The condition of having a tooth extruded from its socket such that the occlusal surface of the tooth extends beyond the normal occlusal plane. It is particularly likely to occur when a tooth is unopposed; the contact area between the over-erupted tooth and the adjacent teeth is lost. This creates an increased clinical risk of dental caries and periodontal disease on the exposed root surface of the over-erupted tooth.
Craddock H. L., Franklin P. Overeruption – another challenge? Dent Update 2005;32(10):605–8, 610.