Bacteriology of maxillary sinuses in rabbits.

To study whether normal sinus flora exist in normal sinus, we used 40 sinuses from 20 New Zealand white rabbits as the animal model. The histological examination was performed on sinus mucosa from each sinus and bacteria from these sinuses were cultured. Surprisingly, 70% of them (28 sinuses) were found to have sinusitis. These sinuses not only contained bacteria in culture but also showed various degree of histological inflammatory reaction in mucosa examination. Of the other 12 normal or near normal sinuses, only two showed positive bacterial culture, and ten of them showed negative bacterial culture either from discharge or mucosa studies. Accordingly, these data suggest that these two studies (bacterial culture and histological mucosa examination) are consistent. Thus, from this study it was concluded that there is no bacteria or few bacteria in normal sinus.