The inferior alveolar nerve block is a Mandibular nerve block given to anesthetize the Mandibular teeth, due to its proximity to other Nerves and muscles and salivary glands it has many complications if the technique in which it is given is wrong. Here we have mentioned the most common to some of the rarest complications which have arisen due to an improper technique of Inferior Alveolar Nerve block.
Complication Specific to Inferior Alveolar Nerve Block:
Undesirable Never Block: Due to the proximity of the Inferior alveolar nerve block needle position to the facial nerve and the Parotid through which it passes is the result of this complication where we can see the characteristic complications when the Facial nerve is anesthetized:
Transient Hemifacial Paralysis: In this, we can see from the image below that the muscles being supplied by that side of the facial nerve is affected and cannot contract, and this results in loss of muscle action of the affected side of the face.
- Where the eyelids cannot be closed by the patient
- Loss of maintaining of lips position on the affected side and drooping of the lips on the affected side is seen in the image below.
How to manage Transient Hemifacial Paralysis due to the complication of Inferior alveolar nerve block
- If this condition is ever encountered be calm and explain the patient about the problem which has occurred and assure him/her that it is temporary and will be back to normal in 3 hours after the effect of local anesthesia is gone.
- Prescribe any Lubricating Eye drops and ask the attendant or the patient to keep putting 2 drops for every 15 mins on the affected eye to keep the eyes wet as the eyelids cannot be closed due to paralysis of the facial nerve.
- Ask the patient to use a clean cloth to keep over the eye to prevent dust from entering the open eye.
- Lastly, ask the patient to stay in the clinic for 3 hours if possible to monitor the condition after the effect of local anesthesia wears off.
The General Complications of Inferior Alveolar Nerve Block which is common with other nerve blocks:
- Muscle Trismus: It is due to muscle spasm which is caused when the injection is given into the Medial Pterygoid muscle causing tearing of the muscle fibers. It is called as Medial Pterygoid Trismus or Myospasm. The onset of Muscle trismus in inferior alveolar nerve block is after 24 hours of the injection and it resolves by itself without any treatment. In some cases, anti-inflammatory drugs and muscle relaxants might be required.
- Hematoma: It is also caused when there is an accidental injection to the Blood vessel which in turn leads to Hematoma formation.
- Mucosal Irritation: The Irritation of the Mucosal tissue can be either due to allergic reaction to the needle itself or the anesthetic agent.
- Infection:
- Needle Breakage: If care is not taken in maintaining the proper position of the needle or excess force is applied, there have been instances of needle breakage during IAN block.
- Numbness of Auricle or Ear Lobe: This is a very rare complication which has been reported where the patient has experienced numbness of the auricle on the side of Inferior Alveolar injection which lasted for an hour. This is seen due to the accidental anesthetic injection to the auriculotemporal nerve resulting in numbness.
Click here for: List of Complications due to Nerve Block
About The Author
Varun Pandula
I am Varun, a Dentist from Hyderabad, India trying my bit to help everyone understand Dental problems and treatments and to make Dental Education simplified for Dental Students and Dental fraternity. If you have any doubts feel free to contact me or comment in the post, thanks for visiting.
yes.. This is 1 of the best ans… Most comoon complication is Needle Breakage,,Trismus,, Haematoma….
hematoma formation occurs if there is accidental injection in to blood vessel not in medial pterygoid muscle.kindly correct this.
Thanks, corrected the mistake
My patient is having pain in head of that side after inferior alveolar nerve block
But not having pain in tooth, what can be the cause?
Hi rashmi, is the patient having any difficulty in opening the mouth or pain while opening the mouth ? Usually pain in the head on the side of injection is caused due to any damage to the muslce in the path of the injection.
If hematoma occured after inf.alveolar nerve block…when can we proceed the next step of rct??
If there is sufficient mouth opening and patient is not having any discomfort, you can go ahead with RCT.
Sir i had a patient with pain and trismus and mild swelling on d side where i had injected d LA he is not able to open his mouth
i precribed him tab.flexon-MR But he has no improvement in his condition.
what should i do sir
I had an infraorbital nerve block done on my cheek for nerve pain by a pain doctor. My pain before was 3-6 my pain after is 8-10. I am in constant pain what could have gone wrong to cause this.
Thanks
Are you having any other symptoms such as – swelling or redness in the area?
Where is the pain extending from and to?
It can be because of injury to the buccinator muscle which you might have pierced during the path of insertion of injection. Asure the patient that it will be fine in a weeks time and continues the MR tablets and if there is any redness or swelling Chymoral Forte can be prescribed as wel.
Help sir..during inferior alveloar nerve if their is hametoma formation…what are the symptoms we can see and what is the treatment plan?
There are no significant symptoms which are seen during hematoma formation, you can only see that there is a bruising or red color discoloration in the injection site. Only immediate management is required by applying force on the medial aspect of the mandibular ramus. Just wait it out for the hematoma to subside.
If there is any swelling or pain and inflammation at the site of hematoma, it is better to prescribe analgesics and anti coagulant such as Asprin and ask the patient to prevent from applying any heat at the region. Make sure that you mention to the patient that Hematoma will be present for a period of 7-14 days before it completely subsides.
I had a crown on my lower left tooth. A few days later I can barely open my mouth. The dentist says it is at 24mm. He told me to take ibuprofen, muscle relaxers eat soft food and use moist heat. It has been almost 3 weeks. Dentist also said it might be a disc problem since he could not get opening to widen. Please advise
There can be two explanations to your problem – 1) Injury to the Medial Pterygoid muscle leading to muscle trismus caused when the needle pierces the muscle. This will take time to heal and you will be facing pain and Trismus (difficulty in opening mouth) for a couple of weeks, regular physiptherapy is necessary to get it back to normal.
The second reason can be Disc or TMJ displacement which should be addressed by the dentist.
Hi dr. I had my third molar removed from my lower teeth (surgery) a couple of weeks ago. My tooth was growing sideways towards the second molar. So i had it removed and since then my inner lower gum and part of the side of my tongue are still numb. I literally can’t feel any pain if i puncture my gum, the lower part of the molars from the surgery. My dentist told me last week on my follow up check up to just take vit B complex because a nerve must have been damage upon administering local anes. How long does the numbing takes? I am kind of worried.
Hi Gigie,
It looks like you have Inferior Alveolar nerve parasthesia due to the surgical extraction or damage caused during local anesthesia administration. The time taken for you to get back the feeling depends on the extent of damage to the nerve. If the damage is major then the numbness might never go but if the damage to the nerve is minimal it takes 3-6 months for the sensation to comeback.
There is nothing to worry about but just make sure that you do not bite on your cheek or lip which might cause an ulcer. Be alert while chewing food.
I have problem opening mouth and its been already 4 week almost a month and there is no recovery and having pain while opening mouth, i can only open mouth about one finger after having cement in one teeth on side and they put LA becuase of my pain level while doing it.
I dont know what to do, i am frustrated when trying to eat food. Pain is keep getting more n more on one side until my head. What to do please suggest
I have administered ianb block for restorative process of 47,but during the process I think I have administered the LA in wrong way, now during the process patient was not having any pain but after the process the patient c/o severe pain which is not subsiding in anyway. Kindly help
I gave IANB yday to the patient, did rc opening with 45,46 and pt has come up with swelling of the same side…the side site has turned purple…I guess it’s hematoma…what to prescribe ..I have advice antibiotic analgesic and ice pack application and warm towel application from the next day. What else is to be added?
I gave IANB yday to the patient, did rc opening with 45,46 and pt has come up with swelling of the same side…the injection site has turned purple…..what to prescribe ..I have advice antibiotic analgesic and ice pack application and warm towel application from the next day. What else is to be added?
The dentist I work under administered inferior alveolar nerve block on a patient for extraction of 3rd molar. He went ahead and extracted the tooth; however ever since the injection was administered, the patient has a swelling in the infraorbital area. What could be the reason?
Are there any other symptoms of hemi facial paralysis or just swelling ?
It appears to be a Hematoma and the steps you followed are sufficient. Just aasure the patient that it will be fine and will come down in a few days.
Inferior alveolar nerve block given to the patient 1 and half year back now he is reporting and saying that a cyst has formed in the that region
One and a half year is a very long time, what type of cyst is it ?
Sir I gave inferior alveolar nerve block to a 55 year old female and after block she is unable to blink her left eye ( same side where I gave block).and no other symptoms but my technique was correct ..what could be the possible cause as patient is asthamatic
It is a clear case of Transient Hemi Facial paralysis which means paralysis of the side of the face to which the Inf alveolar nerve block was given. There is nothing to worry about as it is temporary and will be gone once the anesthetic effect subsides.
As mentioned in the post, make the patient understand that it sometimes happens and ask them to relax and wait it out. Prescribe them regular Eye drops to make sure that the Eye which is not closing is kept wet and ask her to cover that eye till she can start to blink.
Sir what mistake I have made during IAN block
And also patient is too weak
any different technique in weak patients.
Hi Dr. Varun, i had a RCT two weeks ago, on my 2nd lower molar right side(4 canals) he gave the inferior alveolar nerve block, after the effect of the anesthesia and get home i noticed that when i opened my mouth, chewing, brushing my teeth pain is there, i took tylenol and massage my lower jaw, when i went back after a week the pain still there i complain, he press my jaw and no pain, the pain was inside where he do the injection, he said is the muscle, he continue the procedure again he gave me IAN he final the setting and put the post, one week pass by the same pain i felt… tylenol won’t work..Dr where this pain came from? Did he hit any nerve? How many months it takes?thanks
Sorry for the pain which you have been suffering from, the complication which points out to your symptoms is Medial Pterygoid Trismus or a myospasm which is the injury to the Medial Pterygoid muscle while giving an inferior alveolar nerve block. This is a common cause of trismus after IAN block and it will subside in a couple of weeks, sometimes it takes just a few days and sometimes it might take a few weeks.
As the muscle is positioned on the inner side of the mandible any application of gels etc wont be of much help. Ask your dentist to prescribe any anti inflammatory drug and muscle relaxants which will help in decreasing the inflammation and also helps in increasing your mouth opening.
Sir.. I gave inf. Alv. N. Block to 55 yrs lady pt.. Bt after block she unable to close the eye.. Same side. Of the tooth region.. Is it so serious?
As mentioned in the post, ask her to remain calm and explain what has happened. Prescribe her eye drops to keep her eye moist and tell her that this will last till the anesthesia effect is present and will subsude as soon as it goes which is around 1-2 hours .
My patient got trismus after giving the IA. I understand that the needle must have punctured the muscle, but how do I make sure I position the needle so it doesn’t happen again? Is there a way to explain to me what I did wrong?
Trismus arises when you inject the Local Anesthetic liquid into the Medial Pterygoid muscle. To avoid this I use two main and simple techniques –
1. Ask the patient to keep their mouth open as wide as possible, this stretches the muscle and clears the Pterygomandibular space. By this, you can prevent injecting the LA Agent into the muscle tissue.
2. Make sure you hit Bone with the needle tip before injecting the LA Agent, this is a sign that the tip of the needle is not inside the muscle but in the Space where it was intended to be. Tactile sensation is the main thing which gives you a mental picture of where the needle tip is located.
Follow these simple steps and never again face Muscle Trismus problem in the future. It is also important to inform the patient that this is a complication which can arise due to the location of the muscle and they need to have patience as it takes anywhere from a few days to weeks to heal in some cases.
It’s Really scary reading all these posts from supposedly qualified Dentists! It’s no wonder why patients are scared to go to the dentist! There are a lot of poor dentists out there! Make sure you know who is going to work on your mouth! Check the State Dental Board first! And check out the dentist! I am recovering from IAN damage from Dental Implant over two years ago! I’m hopeful it may improve further! The problem was an unskilled General Dentist going outside his scope and wrecklessly injuring my nerve! I have the wisdom today thank God To never let a General Dentist do more than a routine filling! It’s that Bad sadly! Never let a General Dentist Attempt Oral Surgery! They are not trained and YOU could be left with a permanent injury! Worse still they are so stupid they don’t know what to tell you when it happens! Wake up Dentists ! And stop giving good competent dentists a bad name!?
Rely sad to hear that you are facing this, being a Dentist I have to support what you say. I always refer to a specialist which is both good for me and to the patient. It gives us peace of mind that the patient who comes to us to relieve their pain and problem with trust should go back with a smile.
In how much time does hematoma occur if inferior alveolar nerve block goes wrong ? Is it immediate or it appear late ?
In most cases, hematoma following Inferior alveolar nerve block is immediate and rarely it takes around 12-24 hours to appear.
Hematoma is seen most commonly in Infraorbital Nerve Block and Posterior Superior Alveolar nerve blocks.
Hi dr
Pt came for extraction of 46 .After I gave IANB block pt told he felt burning shock like sensation ,he never felt like that before .i gave 4 % articaine. That means I have hit the nerve ? Since pt told after I gave I couldn’t change the direction too.
Will that always results in paresthesia
Thank you
Burning Shock like sensation can be seen when you accidentally pierce a muscle in the path of injection.
Thank y
Hello,
I just completed a scaling and root planing procedure. The side which I had the drop cleaning is droopy. I can’t smile on that side or flare my nostrils. Is this normal? I’m getting worried. I called the hygienist and she said it’s normal and it’ll go away once the anesthetic does. Is this correct?
It will come down once the anesthesia effect has come down. There is nothing to worry but make sure that you keep your eye lubricated and do not let it dry if you are having difficulty in closing the eye lid. do not eat anything till the effect comes down. It will usually take around 2 hours for the full effect of anesthesia to come down.