title: Evaluation by dental cone-beam computed tomography of the incidence and sites of branches of the inferior dental canal that supply mandibular third molars.
abstract: Our aim was to assess the incidence and anatomical site of branches of the inferior dental canal that supply mandibular third molars using dental cone-beam computed tomography (CT). We evaluated the incidence and diameter of branches of the inferior dental canal using 272 cone-beam CT mandibular scans from 172 patients referred for imaging before the extraction of impacted mandibular third molars. We found three typical branching patterns from the inferior dental canal in the third molar region: the retromolar canal (in the retromolar triangle), the dental canal (that courses directly beneath the socket of the third molar), and the accessory canal (that courses through the socket and leads from the inferior dental canal to a bony ridge). The incidences of retromolar, dental, and accessory canals were 75 (28%), 223 (82%), and 21 (8%), respectively, with mean diameters of 0.9 (0.4), 0.7 (0.5), and 1.1 (0.4) mm, respectively. Operative injury to the neurovascular contents within the branches of the inferior dental canal can lead to excessive bleeding and postoperative paraesthesia, so identification of its branches on preoperative cone-beam CT images may prove useful during extraction of impacted mandibular third molars or when harvesting bone blocks from the region of mandibular third molars. We also describe two cases of branches detected on panoramic and cone-beam CT images that prompted this research.
authors: Mikinogahara Dental & Oral Surgery Clinic, 10-1 Higashi-Ichiban-Cho, Towada, Aomori 034-0012, Japan. Electronic address: ao@cream.plala.or.jp.
authors: A
authors: A
authors: Ogawa
authors: Meihou Dental Clinic, 4-15-1 Akadate-machi, Odate, 017-0816 Akita, Japan.
authors: Y
authors: Y
authors: Fukuta
authors: Division of Oral and Maxillofacial Surgery, Department of Oral and Maxillofacial Reconstructive Surgery, School of Dentistry, Iwate Medical University, 19-1 Uchimaru, Morioka, Iwate 020-8505, Japan.
authors: H
authors: H
authors: Nakasato
authors: Nakasato Dental Office, 3-2-44 Midorigaoka, Morioka, Iwate 020-0117, Japan.
authors: S
authors: S
authors: Nakasato
mesh_terms: D054893:Cone-Beam Computed Tomography; D006801:Humans; D015994:Incidence; D008334:Mandible; D008963:Molar; D008964:Molar, Third / Q000033:anatomy & histology*; D011862:Radiography, Panoramic; D014095:Tooth, Impacted / Q000000981:diagnostic imaging*
keywords: Accessory canal; Dental canal; Dental cone-beam CT; Impacted mandibular third molar; Retromolar canal