Long root of deciduous anterior teeth.

A 24-year-old female Japanese patient presented with remarkably long roots of retained deciduous anterior teeth and permanent anterior teeth in the upper and lower jaw. Four lower anterior teeth were extracted for esthetic reasons. The patient had no apparent clinical syndrome related to the teeth or jaw, nor did there appear to be a family history of this condition. The extracted teeth and their lengths were as follows: the lower right deciduous lateral incisor was 25.55 mm long (root length, 18.95 mm); the lower left deciduous lateral incisor was 22.10 mm long (root length, 17.25 mm); the lower right deciduous canine was 27.95 mm long (root length, 20.60 mm); and the lower left deciduous canine was 23.90 mm long (root length, 17.65 mm).