BackgroundNeo-osteogenesis of the paranasal sinuses is a radiologic finding of unclear clinical significance. Although current evidence suggests that these bony changes represent an inflammatory response rather than an infectious osteitis, bacteria associated with the sinonasal mucosa may induce inflammatory mediators as a mechanism of neo-osteogenesis. The objectives of this study were (1) to determine whether there is an association between bacteria isolated on sinus culture and neo-osteogenesis, and (2) to identify other predictive factors for neo-osteogenesis. MethodsNinety patients undergoing sinus surgery for medically refractory CRS were recruited. Radiologic evidence of neo-osteogenesis was assessed by the Global Osteitis Scoring Scale (GOSS) and mucosal disease severity was assessed by the Lund-Mackay score (LMS). Bacterial culture was obtained endoscopically at the preoperative office visit or during surgery. Multiple and logistic regression models were used to evaluate the association between the types of bacterial species isolated, number of previous surgeries, and severity of neo-osteogenesis. ResultsThirty of the 90 (33.3%) patients had radiologic evidence of neo-osteogenesis. Pseudomonas aeruginosa was significantly associated with neo-osteogenesis (odds ratio [OR], 3.97; 95% confidence interval [CI], 1.12 to 13.56), whereas Staphylococcus aureus was not. The number of previous surgeries, especially 2 or more previous surgeries, was associated with the extent of neo-osteogenesis (OR, 3.48; 95% CI, 1.14 to 10.51). The LMS was also significantly associated with the extent of neo-osteogenesis. ConclusionThe presence of P. aeruginosa in the sinuses is an independent predictor of neo-osteogenesis, whereas S. aureus is not. The number of previous surgeries and the LMS are also independently associated with the severity of neo-osteogenesis.