The nerve block of the maxillary division of the trigeminal nerve (V2) has an anesthetic effect on the upper dental arch, periodontium, palatal mucosa, maxillary sinus, parts of the nasal cavity, upper cheek and lip, and lower eyelid.
Such an extensive approach is indicated for extensive procedures involving the maxillary dentition and possibly also the mucocutaneous lining tissues. In these the correct implementation of a single procedure saves a series of injections, providing an equally profound anesthetic effect.
The use of such anesthesia methods has also been described in the approach to complex conditions within the scope of headaches and atypical facial pain.
The most effective technique of maxillary nerve blockage is the intraoral approach through the greater palatine canal. This access was first described by Nevin in 1917 and revisited simultaneously by Silverman, Wong and Sved. The greater palatine canal can be located by touch : it corresponds to a slight depression located in the hard part of the palate, at the junction with the alveolar process, usually distally to the second upper molar.
Once the needle has been inserted into the palatine mucosa, it is essential to perform the aspiration test: if this is negative, it is possible to proceed with the administration of an amount of 0.1-0.3 mL of anesthetic solution. The canal (greater palatine) is negotiable using a long needle, which is slowly moved forward at an angle between 45 and 60 degrees to the occlusal plane, up to a depth of about 30 mm. The aspiration test is repeated as needed to avoid injection into the intravascular or nasopharyngeal site.
The main contraindication to the maneuver is the presence of a local inflammatory pattern, which can lead to the spread in the pterygopalatine fossa. Among the most relevant specific complications are nasal nosebleeds and even eye problems.
The difficulty in locating the site for the patient is also a contraindication: for this reason it would be interesting to provide the clinician with a safe and repeatable system to implement this very effective anesthesia procedure.
This is what Jamjoom has proposed to do in his implant case, recently published in the International Journal of Oral & Maxillofacial Implants.
The author has expanded the concept of guided implant surgery, which consists of programming the final position of implant fixtures on CT cone beam. The positioning of the implant fixtures is then conducted in the precise direction using a surgical template designed and manufactured using CAD/CAM technology.
Analyzing the three-dimensional X-ray image, the implantologist recognized the major palatine hole and, from there, the entire path of the canal, clearly visible in the sagittal section. In the design of the surgical template, a custom bushing with an external length of 2 mm and a diameter of 2.5 mm was added. In this way, at the time of the surgery, it was possible to perform the anesthetic procedure safely—always keeping procedures such as multiple aspirations—and with a result that facilitated the execution of the entire treatment.
In conclusion, it should be noted that such an approach is currently only feasible with a view to challenging procedures, such as the multiplant rehabilitation described above. For the daily clinical life, it would seem useful at the moment to focus on alternative techniques, such as the anterior and middle superior alveolar nervous block (AMSA), repeatedly described on these same pages.