OBJECTIVES: This study aims to compare the effects of two orthodontic treatment modalities for skeletal class Ⅲ malocclusion on specific changes in airway volume, morphology, palatal angle, mandibular rotation, and bone displacement. Results provide scientific evidence for the selection of orthodontic treatment plans and reduce the risk of developing obstructive sleep apnea hypopnea syndrome (OSAHS). METHODS: Thirty-six patients diagnosed with skeletal class Ⅲ malocclusion at the Department of Orthodontics, the Affiliated Stomatological Hospital of Nanjing Medical University from September 2018 to December 2023 were divided into two groups: orthodontic-orthognathic treatment group (18 patients) and camouflage orthodontic treatment group (18 patients). Changes in airway volume, cross-sectional area, palatal angle, mandibular, and tongue positions were observed through pre- and post-operative cone beam computed tomography and 3D cephalometric measurements. RESULTS: In the camouflage orthodontic treatment group, nasopharyngeal volume and oropharyngeal volume statistically increased after treatment (P<0.05). In the orthodontic-orthognathic treatment group, changes in nasopharyngeal volume, nasopharyngeal airway, distance from posterior tongue to pharyngeal wall, palatal angle, mandibular rotation, and hyoid bone displacement were statistically significant after surgery (P<0.05). In the comparison between the two groups after treatment, changes in the distance from posterior tongue to pharyngeal wall, palatal angle, and distance from hyoid bone to sella turcica point were statistically significant (P<0.05). CONCLUSIONS Patients in the orthodontic-orthognathic treatment group showed significantly greater changes in oropharyngeal cross-sectional area, palate angle, and tongue position compared with patients in the camouflage orthodontic treatment group. As individuals susceptible to OSAHS often exhibit mandibular retrusion and decreased minimum airway cross-sectional area, special attention should be paid to airway morphology changes when adopting orthodontic-orthognathic treatment to avoid adverse consequences.
Humans ; Hyoid Bone/diagnostic imaging* ; Malocclusion, Angle Class III/therapy* ; Male ; Female ; Cone-Beam Computed Tomography ; Cephalometry ; Orthodontics, Corrective/methods* ; Adult ; Mandible ; Pharynx/diagnostic imaging* ; Sleep Apnea, Obstructive/etiology* ; Orthognathic Surgical Procedures

Objective To explore the feasibility of the CT image reconstruction of laryngeal cartilage and hyoid bone in adult age estimation using data mining methods. Methods The neck thin slice CT scans of 413 individuals aged 18 to <80 years were collected and divided into test set and train set, randomly. According to grading methods such as TURK et al., all samples were graded comprehensively. The process of thyroid cartilage ossification was divided into 6 stages, the process of cricoid cartilage ossification was divided into 5 stages, and the synosteosis between the greater horn of hyoid and hyoid body was divided into 3 stages. Multiple linear regression model, support vector regression model, and Bayesian ridge regression model were developed for adult age estimation by scikit-learn 0.17 machine learning kit （Python language）. Leave-one-out cross-validation and the test set were used to further evaluate performance of the models. Results All indicators were moderately or poorly associated with age. The model with the highest accuracy in male age estimation was the support vector regression model, with a mean absolute error of 8.67 years, much higher than the other two models. The model with the highest accuracy in female adult age estimation was the support vector regression model, with a mean absolute error of 12.69 years, but its accuracy differences with the other two models had no statistical significance. Conclusion Data mining technology can improve the accuracy of adult age estimation, but the accuracy of adult age estimation based on laryngeal cartilage and hyoid bone is still not satisfactory, so it should be combined with other indicators in practice.
Adolescent ; Adult ; Bayes Theorem ; Child ; Data Mining ; Female ; Humans ; Hyoid Bone/diagnostic imaging* ; Image Processing, Computer-Assisted ; Laryngeal Cartilages/diagnostic imaging* ; Male ; Tomography, X-Ray Computed

OBJECTIVEThis research aimed to analyze the three-dimensional position of mandibular canal (MC) and man of MC and its relationship with the surrounding structures dibular morphology of normal young males and females by using data from cone beam computed tomography (CBCT), as well as to provide an anatomical basis for clinical surgery of the mandible.

METHODSNormal occlusion and CBCT scans of 29 normal young people were conducted. InVivo 5 software was used to reconstruct the mandible, anchor the points, and measure the jaw shape and three-dimensional course of MC. All measurements were analyzed with SSPS 17.0 software.

RESULTSThe MC lingual bone cortex was thinner than the MC buccal bone cortex, and the distance of the MC to the buccal bone cortex gradually increased. However, the distance of the MC to the tongue bone cortex and alveolar crest gradually decreased from proximal to distal. In addition, the distance of the MC to the mandibular lower margin was minimal at the first molar and reached the maximum at the second premolar. No significant difference was observed among the heights, widths, and thicknesses of the left and right sides of the cortical bone of the mandibular body cross sections. From the midline to the farthest point, the height and lower one-third thickness of the lingual cortical bone of the mandibular body cross sections gradually decreased, whereas the width of the upper cross section and upper one-third thickness of the buccal cortical bone gradually increased. Significant difference was observed in some measured values.

CONCLUSIONAfter MC enter into the mandibular foramen, it moved away from the lingual to the buccal bone but gradually returned to the lingual bone; its general course is closer to the lingual bone. The mandibles of males are thicker than those of females. CBCT can accurately display the course of MC and its relationship with the surrounding structures.

Alveolar Process ; Bicuspid ; Cone-Beam Computed Tomography ; methods ; Dental Pulp Cavity ; Female ; Humans ; Hyoid Bone ; Male ; Mandible ; anatomy & histology ; diagnostic imaging ; Molar ; Software ; Surveys and Questionnaires ; Tongue ; Zygoma

This study sought to assess the effect of CPAP on the structure and function of upper airway of mini pig with OSAS induced by altitude hypoxia. 12 adult male mini pigs were randomly assigned to 2 groups, named A and B. The mini pigs in group A were treated with altitude hypoxia 6 h per day for 22 days, and then with CPAP 6 h per day for 30 days. The mini pigs in group B were treated with altitude hypoxia only. Pharyngeal CT scanning and respiratory pressure testing were performed after the treatments . At last all mini pigs were sacrificed and their pharyngeal tissue was acquired for pathological examination. Result of pharyngeal CT scanning showed that, in group A, both of transverse diameters of pharyngeal cave in anterior and posterior areas of hyoid bone increased significantly after CPAP treatment (P < 0.05), while the pharyngeal longitudinal diameters exhibited no significant change (P > 0.05). The thickness of pharyngeal posterior wall of the anterior areas of hyoid bone increased significantly (P < 0.05) after CPAP, while the thickness of the lateral wall displayed no significant change. The pharyngeal longitudinal diameters of group A after CPAP were shorter than those of group B, and the transverse diameters were longer than those of group B, but these differences were not statistically significant (P > 0.05). The pharyngeal posterior walls in soft palate area and anterior area of hyoid bone after CPAP were significantly thicker than those of group B (P < 0.05), but there were no significant differences between the two groups as far as lateral wall thickness was concerned (P > 0.05). After CPAP treatment, the pharyngeal inspiration pressure in group A decreased significantly (P < 0.05), and the pressure was significantly lower than that of group B. Microscopic findings showed that the epithelium was proliferated partly after CPAP treatment. The muscle fibers of group A became fatter and were arranged disorderly with unclear transverse striation. The dropsied and congestive subcutaneous tissues were also infiltrated with inflammatory cells. These pathological changes were more obvious in group B. The results suggested that CPAP treatment could normalize the structure and function of pharyngeal tissue in OSAS mini pigs.
Animals ; Continuous Positive Airway Pressure ; adverse effects ; Epithelium ; pathology ; Hyoid Bone ; diagnostic imaging ; pathology ; physiology ; Male ; Pharynx ; diagnostic imaging ; pathology ; physiology ; Random Allocation ; Sleep Apnea, Obstructive ; therapy ; Swine ; Swine, Miniature ; Tomography, X-Ray Computed