title: Proximity of the mandibular molar root apex from the buccal bone surface: a cone-beam computed tomographic study.
abstract: OBJECTIVE
  The purpose of this study was to evaluate the proximity of the mandibular molar apex to the buccal bone surface in order to provide anatomic information for apical surgery.
  
  
  METHODS
  Cone-beam computed tomography (CBCT) images of 127 mandibular first molars and 153 mandibular second molars were analyzed from 160 patients' records. The distance was measured from the buccal bone surface to the root apex and the apical 3.0 mm on the cross-sectional view of CBCT.
  
  
  RESULTS
  The second molar apex and apical 3 mm were located significantly deeper relative to the buccal bone surface compared with the first molar (p < 0.01). For the mandibular second molars, the distance from the buccal bone surface to the root apex was significantly shorter in patients over 70 years of age (p < 0.05). Furthermore, this distance was significantly shorter when the first molar was missing compared to nonmissing cases (p < 0.05). For the mandibular first molars, the distance to the distal root apex of one distal-rooted tooth was significantly greater than the distance to the disto-buccal root apex (p < 0.01). In mandibular second molar, the distance to the apex of C-shaped roots was significantly greater than the distance to the mesial root apex of non-C-shaped roots (p < 0.01).
  
  
  CONCLUSIONS
  For apical surgery in mandibular molars, the distance from the buccal bone surface to the apex and apical 3 mm is significantly affected by the location, patient age, an adjacent missing anterior tooth, and root configuration.
authors: Department of Conservative Dentistry, Kyungpook National University School of Dentistry, Daegu, Korea.
authors: Dokyung
authors: D
authors: Kim
authors: Department of Conservative Dentistry, Kyungpook National University School of Dentistry, Daegu, Korea.
authors: Jung-Hong
authors: 0000-0002-0469-4324
authors: JH
authors: Ha
authors: Department of Conservative Dentistry, Kyungpook National University School of Dentistry, Daegu, Korea.
authors: Myoung-Uk
authors: MU
authors: Jin
authors: Department of Conservative Dentistry, Kyungpook National University School of Dentistry, Daegu, Korea.
authors: Young-Kyung
authors: 0000-0002-2534-9028
authors: YK
authors: Kim
authors: Department of Conservative Dentistry, Kyungpook National University School of Dentistry, Daegu, Korea.
authors: Sung Kyo
authors: 0000-0002-9160-7187
authors: SK
authors: Kim
keywords: Apical surgery; Apicoectomy; Buccal bone thickness; Cone-beam computed tomography; Mandibular molar; Root apex