A transorbital approach to the maxillary nerve block in dogs: a cadaver study.

Langton, Sean D; Walker, Joshua J A

OBJECTIVE To describe a transorbital approach to the maxillary nerve block in dogs and compare it with a traditional approach. STUDY DESIGN Prospective, randomized controlled study. ANIMALS Heads from 17 euthanized dogs (10 Greyhounds, three Border Collies and four of mixed breed). METHODS A volume of 1 mL of methylene blue dye was injected by each of two techniques, a traditional percutaneous approach and a transorbital approach to the maxillary nerve block. Both techniques were used on each head, alternating the left and right sides after random assignment to the first head. The heads were dissected to reveal the maxillary nerve and the length of nerve stained was measured. RESULTS There was no significant difference (p = 0.67) in the proportion of nerves stained for a length >6 mm by either technique (88.2% transorbital versus 82.3% percutaneous). The mean length of nerve stained did not differ significantly between the techniques (p = 0.26). CONCLUSIONS AND CLINICAL RELEVANCE The transorbital approach to the maxillary nerve block described here presents a viable alternative to the traditional percutaneous approach. Further study is required to confirm its efficacy and safety under clinical conditions.