Alternative mandibular nerve block techniques

Alternative mandibular nerve block techniques
A review of the Gow-Gates and Akinosi-Vazirani closed-mouth mandibular nerve block techniques
1. Daniel A. Haas, DDS, PhD
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Abstract
Background and Overview. The limited success rate of the standard inferior alveolar nerve block (IANB) has ledto the development of alternative approaches for providing mandibular anesthesia. Two techniques, the Gow-Gates mandibular nerve block and the Akinosi-Vazirani closed-mouth mandibular nerve block, are reliable alternatives to the traditional IANB. The Gow-Gates technique requires the patient’s mouth to be open wide, and the dentist aims to administer local anesthetic just anterior to the neck ofthe condyle in proximity to the mandibular branch of the trigeminal nerve after its exit from the foramen ovale. The Akinosi-Vazirani technique requires the patient’s mouth to be closed, and the dentist aims to fill the pterygomandibular space with local anesthetic.
Conclusion. Both techniques are indicated for any type of dentistry performed in the mandibular arch, but they are particularlyadvantageous when the patient has a history of standard IANB failure owing to anatomical variability or accessory innervation.
Clinical Implications. Having the skill to perform these alternative anesthetic techniques increases dentists’ ability to provide successful local anesthesia consistently for all procedures in mandibular teeth.
* Local anesthesia-------------------------------------------------
 
* mandibular nerve block
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* inferior alveolar nerve
* Gow-Gates
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* Akinosi-Vazirani
Achieving excellence in pain control is an intrinsic, yet challenging, goal of dentistry. Dentists are aware of the relative ease of successfully performing pain-free intraoperativeprocedures in maxillary teeth. The maxilla’s relatively porous alveolar bone allows for the use of straightforward local anesthetic techniques of paraperiosteal field blocks or infiltrations. The mandible is different. The outer layer of cortical bone is thick and nonporous and thus normally requires the use of a nerve block at a site away from the teeth being treated. Traditionally, the inferioralveolar nerve block (IANB), also known as the “standard mandibular nerve block” or the “Halsted block,” has been used to provide anesthesia in mandibular teeth. This technique, however, has a success rate of only 80 to 85 percent,1(p227) with reports of even lower rates.2,3,4,5 Investigators have described other techniques as alternatives to the traditional approach, of which the Gow-Gatesmandibular nerve block6 and Akinosi-Vazirani closed-mouth mandibular nerve block7,8 techniques have proven to be reliable. Dentists who know how to perform all three techniques increase their probability of providing successful mandibular anesthesia in any patient.
There are many reasons why the success rate of the IANB is low. One is that the dentist might make technique errors such as improperlylocating a landmark or angling the syringe. These problems are resolved easily by reviewing the landmarks and steps for performing the technique involved. A second reason is the presence of inflamed or infected tissue. Infection sites are acidic, which may impair appropriate onset of action. When infection occurs, administer an injection at a deeper site away from the infection to avoid this problem.By itself, inflamed pulp can be more difficult to anesthetize profoundly. A third reason is that a patient’s apprehension often can cause local anesthetic failure.9 Nerve conduction may be blocked successfully from a neurophysiological perspective, but as soon as the patient anticipates or hears the sound of the drill, he or she perceives pain. This problem can be resolved by discussing with the...