“…It was reported that the improvement after FESS is significantly better in patients with severe olfactory dysfunction whereas it is not in patients with mild olfactory dysfunction (Litvack et al, 2009b, Soler et al, 2010. The degree of nasal obstruction, the extent of the rhinosinusitis disease (evaluate by symptom score or CT scan), the coexistence of nasal polyps or allergic rhinitis do not predict the possibility of olfactory improvement after FESS (Bhattacharyya, 2006;Jiang et al, 2009;Wright and Agrawal, 2007). In addition, Jankowski et al (Jankowski and Bodino, 2003) demonstrated that there was a correlation between the improvement of subjective olfactory function after oral corticosteroids given preoperatively and olfactory function 1 year after nazalisation.…”