Dens invaginatus, also known as dens in dent, "Tooth within a tooth" is a condition found in teeth where the outer surface folds inward. There are coronal and radicular forms, with the coronal form being more common.

Dens invaginatus is a malformation of teeth probably resulting from an infolding of the dental papilla during tooth development

Tooth development

Tooth development or odontogenesis is the complex process by which teeth form from embryonic cells, grow, and erupt into the mouth. Although many diverse species have teeth, non-human tooth development is largely the same as in humans...

or invagination of all layer of enamel organ in dental papillae. Affected teeth show a deep infolding of enamel and dentine starting from the foramen coecum or even the tip of the cusps and which may extend deep into the root. Teeth most affected are maxillary lateral incisors and bilateral occurrence is not uncommon. The malformation shows a broad spectrum of morphologic variations and frequently results in early pulp necrosis. Root canal therapy may present severe problems because of the complex anatomy of the teeth. Aetiology, prevalence, classification, and therapeutic considerations including root canal therapy, apical surgery and prevention of pulpal involvement are reviewed.

Clinical case

A patient presents with symptoms of an acute abscess on the maxillary left lateral incisor. There are no clinical signs of decay or restoration. The cause can be evaluated radio graphically i.e. dens in dente