Oroantral Fistula Originating from Osteomyelitis Accompanied by Maxillary Sinusitis

Osteomyelitis caused by maxillary sinusitis is clinically rare. We report a case of a 43-year-old woman who presented with an oroantral fistula on the hard palate, originating from osteomyelitis complicated by maxillary sinusitis. To our knowledge, oroantral fistula on the hard palate caused by chronic rhinosinusitis is rare. Physical, radiological, and cytological findings revealed the clues suggesting osteomyelitis. We performed endoscopic sinus surgery for the sinus lesion and the fistula healed spontaneously after the procedure.