Study On The Characteristics Of Upper Airway Morphology And Hyoid Bone Position In Mouth-breathing Patients

Objective:In this study,Cone-Beam Computer Tomography(CBCT)was used to evaluate the upper airway morphology and hyoid bone position of normal-angle and skeletal class I malocclusion patients with mouth-breathing and nasal-breathing.Exploring the characteristics of upper airway morphology and hyoid position in patients with mouth-breathing,in order to provide theoretical basis for prevention,diagnosis and treatment of malocclusion caused by mouth-breathing..Methods:According to the inclusion criteria,78 patients(age 12-16)with normal-angle and skeletal class I malocclusion in the Department of Orthodontics,the first Hospital of Shanxi Medical University from 2018 to 2021 were divided into mouth breathing group(n = 39)and nasal breathing group(n = 39).CBCT was taken.The upper airway was reconstructed by Dolphin11.95 software.The reconstructed upper airway was divided into nasopharyngeal segment,palato pharyngeal segment,hyold pharyngeal segment and laryngopharyngeal segment.The volume,sagittal surface area,minimum cross-sectional area,three-dimensional structural surface area of the upper airway and the position of the hyoid bone were measured respectively.Statistical analysis of the data using SPSS22.0software.Chi-square test was used to compare counting data between groups,and independent sample t-test was used to compare measurement data between groups.Results:1.The volume,sagittal surface area,minimum cross-sectional area and three-dimensional structural surface area of palato pharyngeal segment and hyold pharyngeal segment of upper airway in mouth breathing group were significantly lower than those in nasal breathing group(P < 0.05)2.There was no significant difference in the measurement items of nasopharyngeal segment and laryngopharyngeal segment of upper airway between mouth breathing group and nasal breathing group(P > 0.05).3.There was no significant difference in the vertical and horizontal distance between the hyoid and the anterior skull base plane between the two groups(P > 0.05).Conclusion:In this experiment,the upper airway morphology and hyoid position of patients with mouh breathing and nasal breathing were compared.it was found that:1.The upper airway palatopharynx and glossopharyngeal segment of normal-angle and skeletal class I malocclusion patients with mouth-breathing were significantly narrower than those with nasal-breathing.2.Mouth-breathing had no effect on the position of nasopharyngeal segment,laryngopharyngeal segment and hyoid bone of normal-angle and skeletal class I malocclusion patients.