Abstract
Dentigerous cysts are characterised by the formation of cysts containing dental material with a variable level of development. They are the result of a distinct embryological phenomenon. Usually, they are of significant clinical relevance in horses, especially in tandem with ectopic tooth. Contrarily, supernumerary teeth or typical polyodontias usually have limited impact. In this case report, we describe the occurrence of a supernumerary first premolar (Triadan 105). Dissimilar to known scientific literature however was the formation of a cystic structure around the supernumerary tooth. Surgical removal of the dentigerous cyst is discussed, as are the possible causes for the formation of the cystic structure. Based on this case report, we suspect that the formation of a cystic structure may not be limited to atypical polyodontias, as they may also occur in supernumerary teeth.