title: A histomorphometric analysis of the nature of the mandibular canal in the anterior molar region.
abstract: OBJECTIVE
  Knowledge of the position and configuration of the mandibular canal is a basic requirement before implant placement in the mandible. Radiological studies suggest a positive correlation between alveolar trabecular bone quality and mandibular canal corticalization. The aim of this study was to test this assumption histomorphometrically in the anterior molar region, which is one of the most frequent places for implantation.
  
  
  METHODS
  Fifty thin ground sections (from 28 male and 22 female cadavers) of the first molar region were investigated for trabecular bone volume and thickness and the presence of a mandibular canal wall.
  
  
  RESULTS
  Trabecular bone volume was significantly higher in males (p = 0.009). Further, it correlated significantly with the presence of a canal wall (rho = 0.585, p < 0.001), indicating that a reduced trabecular bone volume is associated with a reduced amount of bone surrounding the alveolar nerve. The cranial aspects of the canal wall were present at a significantly lower frequency (64.64 %) than the buccal, lingual, or caudal sides (p < 0.006).
  
  
  CONCLUSIONS
  The present study demonstrated that low trabecular bone volume correlates with only a fragmentarily present mandibular canal wall. This suggests that bone surrounding the alveolar nerve is of trabecular, not cortical, origin and possibly affected by reduction of the trabecular bone.
  
  
  CONCLUSIONS
  These results imply that oral surgeons should pay particular attention to implant placement in patients with low alveolar bone quality. The cranial aspects of the mandibular canal might be only fragmentarily or even completely missing. Consequently, they hardly present resistance during implant site preparation, and the risk for nerve injury, e.g., due to post-surgery hematoma, could be increased.
authors.affiliation: Division of Oral Surgery, Bernhard Gottlieb School of Dentistry, Medical University of Vienna, Sensengasse 2a, 1090, Vienna, Austria.
authors.forename: Kristina
authors.initials: K
authors.lastname: Bertl
authors.forename: Patrick
authors.initials: P
authors.lastname: Heimel
authors.forename: Karoline Maria
authors.initials: KM
authors.lastname: Reich
authors.forename: Uwe Yacine
authors.initials: UY
authors.lastname: Schwarze
authors.forename: Christian
authors.initials: C
authors.lastname: Ulm
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002102:Cadaver; D005260:Female; D006801:Humans; D008297:Male; D008334:Mandible / Q000033:anatomy & histology*; D008875:Middle Aged; D008963:Molar / Q000033:anatomy & histology*