Development of maxillary accessory ostium following sinusitis in rabbits

OBJECTIVES/HYPOTHESIS: Maxillary accessory ostium is one of the anatomical variations that may play a role in the development of chronic maxillary sinusitis. Although some authors claim that accessory ostia develop following acute maxillary sinusitis, it is not clear whether they are congenital or acquired. STUDY DESIGN: Animal experimental study. METHODS: Ten New Zealand type rabbits were used in the study. In phase 1, lateral nasal walls of five New Zealand type rabbits were examined for the presence of natural and accessory ostia of the maxillary sinus and any area resembling fontanelles in humans. In phase 2, experimental sinusitis was induced in the right sides of the other five rabbits. Following sacrifice, lateral nasal walls were examined for the development of accessory ostia. RESULTS: Six of the ten sides of phase 1 animals contained a membranous part in the medial wall of the maxillary sinus resembling the fontanelles in humans (60%). None of them had an accessory maxillary ostium. Accessory ostia developed in two of the five sides with sinusitis (40%). CONCLUSIONS: We have shown for the first time that accessory maxillary ostia develop following experimental sinusitis in rabbits. Further studies in humans are indicated.