Tomographic evaluation of the oropharynx (original) (raw)
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Accuracy of MDCT and CBCT in three-dimensional evaluation of the oropharynx morphology
European Journal of Orthodontics, 2017
Objective: To assess the accuracy of five different computed tomography (CT) scanners for the evaluation of the oropharynx morphology. Methods: An existing cone-beam computed tomography (CBCT) data set was used to fabricate an anthropomorphic phantom of the upper airway volume that extended from the uvula to the epiglottis (oropharynx) with known dimensions (gold standard). This phantom was scanned using two multi-detector row computed tomography (MDCT) scanners (GE Discovery CT750 HD, Siemens Somatom Sensation) and three CBCT scanners (NewTom 5G, 3D Accuitomo 170, Vatech PaX Zenith 3D). All CT images were segmented by two observers and converted into standard tessellation language (STL) models. The volume and the cross-sectional area of the oropharynx were measured on the acquired STL models. Finally, all STL models were registered and compared with the gold standard. Results: The intra-and inter-observer reliability of the oropharynx segmentation was fair to excellent. The most accurate volume measurements were acquired using the Siemens MDCT (98.4%; 14.3 cm 3) and Vatech CBCT (98.9%; 14.4 cm 3) scanners. The GE MDCT, NewTom 5G CBCT, and Accuitomo CBCT scanners resulted in smaller volumes, viz., 92.1% (13.4 cm 3), 91.5% (13.3 cm 3), and 94.6% (13.8 cm 3), respectively. The most accurate cross-sectional area measurements were acquired using the Siemens MDCT (94.6%; 282.4 mm 2), Accuitomo CBCT (95.1%; 283.8 mm 2), and Vatech CBCT (95.3%; 284.5 mm 2) scanners. The GE MDCT and NewTom 5G CBCT scanners resulted in smaller areas, viz., 89.3% (266.5 mm 2) and 89.8% (268.0 mm 2), respectively. Limitations: Images of the phantom were acquired using the vendor-supplied default airway scanning protocol for each scanner. Conclusion: Significant differences were observed in the volume and cross-sectional area measurements of the oropharynx acquired using different MDCT and CBCT scanners. The Siemens MDCT and the Vatech CBCT scanners were more accurate than the GE MDCT, NewTom 5G, and Accuitomo CBCT scanners. In clinical settings, CBCT scanners offer an alternative to MDCT scanners in the assessment of the oropharynx morphology.
Annals of Anatomy - Anatomischer Anzeiger, 2018
DPG maximum opening of the oropharyngeal isthmus in the palatoglossus muscles DPF maximum opening of the oropharyngeal isthmus in the palatopharyngeus muscles DEH distance between the top of the epiglottis and the body of the hyoid bone DEL distance between the top of the epiglottis and the base of the tongue DECV distance between the top of the epiglottis and the vertebral column GP skeletotopic projection of glottis ASMV maximum sagittal amplitude of valleculae AAMV maximum axial amplitude of valleculae PVP the position of the palatine veil VPP skeletotopic projection of the palatine veil free edge MLH maximum laryngeal height mLH minimum laryngeal height MP mimed phonation
Influence of tonsil size on sagittal cephalometric measurements
International Orthodontics, 2015
Introduction: The role of tonsils in the origin of sagittal skeletodental abnormalities has been widely discussed in the literature but remains controversial. Data on the probable relationship between enlarged tonsils and the presence of these abnormalities were subjective. The aim of this study was to quantify the relationship between the space occupied by the palatine tonsils and sagittal cephalometric measurements. Materials and methods: A cross-sectional study was performed on a group of children divided into 5 subgroups according to the standardized tonsillar hypertrophy grading scale. Cephalometric measurements were recorded for each child. Data were analyzed using SPSS 20.0 for Windows. The strength of the association between tonsil grades and quantitative variables was assessed using Spearman's rank correlation coefficient (Rho). The level of significance was fixed at P = 0.05. Results: Lengths SN, t2-p3, h-Gn and Xi-pm, and angles I/F, I/ SN, i/M, SNB, SNPog and SNGn were significantly and negatively correlated with grades. The ANB angle, the sagittal position of the pogonion and the angle of facial convexity were significantly and positively correlated with grades.
European Journal of General Dentistry, 2019
The upper airway can be divided into three parts: nasopharynx, oropharynx, and hypopharynx. [1] Constrictions in the upper airway may result in sleep breathing disorder like obstructive sleep apnea (OSA). [2-8] Therefore, an evaluation of upper airway anatomy is paramount. Different imaging modalities have been used for evaluation of the upper airway such as cephalometric radiography, cone beam computed tomography (CBCT), CT, and magnetic resonance imaging. [9] Among these modalities and unlike cephalometric radiography, CBCT is considered a reliable three-dimensional (3D) imaging modality for assessing the airway. [10] Moreover, the scanning time is short, and the radiation dose is low in comparison with normal CT. [9] CBCT is commonly ordered by dentists for implant site assessment and other dental purposes. If the upper airway is included on the CBCT images, dentists can identify patients at risk of OSA by analyzing different airway parameters on CBCT images such as airway volume, minimum cross-sectional area, anteroposterior distance, and width on smallest axial slice. [8,11-13] Having smaller and narrower airway measurements is associated with OSA. [8,11-13] In addition to other risk factors for OSA, patients older than 40 years are at risk of developing OSA; [14] however, no previous study has examined the differences in oropharyngeal airway measurements in patients older than 40 years, so this study was conducted. MaterIaLS and MethodS Patients In our retrospective study, images for all patients aged over 40 years who underwent CBCT between January
Journal of Oral and Maxillofacial Surgery, 2019
Purpose: To evaluate the equivalence of the volumes obtained using different anatomic references to measure the nasopharynx and oropharynx on cone-beam computed tomography (CBCT) scans. We hypothesized that no variations would be found in the nasopharynx and oropharynx dimensions when measured using different measurement methods. Materials and Methods: A total of 40 CBCT scans of patients with skeletal Class I (age range, 20 to 50 years) were measured independently by 2 of us. The nasopharynx and oropharynx subregions were volumetrically measured using the adopted limits of 5 different measurement methods (3 for the nasopharynx and 2 for the oropharynx) and InVivoDental software, version 5.4 (Anatomage, San Jose, CA). The minimum area and the minimum area of localization were also evaluated. The intra-and interexaminer concordance for the measurements from the different methods were verified using the interclass correlation coefficient (ICC). The analysis of variance for repeated measures was used to compare the measurements from the 3 nasopharynx methods. The paired t test was used to compare the measurements from the 2 oropharynx methods. The statistical tests were performed at the 5% significance level using SPSS software, version 22.0 (IBM Corp, Armonk, NY). Results: The intra-and interexaminer ICC values were greater than 0.8. We found a statistically significant difference in the volume measurements among the 3 nasopharynx methods (P = .001). However, no differences were found in the minimum area or minimum area of localization comparisons. Statistically significant differences were also observed for the volume, minimum area, and minimum area of localization between the 2 oropharynx methods (P = .001).
Dental Research Journal, 2016
Background: Obstructive Sleep Apnea (OSA) is a potentially life-threatening condition in which there is a periodic cessation of breathing (for 10 sec or longer) that occurs during sleep in the presence of inspiratory effort. The aim of the study was to assess volumetric and dimensional differences between OSA patients and normal individuals in the upright posture. Material and Method: The present study was conducted on CBCT scans of 32 patients who were divided into two groups-Group I (control group) and Group II (OSA subjects). Group I consisted of 16 patients with normal airway with ESS score from 2 to 10, STOP BANG Questionnaire score of <3 and who had undergone CBCT for various diagnostic reasons. Group II had patients with ESS score >10, STOP BANG Questionnaire score of > 3, AHI index >5. Linear and angular parameters, volume and minimum cross-section area (MCA) of oropharyngeal airway, anteroposterior length and lateral width at MCA was compared amongst the groups. Results: The oropharyngeal volume, MCA, and the anteroposterior and lateral width of the airway at MCA of the OSA subjects was significantly lesser than that of normal subjects. The length of both soft palate and tongue was significantly more in Group II. The angle between the nasopharyngeal airway and the oropharyngeal airway was significantly more obtuse in Group II. Conclusion: The reduction in oropharyngeal volume in OSA patients could be attributed to different anatomical and pathophysiological factors that were corroborated with the findings of the present study.
Author eBooks, 2015
BACKGROUND: Airway dimensions are closely linked to the bone and soft tissue cranio-facial anatomy. Reduction of the airway is seen with airway disorders and can cause impairments to life. The purpose of this retrospective study was to determine whether changing from open to closed jaw position affects the volume of the nasal cavity, nasopharynx, oropharynx, soft palate, soft tissue thickness of the airway and most constricted area of the airway. MATERIALS AND METHODS: Following reliability studies, this retrospective study analyzed CBCT scans taken in both closed jaw and open jaw positions of 60 subjects who were undergoing diagnosis and treatment of temporomandibular disorder. On each scan, condyle/fossa measures, the volume of airway segments (nasal cavity, nasopharynx, oropharynx), soft palate area, soft tissue thickness of the airway and the most constricted area of the airway and its location were measured using Dolphin® imaging software version 11.5. Differences between the two jaw positions were analyzed using paired t-tests, accepting p≤0.05 as significant. RESULTS: Significant changes in airway dimensions were found between closed and open jaw positions. With jaw opening the nasopharynx volume increased, while oropharynx volume decreased. Significant decreases were also found for measurements of Ba-Posterior airway wall, CV2ia-Posterior airway wall, most constricted area, nasal cavity volume, and soft palate area when the jaw was open. CONCLUSIONS: Changing jaw position significantly affects airway dimensions.
Journal of Oral and Maxillofacial Surgery, 2019
Purpose: To evaluate the equivalence of the volumes obtained using different anatomic references to measure the nasopharynx and oropharynx on cone-beam computed tomography (CBCT) scans. We hypothesized that no variations would be found in the nasopharynx and oropharynx dimensions when measured using different measurement methods. Materials and Methods: A total of 40 CBCT scans of patients with skeletal Class I (age range, 20 to 50 years) were measured independently by 2 of us. The nasopharynx and oropharynx subregions were volumetrically measured using the adopted limits of 5 different measurement methods (3 for the nasopharynx and 2 for the oropharynx) and InVivoDental software, version 5.4 (Anatomage, San Jose, CA). The minimum area and the minimum area of localization were also evaluated. The intra-and interexaminer concordance for the measurements from the different methods were verified using the interclass correlation coefficient (ICC). The analysis of variance for repeated measures was used to compare the measurements from the 3 nasopharynx methods. The paired t test was used to compare the measurements from the 2 oropharynx methods. The statistical tests were performed at the 5% significance level using SPSS software, version 22.0 (IBM Corp, Armonk, NY). Results: The intra-and interexaminer ICC values were greater than 0.8. We found a statistically significant difference in the volume measurements among the 3 nasopharynx methods (P = .001). However, no differences were found in the minimum area or minimum area of localization comparisons. Statistically significant differences were also observed for the volume, minimum area, and minimum area of localization between the 2 oropharynx methods (P = .001).
International Journal of Environmental Research and Public Health, 2021
Background: The present study aimed to determine the correlation between pharyngeal airway volume and craniofacial morphology through cone-beam computed tomography (CBCT). Additionally, the study analyzed the influence of gender on pharyngeal airway volume. (2) Methods: 80 CBCT scans of 40 male and 40 female patients (mean age: 15.38 + 1.10 years) fulfilling the eligibility criteria were included. CBCT scans were evaluated for pharyngeal airway volume using the In Vivo Dental 5.1 software. Additionally, CBCT-derived lateral cephalograms were used to assess various craniofacial morphology parameters. To examine the influences of gender on airway volume, T-test was carried out. Correlation between airway volume and craniofacial parameters were measured using Pearson correlation followed by regression analysis. The value of p < 0.05 was considered statistically significant. Results: The mean airway volume was significantly greater in males than in females. A statistically significan...