title: A microcomputed tomographic study of canal isthmuses in the mesial root of mandibular first molars in a Chinese population.
abstract: Untreated isthmuses can be a cause of endodontic treatment failure. We investigated the anatomic features of the isthmus in the mesial root of mandibular first molars using microcomputed tomography scans. Thirty-six extracted mandibular first molars were collected from the Chinese population and divided into three age groups as follows: 20 to 39 years (group A), 40 to 59 years (group B), and > or = 60 years (group C). Each tooth was scanned and reconstructed, and then the prevalence and type of isthmus were recorded. The percentage of sections showing isthmuses for groups A, B, and C were 50%, 41%, and 24%, respectively. The chi-square test indicated a significant correlation of the distribution of isthmuses with age (p < 0.001). The ratio of partial isthmus to complete isthmus for group C (17.1:1) was significantly higher than group A (5.9:1) and group B (7.0:1) (p < 0.001). By understanding the configuration and location of isthmus, a more efficient endodontic microsurgery can be guaranteed.
authors.affiliation: Department of Operative Dentistry and Endodontics, Guanghua School of Stomatology, Sun Yat-Sen University, Guangzhou, Guangdong, China.
authors.forename: Lisha
authors.initials: L
authors.lastname: Gu
authors.forename: Xi
authors.initials: X
authors.lastname: Wei
authors.forename: Junqi
authors.initials: J
authors.lastname: Ling
authors.forename: Xiangya
authors.initials: X
authors.lastname: Huang
mesh_terms: D000328:Adult; D000367:Age Factors; D044466:Asian People; D002681:China; D003786:Dental Pulp Cavity / Q000000981:diagnostic imaging*; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods; D008334:Mandible; D008875:Middle Aged; D008963:Molar / Q000000981:diagnostic imaging; D019227:Tooth Apex / Q000000981:diagnostic imaging*; D055114:X-Ray Microtomography; D055815:Young Adult