Pneumosinus dilatans frontalis: Its aetiology, symptoms and operative technique.

Background: Pneumosinus dilatans of the frontal sinus is a very rare condition in which deformity is caused by progressive enlargement of the brow ridges and lower forehead. patients: Etiology of the reported two cases was unknown although some hypotheses have been presented. Results and Conclusions: We corrected the aesthetic deformity using an osteoplastic flap and removing horizontal bone chips from the anterior wall of the frontal sinus. Postoperative results were satisfactory. In one case, obliteration of the sinus with fat was necessary, because of polypous mucosa.