In the introduction to their own study, recently published in the Journal of Maxillofacial and Oral Surgery, Jendi and Thomas explain how the significant failure rates associated with the classic inferior alveolar nerve block technique also have an anatomical basis, linked to the presence of accessory innervation with no relation to the inferior alveolar nerve. The authors therefore propose the Vazirani-Akinosi “Closed Mouth Technique” as a way to overcome these limits, like the Gow-Gates technique, and not only as the obligatory approach for cases of trismus or limited opening.
The investigation involved a total of 140 healthy patients of both genders, aged 16–45, all concerning the extraction of lower molars. The sample was randomly divided into two groups of equal size. Group A was approached from an anesthesiological point of view through the classic inferior nerve block method, thus acting as a control group. Group B underwent infiltration of the same amount of the same anesthetic solution (lidocaine 2% associated with adrenaline in a concentration of 1:200000) via the Closed Mouth Technique.
Before the injection procedure, each patient was shown a decimal visual-analog scale (VAS) and asked to use it to express their perception of pain related to the injection. The second parameter assessed is the onset time, timed from the end of the injection procedure until the patient reports the onset of perceptual alteration in the lower lip. The subjective symptom was clinically confirmed by using a probe to prick the soft tissues in the premolar region.
The electric pulp test was also carried out on the ipsilateral first molar, at two consecutive 5-minute intervals: a reading of 80/80 is considered positive (success).
Finally, clinical elements were evaluated, like a positive result in the aspiration test.
The average onset time was significantly lower when using the conventional technique: 68.70 s, against 92.55 s in group B, respectively corrected to 78.36 and 104.24 s with the electric test.
On the other hand, the test group (Vazirani-Akinosi) recorded a higher success rate (97.14% versus 81.42%) and a lower positive aspiration rate (2.86% versus 15.71%).