[Pneumosinus dilatans. Long-term result of modelling osteoplasties].

Pneumosinus dilatans is a rare disease characterized by an evolutive hyperpneumatization of the sinuses. The frontal sinus is most often involved, but any other sinus of the face can be affected. Three cases of pneumosinus dilatans, including two in the frontal sinus and one in the maxillary sinus, are reported. Modelling osteoplasty without drainage of the sinus was performed in all three cases and yielded satisfactory and stable results with a minimal period of observation of 5 years. The long-term effectiveness of modelling osteoplasty must be taken into account to study the physiopathology of pneumosinus dilatans. The most likely etiopathogenetic hypothesis is a disorder in the local growth of the sinus.