Inverted Maxillary Third Molar Impaction within the Maxillary Sinus: A Rare Case Report

BACKGROUND The maxillary third molar is considered one of the most impacted teeth and can present in different types based on the direction and depth of the impaction. However, the inverted type of maxillary third molar impaction is a rare condition, with few reported cases in the current literature. CASE REPORT We report an extremely rare case of a 48-year-old man with an inverted maxillary third molar situated in the maxillary sinus in direct contact with the posterior wall of the sinus, with a portion of the coronal part perforating the infratemporal fossa. Because of the anatomical and structural complexity of the impaction and because the tooth has never been symptomatic, the case was conservatively managed after weighing the risks and benefits of surgical intervention. A 2-year follow-up was made to ensure no changes in the impaction location, confirming the validity of the conservative approach. CONCLUSIONS This case is the first reported inverted maxillary third molar impacted in such an anatomical location. This reported case contributes to existing knowledge regarding this rare type of impaction and that this rare impaction location can present congenitally with a non-iatrogenic origin. A thorough dental history and clinical and radiographical examinations will aid dental professionals in their clinical decision making for patients with similar presentations.