Are Fast Braces Dangerous?

As an orthodontist for over 35 years I have worked constantly to try to improve the quality of treatment for my patients and decrease the time that it takes.  I have researched the "fast orthodontic treatments" and essentially they are simply short incomplete treatments that do not address some of the the primary issues of orthodontics. They are akin to what the orthodontist refers to as "initial alignment".  Initial alignment  is what orthodontists usually do first before trying to make the bite corrections to make the teeth fit each other properly.     When you begin to move any of the teeth the bite will usually change and now you have to fit all the teeth back together again in a different way to get them to fit properly and work properly upper to lower.  I can often get great initial alignment in 3 months and then spend another 12 to 18 months trying to get everything to really fit together and work really well, that is really the hard part.  These "fast" treatments are usually being promoted by a few by non orthodontist dentists who do not share the treatment goals of the orthodontist regarding achieving a good fit of the bite.  They just  want to get a little improvement in the alignment usually just in front.    Their assumption is that they won't change the bite, the fact is that having the bite change is almost unavoidable when you try to move even just a few teeth.  These "fast" reatments often cost almost as much as a very complete, comprehensive, and well planned orthodontic treatment that includes bite correction.

Regarding root resorption, I would not expect any more problems than with an orthodontic treatment like I  would do as long as the forces are kept as light as possible.  It is very similar to what I would call initial alignment.

Why don't orthodontists embrace these "fast" treatments" ?   We certainly have the equipment and the know how.  Mainly because we know how many problems and how much aggravation can result for the patient when unintended movements cause the teeth to not fit very well even though they "look" straighter.

Hi!
Fast Braces is a company that markets to general dentists to do braces in their dental offices. However, most general dentists are not trained in orthodontics, especially with more complex cases. Fast Braces patients almost always go over the original promised timeline, and they also don't get great finishes.

Fast braces are not intended for extreme/severe cases of overcrowding or TMJ/TMD disorders. With the proper diagnoses and treatment, fast braces are safe and effective for the right candidate.

It a person were to consider cramming an 18 month ortho treatment into 5 months with heavy forces, that would be a bad idea and you could have some of the complications that you described.
That is not what short term orthodontics is.
Short term orthodontics applies the same amount of forces as comprehensive orthodontics, but the braces are simply taken off earlier in the process than comprehensive orthodontics.
There are many goals in comprehensive orthodontics, such as root orientation. Most adult patients, however, only care about getting crooked or overly spaced teeth to line up and look nice. If that is your only goal, then short term orthodontics would be a good choice to consider. There would be no difference to a long term plan, just your braces would be taken off after you've attained the smile you desire, and some of the other goals of long term orthodontics are left alone.