Dental nerve injury

Injury to the IAN or other nerve can occur due to wisdom tooth extraction, implant placement, root canal, or even injection of the anesthetic.  A consent form with IAN (or other nerve) injury and results of said injury for these procedures should be signed by both patient and dentist.  Nerve damage in dentistry by Pogrel is a nice article.

It should never be said that “this never happens” or “numbness almost always go away”.  It is a known risk and just leave it at that.

Dental nerve injury tests

Steps after dental nerve injury occurs – all signs or symptoms (eg, pain, altered sensation, numbness) should be documented.  Both subjective and objective sensory tests can be employed to document and evaluate injuries. There are two basic categories of tests: mechanoceptive (response to mechanical pressure or distortion) and nociceptive (perception of pain).

1. Pin prick test to document extent of paresthesia and mark with marker.
2. Other mechanoceptive tests include static light touch, two-point discrimination, and brush-stroke direction.
3. Thermal testing is nociceptive test
4. Take a photo of area(s) of neurosensory deficit that is mapped
5. Taste loss tested with salt or sugar on cotton swab
6. Detailed documentation of all testing and conversations
7. Repeat tests on opposite for comparison
8. Referral to someone with more experience with paresthesia like OS in first few weeks
9. If watching on own repeat steps 1-7 at each visit
10. Never assume everything is OK.  Follow up until know how resolved.

Mapping area of dental nerve damage paresthesia.

Neurosensory tests post damage

Description of neurosensory tests

References for dental nerve injury

This nerve evaluation protocol pdf is a fantastic source for dentists and oral surgeons. It has an excellent flow chart for treatment.

Treatment of Nerve damage from Root canal therapy

The nerve damage occurs for different reasons and the treatments depend on the matter of injury.  If the damage occurs due to sealer around the nerve treat ASAP, as in a matter of hours. Pogrel JADA 2007 shows treatment within 48 hours can stop any permanent damage from occurring.   Nerve damage results in dysethesia in around 30% for root canal sealer injuries.  If we do not remove the sealer soon the damage is permanent.  If damage is from files or other chemicals, the results are much better and surgery is not indicated.  Pogrel AGD Gen Dent 2017

If this occurs, then go to the references in Gluskin JADA 2020 and look for OMFS that can do decompression surgery. Another resource would be Sonneveld 2021.