Objective Palatopharynx is the most common area for upper airway obstructions in obstructive sleep apnea (OSA) patients.One of the most popular surgical treatments for these patients is the Han-uvulopalatopharyngoplasty (H-UPPP).As an important part of the surgery, tonsils are removed to enlarge the pharyngeal airway and improve the ventilation.The suture after a surgery can change the stress distribution in the surrounding tissues, which may directly affect the geometry of the pharyngeal wall and surgery results.However, there are currently no effective simulation methods that can be used to evaluate the effects of suture selections on surgery results.In this study, we develop a new finite element model to analyze the effects of different selections for tonsillar fossa suturing on the pharyngeal structure, which can provide theoretical references for suture selections in H-UPPP surgeries.Methods Based on magnetic resonance images of the head and neck for an OSA patient, we built an anatomically realistic three-dimensional mechanical and finite element model of the upper airway with surrounding tissues.By shrinking the volume representing tonsils in the model and limiting the displacements of its certain surfaces, we simulated the surgery with three different suture schemes.The numerical simulations were performed by using the software ADINA.By observing the changes in the narrowest cross section of the airway and the pharyngeal space, we evaluated the effects of different suture selections on the size of the pharyngeal airway.Results Using the three-dimensional finite element model, we simulated the three suture selections: the interrupted suture, the pulling-forward suture, and the pulling-backward suture.The numerical results showed that in the case of a pulling-forward suture for the tonsillar fossa, there was a 27.82% increase in the cross-sectional area at the narrowest part of the upper airway, which was larger than 24.76% for an interrupted suture and 27.11% for a pulling-forward suture.However, the space increase in the region near the tip of the uvula was large in the last two cases.The average cross-sectional area was 5 times as large as that before the surgery for the interrupted suture and pulling-backward suture simulations, while the value was 4.3 times as large as that in the pulling-forward suture case.Conclusions The methods for suture cuts in an H-UPPP surgery have significant effects on the stress distributions in the surrounding soft tissues, and the cross-sectional shape and size of the upper airway.This method can be used for individual simulations in different patients.For the type of anatomical structures in this study, the model-predicted results suggest that a pulling-forward suture can provide more help in improving the structure of narrowest part of the upper airway for patients, compared to the other two suture selections.