RESUMO
BACKGROUND: Smoking and chewing tobacco are associated with numerous oral mucosal lesions and conditions, often leading to cancer progression. AIM: To investigate the prevalence of precancerous lesions and conditions among the Indian population. METHODS: Systematic search was conducted for population or community-based observational epidemiological studies in PubMed, EMBASE, Web of Science, IndMED, Google Scholar, reports of the WHO South-East Asia Region, MOHFW India reports, Science Citation Index, WHO Index Medicus of the South-East Asian Region, Reference Citation Analysis (https://www.referencecitationanalysis.com/) and Open Grey from the earliest available up to 31st January 2022. The effect size was calculated for the prevalence of precancerous lesions and conditions. RESULTS: One hundred sixty-two estimates from 130 studies yielded 52 high, 71 moderate, and seven low-quality studies from 823845. Point estimate based on cross-sectional studies for leukoplakia was 4.3% (95%CI: 4.0-4.6), oral submucous fibrosis was 2.7% (95%CI: 2.5-3.0), palatal lesions in reverse smokers and nicotine palatine were 5.8% (95%CI: 4.4-7.2), and Erythroplakia was 1.2% (95%CI: 0.7-1.7), and lichen planus was 1.1% (95%CI: 0.9-1.2). Amongst hospital-based studies, the pooled prevalence for Leukoplakia was 6.7% (95%CI: 6.0-7.3), oral submucous fibrosis was 4.5% (95%CI: 4.2-4.9), lichen planus was 7.5% (95%CI: 5.3-9.6), and erythroplakia was 2.5% (95%CI: 0.4-4.5), and palatal lesions in reverse smokers and nicotine palatini were 11.5% (95%CI: 8.0-15.0). CONCLUSION: Precancerous lesions and conditions are prevailing problems among the Indian population. It is mainly due to tobacco use, the smokeless form of tobacco. The meta-analysis indicates that hospital-based studies have a higher effect size of 6.7% than community-based studies. Patients who have already developed this condition may be advised to reduce their exposure to the risk factor to prevent the condition from progressing further.
RESUMO
The aim of this paper is to review the literature on root canal configuration (RCC) and the frequency of occurrence of a second mesiobuccal canal (MB) in human permanent maxillary first molars where cone-beam computed tomography (CBCT) is used. Online electronic databases such as PubMed-Medline, Embase, Scopus and Cochrane Library were searched using appropriate keywords from the earliest available date until 12th June 2022, without restriction on language. In the mesiobuccal root, type I was the most frequent (33.29%), followed by types II and IV (27.18% and 26.36%, respectively). Moreover, 68.2% of maxillary first molars had a second MB canal. For both the distobuccal and palatal roots, type I was the most prevalent, with 99.08% and 97.83% occurrence, respectively. All other types were infrequent. Type I RCC is most frequent in all the roots of the maxillary first molars. Hence, care must be taken during biomechanical preparation of the MB roots.