title: Comparison of two approaches to performing an inferior alveolar nerve block in the horse.
abstract: OBJECTIVE
  To compare two approaches to performing the inferior alveolar nerve block in the horse and to evaluate the consistency of described topographical landmarks.
  
  
  METHODS
  Experimental cadaver model.
  
  
  METHODS
  Eleven cadaver heads were positioned to mimic a standing sedated horse and the position of the mandibular foramen approximated. The vertical approach to the approximate location of the mandibular foramen was undertaken and red dye was deposited. The angled approach was then undertaken and blue ink was used to identify it. The heads were then dissected to determine the location of the dye. Placement was categorised as a hit or a miss for each technique for each side of the head. The distance of the dye from the nerve was recorded. Straight lateral radiographs of the sectioned heads were taken to evaluate the topographical landmarks for performing this nerve block.
  
  
  RESULTS
  Each method was performed 22 times. A hit was achieved 16 times (73%) for the angled approach and 13 times (59%) for the vertical approach. There was no significant difference between the two approaches (P = 0.34). Radiographs revealed that the topographical landmarks used to approximate the mandibular foramen were relatively accurate.
  
  
  CONCLUSIONS
  Both methods were found to be equivalently accurate. The previously reported topographic landmarks for locating the approximate position of the mandibular foramen on the medial aspect of the mandible were found to be accurate, but currently recommended doses of local anaesthetic may be excessive.
authors.affiliation: Department of Equine Medicine and Surgery, Murdoch University, 90 South St, Murdoch, Western Australia 6159, Australia. p.harding@murdoch.edu.au
authors.forename: P G
authors.initials: PG
authors.lastname: Harding
authors.forename: R L
authors.initials: RL
authors.lastname: Smith
authors.forename: S Z
authors.initials: SZ
authors.lastname: Barakzai
mesh_terms: D000818:Animals; D002102:Cadaver; D002508:Cephalometry / Q000379:methods / Q000662:veterinary*; D006736:Horses; D008334:Mandible / Q000294:innervation*; D008340:Mandibular Nerve; D009407:Nerve Block / Q000379:methods / Q000662:veterinary*