RESUMO
Maxillary sinus retention cysts (MRCs) are typically asymptomatic and require no treatment. An early 30s man presented with a decade-long history of severe left-sided chronic facial pain (CFP). Multiple prior treatments resulted in an edentulous patient with persistent pain. Imaging revealed a dome-shaped radiopaque change in the left maxillary sinus. History and clinical examination suggested persistent idiopathic facial pain, and doubts about the outcome of a surgical intervention were explained to the patient. Surgical removal of the MRC via lateral antrotomy led to complete symptom resolution of CFP. This case substantiates the importance of considering MRCs as a possible cause of CFP. It also emphasises the need for a systematic multidisciplinary approach in cases of unexplained CFP.