Orthodontically induced external apical root resorption (OIEARR) has been classified as surface resorption caused by loss of cementum.  Usually this is superficial and unidentifiable radiographically but if this occurs apically it can be seen as shortening of the tooth.  Typically OIEARR is less than 2mm and clinically insignificant. OIEARR greater than 4mm is severe and … Continue reading Scant evidence to assess whether root-filled teeth are more at risk of external root resorption during orthodontic treatment