CBCT Study On The Relationship Between Hyoid Bone And Surrounding Tissue In Bone Class ? And Bone Class ?

Objective: In this study,three-dimensional reconstruction of the hyoid bone and its surrounding tissue and the related data measurement were carried out by using the digital three-dimensional reconstruction technique. The relationship between the shape and location of the hyoid bone and the different parts of the upper airway were observed more accurately.It is helpful to provide a theoretical basis for orthognathic surgery and prevention of OSAHS in clinical practice, and to prevent the postoperative airway stenosis and other related complications.Methods: 1. The patients were photographed using NEW TOM 3G (Quantitative Radiology s.r.l., Verona, Italy) and these data was imported into the Mimics 17.0 software workstation in DICOM format. The three - dimensional visualization model of hyoid bone and its surrounding tissue were reconstructed by using graphic reconstruction and segmentation tool in software. While focusing on the hyoid bone,mandible,cervical and upper airway reconstruction, the clinical anatomy and interrelationships of hyoid bone and its surrounding tissues were explored. 2. The morphological, location and upper airway of the hyoid bone were measured and quantitatively measured by Mimics17.0 software. The measurement data and results were recorded, and the volume of the hyoid bone was recorded.3. Data measurement were statistical analyzed using SPSS software.Results: In this study, 100 cases of Bone Class ? and Class ? were reconstructed and analyzed. The results showed that there was no significant difference in hyoid bone morphology between the two groups (P>0.05) ); the distance between hyoid bone -mandibular plane and hyoid bone - cervical plane was significantly different (P<0.05), that is,hyoid bone position in adult Bone Class ? and Class ? is different; there was significant difference between the two groups of the volume of the airway sections (nasopharynx,palatopharynx, glossopharynx, hypopharynx) (P<0.05), and the volume of each segment is different. There was significant difference in the shape and location of hyoid between adult males and females (P<0.05). There was no significant correlation between hyoid bone morphology and the volume of nasopharyngeal, there was a positive correlation between palatopharynx ? glossopharynx? hypopharynx volume and the distance between the upper point of the hyoid bone to the large corners of the hyoid bone, there was a negative correlation between palatopharynx volume and the angle of the two sides of the hyoid bone,there was a positive correlation between hypopharynx volume and the distance between both sides of the large corners of the hyoid bone ; there was no significant correlation between the location of the hyoid bone and the volume of the nasopharynx area of the upper airway, there was a positive correlation between the distance between the hyoid bone to the cervical plane and the volume of the palatopharynx, there was a positive correlation between the hyoid bone - mandibular plane?hyoid bone - cervical plane and the volume of the glossopharynx and hypopharynx.Conclusions: Based on CBCT data, three-dimensional reconstruction of hyoid bone and upper airway with Mimics three-dimensional reconstruction software and related measurement analysis,were used to avoid the shortcomings of the Head lateral slice,and the obtained data were accurate. In this study, adult hyoid bone morphology, location and the upper airway volume were compared between Bone Class ? and Bone Class ?, conclusions as follows:1 ? In the comparison of hyoid bone between Bone Class ? and Bone Class ?, the results showed that there was no significant difference in the shape of hyoid bone between the two groups, which indicated that the hyoid bone was relatively stable after the growth and development were completed;2? In the comparison of bone type ? and bone type ? hyoid bone position, the hyoid bone position and the upper airway were statistically different between the two groups. It was found that the hyoid bone position was more front and under in bone type ?;3.In the comparison of the volume of upper airway sections between the bone class ?and the bone class ?, the bone class ? was higher than the class I, indicating that craniofacial horizontal growth and development impacted the hyoid bone position and the upper airway;4.In the correlation analysis between the hyoid bone shape?position and the upper airway, the results showed that the hyoid bone shape and the position were correlated with the upper airway respectively;5 ? There was gender differences in the hyoid bone shape and location between the bone class ? and bone ? group in adult.Therefore, there is close relationship between the hyoid bone and the airway. It should control the mandibular retraction in the bone class ? orthognathic surgery, in order to avoid the retraction of the jaw, which may cause the mouth and other changes in the structure of the wound and result in hyoid bone shape and location changes. And it should control the impact of airway morphology and function which may cause OSAHS and other postoperative complications.