Root Resorption means that there are apical granulomas on the roots of the teeth which can lead to the appearance of small dimples or even to the whole root tips disappearing. This can of course occur as part of normal bite even in the absence of orthodontic treatment, but it does tend to be a natural side-effect of orthodontic treatment. Minor root resorption can, to a certain extent, repair itself, but the more serious flaws remain even after treatment. Most root resorption is so slight that it cannot be detected on a panoramic X Ray (Pano or OPG) and only becomes evident as a result of some long-term damage.
Only in around 20% of those patients who receive orthodontic treatment can any changes be seen on a panoramic X-ray. However, these changes rarely amount to anything in later life. Losing one’s teeth as a result of root resorption is theoretically possible, but there are very few references to such cases in any of the scientific literature. The main risk factors that we know about, apart from any genetic disposition, are the length of treatment and the distance that the roots have to cover. But it has never been completely proven that certain orthodontic appliances or treatment procedures actually cause this problem.