The question is why in similar narrow anatomical nose sinus complex, some suffer from drainage and aeration, some are not? This is obvious that there are mechanical and physiological factors that plays role in the outcome. These factors creates the perfect storm separately or in combination.
Anatomic narrowing variations that creates mechanical factors:
1. Comparatively big ethmoid cells
2. Ager nasi
3. Pneumotized concha media
4. Nasal septal deviation
5. Hypertrophic mucosal thickening
6. Changes in air flow pathways
7. Outdoor stimulants like allergens or particles
Physiological factors:
1. Body chemicals that cause excess and/or thick mucus secretion
2. Neurologic factors that determines the composition of mucus
3. Neurologic factors that determines the activity of mucocilliary system functions