Unusual case of rootless premolar.

T ooth eruption with little or no root development is rare and is usually associated with neonatal teeth or defects in root formation due to irradiation therapy of the head and neck. Possible causes of root absence are hereditary anomalies such as dentinal dysplasia, morphological anomalies known as dystrophies, and idiopathic root resorption. A tooth in a very early stage of root development can erupt prematurely when a periapical infection of the overlying primary tooth causes extensive bone destruction. Failure of the tooth germ to develop as a sequelae to periapical or inter-radicular infection of the primary tooth is uncommon but has been reported. We present a case of premolar eruption with a morphologically anomalous root.