Microflora of normal maxillary sinuses: does it justify perioperative antibiotic treatment in sinus augmentation procedures

Objectives: To investigate bacterial flora of normal maxillary sinuses in order to facilitate perioperative antibiotic management in sinus augmentation procedures. Materials and methods: Specimens of maxillary sinus mucosa were harvested during planned orthognatic surgery in 18 patients with no evidence of rhinosinusitis. The samples were processed according to hospital routine for aerobic and anaerobic cultures. Results: Ten maxillary sinuses were found sterile. Twenty-six (72%) maxillary mucosa specimens were culture-positive. Aerobes were recovered in 21 sinus samples (58%), predominantly as polymicrobial flora (18 cultures, 50% of all specimens), S. aureus in 2 sinuses of the same patient (6% of the samples), and Bacillus sp. in 1 sinus (3%). Anaerobes were isolated in 20 of 26 culture-positive specimens (56% of all sinus samples). They were recovered alone in 5 samples. Fifteen anaerobic cultures were polymicrobial (42% of all samples). Propionibacterium acnes was isolated from another 5 sinuses (14%) of 3 patients. Conclusions: Our data support the policy of perioperative antibiotic prophylaxis in sinus augmentation procedures where Schneiderian membrane is perforated. Clinical relevance: Evaluating the need of a perioperative antibiotic therapy in sinus augmentation procedures.