Jorge N R Martins1, Duarte Marques2, Emmanuel João Nogueira Leal Silva3, João Caramês4, António Mata5, Marco A Versiani6. 1. Unidade de Investigação em Ciências Orais e Biomédicas (UICOB), Faculdade de Medicina Dentária, Universidade de Lisboa, Portugal; Centro de Estudo de Medicina Dentária Baseada na Evidência, Faculdade de Medicina Dentária, Universidade de Lisboa, Portugal; Instituto de Implantologia, Lisboa, Portugal. Electronic address: jnr_martins@yahoo.com.br. 2. Centro de Estudo de Medicina Dentária Baseada na Evidência, Faculdade de Medicina Dentária, Universidade de Lisboa, Portugal; Instituto de Implantologia, Lisboa, Portugal; LIBPhys-FCT UID/FIS/04559/2013, Lisboa, Portugal. 3. Department of Endodontics, School of Dentistry, Grande Rio University, Rio de Janeiro, Brazil; Department of Endodontics, Rio de Janeiro State University, Rio de Janeiro, Brazil. 4. Instituto de Implantologia, Lisboa, Portugal; LIBPhys-FCT UID/FIS/04559/2013, Lisboa, Portugal; Faculdade de Medicina Dentária, Universidade de Lisboa, Portugal. 5. Centro de Estudo de Medicina Dentária Baseada na Evidência, Faculdade de Medicina Dentária, Universidade de Lisboa, Portugal; LIBPhys-FCT UID/FIS/04559/2013, Lisboa, Portugal. 6. Dental Specialty Center, Brazilian Military Police, Minas Gerais, Brazil.
Abstract
OBJECTIVE: The purpose of this systematic review was to assess the influence of population demographic characteristics on the prevalence of a second canal in mandibular anterior teeth. DESIGN: Four electronic databases and five peer-reviewed journals were searched from May 2018 to September 2019 for prevalence studies using cone-beam computed tomographic imaging on second canal morphology in mandibular anterior teeth. The identified studies were subjected to a hand search of bibliographic references followed by contact with the authors. Full text analysis and critical appraisal (JBI) was undertaken on 40 papers by 2 evaluators. Sixteen studies were included into a meta-analysis. Forest plots with proportion and odds ratios with a 95% confidence interval were calculated. Meta-regression was performed in order to identify possible sources of heterogeneity. RESULTS: The 16 selected studies presented an average JBI score of 77.7% and revealed data from 40,784 mandibular anterior teeth (14,278 central incisors, 14,433 lateral incisors, and 12,073 canines). The overall prevalence of a second canal for central incisors, lateral incisors and canines was 20.4% (15.0%-25.7% CI 95%), 25.3% (20.0%-30.7% CI 95%) and 5.9% (4.1%-7.7% CI 95%), respectively. Males showed significantly higher odds of having a second canal for both incisors (p < 0.05). East Asia studies presented lower proportions of a second canal in mandibular anterior teeth (p < 0.05). CONCLUSIONS: The overall prevalence of a second canal in the mandibular central and lateral incisors and canines was 20.4%, 25.3% and 5.9%, respectively. Meta-analysis calculation revealed gender and patient geographic origin as possible confounding factors of the proportion outcomes.
OBJECTIVE: The purpose of this systematic review was to assess the influence of population demographic characteristics on the prevalence of a second canal in mandibular anterior teeth. DESIGN: Four electronic databases and five peer-reviewed journals were searched from May 2018 to September 2019 for prevalence studies using cone-beam computed tomographic imaging on second canal morphology in mandibular anterior teeth. The identified studies were subjected to a hand search of bibliographic references followed by contact with the authors. Full text analysis and critical appraisal (JBI) was undertaken on 40 papers by 2 evaluators. Sixteen studies were included into a meta-analysis. Forest plots with proportion and odds ratios with a 95% confidence interval were calculated. Meta-regression was performed in order to identify possible sources of heterogeneity. RESULTS: The 16 selected studies presented an average JBI score of 77.7% and revealed data from 40,784 mandibular anterior teeth (14,278 central incisors, 14,433 lateral incisors, and 12,073 canines). The overall prevalence of a second canal for central incisors, lateral incisors and canines was 20.4% (15.0%-25.7% CI 95%), 25.3% (20.0%-30.7% CI 95%) and 5.9% (4.1%-7.7% CI 95%), respectively. Males showed significantly higher odds of having a second canal for both incisors (p < 0.05). East Asia studies presented lower proportions of a second canal in mandibular anterior teeth (p < 0.05). CONCLUSIONS: The overall prevalence of a second canal in the mandibular central and lateral incisors and canines was 20.4%, 25.3% and 5.9%, respectively. Meta-analysis calculation revealed gender and patient geographic origin as possible confounding factors of the proportion outcomes.