Ultrasound-Guided Mandibular Alveolar Nerve Block in Rabbits: A Cadaveric Comparison of In-Plane and Out-of-Plane Approaches

Mandibular dental disease is common in pet rabbits and often requires invasive procedures associated with significant nociceptive input. Mandibular alveolar nerve blocks have been described in this species using blind techniques; however, their accuracy has not been objectively evaluated, and ultrasound-guided approaches have not been reported. This cadaveric study aimed to describe an ultrasound-guided mandibular alveolar nerve block in rabbits and to compare in-plane and out-of-plane approaches. Twelve adult New Zealand White rabbit cadavers (24 mandibular alveolar nerves) were included. For each rabbit, one nerve was assigned to an in-plane ultrasound-guided approach, while the contralateral nerve was assigned to an out-of-plane approach. Following ultrasound-guided needle placement, 0.1 mL/kg of a mixture of 2% lidocaine and 1% methylene blue was injected. Ultrasound image quality and perineural staining were assessed and scored, and longitudinal dye spread was measured after anatomical dissection. Both approaches allowed consistent identification of the target region and resulted in comparable ultrasound image quality scores, staining scores, and longitudinal dye spread, with no statistically significant differences between techniques. These results demonstrate the anatomical feasibility of ultrasound-guided mandibular alveolar nerve blocks in rabbits using either approach. Further in vivo studies are required to assess clinical efficacy and safety.