Introduction
Many patients have nasal obstruction in rhinology disease. For the
evaluation of nasal obstruction, rhinomanometry is very popular
worldwide.1 Rhinomanometry can measure nasal pressure
and airflow during inspiration and expiration. Additionally, it can
measure nasal resistance to measure the pressure difference between the
nostril and choana. Nasal resistance can be affected by alternating
congestion and decongestion of the nasal mucosa, which is termed the
nasal cycle.2, 3 Lang et al. investigated the nasal
cycle using endoscopy, rhinoresistometry, and acoustic
rhinometry.4 Gogniashvili et al. also investigated the
nasal cycle in the same manner.5 In general
anesthesia, nasal patency is investigated before nasal
intubation.6 Rhinomanometry can measure nasal
resistance during the nasal cycle; however, it cannot measure the direct
airflow pressure in the nasal cavity.
Recently, computational fluid dynamics (CFD) in rhinology has been
popular for measuring airflow or pressure.7, 8 This
enables the observation of the airflow, pressure, heat, and streamline,
which cannot be determined directly. Kim et al. reviewed
patient-specific CFD models of nasal airflow.9Moreover, Wang et al. simulated applying CFD to the study of the nasal
cavity in 2005.10 In turn, Xiong et al. reported a
numerical flow simulation in virtual post-endoscopic sinus
surgery.11 Twenty-two healthy adults were studied to
determine the normal nasal airflow.12 It was found
that nasal resistance affected nasal obstruction. Recently, these
phenomena were simulated using CFD. Radulesco reported a comparison of
nasal obstruction with CFD variables.13 Finally,
Berger reported the agreement between rhinomanometry and CFD regarding
nasal resistance.14
CFD can be achieved by creating a 3D model and using numerical
simulation. However, the nose is composed of the nasal cavity and
paranasal sinus and is a very complicated structure. Thus, it is very
difficult to create a highly accurate nasal cavity and paranasal sinus
3D model. The recent literature includes many CFD rhinology documents,
with absence of accurate nose 3D models. Therefore, we created a nose 3D
model to check the all-natural ostium of all paranasal sinuses. It was
unclear whether the simulation in reality reflected the human body. By
comparing the real nasal resistance value, which can be measured, with
the numerical simulation value, it is possible to judge whether or not
it is closer to the human body.