Impaction is pretty an uncommon process in the deciduous dentition. The etiology of deciduous tooth impaction is not known and, if there is an indication, optimal treatment is surgical removing or extraction. A 20-year-old male presented with a complaint of chronic infection in the maxillary right premolar region. The maxillary right first premolar was absent. Orthopantomograph and computed tomography revealed an impacted maxillary right deciduous molar embedded within cyst close to the anterior wall of the maxillary sinus and missing maxillary permanent first premolar. The impacted tooth and cyst were removed under local anesthesia. Caries was detected on the impacted tooth. A dentigerous cyst was shown on histopathological examination. The presence of caries on the impacted deciduous tooth indicated it had previously erupted. To our knowledge, no case, involved in impacted deciduous tooth with caries in dentigerous cyst, has been reported in the literature. The aim of this case report was to present the diagnosis and treatment of impacted deciduous molar with caries in dentigerous cyst.

Keywords: Caries, deciduous molar, dentigerous cyst, impacted tooth