Abstract
INTRODUCTION. Local anesthesia is a critical part of dentistry and a skill clinicianswill utilize throughout their careers. Local anesthetic prevents the depolarization of
neurons, thus blocking the transmission of nerve impulses to the brain and ultimately the
perception of pain. Inferior alveolar nerve (IAN) blocks have the highest incidence of
failure of any block injections, ranging from 15-20% (AlHindi, Rahsed, and AlOtaibi,
2016, p. 85). Factors, such as inflammation, can contribute to the high failure rate, but the
most common cause is poor technique (AlHindi et al., 2016, p. 85). Understanding
anatomical relationships, variations, and proper technique are critical to mastering the
IAN block. This project aims to develop an educational module for IAN blocks in the
hope of decreasing the failure rate, increasing one’s confidence and therefore the success
rate of the block while minimizing discomfort to the patient. MATERIALS AND
METHODS. A 2% methylene blue (PBS) solution was administered into the
pterygomandibular space (PMS) in an unembalmed cadaver oral cavity. The methylene
blue solution served as a marker for local anesthetics to visualize the spread in the PMS.
A 27-gauge needle, 1.8mL carpule, and syringe were used to administer the solution.
Following the injection, the PMS was dissected to expose where the dye had aggregated.
A Vinca (DCLA-0605) caliper was used to measure the dispersion of the solution within
the PMS. RESULTS: The methylene blue (PBS) dye solution aggregated in the area of
the inferior alveolar and lingual nerves, indicating a successful injection. The mandibular
foramen was used as a starting point for measuring the dispersion of the dye superiorly
(37.55mm) where the lateral pterygoid muscle inserts into the neck of the mandible.
Measurements were also taken in an anterior-posterior direction, measuring from the
anterior border to the posterior border of the ramus (29.51mm). CONCLUSIONS. This
educational module will provide insight into IAN blocks. Although this project’s goal
was to visualize IAN blocks, future research regarding using pre-clinical models (i.e.,
fresh cadaver heads, simulations, etc.) in dental school curriculums may provide future
clinicians with the tools necessary to administer this block successfully.