title: Second canal in mesiobuccal root of maxillary molars is correlated with root third and patient age: a cone-beam computed tomographic study.
abstract: BACKGROUND
  There is little evidence supporting the use of cone-beam computed tomographic (CBCT) scanning in root canal anatomy investigation. This study aimed to investigate the presence of second mesiobuccal canals (MB2) in different thirds of the mesiobuccal root of first and second maxillary molars using CBCT scanning and to correlate findings with patient sex and age.
  
  
  METHODS
  A total of 100 male and female adult patients with healthy, untreated, well-developed maxillary molars were enrolled. A total of 343 teeth were analyzed in vivo using CBCT scanning: 79 right and 79 left maxillary first molars (1MR and 1ML) and 94 right and 91 left maxillary second molars (2MR and 2ML). Teeth with 3 roots were identified, and the presence of MB2 canals in different thirds was correlated with patient sex and age.
  
  
  RESULTS
  Maxillary molars with 3 roots showed a high percentage of MB2 canals: 1MR, 86.1%; 1ML, 91.0%; 2MR, 87.5%; and 2ML, 79.3%. MB2 canals were less prevalent in the middle and apical thirds than in the coronal third. There were no significant associations between the overall presence of MB2 canals and patient sex. Older age (ie, 51-70 years) was associated with fewer canals in 1ML and 2ML. All age groups showed fewer MB2 canals in the apical versus the coronal third.
  
  
  CONCLUSIONS
  The prevalence of MB2 canals decreases as the root canal approaches the apical third and as age increases. No association with sex was observed. CBCT scanning proved effective in mapping MB2 canals present in different thirds of the root.
authors.affiliation: Department of Dental and Maxillofacial Radiology, School of Dentistry, Universidade Luterana do Brasil, Canoas, Rio Grande do Sul, Brazil.
authors.forename: Adriana Gurgel de Araújo Rebouças
authors.initials: AG
authors.lastname: Reis
authors.forename: Renata
authors.initials: R
authors.lastname: Grazziotin-Soares
authors.forename: Fernando Branco
authors.initials: FB
authors.lastname: Barletta
authors.forename: Vania Regina Camargo
authors.initials: VR
authors.lastname: Fontanella
authors.forename: Celia Regina Winck
authors.initials: CR
authors.lastname: Mahl
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D063405:Anatomic Variation; D054893:Cone-Beam Computed Tomography / Q000379:methods*; D003786:Dental Pulp Cavity / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008297:Male; D008437:Maxilla; D008875:Middle Aged; D008963:Molar / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D012737:Sex Factors; D019227:Tooth Apex / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D019237:Tooth Cervix / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D014092:Tooth Root / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D055815:Young Adult