Can A Mandibular Nerve Injury After Jaw Reduction Be Fixed?

Q: Dr. Eppley, I write to you in hopes that someone of your expertise can help as my case of jaw reduction is an uncommon one. I had a sagittal split osteotomy two years ago. I had excessively wide and disproportional jaws so I wished to have them reduced. An obvious solution would be to have both the osteotomy and masseter muscle resection as mine was quite prominent. My surgeon refused to do the muscle resection claiming that the muscle can grow back and undergo hypertrophy or something along those lines. Trusting his expertise, I agreed to undergo just the osteotomy and not any muscle resection. Due to this, I had him assure me he would shave off as much as he possibly and safely could, and he did so.

The results were mediocre as my hunch about most of the volume in my jaws were from my muscles was correct. But this is not the issue. About six months later, I woke up one morning and I felt a loss of sensation on my lower jaws, that made me think that it was swelling because it felt like my cheeks were drooping. It happened literally overnight. I saw my dentist and he couldn’t find any swelling or infection. I mentioned that there was a tingling sensation when he touched the affected area to which he advised that it was probably nerve damage. The affected area starts from the outer corners of my mouth going to the middle of my jawline. It feels like a loss of sensation which makes it feel like my lower cheeks are dropping and very intense tingling when touched. This makes activities such as talking more difficult due to the feeling of droopiness. I have attached an image to illustrate the affected area. 

I have read that nerve damage heals by itself, but after over year and a half,  there has been no signs of improvement. Some days are tolerable, but some days the feeling of droopiness is so severe that I can barely talk. I had a CT scan and the doctor advised me that my mandibles have been reduced significantly and possibly excessively. 

Please advise me on your thoughts on my predicament, and possible steps I can take to deal with it. I honestly don’t know what to do, as all issues in regards to nerve damage are advised to wait it out. 

A: Thank you for sharing your jaw reduction story and there are several aspects to it that defy a clear biologic explanation. The procedure you had done was most likely a lateral corticotomy where the outer layer of the bone over the jaw angles was removed. It is a form of a sagittal split osteotomy but not in the classic sense that the entire jaw was not moved. This is the most aggressive form of bony jaw angle reduction over shaving/burring and is aesthetically better than traditional jaw angle amputation. However it does run the risk of exposing and injuring the inferior alveolar nerve which runs in the medullary space of the mandibular ramus right below the outer cortex. Since you had the outer cortex removed this is the sensory nerve at risk for injury.

However, such nerve injury would have been apparent right after surgery and would not spontaneously appear nearly half a year later. In addition, your description and illustration of sensory nerve loss does not follow the well known anatomic distribution that this nerve covers. (lips and chin…not cheeks and side of the jawline) The only other nerve that could remotely explain your symptoms is that of the long buccal nerve which supplies sensation to the inside of the cheeks along the mucous lining. It is often inadvertently cut from any procedure of the mandibular ramus from the incision location but usually is of no consequence. But again, such a nerve injury would not just spontaneously appear many months later.

But any of these potential nerve issues are usually not repairable. In rare cases nerve decompression and/or nerve grafting are done. But these are only attempted when the location of the nerve injury is very clear.

I am afraid that I have neither an explanation or a solution to your postoperative concerns.

Dr. Barry Eppley

Indianapolis, Indiana