I read with interest this technical note on the use of the inferior alveolar nerve block as an adjunct to complement cervical plexus blocks for carotid endarterectomies.
The inferior alveolar nerve block is the most widely used technique for blocking the hemi-mandible. It is routinely used in everyday dental and oral surgical practice and, when combined with infiltration of the lingual and long buccal nerves, it provides adequate anaesthesia of a wide anatomical area. This includes all ipsilateral mandibular teeth and gingivae, body and inferior ramus of the mandible, and anterior two-thirds of the tongue and floor of mouth. However, due to neuro-anatomical and skeletal variations, there is a failure rate of 15–20% in achieving complete anaesthesia. This together with intra-arterial injection and nerve injury are some of the known complications of this mode of anaesthesia.
The authors' technique results in an injection that is higher than the level of the intended target – the mandibular lingula or foramen. This, together with injections that are too low, are common reasons for failure of the technique. To prevent this, the needle of the syringe should be level with the occlusal plane of the mandibular teeth, not above the maxillary occlusal plane, as stated by Fassiadis and colleagues. The expected depth of needle penetration is 20–25 mm.
The technique is facilitated, and made less painful, by the use of a dental cartridge syringe mounted with a 26-G Schimmel needle.