Receding gums or gum recession refers to the condition where the tissue that protects and supports that teeth is pulling away from the root.  Causes of the occurrence of receding gums are improper brushing of teeth and by periodontal or gum disease.  These can cause the teeth to become extremely sensitive and the exposes the root area of the tooth to decay. Improper brushing can also be called toothbrush abrasion, and the enamel at the gum line is worn away through washboard fashion way of scrubbing the sides of teeth. The protective enamel is worn away by the horizontal brushing over time and can get the inner nerve-containing the part of the tooth called dentin exposed.