Current investigation techniques (Rhinomanometry, Endoscopy, e.g.) of the nasal cavity are not always able to diagnose a successful surgery outcome to relieve breathing. The presented approach uses medical imaging datasets (i.e. cone beam Computer Tomography) to simulate the flow through the nasal cavity with a Laser Doppler Anemometry (LDA) validated lattice Boltzmann (LB) simulation. In order to find potential surgically relevant points (SRP), the determination of the patient’s LB-simulated pressure drop is used for comparison with a critical pressure drop found by a sensitivity analysis (3 patients with nasal septum deviation, 1 person without breathing problems). Based on SRPs a developed optimizer shapes the nasal cavity. All locations of SRPs in postoperative CT datasets show an increase of the crosssection of the nasal cavity. The difference of cross-section between pre- and optimized nasal cavity in the postoperative CT is smaller than 15%. The optimization result shows good and this method will be validated in a future clinical trial.