title: Proximity of the Mandibular Canal to Teeth and Cortical Bone.
abstract: BACKGROUND
  The proximity of the inferior alveolar canal to the mandibular molar roots may pose a risk of injury during various dental surgeries. The purpose of this study was to evaluate age-related and gender-related changes by using cone-beam computed tomography images between the roots of the second molars, mandibular cortex, and the inferior alveolar canal.
  
  
  METHODS
  One hundred fifty-five patients (68 men, 87 women), 20 years and older, who had previous cone-beam computed tomography scans were enrolled in this study. The patients were subcategorized by gender and age (group I, <21 years; group II, 21-40 years; and group III, >40 years). Distance between the mandibular canal (MC) and the second molar distal root apex as well as the 3 mandibular cortical regions (inferior cortex, buccal cortex, and lingual cortex) were measured.
  
  
  RESULTS
  In men, the second molar root apex to the MC distance was significantly shorter in group I than in group III (P < .01). In women, the second molar root apex to the MC distance was significantly shorter in group I than in group II and group III (P < .05). In both men and women, the buccal cortex of the mandible to the MC distance was significantly shorter on the right side compared with the left side (P < .01).
  
  
  CONCLUSIONS
  Our study shows that age, gender, and region have an influence on the location of the MC in the second molar area.
authors.affiliation: Department of Radiology, Boston Medical Center, Boston University School of Medicine, Boston, Massachusetts; Department of Radiology, Nihon University School of Dentistry at Matsudo, Chiba, Japan. Electronic address: yusukekawashima05@gmail.com.
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Kawashima
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Boston Medical Center, Boston University School of Medicine, Boston, Massachusetts; Department of Radiation Oncology, Boston Medical Center, Boston University School of Medicine, Boston, Massachusetts.
authors.forename: Osamu
authors.initials: O
authors.lastname: Sakai
authors.affiliation: Division of Oral and Maxillofacial Radiology, Boston University Henry M. Goldman School of Dental Medicine, Boston, Massachusetts.
authors.forename: Dhurata
authors.initials: D
authors.lastname: Shosho
authors.affiliation: Department of Radiology, Nihon University School of Dentistry at Matsudo, Chiba, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Kaneda
authors.affiliation: Division of Oral and Maxillofacial Radiology, Boston University Henry M. Goldman School of Dental Medicine, Boston, Massachusetts.
authors.forename: Anita
authors.initials: A
authors.lastname: Gohel
mesh_terms: D000328:Adult; D000367:Age Factors; D054893:Cone-Beam Computed Tomography / Q000379:methods; D000071538:Cortical Bone / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D003786:Dental Pulp Cavity / Q000000981:diagnostic imaging; D005260:Female; D006801:Humans; D008297:Male; D008334:Mandible / Q000033:anatomy & histology* / Q000000981:diagnostic imaging / Q000294:innervation; D008340:Mandibular Nerve / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D008875:Middle Aged; D008963:Molar / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D009811:Odontometry; D012737:Sex Factors; D019227:Tooth Apex / Q000033:anatomy & histology / Q000000981:diagnostic imaging / Q000294:innervation; D014092:Tooth Root / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D055815:Young Adult
keywords: Inferior alveolar nerve; mandibular canal; mandibular cortex; mandibular second molar