A unilateral Dentigerous cyst associated with impacted mandibular canine crossing the midline: a rare case report

Abstract

Introduction: A dentigerous cyst is the most common developmental odontogenic cyst and is frequently noted as an incidental finding on radiographs. The most common teeth affected are impacted mandibular third molars and permanent maxillary canines. This case involves a dentigerous cyst encompassing the right impacted mandibular canine and crossing the midline. This is a rare case of dentigerous cyst encompassing non-adjacent teeth and crossing the midline reported in recent literature. Case presentation: The patient presented to our department of oral and maxillofacial surgery for treatment of swelling in the lower chin area. The patient was a 10-year old girl with a dentigerous cyst extending from right to left mandibular canines and crossing the midline with the right mandibular canine being impacted. Conclusion: This case involves an unusual clinical and radiographic presentation of a dentigerous cyst crossing midline. It shows a new variant of presentation that dentists, especially maxillofacial surgeons, paedodontists and radiologists, should be aware of, since a dentigerous cyst crossing the midline is rare. I. Introduction: Dentigerous cysts are the second most common developmental odontogenic cysts. They are frequently noted as an incidental finding on radiographs because a majority of these cysts are asymptomatic and are mostcommonly associated with impacted mandibular third molars and permanent maxillary canines 1 . A dentigerous cyst presents as a well-defined radiolucent entity surrounding the crown of an impacted tooth. The border of the cyst is continuous with the cemento-enamel junction of the impacted tooth. This radiographic finding is pathognomonic for a dentigerous cyst. Majority of the reported cases to date have involved cysts localized to one quadrant of the jaws and have encompassed adjacent teeth. As a dentigerous cyst enlarges, it displaces the affected tooth or teeth apically. Dentigerous cysts enlarge as a result of the accumulation of fluid between the crown of an unerupted tooth and the reduced enamel epithelium. 2 Migration of an impacted tooth across the midline is a rare anomaly. Transmigration is defined as ‘migration of impacted tooth from its normal position to contralateral hemi arch. Ando et al were the first to use the term ‘transmigration’. The transmigrated teeth may be impacted in a horizontal or semi-horizontal position. The dentigerous cyst encloses the crown of an un-erupted tooth and is attached to the tooth at the cemento-enamel junction. This cyst develops by accumulation of fluid between the reduced enamel epithelium and the tooth crown. Here we present a case of dentigerous cyst associated with transmigrated impacted right mandibular canine. 3