Despite several critical issues raised on the lower alveolar nerve block, that is the classical inferior alveolar nerve block anaesthesia, this technique is still widespread – probably the most widespread – in the approach to the lower posterior dental region in oral surgery and in different endodontic and restorative procedures. Beyond the possible doubts related to the failure rate and repeatability of the procedure, it is always interesting to look at the less common complications related to it, reported by professionals from different parts of the world, with the aim of highlighting the problems and perfecting the operative protocol . A good example is given in the report by Kang and Won. The patient is a young (25-year-old) Korean woman, without a significant medical history, who reported simple gastrointestinal discomfort concomitant with antibiotic and anti-inflammatory prophylaxis related to the extraction of the third lower left molar. As often reported in clinical experience, especially outside Europe, the drug of choice turned out to be the classic lidocaine, here mixed with vasoconstrictor. Immediately after injection, the patient began to report discomfort and pain on the left-hand side, and in the meantime had begun to look paler. The reported symptom reached the middle third of the left side of the face, including the orbital-ocular region in its entirety. The altered (ischemised) area inspected involved the external part of the nose, the upper lip, and the central part of the face up to the cheekbone.
The symptoms occured immediately as mentioned, reached a peak after 1-2 minutes, and then began improving after 10 minutes. The neurological examination excluded involvement of the facial nerve (in which case it would have been essential to prevent xerophthalmia). Once the situation had stabilised and things had been explained to the patient, the treatment was completed. It was followed by postoperative observation for 40 minutes and a follow-up, both with asymptomatic results.
According to the authors, the phenomenon can be explained by an intravascular administration of the maxillary artery, which followed involvement in the region of the infraorbital branch. The ischemic sign evidently depends on the vasoconstrictor’s action, just as the pain response is due to damage to the tissue involved.
As expected, the episode could be avoided with a simple integration of the adopted injection protocol: the same authors admit that the surgeon omitted the aspiration test. Even the choice of an anaesthetic with vasoconstrictor can be the subject of debate.
The authors conclude by observing how the course of the maxillary artery is in any case subject to variability, hoping for greater technological support in the future to help identify anatomical landmarks in the individual patient.