Evaluation of the influence of hyoid bone position, volume, and types on pharyngeal airway volume and cephalometric measurements.

OBJECTIVES: We aimed to explore the position, morphological, and morphometric properties of the hyoid bone (HB) and to investigate the effect of HB on the pharyngeal airway (PA) volume and cephalometric measurements. METHODS: A total of 305 patients with CT images were included in the study. DICOM images were transferred to the InVivoDental three-dimensional imaging software. The position of the HB was determined based on the cervical vertebra level and in volume render tab, the bone was classified into six types after all structures around the HB were removed. Also, final bone volume was recorded. In the same tab, the pharyngeal airway volume was divided and measured in three groups (nasopharynx-oropharynx-hypopharynx). The linear and angular measurements were performed on the 3D cephalometric analysis tab. RESULTS: HB was most commonly located in C3 vertebra level (80.3%). While B-type was found to be the most frequent (34%), V-type was the least frequent (8%). The volume of the HB was found to be significantly higher in male (3205 mm3) than female (2606 mm3) patients. Also, it was significantly higher in the C4 vertebra group. The vertical height of the face was positively correlated with the HB volume, C4 level position, and increased oro-nasopharyngeal airway volume. CONCLUSION: The volume of the HB is found to differ significantly between genders and can potentially serve as a valuable diagnostic tool for understanding respiratory disorders. Its morphometric features are associated with increased face height and airway volume; however, are not related with the skeletal malocclusion classes.

AI-based automatic segmentation of craniomaxillofacial anatomy from CBCT scans for automatic detection of pharyngeal airway evaluations in OSA patients.

This study aims to generate and also validate an automatic detection algorithm for pharyngeal airway on CBCT data using an AI software (Diagnocat) which will procure a measurement method. The second aim is to validate the newly developed artificial intelligence system in comparison to commercially available software for 3D CBCT evaluation. A Convolutional Neural Network-based machine learning algorithm was used for the segmentation of the pharyngeal airways in OSA and non-OSA patients. Radiologists used semi-automatic software to manually determine the airway and their measurements were compared with the AI. OSA patients were classified as minimal, mild, moderate, and severe groups, and the mean airway volumes of the groups were compared. The narrowest points of the airway (mm), the field of the airway (mm2), and volume of the airway (cc) of both OSA and non-OSA patients were also compared. There was no statistically significant difference between the manual technique and Diagnocat measurements in all groups (p > 0.05). Inter-class correlation coefficients were 0.954 for manual and automatic segmentation, 0.956 for Diagnocat and automatic segmentation, 0.972 for Diagnocat and manual segmentation. Although there was no statistically significant difference in total airway volume measurements between the manual measurements, automatic measurements, and DC measurements in non-OSA and OSA patients, we evaluated the output images to understand why the mean value for the total airway was higher in DC measurement. It was seen that the DC algorithm also measures the epiglottis volume and the posterior nasal aperture volume due to the low soft-tissue contrast in CBCT images and that leads to higher values in airway volume measurement.

Comparison of hyoid bone morphology between obstructive sleep apnea patients and healthy individuals.

OBJECTIVE: We aimed to find morphological properties of the hyoid bone, which are predominant among the patients diagnosed with obstructive sleep apnoea (OSA), and compare them with healthy individuals. METHODS: A total of 67 cone-beam computed tomography (CBCT) image sequences of patients (44 males, 23 females) diagnosed with OSA and a total of 70 multislice computed tomography (MSCT) data of non-OSA patients (45 males, 25 females) were selected in this study. DICOM images were imported into InVivo 5.1.2 (Anatomage) software. The position of the hyoid bone relative to the C3 and C4 cervical vertebrae, as well as its morphological type (B, V, U, H, D, HK-type) and its total volume was determined. RESULTS: The volumetric values of the hyoid bone of OSA patients (2384.49 ± 682.073 mm3 ) were significantly (P < .001) lower compared to the values derived from non-OSA patients (2952.96 ± 932.5 mm3 ). The difference was independent of gender, and volumetric values showed a strong significant (P < .01) difference between male OSA and non-OSA (2709.18 ± 608.05; 3157.87 ± 926.5 mm3 ) and female OSA and non-OSA patients (1763 ± 242.51 2584; 2584.12 ± 840.21 mm3 ), as well. In the case of B and V-types, the volumetric values showed significant differences (P < .05), when the OSA (2300,77 ± 622; 2166 ± 312 mm3 ) and non-OSA patients were compared (2823,48 ± 780; 3216 ± 463 mm3 ). CONCLUSION: Our results suggest that the volume of the hyoid bone might be a potential biological marker for OSA, especially in the case of B and V hyoid bone types.