CLINICAL CASE: Endodontic Treatment of dental formation anomalies

Tooth formation anomalies are rare disturbances, which are capable of originating dental elements with very unusual anatomy. These anatomic changes can occur in the tooth crown, root and root canal.

Gemination and fusion are developmental anomalies of hard tissues with close similarity inherited by different aetiology.

In cases of fusion, the crowns are united by enamel and/or dentin, but there are two roots or two root canals in a single root. 

It has been suggested that there may be fusion between the teeth of the normal series or between one of the normal series and a supernumerary tooth.

Dental fusion is characterized by the union of two dental germs during the developmental stage, in consequence of aberration of both the ectoderm and mesoderm.

It is mainly observed in deciduous dentition, which may be complete or incomplete, depending on the stage of development in which the union occurred. 

The incidence is greater in incisors and canines with apparent equal distribution between the two jaws, and cases involving molar teeth are rare. It is more common in the anterior region, approximately 0.1% occurs in permanent and 0.5% in primary dentition, with an equal distribution in females and males, among Caucasians. 

The etiology of this type of anomaly is unknown. Some authors believe that there is a physical force that approaches and causes contact between the dental germs, leading to necrosis of the epithelium that separates them, causing fusion.


Fused teeth are normally more susceptible to caries and periodontal problems because they present a large number of scratches and gaps at the site of the junction. These gaps may be located subgingivally, being a bacterial plaque accumulation site, and could cause misalignment of the adjacent teeth. 

The aim of this study was to describe two cases of successful endodontic treatment in anterior teeth with fusion/gemination anomalies.