title: A Cone-Beam Computed Tomographic Study on Mandibular First Molars in a Chinese Subpopulation.
abstract: The purpose of this study was to conduct a cone-beam computed tomographic (CBCT) investigation on the root and canal configuration of the mandibular first molars, especially the morphology of the disto-lingual (DL) root, in a Chinese subpopulation. A total of 910 CBCT images of the mandibular first molars were collected from 455 patients who underwent CBCT examinations as a preoperative assessment for implants or orthodontic treatment. The following information was analyzed and evaluated: tooth position, gender, root and root canal number per tooth, root canal type of the mesial root(s) and distal root(s), angle of the DL root canal curvature, distance between two distal canal orifices in the teeth with DL root, and angle of disto-buccal canal orifice-disto-lingual canal orifice-mesio-lingual canal orifice (DB-DL-ML). Most of the mandibular first molars (64.9%, n = 591) had two roots with three root canals, and most of the mesial root canals (87.7%, n = 798) were type VI. The prevalence of the DL root was 22.1% (n = 201). The right side had a higher prevalence of DL root than the left side (p<0.05). Additionally, the curvature of the DL root canal were greater in the bucco-lingual (BL) orientation (30.10°±14.02°) than in the mesio-distal (MD) orientation (14.03°± 8.56°) (p<0.05). Overall there was a high prevalence of DL root in the mandibular first molars, and most of the DL roots were curved in different degrees. This study provided detailed information about the root canal morphology of the mandibular first molars in a Chinese subpopulation.
authors.affiliation: VIP Center and Shandong Provincial Key Laboratory of Oral Biomedicine, School and Hospital of Stomatology, Shandong University, Jinan, Shangdong, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Zhang
authors.affiliation: VIP Center and Shandong Provincial Key Laboratory of Oral Biomedicine, School and Hospital of Stomatology, Shandong University, Jinan, Shangdong, China.
authors.forename: Shijiang
authors.initials: S
authors.lastname: Xiong
authors.affiliation: VIP Center and Shandong Provincial Key Laboratory of Oral Biomedicine, School and Hospital of Stomatology, Shandong University, Jinan, Shangdong, China.
authors.forename: Yue
authors.initials: Y
authors.lastname: Ma
authors.affiliation: Department of Endodontics, School and Hospital of Stomatology, Shandong University, Jinan, Shangdong, China.
authors.forename: Ting
authors.initials: T
authors.lastname: Han
authors.affiliation: VIP Center and Shandong Provincial Key Laboratory of Oral Biomedicine, School and Hospital of Stomatology, Shandong University, Jinan, Shangdong, China.
authors.forename: Xinyu
authors.initials: X
authors.lastname: Chen
authors.affiliation: VIP Center and Shandong Provincial Key Laboratory of Oral Biomedicine, School and Hospital of Stomatology, Shandong University, Jinan, Shangdong, China.
authors.forename: Fang
authors.initials: F
authors.lastname: Wan
authors.affiliation: VIP Center and Shandong Provincial Key Laboratory of Oral Biomedicine, School and Hospital of Stomatology, Shandong University, Jinan, Shangdong, China.
authors.forename: Yating
authors.initials: Y
authors.lastname: Lu
authors.affiliation: VIP Center and Shandong Provincial Key Laboratory of Oral Biomedicine, School and Hospital of Stomatology, Shandong University, Jinan, Shangdong, China.
authors.forename: Songhe
authors.initials: S
authors.lastname: Yan
authors.affiliation: VIP Center and Shandong Provincial Key Laboratory of Oral Biomedicine, School and Hospital of Stomatology, Shandong University, Jinan, Shangdong, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Wang
mesh_terms: D044466:Asian People; D054893:Cone-Beam Computed Tomography; D003786:Dental Pulp Cavity / Q000000981:diagnostic imaging; D005006:Ethnicity; D005260:Female; D006801:Humans; D008297:Male; D008334:Mandible / Q000000981:diagnostic imaging*; D008963:Molar / Q000000981:diagnostic imaging*; D009811:Odontometry; D014092:Tooth Root / Q000000981:diagnostic imaging