Three-Dimensional Evaluation of the Upper Airway in Children of Skeletal Class III

2017 ◽  
Vol 28 (2) ◽  
pp. 394-400 ◽  
Author(s):  
Jingjing Zhang ◽  
Weitao Liu ◽  
Weiran Li ◽  
Xuemei Gao
2017 ◽  
Vol 87 (4) ◽  
pp. 526-533 ◽  
Author(s):  
Xi Wen ◽  
Xiyu Wang ◽  
Shuqi Qin ◽  
Lorenzo Franchi ◽  
Yan Gu

ABSTRACT Objective: To compare the three-dimensional (3D) morphology of the upper airway in skeletal Class III patients with and without mandibular asymmetry and to investigate the possible underlying correlations between the morphology of the upper airway and mandibular deviation. Materials and Methods: Cone-beam computed tomography images of 54 subjects with skeletal Class III malocclusion (ANB angle ≤ 0.4°, Wits ≤ −5.5°) were taken and 3D upper airway models were reconstructed using Dolphin 3D software. According to the distance (d) from symphysis menti to the sagittal plane, all subjects were divided into a symmetry group (d ≤ 2 mm) and an asymmetry group (d ≥ 4 mm). Based on the severity of mandibular deviation, the asymmetry group was divided into subgroup I (4 mm ≤d <10 mm) and subgroup II (d ≥ 10 mm). Cross-sectional linear distances, areas, and volumetric variables of the upper airway were measured in the 3D airway model. Results: Width of the inferior limit of the glossopharynx (P3W), cross-sectional area of the anterior limit of the nasal airway (P5S), and height of the glossopharynx (GPH) in the asymmetry group were significantly larger than in the symmetry group. As for subjects with severe mandibular deviation in subgroup II (d ≥ 10 mm), volume of the glossopharynx (GPV), total volume of the pharynx (TPV), length of the inferior limit of the velopharynx (P2L), and ratio of length to width of the inferior limit of the velopharynx (P2L/P2W) showed significantly negative correlations with mandibular deviation (r > 0.7, P < .05). Conclusions: In Class III subjects with severe mandibular asymmetry, the pharyngeal airway showed a tendency toward constriction and presented a more elliptical shape as mandibular deviation became more severe (P < .01).


2018 ◽  
Vol 56 (3) ◽  
pp. 314-320 ◽  
Author(s):  
Marilia Sayako Yatabe-Ioshida ◽  
Letícia Dominguez Campos ◽  
Renato Yassukata Yaedu ◽  
Ivy Kiemle Trindade-Suedam

Objectives: The purpose of this study was to 3-dimensionally assess the airway characteristics of patients with unilateral cleft lip and palate (UCLP) and bilateral cleft lip and palate (BCLP) who underwent orthognathic surgery. Design: This was a retrospective study. Setting: The study took place at a national referral center for cleft lip and palate rehabilitation. Patients and Participants: The sample comprised cone-beam computed tomography (CBCT) scans obtained before and after orthognathic surgery of 15 individuals (30 CBCT scans), divided into 2 groups: UCLP group (n = 9 patients/18 CBCT scans) and BCLP group (n = 6/12 CBCT scans). All patients had a nonsyndromic UCLP or BCLP and a skeletal class III malocclusion at the preoperative period. Interventions: Airway volume, pharyngeal minimal cross-sectional area (mCSA), location of mCSA, sella-nasion-A point (SNA) and sella-nasion-B point (SNB) angles, and condylion-A point and condyloid-gnathion linear measurements were assessed in open-source software (ITK-SNAP and SlicerCMF). Main Outcome Measure: Airway dimensions of patients with UCLP and BCLP increase after orthognathic surgery. Results: After orthognathic surgery, UCLP group showed a significant 20% increase in nasopharynx volume. Although not significant, BCLP group also showed an increase of 18% in the same region. Minimal cross-sectional area remained dimensionally stable after surgery and was all located in the oropharynx region, on both groups. Additionally, a positive correlation was observed between volume and mCSA on both groups. Conclusion: Overall, individuals with UCLP and BCLP showed an increase in the upper airway after orthognathic surgery and this might explain the breathing and sleep improvements reported by the patients after the surgery.


2019 ◽  
Vol 8 (12) ◽  
pp. 2106 ◽  
Author(s):  
Cheng-Ting Ho ◽  
Rafael Denadai ◽  
Hsin-Chih Lai ◽  
Lun-Jou Lo ◽  
Hsiu-Hsia Lin

Three-dimensional (3D) computer-aided simulation has revolutionized orthognathic surgery treatment, but scarce 3D cephalometric norms have been defined to date. The purposes of this study were to (1) establish a normative database of 3D Burstone cephalometric measurements for adult male and female Chinese in Taiwan, (2) compare this 3D norm dataset with the two-dimensional (2D) Burstone norms from Caucasian and Singaporean Chinese populations, and (3) apply these 3D norms to assess the outcome of a computer-aided simulation of orthognathic surgery. Three-dimensional Burstone cephalometric analysis was performed on 3D digital craniofacial image models generated from cone-beam computed tomography datasets of 60 adult Taiwanese Chinese individuals with normal occlusion and balanced facial profile. Three-dimensional Burstone analysis was performed on 3D image datasets from patients with skeletal Class III pattern (n = 30) with prior computer-aided simulation. Three-dimensional Burstone cephalometric measurements showed that Taiwanese Chinese males had significantly (p < 0.05) larger anterior and posterior facial heights, maxillary length, and mandibular ramus height than females, with no significant (p > 0.05) difference for facial soft-tissue parameters. The 3D norm dataset revealed Taiwanese Chinese-specific facial characteristics, with Taiwanese presenting (p < 0.05) a more convex profile, protrusive maxillary apical bases, protruding mandible, protruding upper and lower lips, and a shorter maxillary length and lower facial height than Caucasians. Taiwanese had significantly (p < 0.05) larger maxillary projection, vertical height ratio, lower face throat angle, nasolabial angle, and upper lip protrusion than Singaporean Chinese. No significant (p > 0.05) difference was observed between 3D norms and computer-aided simulation-derived 3D patient images for horizontal skeletal, vertical skeletal, and dental measurements, with the exception of two dental parameters (p < 0.05). This study contributes to literature by providing gender- and ethnic-specific 3D Burstone cephalometric norms, which can assist in the multidisciplinary-based delivery of orthodontic surgical care for Taiwanese Chinese individuals worldwide, including orthodontic management, computer-assisted simulation, and outcome assessment.


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