Avaliação do espaço aéreo faríngeo por meio da tomografia computadorizada de feixe cônico

The role of cone-beam computed tomography in the radiographic evaluation of obstructive sleep apnea: A review article

The apnea-hypopnea index is widely regarded as a measure of the severity of obstructive sleep apnea (OSA), a condition characterized by recurrent episodes of apnea or hypopnea during sleep that induce airway collapse. OSA is a catastrophic problem due to the wide range of health issues it can cause, including cardiovascular disease and memory loss. This review was conducted to clarify the roles of various imaging modalities, particularly cone-beam computed tomography (CBCT), in the diagnosis of and preoperative planning for OSA. Unfortunately, 2-dimensional imaging techniques yield insufficient data for a comprehensive diagnosis, given the complex anatomy of the airway. Three-dimensional (3D) imaging is favored as it more accurately represents the patient's airway structure. Although computed tomography and magnetic resonance imaging can depict the actual 3D airway architecture, their use is limited by factors such as high radiation dose and noise associated with the scans. This review indicates that CBCT is a low-radiation imaging technique that can be used to incidentally identify patients with OSA, thereby facilitating early referral and ultimately enhancing the accuracy of surgical outcome predictions.

[Comparison of pharyngeal airway space on lateral head radiographs of skeletal class I and II individuals]

Objective

To compare the space of the pharyngeal airway (nasopharynx and oropharynx) through lateral X-ray analysis in skeletal class II individuals with a control group composed of skeletal class I individuals.

Materials and methods

This study was of the observational, descriptive, transversal, and prospective type. The sample was made up by 60 lateral head radiographs distributed between 30 class I (ANB 2°±2° and class I malocclusion) and 30 skeletal class II radiographs (ANB>5° and malocclusion class II-1). Measurements of the airway space in the oropharynx and nasopharynx were taken in mm through the McNamara method on lateral head radiographs.

Results

The average space found in the oropharynx in class I was 11.71mm ± 3.18mm. In the class II group, it was 10.73mm ± 2.36mm. No significant differences were found (p=0.18). The average space found in the nasopharynx in the class I group was 18.45mm ± 4.11mm. In the class II group, it was 19.10mm ± 3.89mm. There were no significant differences found (p=0.53).

Conclusion

The airway space in mm. of the nasopharynx presents similar values in millimeters in subjects with Class I and Class II skeletal malocclusion. There is no difference in the airway spaces of the oropharynx in subjects with Class I and Class II Malocclusions.

Upper airways after mandibular advancement orthognathic surgery: A 4-year follow-up

INTRODUCTION

The purpose of this study was to assess the stability of changes in the upper airways 4 years after orthognathic surgery in patients with skeletal Class II malocclusion.

METHODS

A retrospective clinical study was conducted including 33 cone-beam computed tomography images from 11 patients (average age of 35.91 years) followed up longitudinally for 4 years. The airways were measured with the help of the Dolphin Imaging software (Dolphin Imaging and Management Systems, Chatsworth, Calif) at 3 points: T1 (preoperative), T2 (6 months after surgery), and T3 (4 years after surgery). The parameters assessed were surface area (SA), minimum axial area, and volume (VOL) of the pharyngeal airway space. The times were compared using analysis of variance and Tukey's test. Pearson's analysis was performed to assess the correlation with surgical changes and age (P <0.05).

RESULTS

Four years after operating on the airway spaces, the means of SA and VOL were significantly higher than those observed before the surgery (P <0.05). The means at 6 months were intermediate, with no significant difference before the surgery and 4 years after it (P >0.05). There was no significant correlation of the changes in SA, VOL, and minimum axial area with the amount of mandibular advancement, counterclockwise rotation of the occlusal plane, and age of the patient (P >0.05).

CONCLUSIONS

Four years after mandibular advancement surgery in patients with skeletal Class II malocclusion, the increases in the airways remained stable.

Pharyngeal airway dimension in patients before and after treatment of myofascial pain syndrome

Objective: This study aimed: (1) to assess the localization of the anatomic landmarks of the pharyngeal airway on cone beam computed tomography (CBCT) images; and (2) to evaluate if resolution of myofascial pain syndrome (MPS) changed the airway dimensions.Methods: Twenty-nine patients with pre- and post-treatment CBCT scans were randomly selected to locate five landmarks twice, with a two-week interval. The same landmarks were used to measure the airway volume and minimal cross-sectional area (CSA_min).Results: The intra-observer reliability (ICC) was 0.99-1.00 for volumetric and CSA_min measurements, based on the five landmarks used. The paired t test showed no significant difference in the airway volume (p = 0.68) and CSA_min (p = 0.96).Discussion: The outcomes showed that the landmarks used had excellent ICCs for the volumetric and CSA_min measurements. There was no change in volume and CSA_min of the pharyngeal airway after resolution of MPS.

Cone Beam Computed Tomography

In the last several decades, the need for 3D images in dentistry have developed. Computerized tomography was first introduced mainly with the advent of implantology, but its use remained limited to a small number of specialists, due to its indications, access and dose radiation. In the late 90's, a new technology using a cone-shaped beam and a reciprocating detector, which rotates around the patient 360 degrees and acquires projected data in a single rotation, namely the cone beam computerized tomography (CBCT), invaded dentistry, making the perception of 3D easily acceptable to dentists and their patients.

Comparison of automatic airway analysis function of Invivo5 and Romexis software

Background

Visualization and calculation of the airway dimensions are important because an increase of airway resistance may lead to life-threatening emergencies. The visualization and calculation of the airway are possible using radiography technique with their advance software. The aim of this study was to compare and to test the reliability of the measurement of the upper airway volume and minimum area using airway analysis function in two software.

Methods

The sample consisted of 11 cone-beam computed tomography (CBCT) scans data, evaluated using the Invivo5 (Anatomage) and Romexis (version 3.8.2.R, Planmeca) software which afford image reconstruction, and airway analysis. The measurements were done twice with one week gap between the two measurements. The measurement obtained was analyzed with t-tests and intraclass correlation coefficient (ICC), with confidence intervals (CI) was set at 95%.

Results

From the analysis, the mean reading of volume and minimum area is not significantly different between Invivo5 and Romexis. Excellent intrarater reliability values were found for the both measurement on both software, with ICC values ranging from 0.940 to 0.998.

Discussion

The results suggested that both software can be used in further studies to investigate upper airway, thereby contributing to the diagnosis of upper airway obstructions.

Pharyngeal Airway Space Changes After Condylar Replacement and Mandibular Advancement Surgery

PURPOSE

The aim of this study was to examine the total volume and cross-sectional areas of the pharyngeal airway after bilateral condylar replacement and mandibular advancement surgery.

MATERIALS AND METHODS

A total of 137 patients (126 women and 11 men) underwent bilateral temporomandibular joint total joint replacement performed by 1 surgeon. A subsample of 30 patients who underwent condylar replacement and only mandibular advancement were evaluated for impact on the airway. Measurements were taken preoperatively, postoperatively, and at a follow-up 1 year after surgery on cone beam computed tomography scans. InVivoDental 3-dimensional imaging (Anatomage, San Jose, CA) was used to measure airway space regarding total volume (in cubic centimeters); minimum cross-sectional area (in square millimeters); minimum cross sections of the first, second, and third cervical vertebrae; and whether the patient had mandibular retrognathia before surgery. A second operator was used to test for interoperator error. Descriptive and bivariate statistics were computed, and the P value was set at .05.

RESULTS

There was a significant increase in all measurements at the follow-up visit compared with the preoperative visit. There were no significant differences between groups based on simultaneous Le Fort I surgery, mandibular retrognathia, and gender. However, there were statistically significant differences in cross sections 1 and 2, as well as minimum cross-sectional area, regarding age. Condylar replacement and mandibular advancement have a significant association with an increase in airway space. The intraclass correlation coefficient showed excellent agreement between interoperator measurements.

CONCLUSIONS

Patients undergoing bilateral temporomandibular joint replacement and mandibular advancement surgery showed an increase in pharyngeal airway space at a 1-year follow-up. In this study, age was significantly associated with the cross-sectional areas of the airway, with older patients having smaller values.

Pharyngeal airspace of asthmatic individuals and those suffering from obstructive sleep apnea syndrome: Study by CBCT

PURPOSE

The objective of the present study was to comparatively evaluate the oropharyngeal space of patients with obstructive sleep apnea syndrome (OSA) and asthma by means of Cone Beam Computed Tomography (CBCT) images.

MATERIAL AND METHODS

The study included individuals with OSA and asthma (n=10), with OSA and without asthma (n=6), asthmatics without OSA (n=6) and healthy individuals (n=25). All patients were evaluated by a pneumologist and submitted to a nocturnal polysomnogram. Participants underwent CBCT examinations using an I-CAT^® device (Imaging Sciences International, Hatfield, PA, U.S.A.) and all images were exported to Dolphin Image 3D^® software. Cephalometric measurements were taken, as well as measurements of length (C), volume (VOL), sagittal area (SA) and minimum cross-sectional area (MCA); an evaluation was made of the format and contour of the upper airway in three dimensions, with p<0.05 considered significant.

RESULTS

In the results of the present study, a statistically significant difference was found between VOL, SA and MCA (p=0.011; p=0.009; p=0.010) with reduced elevated values among the OSA+Asthma, OSA, Asthma and Control groups. Significant differences were seen between the linear (AP), cross-sectional (TR) and mean transverse area (TA) measurements in the group of patients with OSA and asthma as compared to the control group. In the control group, the greatest narrowing of the airway was observed either in the retroglossal or retropalatal area, while more patients in the experimental groups showed narrowing in the retropalatal area.

CONCLUSION

The condition of OSA+asthma was associated with a substantial reduction in upper airway measurements in comparison to controls.

Pharyngeal airway dimensions in skeletal class II: A cephalometric growth study

Purpose

This retrospective study aimed to evaluate the nasopharyngeal and oropharyngeal dimensions of individuals with skeletal class II, division 1 and division 2 patterns during the pre-peak, peak, and post-peak growth periods for comparison with a skeletal class I control group.

Materials and Methods

Totally 124 lateral cephalograms (47 for skeletal class I; 45 for skeletal class II, division 1; and 32 for skeletal class II, division 2) in pre-peak, peak, and post-peak growth periods were selected from the department archives. Thirteen landmarks, 4 angular and 4 linear measurements, and 4 proportional calculations were obtained. The ANOVA and Duncan test were applied to compare the differences among the study groups during the growth periods.

Results

Statistically significant differences were found between the skeletal class II, division 2 group and other groups for the gonion-gnathion/sella-nasion angle. The sella-nasion-B-point angle was different among the groups, while the A-point-nasion-B-point angle was significantly different for all 3 groups. The nasopharyngeal airway space showed a statistically significant difference among the groups throughout the growth periods. The interaction among the growth periods and study groups was statistically significant regarding the upper oropharyngeal airway space measurement. The lower oropharyngeal airway space measurement showed a statistically significant difference among the groups, with the smallest dimension observed in the skeletal class II, division 2 group.

Conclusion

The naso-oropharyngeal airway dimensions showed a statistically significant difference among the class II, division 1; class II, division 2; and class I groups during different growth periods.