LAST EDITED ON Aug-23-08 AT 11:35 PM (CST)
This thread is devoted to the development of a global protocol to be enacted in the event of an injectional injury to the lingual and/or inferior alveolar nerve, or any other nerves as they pertain to needle injection during dental, oral and maxillofacial, or facial surgery.This post marks a time in the evolution of a protocol that can be accessed and enacted based on the current scientific literature and the anecdotal and circumstantial evidence created here by posters on this site. Any poster is welcome to add to this protocol as he sees fit and I will alter this document as needed should there by merit to the claim. Ultimately, a technique to minimize the chance of lingual nerve injury is needed during the IAN block technique. Currently there is no iron-clad way to fully prevent a lingual or inferior alveolar nerve injury given the time-honoured injection method. A newer approach to this nerve block that hopefully minimizes this risk will be addressed shortly as a website of this nature is being constructed (6/08).
NERVE INJURY PROTOCOL
1) Report signs of continued numbness in excess of 24 hours of your appointment to your treating practitioner at once. Referral to an oral and maxillofacial surgeon at this point as a second opinion. A delay here by the patient may preclude the window where steroid anti-inflammatory medications can be employed. Steroid anti-inflammatory drugs such as dexamethasone or prednisone are given by phone or personally.
2) Next day or first clinical follow up: evaluation of the nerve(s) involved; assessment of injectional or extraction causation or both to allow localization of the site of injury. Steroid anti-inflammatory drugs such as Decadron 4mg bid or Medrol for up to 7 days (medical history permitting) should be initiated. Additionally, although there is no good evidence to support the following, sublingual methyl cobalamin at 1000 mcg/day (better absorbed than oral route) or Nerve Fx as a standby.
3) 5 day clinical follow up: mapping of the extent of neural deficit should be initially recorded and cross-referenced with the medications used, the needle diameters used, the injection type and number of administrations and the volume of anesthetic used. This information should be in the patient chart. This is done either by the treating practitioner or the oral and maxillofacial surgeon. Preferential follow up with oral and maxillofacial surgeon for evaluation. Two way sensation and pain sensation should be mapped out or preferably photographed.
4) STEPS 4-8 SHOULD HAPPEN CONCURRENTLY At this visit, 2-way touch with Von Frey hairs and pain reception to the affected area should be assessed and clinically mapped or photographed. Subjective description of deficit should be included.
5) If significant trauma to IA or lingual nerve is suspected by early and complete anesthesia of these nerves, a prompt referral to a neuromicrosurgeon should also be arranged -- given that the wait list for treatment by these specialists is long, early referral is recommended; a false alarm can always be cancelled. Many newer studies show that early surgical intervention in nerve transection is preferred as a stretching anastomosis is more efficacious than transneuronal bridging. Surgical correction, even with a 50% success rate is advocated by some researchers within the first 3 months of nerve injury; success rates fall with time thereafter.
6) While surgical referral is progress, patients should be seen biweekly in the first month and second month, monthly in the 3rd month and bimonthly until the 1st year. Evaluations, mapping and photographs should be taken to monitor the progression of sensation. Patients with sensations of tingling or gripping of the lower jaw have a better chance and encouragement in these cases is indicated. Complete anesthesia has a poorer prognosis at this time but recovery is not impossible.
7) During this period, medications such as Tegretol (carbamazepine), Trileptal (oxcarbazepine), Neurontin (gabapentin), low dose Elavil (amitriptyline) or Lyrica (pregabalin), and their may be others such as Tramadol, should be considered to modulate neural side effects and dysesthesias. Clonazepam is also indicated with a lesser degree of success. The general practitioner physician and dentist/oral surgeon and ideally a neurologist should act as a team in applying these meds. Pain medication is often needed, often involving opiates (Tyl 3, Percocet, Vicodin), but the addiction potential should be weighed against the need for pain resolution. Naproxen is a good anti-inflammatory that can be used for some duration without any addiction. Some studies suggest high doses (1-5 mg) of the methylcobalamin form of vitamin B12 are helpful and no prescription is required for this. These medications can be administered by the oral and maxillofacial surgeon or the referred neurologist as early on as the symptoms suggest.
8) At the 3 month interval if there is no improvement to tests with 2-way or pain tests, the consideration of microneurosurgical repair gains traction. The low success rate and the high magnitude of recovery from this surgery should be weighed by the symptoms and candidacy of surgery with the microneurosurgeon (oral and maxillofacial surgeon or neurologist).
9) The alternate option at 3 months is to wait. Thirty percent of patients go on to majority recovery in the next years; recoveries up to 5 years have been recorded. Recovery is a mixed equation of gender and age but the younger the patient the better the prognosis.
10) Nerve injury does rise with age, particularly in women. Early extraction of foreseeably mencacing third molars is still, despite its comparatively small risks, is the best choice. Injectional injuries, being in their relative infancy of active treatment, are unconfirmed in their incidence, however, it would seem likely that their current gender predilection follows the same distribution as third molar extraction.
11) YOUR COMMENTS ARE WELCOME HERE. Add to the above as anyone would see fit. I can be reached at drgmc@shaw.ca if needed.