title: Variation in Location of the Mandibular Foramen/Inferior Alveolar Nerve Complex Given Anatomic Landmarks Using Cone-beam Computed Tomographic Scans.
abstract: BACKGROUND
  The inferior alveolar nerve (IAN) injection is 1 of the most commonly administered and useful injections in the field of dentistry. Practitioners use intraoral anatomic landmarks, which vary greatly among patients. The objective of this study was to assist practitioners by identifying a range of normal variability within certain landmarks used in delivering IAN anesthesia.
  
  
  METHODS
  A total of 203 randomly selected retrospective cone-beam computed tomographic scans were obtained from the Midwestern University Dental Institute cone-beam computed tomographic database. InVivoDental5.0 volumetric imaging software (Anatomage, San Jose, CA) was used to measure 2 important parameters used in locating the mandibular foramen (MF)/IAN complex: (1) the angle from the contralateral premolar contact area to the MF and (2) the distance above the mandibular occlusal plane to the center of the MF. The variation of these measurements was compared with established reference values and statistically analyzed using a 1-sample t test.
  
  
  RESULTS
  The angle from the contralateral premolar contact area to the MF for the right and left sides was 42.99° and 42.57°, respectively. The angulations varied significantly from the reference value of 45° (P < .001). The minimum height above the mandibular occlusal plane for the right and left sides was 9.85 mm and 9.81 mm, respectively. The heights varied significantly from the minimum reference value of 6 mm but not the maximum reference value of 10 mm (P < .001).
  
  
  CONCLUSIONS
  Orienting the syringe barrel at an angulation slightly less than 45° and significantly higher than 6 mm above the mandibular occlusal plane can aid in successfully administering anesthesia to the MF/IAN complex.
authors.affiliation: Dental Institute, College of Dental Medicine-Arizona, Midwestern University, Glendale, Arizona; Division of Endodontics, University of Connecticut Health Center, Farmington, Connecticut.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Blacher
authors.affiliation: Dental Institute, College of Dental Medicine-Arizona, Midwestern University, Glendale, Arizona.
authors.forename: Scott
authors.initials: S
authors.lastname: Van DaHuvel
authors.affiliation: Dental Institute, College of Dental Medicine-Arizona, Midwestern University, Glendale, Arizona.
authors.forename: Vijay
authors.initials: V
authors.lastname: Parashar
authors.affiliation: Dental Institute, College of Dental Medicine-Arizona, Midwestern University, Glendale, Arizona. Electronic address: jmitch@midwestern.edu.
authors.forename: John C
authors.initials: JC
authors.lastname: Mitchell
mesh_terms: D000328:Adult; D000368:Aged; D059925:Anatomic Landmarks / Q000033:anatomy & histology / Q000000981:diagnostic imaging* / Q000294:innervation*; D001641:Bicuspid / Q000294:innervation; D054893:Cone-Beam Computed Tomography / Q000379:methods; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008297:Male; D008334:Mandible / Q000033:anatomy & histology / Q000000981:diagnostic imaging* / Q000294:innervation*; D008340:Mandibular Nerve / Q000033:anatomy & histology* / Q000000981:diagnostic imaging*; D008875:Middle Aged; D009407:Nerve Block / Q000379:methods; D012189:Retrospective Studies
keywords: CBCT; IAN; inferior alveolar nerve; mandibular anatomy; mandibular foramen