What Is a Mandibular Block?

A mandibular block is a nerve block dentistry technique in which anesthesia is injected into one of the mandibular nerve branch locations. This procedure numbs the sensitive nerves in the lower gums and jaw and up the side of the face along the masseter muscle of the skull. The mandibular block technique is one of the most common dental major nerve block techniques. Along with the standard technique, in which anesthesia is injected into the soft inner tissue of the cheek, other, more effective and specific mandibular blocks have been developed. Some of these include the Gow-Gates technique, the Akinosi closed-mouth technique and the incisive and mental nerve blocks.

The term "mandibular" refers to the mandible, the part of the cranium that constitutes the lower jaw or jawbone. Two major roots are nestled within the mandible, a large sensory root and a smaller motor root. Clusters of roots branch off from the major roots, including the buccal, mental, lingual and inferior alveolar nerves. The type and technique of mandibular block given to the patient depends on the dental procedure, location of the operation within the jaw and the sensitivity of the patient.

The Gow-Gates technique was developed by an Australian dentist in the mid-1970s. In this technique, the needle passes through less muscle and fewer nerve receptors than in the standard mandibular block, which causes less discomfort and pain during the injection. The anesthesia effect also lasts longer, and the technique limits adverse side effects such as increased heart rate, because the Gow-Gates is distributed in an area of the jaw that is less vascularized. In addition, the Gow-Gates mandibular block numbs the main nerve trunk that connects the lingual, buccal and alveolar nerve branches. With one injection, this nerve block anesthetizes the mandibular teeth to the midline, the lower mouth and tongue to the midline, lingual bone and tissues, buccal bone and tissues and the body of the mandible.

The Akinosi closed-mouth mandibular block is useful for patients whose jaw opening is limited because of infection or trauma. This nerve block numbs the mandibular teeth to the midline, buccal and lingual bone and tissues, the lower mouth and tongue to the midline, the body of the mandible and some of the ramus. The patient must sit upright to allow the anesthesia to diffuse. After being numbed, the motor nerves in the jaw relax, allowing the patient to open his or her jaw freely. In some cases, an additional injection with the Gow-Gates technique can be applied.

The mental nerve mandibular block does not numb the teeth but numbs the soft tissues surrounding the foramen instead. This nerve block is applied for a biopsy or removing tissue with surgical instruments. An incisive nerve block numbs the teeth of the mandible from the anterior to the midline. Other mandibular block techniques, such as the periodontal ligament technique, are applied to specific teeth in the lower jaw without involving the tongue, lip or surrounding teeth and tissues.