2 things I wish I knew 8 years ago while administering Inferior Alveolar Nerve Block

Updated: Sep 5, 2019

The year is 2011. It has been 6 months since I completed my graduation.

I am in the operator’s chair in a dental clinic administering Inferior Alveolar Block & Long Buccal Nerve Block for Extraction of a Mandibular second molar.

I waited for a few minutes and proceeded to check if L.A. has acted properly or not.

The patient complained of pain on instrumentation, which meant that the nerve block I administered didn’t work. I gave another nerve block, still didn’t work.

I started getting nervous, heartbeat slowly rising and the patient could see that I am getting stressed.

To my luck, the senior dentist in the clinic came to my rescue and the procedure was completed properly.

Does this sound familiar? Has this ever happened to you?

If your answer is yes then keep reading. Today, I am going to tell you how you can give IANB confidently.

In the last 8 years since that incident, I have been trained extensively in different nerve block techniques and Oral & Maxillofacial Surgery procedures.

In the hindsight, I now realize what mistakes I made. And I am going to list them one by one and tell you how to rectify them.

Now let me be clear, I am not going to explain the technique of IANB here. I will just be listing out the things that I went wrong with. If you want to learn about the technique of the IANB then you can go to this link.

So, let’s get started.

I didn’t know the anatomy well

I didn’t have good knowledge of anatomy at that time.

If I have read well and was well versed with the anatomy, I would’ve known that anatomy does not come in fixed dimensions. It always varies from person to person. Angle of ramus, position of the nerve in pterygomandibular space, placement of pterygomandibular raphe is not same for every patient.

Following the proper IANB technique in an average mandible, the needle is positioned over the mandibular foramen. So the needle will hit the medial surface of the mandible and LA solution can be deposited over the nerve as it enters the foramen

Even with proper IANB technique in a mandible with greater angle between Body & Ramus, the needle is not positioned at the mandibular foramen. So even if the needle is inserted further, the needle will not hit the medial surface of the Ramus.

Other reasons such as bifid inferior alveolar nerve, accessory innervation or cross innervation; although rare; are also responsible for the failure of nerve block. Click here to read about them.

Diagram showing different patterns of Bifid Inferior Alveolar Nerve

So even when I follow each and every word given in the textbook, chances are that the needle may still not hit the medial surface of ramus or I may get positive blood aspiration.

That is the reason we have fail-safes about what to do if the needle hit the bone early or do not hit the bone at all, what to do when there is bifid nerve or accessory innervation.

Know your nerve block technique well, and then you can always blame the patient’s anatomy for the failure of nerve block.

I didn’t wait for enough time for the L.A. to act

This is what I did 8 years ago,

I used to first prepare for the surgery (arrange the instruments in the tray, connect & check the handpiece which takes around 5-10 minutes).

Then i would administer nerve block.

Wait for a few minutes.

I am not much of a talker, so those few minutes would seem like a lot longer and I used to start with the procedure within 2-3 mins of giving nerve block.

This is what I do nowadays :-

First administer nerve block.

Then prepare for the surgery.

Call the patient immediately after the preparation.

Start with the procedure.

The benefit here is two folds.

Pt had to wait anyways for 5-10 minutes during preparation stage, I utilize that time for the block to act. And we all know that 5 minutes is longer than 2 minutes. So waiting time for the patient is less. Even if I have not deposited local anaesthesia solution exactly at the mandibular foramen, given enough time the solution flows to the nerve. But for that the solution has to be deposited into the pterygomandibular space.

I have deliberately not included factors such as infection or Defective Anesthetic solution in the discussion.


If you want your IANB to work perfectly then you should know your anatomy well and wait for enough duration to let the LA solution to act effectively.

Never stop learning. Learning can be from Textbooks, PowerPoint presentations, YouTube videos, online articles, blogs or even Facebook. Only learning can help you overcome your fears.

If you have any queries or you want to add something to the post, please feel free to comment below.

If you want to know what I do to make an injection technique as painless as possible, that is a topic of another post. So stay tuned.


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