Abstract
INTRODUCTION. Mandibular anesthesia is essential to numerous dental procedures. The standard inferior alveolar nerve (IAN) block, or Halstead technique, is utilized to anesthetize mandibular teeth and supporting structures; however, this approach fails in approximately 15-30% of cases. The Gow-Gates and Vazirani-Akinosi techniques are alternative approaches to the Halstead approach, yet their success rate remains inconsistent in the literature. Low success rates are attributed to anatomical variation in the location of the mandibular foramen and sensory innervation. Dye spread has been evaluated for the Halstead technique to determine the extent of sensory nerve staining but not for other techniques. This study aimed to compare the range of dye spread between the traditional Halstead, Vazirani-Akinosi and Gow-Gates techniques. Moreover, we assessed the variation in the location of the mandibular foramen. METHODS. Preliminarily, three fresh-frozen cadaver heads were injected bilaterally (n=6) with 2% methylene-blue dye utilizing a different nerve block technique for each head. Dissection of cadavers evaluated the extent of dye spread and nerve involvement within the infratemporal fossa. Bilateral mandibles from embalmed (n=16) and fresh-frozen heads (n=6) were measured to determine variation in the location of the mandibular foramen. SUMMARY. Assessment of dye spread revealed that the Vazirani-Akinosi technique stained the origin of the IAN. These findings suggest that the Vazirani-Akinosi technique could minimize anesthetic failure by targeting the origin of variation in sensory innervation, the V3 root. Measurements indicated a significant number (p<0.05) of mandibular foramina were located anterior to the midpoint of the ramus. CONCLUSION. The impact of this study suggests that alternative approaches need to be considered to increase mandibular nerve block success rates and patient comfort.