Regional nerve blocks
Rounding out the triad, regional nerve blocks should be employed to eliminate cortical sensory perception generated by surgical
manipulation of tooth, bone or soft tissue. The four blocks used in mesocephalic and dolichocephalic dogs are the rostral
and caudal maxillary, and the rostral and caudal mandibular.
Photo 3: Due to the short infraorbital canal in cats and brachycepalic dogs, the rostral maxillary (infraorbital) block delivers
the agent adjacent to the pterygopalatine and infraorbital nerves to block the entire quadrant including palatal bone and
Only three blocks are required in cats and brachycephalic dogs. The rostral maxillary (infraorbital) block provides complete
quadrant blockade in these animals due to their short infraorbital canal (Photo 3). The caudal mandibular (inferior alveolar,
mandibular alveolar) block has been associated with severe tongue trauma in rare instances (Photo 4). This occurs in the immediate
postoperative period and can be avoided by manually placing the tongue in a normal intraoral position and visually monitoring
the patient until it can maintain sternal recumbency.
Photo 4: The caudal mandibular (inferior alveolar, mandibular alveolar) block has been implicated in the induction of tongue
trauma. Proper patient monitoring during recovery can totally eliminate this rare problem.
Taking advantage of regional nerve blocks allows blood pressure, cardiac output and respiration rate to approximate levels
expected in patients not experiencing surgical tissue manipulation. Tissue oxygenation and perfusion are positively affected,
making it easier to avoid hypothermia. Properly administered regional nerve blocks allow the patient to wake up pain free,
provide smoother recoveries and minimize or eliminate the immediate need for additional postoperative analgesics. Proper planning
provides for the other components of the triad to be on board when regional block efficacy wanes.
Chronic pain pathophysiology is extremely complex. This "analgesic triad" for patients with chronic oral pain simplifies the
approach to pain management while spanning the scope of the major mechanisms involved in pain generation and perpetuation.
Dr. Beckman is acting president of the American Veterinary Dental Society and owns a dentistry and oral surgery practice in Punta Gorda,
Fla. He sees referrals at Affiliated Veterinary Specialists in Orlando and at Georgia Veterinary Specialists in Atlanta, lectures
internationally and operates the Veterinary Dental Education Center in Punta Gorda.