Hi there. Yes there are some major concerns with braces. Many of the same concerns are true with "silver" fillings. Basically whenever two metals are mixed with an acid (in our saliva)a type af battery is formed. The electrical currents that begin to flow through our mouths as a result of fillings, crowns, partials and braces cause many problems in the body.
Exerpt from "A Battery in Your Mouth!" by Jimmy Scott Ph.D. leading nutritionist and founder of "Health Kinesiology" (worth doing a search on)-
"Mouth currents may be small in relation to a flashlite, but are massive when compared to our nervous system, and they simply overwhelm the body's natural functions. Not only is the nervous system affected, but so too is every body function which utilizes ions-and that means most metabolic processes. Obviously such effects could cause widespread dysfunction...Some well-informed dentists now regularly check for mouth currents and will be able to take proper measure to eliminate them...The range of effects from these mouth currents is astonishing. I have had clients who have lost bone from the neck (osteoporosis) because the currents prevent proper calcium ( and other minerals) deposition. Deterioration of the teeth and supporting bony structures also occurs...Unexplained pains can often be traced to currents. I believe many cavities to be caused by currents since they interfere with the normal repair process, even those which occur within teeth...Effects are not limited to the mouth. I have seen many cases where disturbance of vision, hearing, skin sensitivity...have been traced to mouth currents Since the brain itself can be affected, the effects of mouth currents seem to be unlimited. Indeed, the psychological effects may well be the most significant. This is particularly true since physical causes of mental symptoms are so little suspected and consequently, they are commonly ignored. People may feel "fuzzy minded" be indecisive, feel anxious, be forgetful, or have any myriad of other psychological symptoms...Although it may be expensive to have your dental work redone, what will it cost if you don't?"
Hope this helps...