The relationship between upper airways and craniofacial morphology studied in 3D. A CBCT study.

To assess whether morphology and dimension of the upper airway differ between patients characterized by various craniofacial morphology. Ninety young adult patients from the Postgraduate Clinic, Section of Orthodontics, Department of Dentistry, Health, Aarhus University, Denmark, with no obvious signs of respiratory diseases and no previous adeno-tonsillectomy procedures. Thirty patients were characterized as Class I (-0.5 < ANB < 4.5), 30 as Class II (ANB > 4.5), and 30 as Class III (ANB < -0.5). Cone-beam computed tomography (CBCT) scans obtained in a supine position for all patients. Cephalometric landmarks were identified in 3D. Sagittal and transversal dimensions, cross sections, and partial and total volumes of the upper airway were correlated with the cephalometric measurements in all three planes of space. The cross-sectional minimal area of the upper airway was assessed as well. No statistical significant relationships between dimension and morphology of upper airways and skeletal malocclusion were found. Differences in craniofacial morphology as identified by the sagittal jaw relationship were not correlated with variation in upper airway volumes. A clinical significant relation was detected between minimal area and total upper airway volume.

Di Carlo G ，Polimeni A ，Melsen B ，Cattaneo PM ... -  《-》

A comparative study of the pharyngeal airway space, measured with cone beam computed tomography, between patients with different craniofacial morphologies.

The present study aims to determine any existing association between airway dimensions, measured with cone beam computed tomography (CBCT), and the different patient craniofacial morphologies. Sixty CBCT (Dental Picasso Master 3D) images, from patients treated at the Orthodontics Master at Valencia University were selected. The program InVivoDental 5.1 was used to visualize sections, analyze three-dimensional images, and perform airway measurements in the three planes of the space. Intra- and interobserver error methods were recorded. After that, measurements at three different levels of the airway (upper, medium, lower) were taken, in both the anteroposterior and transversal directions of the airway space. The area (mm(2)) of the airway space at the three levels was also measured. In the anteroposterior airway measurements, there were differences between the measurements by level. The magnitude of these differences depended on the skeletal pattern of the individual. In the transversal airway measurements and in the area airway measurements, there were no differences according to the skeletal pattern. However, in the transversal direction, measurements in the lower level were significantly higher than in the superior level in all cases. When measuring the area, significantly higher measurements in the upper level were recorded. The homogeneity between medium and lower levels decreased gradually from class I to class III subjects. No statistically significant results were observed that related the anteroposterior and vertical skeletal craniofacial morphology with airway dimensions, although some specific associations have been detected for certain airway levels or for pattern combinations.

Dalmau E ，Zamora N ，Tarazona B ，Gandia JL ，Paredes V ... -  《-》

Three-dimensional analysis of pharyngeal airway volume in adults with anterior position of the mandible.

The purpose of this study was to examine whether the pharyngeal airway volume in adults with skeletal Class III malocclusion is greater than in subjects with Class I occlusion and whether the pharyngeal airway volume correlated with facial morphology. Cone-beam computed tomography scans were obtained from 60 subjects, who were assigned to 2 groups. The skeletal Class III malocclusion group consisted of 31 subjects (16 men, 15 women) who had planned on orthodontic treatment with orthognathic surgery. The Class I malocclusion group consisted of 29 subjects (14 men, 15 women). The pharyngeal airway volumes and areas were measured and compared with cephalometric variables. The cross-sectional areas of the lower part of the pharyngeal airway and the volume of the upper part of the pharyngeal airway were greater in skeletal Class III malocclusion patients than in Class I malocclusion patients. The volume of the upper part of the pharyngeal airway showed negative correlations with ANB angle and the Wits appraisal, and positive correlations with SNB, APDI, pogonion to N-perp, gonial angle, and FMA. The volume of the upper part of the pharyngeal space was greater in patients with skeletal Class III malocclusion, and the increased volume of the upper part of the pharyngeal airway showed significant correlations with measurements characterizing the anterior position of mandible.

Hong JS ，Oh KM ，Kim BR ，Kim YJ ，Park YH ... -  《-》

Postsurgical volumetric airway changes in 2-jaw orthognathic surgery patients.

Findings from early cephalometric studies on airway changes after 2-jaw orthognathic surgery have been challenged because the previous anteroposterior interpretation of airway changes can now be evaluated in 3 dimensions. The aims of this study were to use cone-beam computed tomography to quantify the nasopharynx, oropharynx, and total airway volume changes associated with skeletal movements of the maxilla and mandible in a sample of patients undergoing 2-jaw orthognathic surgery for correction of skeletal malocclusion. Skeletal movements and airway volumes of 71 postpubertal patients (31 male, 40 female; mean age, 18.8 years) were measured. They were divided into 2 groups based on ANB angle, overjet, and occlusion (Class II: ANB, >2°; overjet, >1 mm; total, 35 subjects; and Class III: ANB, <1°; overjet, <1 mm; total, 36 subjects). Presurgical and postsurgical measurements were collected for horizontal, vertical, and transverse movements of the maxilla and the mandible, along with changes in the nasopharynx, oropharynx, and total airways. Associations between the directional movements of skeletal structures and the regional changes in airway volume were quantified. Changes in the most constricted area were also noted. Horizontal movements of D-point were significantly associated with increases in both total airway (403.6 ± 138.6 mm(3); P <0.01) and oropharynx (383.9 ± 127.9 mm(3); P <0.01) volumes. Vertical movements of the posterior nasal spine were significantly associated with decreases in total airway volume (-459.2 ± 219.9 mm(3); P = 0.04) and oropharynx volume (-639.7 ± 195.3 mm(3); P <0.01), increases in nasopharynx (187.2 ± 47.1 mm(3); P <0.01) volume, and decreases in the most constricted area (-10.63 ± 3.69 mm(2); P <0.01). In the Class III patients only, the vertical movement of D-point was significantly associated with decreases in both total airway (-724.0 ± 284.4 mm(3); P = 0.02) and oropharynx (-648.2 ± 270.4 mm(3); P = 0.02) volumes. A similar negative association was observed for the most constricted area for the vertical movement of D-point (-15.45 ± 4.91 mm(2); P <0.01). Optimal control of airway volume is through management of the mandible in the horizontal direction and the vertical movement of the posterior maxilla for all patients. The surgeon and the orthodontist should optimally plan these movements to control gains or losses in airway volume as a result of orthognathic surgery.

Hart PS ，McIntyre BP ，Kadioglu O ，Currier GF ，Sullivan SM ，Li J ，Shay C ... -  《-》

Three-dimensional evaluation of upper airway in patients with different anteroposterior skeletal patterns.

To investigate variability in the upper airway of subjects with different anteroposterior skeletal patterns by evaluating the volume and the most constricted cross-sectional area of the pharyngeal airway and defining correlations between the different variables. The study sample consisted of 60 patients (29 boys, 31 girls) divided into three groups: Class I (1 ≤ ANB ≤ 3), Class II (ANB>3), and Class III (ANB<1), to evaluate how the jaw relationship affects the airway volume and the most constricted cross-sectional area (Min-CSA). Differences between groups were determined using the Tukey-Kramer test. Correlations between variables were tested using Pearson's correlation coefficient. The volume and the Min-CSA of the pharyngeal airway (PA) were significantly related to anteroposterior skeletal patterns (p < 0.05). The nasopharyngeal airway (NA) volume of Class I and Class III subjects was significantly larger than that of Class II subjects (p < 0.05). The Min-CSA and the length of PA were significantly related to the volume of PA (p < 0.05). The site and the size of the Min-CSA varied among the three groups. The volume and the most constricted cross-sectional area of the airway varied with different anteroposterior skeletal patterns. The NA volume of Class I and Class III subjects was significantly larger than that of patients with a Class II skeletal pattern.

Zheng ZH ，Yamaguchi T ，Kurihara A ，Li HF ，Maki K ... -  《-》