Regional Anesthesia for Dentistry and Orofacial Surgery in Rhesus Macaques (Macaca mulatta)

Regional anesthesia is a commonly used adjunct to orofacial dental and surgical procedures in companion animals and humans. However, appropriate techniques for anesthetizing branches of the mandibular and maxillary nerves have not been described for rhesus monkeys. Skulls of 3 adult rhesus monkeys were examined to identify relevant foramina, establish appropriate landmarks for injection, and estimate injection angles and depth. Cadaver heads of 7 adult rhesus monkeys (4 male, 3 female) were then injected with thiazine dye to demonstrate correct placement of solution to immerse specific branches of the mandibular and maxillary nerves. Different volumes of dye were injected on each side of each head to visualize area of diffusion, and to estimate the minimum volume needed to saturate the area of interest. After injection, the heads were dissected to expose the relevant nerves and skull foramina. We describe techniques for blocking the maxillary nerve as well as its branches: the greater palatine nerve, nasopalatine nerve, and infraorbital nerve. We also describe techniques for blocking branches of the mandibular nerve: inferior alveolar nerve, mental (or incisive) nerve, lingual nerve, and long buccal nerve. Local anesthesia for the mandibular and maxillary nerves can be accomplished in rhesus macaques and is a practical and efficient way to maximize animal welfare during potentially painful orofacial procedures.