CrossRef
  • Patterns of Tobacco Consumption among Oral Squamous Cell Carcinoma Cases Attending a Tertiary Care Dental Hospital in Coastal Karnataka of India
    Sukanya Shetty, Shankaran V Sreelatha, Vimal K Karnaker, Chitta R Chowdhury
    World Journal of Dentistry.2019; 10(5): 350.     CrossRef
  • Oral Health Behavior and Factors Influencing the Selection of Oral Hygiene Products among the Adolescent Tobacco Consumers in Jharkhand
    Virendra K Prajapati
    The Journal of Contemporary Dental Practice.2019; 20(10): 1200.     CrossRef
  • Development of α-tocopherol surface-modified targeted delivery of 5-fluorouracil-loaded poly-D, L-lactic-co-glycolic acid nanoparticles against oral squamous cell carcinoma
    Saurabh Srivastava, Shalini Gupta, Shadab Mohammad, Irfan Ahmad
    Journal of Cancer Research and Therapeutics.2019; 15(3): 480.     CrossRef
  • A Study on Tobacco Use Among School Children
    Arun Kurupath, Pankaj Sureka
    Community Mental Health Journal.2018; 54(8): 1253.     CrossRef
  • A potential association between mutations in the iNOS cDNA 3′ stretch and oral squamous cell carcinoma - A preliminary study
    Sapna Khowal, Swatantra Kumar Jain, Saima Wajid
    Meta Gene.2018; 16: 189.     CrossRef
  • Areca Nut Chewing and the Risk of Re-hospitalization and Mortality Among Patients With Acute Coronary Syndrome in Pakistan
    Muhammad Tariq Karim, Sumera Inam, Tariq Ashraf, Nadia Shah, Syed Omair Adil, Kashif Shafique
    Journal of Preventive Medicine and Public Health.2018; 51(2): 71.     CrossRef
  • Cigarette smoke and chewing tobacco alter expression of different sets of miRNAs in oral keratinocytes
    Mohd Younis Bhat, Jayshree Advani, Pavithra Rajagopalan, Krishna Patel, Vishalakshi Nanjappa, Hitendra S. Solanki, Arun H. Patil, Firdous A. Bhat, Premendu P. Mathur, Bipin Nair, T. S. Keshava Prasad, Joseph A. Califano, David Sidransky, Harsha Gowda, Adi
    Scientific Reports.2018;[Epub]     CrossRef
  • Association ofDFNA5, SYK, andNELL1variants along with HPV infection in oral cancer among the prolonged tobacco-chewers
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    Tumor Biology.2018; 40(8): 101042831879302.     CrossRef
  • Epidemiologic Pattern and Types of Oral Smokeless Tobacco Usage in Saudi Arabia
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    The Journal of Contemporary Dental Practice.2018; 19(4): 456.     CrossRef
  • Environmental toxicants, incidence of degenerative diseases, and therapies from the epigenetic point of view
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    Archives of Toxicology.2017; 91(7): 2577.     CrossRef
  • Cell-free mitochondrial DNA copy number variation in head and neck squamous cell carcinoma: A study of non-invasive biomarker from Northeast India
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    Tumor Biology.2017; 39(10): 101042831773664.     CrossRef

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