Orthognathic surgical relapse

Orthognathic surgical relapse. I (am not an oral surg, I have a Dr/DDS and MS in orthodontics) get a lot of questions about orthodontic surgical relapse and how one might be able to prevent it. I have done a lot of research on this subject over the years and I have talked to a number of surgeons and orthodontists who have done 1000s and 1000s of cases and this is what I have found.

1. The evidence for what causes relapse is not great. There are very few good studies as it is very hard to track surgical cases over the years.

2. Maxillary surgeries seem to relapse less then mandibular surgical cases. “Maxillary advancement procedures were found to be less susceptible to relapse-resulting in more stable outcomes-and mandibular setback distances correlated positively with the degree of the relapse. No statistically significant differences were observed between the procedures conducted in both jaws versus in the lower jaw only, or in the extent of upper-jaw repositioning.”https://www.ncbi.nlm.nih.gov/pubmed/23974439
Sometimes relapse can occur from late growth or problems during healing;https://selectedreadingsoms.com/wp-content/uploads/2017/07/Stability-and-Relapse-in-Orthognathic-Surgery.pdf
Relapse can also be caused by changes in the TMJ area.
It seems that the lower jaw advancement cases relapse more easily probably due to a mandibular muscle pull.

3. There is no great evidence for this, but it seems to be true that open bite cases can relapse and it is possible that some of the contributing factors are the lower and forward tongue position that used to seal the open bite during eating and drinking. Patients with open bite often have this tongue posture so they can eat without food spilling out of their mouth when they have the open bite. After the open bite is closed surgically and with braces if the tongue posture persists, it’s is possible that the tongue will force the bite open again. We know that tongue sucking in kids can cause an open bite, so it is reasonable to believe that a low and forward tongue position will do the same.
So, what can a patient do to prevent a surgical relapse? Often sadly it’s not that clear, but there are a couple of things that may help.
a. Make sure to follow your Oral surg and orthod’s instructions after surgery.
b. in open bite cases (no great evidence for this but) talk to your doctors but I feel it is possibly important to make sure that you do not have a low and forward tongue posture after the surgical correction. Normally when you swallow and when you are at rest your tongue is on the roof of your mouth and not between the teeth. So, maybe talk to a speech therapist and your dr before your surgery, and start some therapy to make sure that you do not have parafunctional habits that can cause or contribute to the reoccurrence of the open bite.
I usually have our patients practice with a sugar-free lifesaver during the orthodontic treatment but holding the lifesaver on the upper front part of the palate with their tongue until it melts. Also, we have them do some speech exercises too or see a speech therapist.
As for regaining presurgical maximum opening; it seems that patients who do the best are the ones who once cleared for it by their doctor do the regular opening and closing exercises multiple times during the days. Patients who were not wired shut seem to do much better at regaining pre-surgical max opening in a shorter period of time. I wish I had more specifics but this is what we know right now. I hope this helps some 🙂