VAZIRANI-AKINOSI: The Other Mandibular Block

You don't have to say it correctly to be able to administer this injection.

WHAT IS IT?

The Vazirani-Akinosi (VA) is a mandibular nerve block which anesthetizes all teeth in the quadrant injected. This includes the periodontium and gingival tissue from the third molar to midline along with the lingual tissue and half of the tongue. The cool thing about this injection is that's considered a closed mouth technique. Which makes it ideal for patients with limited opening, or for your patients who have tongues and buccal soft tissue that is just in the way to get proper placement for the Inferior Alveolar (IA)or Gow-Gates (GG) injection. Another nice feature of this technique is its ease of penetration into the tissue, because the needle doesn’t travel through as much fascia as it does for the IA or the GG injections. 

HOW DO YOU ADMINISTER?

This is one of those injections which is hard to explain in writing, but I will do the best I can (to gain further understanding sign up for the HIT ME WITH YOUR BEST SHOT anesthesia course).

Make sure you grab a 25 or 27 gage long needle, this will help you get to the proper depth to bathe the mandibular nerve. The site of injection is a little different than you would think. It is actually close to the same area as a Posterior Superior Alveolar (PSA) injection.

Place your topical at the soft tissue just behind the maxillary tuberosity near the height of the mucogingival junction. If you palpate that area you will feel a soft fold of tissue between the maxillary tuberosity and the medial portion of the mandible.

After about a minute remove the topical and retract the buccal tissue. I like to use a tongue blade (tongue depressor) to retract because it is long and flat, which makes it easier to see your injection site. You can use a mouth mirror or Minnesota retractor as well; it just may slide out of the patients mouth a little. Also, have the patient in relaxed closed state. They should not be clenching their teeth. If they do, it will activate the masseter and medial pterygoid muscles making it more challenging for you to retract and see.

With the barrel of the syringe as close to parallel and at level with the mucogingival junction insert into the mucobuccal fold near the maxillary second molar. Advance your long needle slowly about 20-25 millimeters. I suggest not going deeper so you don’t miss your target. Basically, you will go about half the distance as the width of the ramus. The goal is to deposit the solution along the nerve trunk as it travels down the medial portion of the mandible. You can also put a very slight bend* in the needle towards the mandible to aid in getting the needle to the correct area. *Please note to be very careful if bending as this can weaken the integrity of the needle and increase opportunity for needle breakage.

Unlike the IA or the GG, this is one of the injections you do not want to contact bone. Once you have reached your proper depth aspirate and deposit your solution (1 cartridge). A positive aspiration happens more often with this injection compared to others. About 10% of the time. So please take the time to really aspirate for this injection...it's okay to even do it multiple times.

PROS AND CONS?

There are some pretty major pros with this injection. Because patients do not need to open wide it is a lot more comfortable for them. I most often see this injection used in oral surgery cases, but it is highly effective for patients with high anxiety or developmental disorders in which they cannot stay open. This has been used with patients with Autism and it works perfectly.

Because it is technique sensitive, anesthesia failure for the novice is high, but the learning curve is quick...so be patient with yourself! One of the biggest struggle's clinicians will have is the ability to properly see the site of insertion, especially on the clinicians opposite side of the mouth. For example, a right-handed clinician may have difficulty seeing the site of insertion on the left side.

When given correctly the success rate of this injection is extremely high and with an experienced clinician it is reliable too. My best advice is to be patient with your learning curve. Remember your goal is to have the anesthetic bathe the nerve as it travels down the ramus of the mandible. Make sure you have the barrel parallel with mucogingival junction with a slight angulation towards the condyle.

I want to leave you with this thought...you may have given this injection and not realized it. If you have given your patient a PSA injection and they started to feel their mandible go numb it could be you were more aligned with the mandibular nerve than you were for the PSA nerve (which means we need to talk about proper angulation for this injection too)

Enjoy giving the VA, I cannot wait to hear about YOUR BEST SHOT.

CHEERS!

Tina

Make sure you grab your FREE anesthesia technique guide. Head to www.teachertinardh.com to get your free guide and enroll in the course series HIT ME WITH YOUR BEST SHOT. Reviewing injection techniques and anesthesia management.

References. Bassett, DiMarco, Naughton: Local Anesthesia for the Dental Professionals 2nd ed Malamed: Handbook of Local Anesthesia 6th ed.