Answer: Atrophic rhinitis.
Step 1: Atrophic rhinitis is chronic rhinitis with atrophy of the nasal mucosa, glands, nerves and vessels, producing roomy nasal cavities, foul smelling crusts (ozaena) and merciful anosmia.
Step 2: Surgery aims to narrow these wide cavities so the mucosa is no longer exposed to the drying air currents that drive crust formation, helping the mucosa regenerate.
Step 3: Full closure of the nostril is Young's operation, and partial closure is the Modified Young's operation. These closure procedures are specific to atrophic rhinitis.
Step 4: Allergic, vasomotor and occupational rhinitis are treated medically (allergen avoidance, antihistamines, steroids), not by nostril closure.
Ref: Cummings Otolaryngology, Head and Neck Surgery.