The changes of upper airway flow in adolescents with maxillary cleft before and after bone grafting and orthodontic treatment: a CFD simulation study

This study used CFD to analyze upper airway airflow in a 14-year-old girl with a unilateral incomplete maxillary cleft across three stages: before surgery, after bone grafting, and after orthodontic treatment. Results revealed that the maxillary cleft affected the airway volume. Post-surgery and orthodontics, airway cross-sectional areas changed and turbulence in nasopharynx/oropharynx reduced; One year post-orthodontics, nasal airflow velocity normalized (5.032 m/s vs. healthy adolescents’ 5.024 m/s); the shear stress distribution improved, and total pressure drop from the nostrils to the pharynx was 20.64 Pa, close to healthy adolescents’ 20.69 Pa. These findings indicate that respiratory function normalized after treatment.