Age-related anatomical variations and the impact of adenoid hypertrophy on nasal airflow in Asian children

The human nasal airway grows rapidly in childhood and some children develop pathological changes of adenoid hypertrophy (AH), leading to substantial alterations in airflow dynamics. To ensure the healthy growth of children, we quantified the growth of the nasal airway and analyzed the nasal airflow field and nasal function. Models of 26 children aged 3–12 years were constructed, and the geometric dimensions of the nasal airway were quantified based on parameters such as surface area, volume, cross-sectional area, and hydraulic diameter. Computational fluid dynamics (CFD) methods were employed to simulate the nasal airflow field. Virtual adenoidectomy was performed on children with severe AH, and partitioned airflow volume and warming and humidification were quantitatively compared before and after surgery. The results showed that the turbinate area in children aged 3–12 develops most rapidly and constitutes the main form of the complex shape of the nasal cavity. The majority of airflow in children's nasal cavities passes through the main nasal passage and the middle meatus, with a small portion of the airflow passing though the olfactory fissure. After adenoidectomy, more airflow is redirected to the olfactory region, and the imbalance in airflow distribution between the left and right nasal cavities is reduced. Virtual post-operatively, the warming and humidification of the nasal cavity, especially in the nasopharynx, has decreased, which is significantly correlated with the surface area-to-volume ratio of the airway. The findings contribute to a better understanding of the growth and development of nasal airways in Asian children.