Septal deviation causes nasal airway obstruction, necessitating septoplasty. The effectiveness of septoplasty is often assessed using the “Nasal Obstruction Symptom Evaluation (NOSE) score” and “Visual analogue scale (VAS)”; however, success rates remain limited. Studies on post-septoplasty outcomes and challenges for different septal deviations are rare. Septal corrections redistribute airflow, with symptom improvements depending on post-surgical changes. Investigating a post-septoplasty cavity's defense against particulate exposure and changes in particle deposition hotspots is crucial due to potential toxicological challenges. The current study uses patient-specific anatomies to examine airflow and particle deposition in pre- and post-septal correction in S-shaped, C-shaped, and reverse C-shaped septal deviations. Experiments measure pressure drops throughout the nasal cavity using a differential U-tube manometer attached to probes at various sites within three-dimensionally printed transparent nasal models. Additionally, Eulerian–Lagrangian airflow and particle deposition simulations are performed. In vitro results show a significant reduction in total pressure drop, ranging from 3 to 24 Pa between deviated and corrected models, and the nasal valve region is the most susceptible to pressure loss. In silico results reveal a maximum reduction of 50% in flow rate differences and 21% in wall shear stress (WSS) within nasal cavities for corrected cases. Lagrangian simulations show higher particle deposition in anterior regions of deviated cases, with an 82% reduction in particle deposition for the reverse C-shaped model with 10-μm particles, while the C-shaped model with 25-micron particles sees a 10% increase. These findings may help otolaryngologists evaluate post-surgical nasal cavity performance regarding airflow, filtration abilities, and potential toxicological challenges.