Pharyngeal Volume Research Articles

Upper airway dimensions and craniofacial morphology: A correlation study using cone beam computed tomography.

To determine the correlation between dentoskeletal parameters related to craniofacial morphology and the upper airway (UA) volume. Cone-beam computed tomography images of 106 randomly selected orthodontic patients were analyzed using NemoFab Ortho software. The dentoskeletal variables assessed were anterior facial height (AFH), posterior facial height (PFH), PFH/AFH ratio, hyoid position, maxillary width (MW), and palatal depth. The UA volume (evaluation in anatomical regions and as a whole) was also assessed using the same software. We also evaluated potential differences in UA variables between age and sex groups. The correlation between the dentoskeletal parameters and UA volume was calculated using the Pearson correlation coefficient (R). Analysis of variance and Student's t test were performed to assess differences between age and sex for UA variables. Statistical analyses were performed using SPSS software (version 26 for Windows). This study found that PFH, AFH, and MW were the dentoskeletal parameters most strongly correlated with UA volume. However, the ANB angle did not show any significant correlation with UA volume. Additionally, differences in UA volumes were observed between age groups. Sex differences were found in both the "8-12" and "≥ 16" age groups for oropharyngeal and pharyngeal volumes. In conclusion, our findings indicate a significant correlation between UA volume and dentoskeletal parameters, particularly those related to facial height and MW.

Correlation between the three-dimensional hyoid bone parameters and pharyngeal airway dimensions in different sagittal and vertical malocclusions

ObjectiveThis study aimed to explore the relationship between three-dimensional (3D) measurements of the hyoid bone (HB) and pharyngeal airway space (PAS) in relation to sagittal and vertical malocclusion. MethodsA total of 368 cone-beam computed tomography (CBCT) scans were classified into three skeletal groups (Class I, II, and III) and subdivided by vertical growth patterns (hypodivergent, normodivergent, and hyperdivergent). PAS dimensions, including nasopharyngeal, oropharyngeal, hypopharyngeal, and total airway spaces, were measured in surface area, volume, minimum constricted area (MCA), length, and width, HB position and dimension were analyzed in 3D using InVivo 6.0.3 and Dolphin 11.8 software. Data were analyzed using two-way ANOVA, and Bonferroni post-hoc tests, with P ≤ 0.05 considered significant. ResultsThe study found that patients with skeletal Class III and hypodivergent growth pattern had the highest sagittal position of the hyoid bone, while those with skeletal Class II and hyperdivergent pattern had the lowest hyoid length. Nasopharyngeal airway space width was significantly lower in skeletal Class III patients, while volume and area were lower in hyperdivergent patients. Oropharyngeal and hypopharyngeal dimensions were also affected by skeletal class and growth pattern, with hyperdivergent patients having the lowest values. Total pharyngeal volume, area, and minimum constricted area were also affected, with hyperdivergent patients having the lowest values and skeletal Class II patients having the lowest minimum constricted area. ConclusionPharyngeal airway dimensions and hyoid bone parameters vary with malocclusions. The hyoid bone's position influences the airway, identifying patients at risk for airway obstruction and sleep-disordered breathing.

Does Reduced Hypopharyngeal Space Affects Respiratory Function and Pharyngeal Volume?

Does Reduced Hypopharyngeal Space Affects Respiratory Function and Pharyngeal Volume?

Three-Dimensional Assessment of Upper Airway Volume and Morphology in Patients with Different Sagittal Skeletal Patterns.

The relationship between respiratory function and craniofacial morphology has garnered significant attention due to its implications for upper airway and stomatognathic development. Nasal breathing plays a key role in craniofacial growth and dental positioning. This study investigated upper airway morphology and volume differences among individuals with class I, II, and III skeletal anomalies. Ninety orthodontic patients' CBCT scans were analyzed to assess the oropharynx and hypopharynx volumes. Skeletal diagnosis was established based on the cephalometric analysis. A significant volume change in the oropharynx and pharynx was demonstrated when comparing class II with class III anomalies (p = 0.0414, p = 0.0313). The total volume of the pharynx was increased in class III anomalies. The area of the narrowest part of the pharynx (MIN-CSA) significantly decreased in classes I and II compared to class III (p = 0.0289, p = 0.0003). Patients with Angle class III anomalies exhibited higher values in the narrowest pharyngeal segment. Gender differences were significant in pharyngeal volumes and morphologies across malocclusion classes. The narrowest segment of the pharynx had the highest values in patients with Angle class III. The volume of the oropharynx was found to be greater in patients with Angle class III versus patients with Angle class II.

Association Between Soft Tissue Measures From Computed Tomography and Upper Airway Collapsibility on Drug-Induced Sleep Endoscopy.

Positive airway pressure (PAP) titration during drug-induced sleep endoscopy (DISE) provides objective measures of upper airway collapsibility. While skeletal measurements relate to collapsibility measures on DISE, the influence of soft tissue dimensions on upper airway collapsibility is not known. We analyzed the relationship of measures of upper airway soft tissue volumes, specifically soft palate, pharyngeal lateral walls, and tongue, with metrics of collapsibility. Cross-sectional analysis from a prospective cohort. Academic medical center. Patients seeking PAP alternative therapies for obstructive sleep apnea (OSA) underwent standardized supine computed tomography (CT) acquisition and DISE protocols. The CT analysis primarily focused on soft tissue volumes and, secondarily, on airway and skeletal volumetric measures. DISE with PAP administration (DISE-PAP) enabled the determination of the pressure at which inspiratory airflow first commenced (pharyngeal critical pressure, PcritA) and the pressure at which inspiratory flow limitation was abolished (pharyngeal opening pressure, PhOP). Both unadjusted and adjusted correlation analyses were performed to understand the relationship between upper airway anatomy and either PcritA or PhOP. One hundred thirty-nine subjects completed both CT and DISE-PAP. On average, patients were male (70.5%), white (84.2%), middle-aged (56.6 ± 13.5 years), and overweight (29.6 ± 4.7 kg/m2), with moderate-severe apnea-hypopnea index (29.7 ± 21.3 events/h). Adjusted for age, sex, body mass index, and skeletal volumes, soft palate, and lateral pharyngeal wall volumes were not associated with PhOP or PcritA, but a larger tongue was associated with more positive PhOP (⍴ = 0.20, P = .02), and more positive PcritA (⍴ = 0.16, P = .07). Exploratory analyses revealed smaller minimum cross-sectional retropalatal area and intramandibular volume were also associated with increased collapsibility measures. After controlling for clinical factors and skeletal volume, greater tongue volume was associated with more severe collapsibility during DISE. These results, in concert with previous work, suggest that greater tongue volume in a smaller skeletal dimensions contribute to the severity of airway collapsibility, a key driver of OSA pathogenesis.

Transoral Robotic Surgery and Radiation Volume Deintensification in Unknown Primary Squamous Cell Carcinoma of the Neck

Patients with unknown primary squamous cell carcinoma (CUP) with cervical metastases typically receive comprehensive radiotherapy (RT) of the pharynx and bilateral neck. Typically, these patients receive comprehensive RT of the pharynx and bilateral neck that may produce treatment-related toxic effects. To determine whether localization of occult oropharyngeal cancers with transoral robotic surgery (TORS) combined with reduced pharyngeal and neck RT volumes provides acceptable disease control. This phase 2, single-group nonrandomized controlled trial at a single institution accrued 32 prospective participants with p16-positive CUP without a primary squamous cell carcinoma on examination and imaging from 2017 to 2019, and 24-month follow-up. The data analysis was conducted from January 2021 to June 2022. Diagnostic- (n = 13) or therapeutic-intent (n = 9) TORS, with pharyngeal-sparing radiotherapy (PSRT) prescribed for negative margins or pT0, and unilateral neck RT (UNRT) prescribed for unilateral lymphadenopathy with lateralized primary tumor or pT0. Out-of-radiation treatment volume failure (<15% was hypothesized to be acceptable) and reports of local and regional recurrence, overall survival, toxic effects, swallowing outcomes (per the MD Anderson Dysphagia Inventory), and videofluoroscopic swallow (per Dynamic Imaging Grade of Swallowing Toxic Effects [DIGEST]) ratings. The study sample comprised 22 patients (mean [SD] age, 59.1 [5.7] years; 3 [14%] females and 19 [86%] male) with CUP. Of these, 19 patients (86%) had tumor stage cN1; 2 (9%), cN2; and 1 (5%), cN3. Five patients (23%), 14 patients (64%), and 3 patients (13%) had 0, 1, or 2 primary tumors, respectively. Twenty patients received RT; of these, 9 patients (45%) underwent PSRT and 10 patients (50%), UNRT. In the diagnostic-intent group, 8 patients (62%) and 5 patients (38%) underwent RT and RT-concurrent chemotherapy, respectively. In the therapeutic-intent group, 6 patients (67%) and 1 patient (11%) received adjuvant RT-concurrent chemotherapy, respectively; 2 patients declined RT. Two-year out-of-radiation treatment volume failure, locoregional control, distant metastasis control, and overall survival were 0%, 100%, 95%, and 100%, respectively. Grade 3 or 4 surgical, acute, and late toxic effects occurred in 2 (9%), 5 (23%), and 1 (5%) patients, respectively. PSRT was associated with lower RT dose to superior constrictors (37 vs 53 Gy; mean difference, 16 Gy; 95% CI, 6.4, 24.9), smaller decline in swallowing scores during treatment (19.3 vs 39.7; mean difference, -20.4; 95% CI, -34.1 to -6.1), and fewer patients with worsening DIGEST grade on findings of videofluoroscopic swallow studies at 2 years (0% vs 60%; difference, 60%; 95% CI, 30% to 90%). These findings indicate that TORS for p16-positive CUP allows RT volume deintensification with excellent outcomes and support future investigation in randomized clinical trials. ClinicalTrials.gov Identifier: NCT03281499.

Changes in Acoustic Pharyngometric Indices After Adenotonsillectomy in Children

Background and Objective This study aimed to assess the effectiveness of acoustic pharyngometry by examining the data before and after adenotonsillectomy in children with sleepdisordered breathing (SDB).Methods This prospective, observational study included 29 children (M/F = 17/12, age = 8.69 ± 2.52 years) with SDB who underwent acoustic pharyngometry before and after adenotonsillectomy. Pre- and postoperative acoustic pharyngometry data, such as the oropharyngeal junction area (OPJ), pharyngeal volume (Vp), glottic area (GL), maximal pharyngeal cross-sectional area (Apmax), minimal pharyngeal cross-sectional area (Apmin), and mean pharyngeal cross-sectional area (Apmean), were compared.Results Before surgery, Apmean was measured at 1.75 ± 0.81 cm&lt;sup&gt;2&lt;/sup&gt; and increased to 2.24 ± 0.89 cm&lt;sup&gt;2&lt;/sup&gt; after surgery (p &lt; 0.001); this difference was statistically significant. Moreover, OPJ demonstrated statistically significant changes from 1.03 ± 0.62 cm&lt;sup&gt;2&lt;/sup&gt; to 1.53 ± 0.77 cm&lt;sup&gt;2&lt;/sup&gt; (p &lt; 0.001); Apmin measured from 0.99 ± 0.51 cm&lt;sup&gt;2&lt;/sup&gt; to 1.38 ± 0.69 cm&lt;sup&gt;2&lt;/sup&gt; (p = 0.003); and Vp increased from 14.45 ± 7.05 cm&lt;sup&gt;3&lt;/sup&gt; to 18.89 ± 7.72 cm&lt;sup&gt;3&lt;/sup&gt; (p &lt; 0.001) after surgical treatment.Conclusions Acoustic pharyngometry, a non-invasive and reproducible method, effectively reflects upper airway changes before and after adenotonsillectomy in children with SDB and ATH. This underscores its potential as a valuable tool for objectively evaluating upper airway obstruction caused by ATH in children.

Assessment of pharyngeal airway space in patients with different maxillofacial skeletal abnormalities using cone beam computed tomography

Background. The patency of the pharyngeal airway has a far-reaching impact on craniofacial development. Conversely, the position of the maxillofacial skeletal components in certain disorders may lead to a compromised airway. Therefore, the evaluation of the airway is an essential step in treatment planning. Objectives. The basic aim of this study was to measure the pharyngeal air space volume in the patients with maxillofacial skeletal abnormalities (like Class II, Class III malocclusion, TMJ Ankylosis, Condylar abnormalities and Syndromic cases) and those without any skeletal abnormalities. The objectives were to assess the Linear, Cross-sectional, and Volumetric dimensions of the pharyngeal airway in patients with and without maxillofacial skeletal abnormalities. (Study and Control group) Materials and methods. The Study group included 49 patients with maxillofacial Skeletal abnormalities like Class II and Class III malocclusion, Temporomandibular Joint Ankylosis, Condylar abnormalities, Syndromic cases. 49 Control group patients did not present with any skeletal abnormalities. The Linear, Cross-sectional, and Volumetric dimensions of the pharyngeal airway in the Study group and Control group were calculated and compared within the groups. Statistical Analysis: Unpaired t -test, ANOVA test and Tukey’s Post Hoc analysis test were for the data analysis of the above study. Outcomes. The Anteroposterior dimension of the airway at the Superiormost level was found to be significantly greater in Class II (p-value-0.039), Class III (p-value-0.002), and Control groups (p-value &lt;0.001) when compared with the TMJ Ankylosis group. The Volume and Cross-sectional area of the airway at the most constricted level of the airway was found to be significantly greater in Class III (p-value &lt;0.001) and Control group (p-value 0.013, 0.003) respectively when compared with the TMJ Ankylosis group. Conclusions. The pharyngeal airway was narrowest anteroposteriorly at all three levels (Superior-most, Most constricted, and Inferior-most levels) in the TMJ Ankylosis group and widest in the Class III group. The least cross-sectional area was found in the TMJ Ankylosis group whereas the greatest was found in the Class III group. The airway volume in the TMJ Ankylosis group and Class II group is significantly lesser than that of the Control group.

Three-dimensional analysis of pharyngeal airway volume in Class I, II, and III malocclusion

Aim: This study aimed to evaluate pharyngeal airway dimensions using cone-beam computed tomography (CBCT) in patients with Class I, II, and III malocclusions and normal growth patterns. Methods: All CBCT images were categorized into three groups: Class I (0° &lt; ANB &lt; 4°, −1 mm &lt; Wits &lt; 0 mm), Class II (ANB &gt; 4°, Wits &gt; 0 mm), and Class III (ANB &lt; 0°, Wits &lt; −1 mm). CBCT images were obtained from individuals with normal growth patterns (32 ± 5° = GN/GO – SN), where GN represents gonion, GN is gnathion, and SN equates to the sella-nasion distance. Measurements were taken for total pharyngeal volume, velopharyngeal volume, glossopharyngeal volume, and oropharyngeal volume, and the narrowest area of the airway was measured. ANOVA and Tukey’s post hoc test were used to compare the airway dimensions among skeletal classes I, II, and III. Results: The CBCT images were captured from 90 patients (45 males and 45 females) aged 17 to 39. The mean volume of the total pharyngeal airway, velopharyngeal, glossopharyngeal, and oropharyngeal and the most constricted area were significantly greater in patients with skeletal Class III malocclusion compared to patients with skeletal Class II malocclusion showing normal growth pattern. Total pharyngeal airway, velopharyngeal, and oropharyngeal volumes were lower in Class II patients compared to Class I and III patients with normal growth patterns. There was a significant difference in the pharyngeal space between males and females with Class II malocclusion. Pharyngeal space in female Class II malocclusion was higher than that in males. There was no difference regarding airway space between female and male patients with Class 1 malocclusion. Pharyngeal space between females and males with Class III malocclusion showed no difference. Conclusion: Class III pharyngeal volumes were generally larger in Class I and II malocclusions. Sex differences in the volumes of various pharyngeal spaces were only present in the case of Class II malocclusions. Relevance for Patients: Class II pharyngeal volumes were generally smaller in Class I and III malocclusions.

Prediction of Pharyngeal 3D Volume Using 2D Lateral Area Measurements During Swallowing.

This study evaluated the validity of pharyngeal 2D area measurements acquired from the lateral view for predicting the actual 3D volume in healthy adults during swallowing. Seventy-five healthy adults (39 females, 36 males; mean age 51.3years) were examined using 320-row area detector computed tomography (320-ADCT). All participants swallowed a 10mL honey-thick barium bolus upon command while seated in a 45° semi-reclining position. Multi-planar reconstruction images and dynamic 3D-CT images were obtained using Aquilion ONE software. Pharyngeal 2D area and 3D volume measurements were taken before swallowing and at the frame depicting maximum pharyngeal constriction. Pharyngeal volume before swallowing (PVhold) was accurately predicted by 2D area (R2 = 0.816). Adding height and sex to the model increased R2 to 0.836. Regarding pharyngeal volume during maximum constriction (PVmax), 2D area also exhibited acceptable predictive power (R2 = 0.777). However, analysis of statistical residuals and outliers revealed a greater tendency for prediction errors when there is less complete constriction of the pharynx as well as asymmetry in bolus flow or movement. Findings highlight the importance of routinely incorporating anterior-posterior views during VFSS exams. Future work is needed to determine clinical utility of pharyngeal volume measurements derived from 320-ADCT.

Adults with Treacher Collins Syndrome Share Comparable 3D Upper Airway Dimensions with Nonsyndromic Individuals.

Sleep apnea symptoms, such as snoring and daytime somnolence, are commonly observed in individuals with Treacher Collins Syndrome (TCS) and may be related to airway obstruction due to micro- and retro-gnathia. This study aims to three-dimensionally evaluate the upper airway using cone-beam computed tomography (CBCT) exams of adolescents (TCS-ADOL) and adults (TCS-ADUL) with TCS compared to a nonsyndromic group (CON). Twenty-six CBCT exams were divided into three groups: TCS-ADOL (n = 7) (13.14 ± 1.67 years): CBCT exams of TCS adolescents; TCS-ADUL (n = 10) (21.80 ± 4.39 years): CBCT exams of TCS adults; and CON (n = 9) (25.33 ± 8.57 years): CBCT exams of adult nonsyndromic individuals with Class II skeletal pattern. The variables analyzed were (1) total upper airway volume; (2) nasal cavity volume; (3) total pharyngeal volume; (4) nasopharyngeal volume; (5) oropharyngeal volume; (6) pharyngeal minimal cross-sectional area; (7) pharyngeal length; and (8) pharyngeal depth. Scans were analyzed by two examiners, and intra- and inter-rater agreement was calculated. A p-value of ≤0.05 was considered significant. Although not statistically significant, the TCS-ADUL group showed decreased airway volume and minimal cross-sectional areas compared to the CON group. There were also significant differences between TCS-ADOL and TCS-ADUL, with significantly lower airway volumes in the TCS-ADOL group. Strong positive correlations were found between certain airway measurements in the TCS-ADOL group, which were not observed in adults. The upper airways of adults with TCS are dimensionally similar to those of nonsyndromic individuals, despite absolute value reductions found in the syndromic group. The reduced airway in the adolescent population suggests significant potential for growth, mainly in pharyngeal dimensions.

Assessment of oropharyngeal respiratory volume and sleep apnoea scores using peripheral arterial tonometry may improve diagnosis and treatment planning of combined dysgnathia therapy approaches.

Increased daytime sleepiness is a frequently reported symptom in patients with pronounced dysgnathia. This study investigated possible correlations using home peripheral arterial tonometry (PAT) and oropharyngeal airway volume determination in patients with dysgnathia and daytime sleepiness. Twenty patients (13 male, median age 27.6 ± 6.8 years) with abnormal sleep history and 10 skeletal neutral configured controls (6 male, median age 29.5 ± 4.2 years) with normal sleep history were examined. Patients and controls were evaluated for apnoea-hypopnoea index (AHI), respiratory disturbance index (RDI), oxygen desaturation index (ODI), snoring volume (dB), total sleep time (TST) and REM-percentage (REM). Airway volumetry was measured via CBCT. Individual user experience for PAT was assessed using the User Experience Questionnaire (UEQ). Patients had significantly higher respiratory scores than controls. AHI increased 4.6-fold (p = .006), RDI 2.5-fold (p = .008) and ODI 6.4-fold (p < .001). Oropharyngeal volumes showed a 30% decrease (p = .003). dB, TST and REM showed no significant differences. AHI (r = -.51; p = .005), ODI (r = -.60; p < .001) and RDI (r = -.45; p = .016) correlated negatively with pharyngeal volume. Wits appraisal correlated negatively with oropharyngeal volume (r = -.47; p = .010) and positively with AHI (r = .41; p = .03) and ODI (r = .49; p = .007). dB and TST (r = -.49; p = .008) and REM and RDI (r = -.43; p = .02) correlated negatively. UEQ-KPI (2.17 ± 0.24) confirmed excellent usability of PAT. Patients with mandibular retrognathia and abnormal sleep history showed significantly higher respiratory indices and smaller oropharyngeal volumes than neutrally configured controls. The dygnathia severity directly influenced the risk of obstructive sleep apnoea.

The morphometrical evaluation after uvulopalatopharyngoplasty.

The aim of this study was to evaluate the efficacy of uvulopalatopharyngoplasty (UPPP) and the corresponding postoperative morphometrical changes. Patients diagnosed with obstructive sleep apnea syndrome who complained of snoring and apnea were enrolled in this study. Pre- and postoperative tests, including CTs, pharyngeal volume (PV), cross-sectional area (CSA), and six-category morphometrical studies, were performed. Of 11 patientsincluded, 10 showed improvement of symptoms. BMI correlated with the respiratory event index (REI). In terms of PV, there was a significantlywider postoperative area. The rate of change between preoperative REI and postoperative REI (ΔREI) correlated with the amount of change of PV between preoperative PV and postoperative PV (ΔPV). CSA increased postoperatively and correlated with REI. Uvula space (UV) and distance between the hyoid bone and the base of the tongue (HB) increased postoperatively, and posterior airway space (PAS) and epiglottic space (Epi) decreased postoperatively. UV and PAS were significant (p = 0.046, 0.014). UV was related to REI. Widening the PV, increasing CSA, and the posterior movement of the tongue base after UPPP surgery were found. The improvement of REI did not depend only on volume. These results suggest that it was important not only to widen the PV but also to improve the shape of the pharynx.

Dosimetric Parameters Correlate with Taste Alterations in Head and Neck Radiotherapy

Dysgeusia is an acute and chronic side effect of head and neck chemoradiation, with persistent taste dysfunction 1-2 years post radiotherapy occurring in 23-50% of patients. Several head and neck clinical trials set oral cavity mean doses between 30 to 40 Gy, however, there are no set guidelines accurately defining the composite structure and anatomic boundaries for the oral cavity or separating the tongue into specific quadrants. In this single institution cross sectional study, we sought to determine the effects of radiation doses to specific regions of the oral cavity and tongue on patient-reported long term dysgeusia. We hypothesize that radiation Dose to specific structures in the oral cavity will correlate with long-term dysgeusia in patients who have received head and neck radiotherapy. Patients with primary head and neck cancer receiving definitive intensity modulated radiation therapy (RT) completed quality of life assessments that included patient-reported gustatory function, 1 year post RT. Dosimetric data from RT plans were collected for specific regions and organs at risk within the oral cavity. These structures included the anterior, posterior, superior and inferior tongue (OT), pharyngeal constrictors (as a surrogate for the corda-tympani) and the oral cavity. A forward binary logistic regression model was performed using these data points with scoring from the QLQ-H&N43 questionnaire subsection on taste (Q45) to determine the most predictive values for dysgeusia and the OR for moderate/severe alterations in taste. A total of 78 patients were included in this study, of these patients, 63 had dosimetric data for the pharyngeal constrictors. The Oral Cavity Volume percentage receiving 50Gy (OC V50) and Pharyngeal Constrictors Volume percentage receiving 55Gy (PC V55) were the most predictive constraints for dysgeusia. (0.042, p = 0.011 and 0.041, p = 0.033). Holding all other variables constant in a forward binary logistic regression including 78 patients, the odds of having moderate to severe taste alterations increased by 56% (OR 1.045, 95% CI 1.012-1.079) for a 1% increase in OCV50. When analyzing the 68 patients with available pharyngeal constrictors data, taste alteration increased 20% for every 1% increase in PCV55 (OR 1.042, 95% CI 1.003-1.082). There was no correlation with taste alterations in any of the dose parameters tested (Dmax, mean and V50 up to V70) for superior, inferior, anterior or posterior regions of the tongue. Dosimetric parameters for the oral cavity (OC V50) and pharyngeal constrictors (PC V55) were positively correlated with taste alterations, however, no other specific regions within the oral tongue predicted taste disfunction. Normal tissue complication probability modeling curves to identify OC V50 and PC V55 constraints for dysgeusia are needed.

Objective Evaluation of Oral and Pharyngeal Areas in Autopsy Cases of Obstructive Sleep Apnea Syndrome via Postmortem CT.

Obstructive sleep apnea syndrome (OSAS) can cause sudden death during sleep. Previous findings have suggested that OSAS development is related to maxillofacial morphology. Evaluation of facial morphology can determine the risk of developing the disease, and establishing an objective method to assess the underlying etiology of OSAS-related death would be advantageous. The objective of this study is to determine the key features of obstructive sleep apnea syndrome (OSAS) using postmortem oral and pharyngeal computed tomography (CT). We retrospectively assessed autopsy cases of patients with (n=25) and without (n=25) OSAS-related death. We used oral and pharyngeal CT images to compare the oral and pharyngeal cavity volume (OPCV), oral and pharyngeal soft tissue volume (OPSV), oral and pharyngeal air space volume (OPAV), and OPAV to OPCV ratio (%air). Receiver operating curve (ROC) analysis was used to determine the accuracy of OSAS prediction. We assessed participants with body mass index (BMI) values within the normal range. Among the 50 subjects, we observed significant between-group differences in OPSV, OPAV, and % air, whereas there were significant between-group differences in OPSV and %air among 28 subjects with normal BMI values. Both comparisons suggested that OSAS-related death was associated with low %air and high OPSV values. The %air and OPSV are useful for assessing postmortem oropharyngeal CT images. OSAS-related sudden death is likely when %air and OPSV values are ≤20.1% and ≥127.2 ml, respectively. Among those with normal BMI values, % air and OPSV values of ≤22.8% and ≥111.5 ml, respectively, predict OSAS-related sudden death.

THE RELATIONSHIP BETWEEN THE ANATOMY FEATURES OF THE STRUCTURES OF THE PHARYNX AND THE DEVELOPMENT OF OBSTRUCTIVE SLEEP APNOEA SYNDROME IN ADULTS.

The aim. To assess the correlation between subjective measurements and objective volume of palatine tonsils in adults, and to test the effect of oropharyngeal anatomy, body mass index, age, and OSA severity on actual tonsil volume. In addition, we evaluated the effect of tonsil size on the development of OSA in adults.&#x0D; Materials and methods. A prospective study of 130 patients with rhonchopathy and obstructive sleep apnea syndrome was conducted. Patients underwent a physical examination, nocturnal polysomnography, Epworth Sleepiness Scale, body mass index (BMI, kg/m²), and a subjective assessment of snoring on an analog scale from 1 (not important) to 10 (worst possible).&#x0D; Results: pharyngeal tissues are also found to be proportional to body size in both patients with rhonchopathy and patients with OSA, which indicates a secondary role of anatomy in the pathogenesis of OSA development. Tonsil volume (p = 0.053) tended to correlate with the degree of severity OSA There were no significant differences in the mean apnea-hypopnea index (AHI) between patients with grade I (30.5), II (29.6), or III (38.2) tonsil hypertrophy. Patients with grade IV tonsil hypertrophy had a higher AHI (mean 103.2) than patients with grade I (p = 0.01), II (p = 0.01) or III (p = 0.03) hypertrophy.&#x0D; Conclusions: In adult patients with rhonchopathy and OSA, there is a reliable correlation between the clinical degree of tonsil hypertrophy and the objective volume of the tonsils. Possible changes in pharyngeal geometry associated with OSA do not affect the clinical ability to determine tonsil volume. Although tonsil volume correlates with AHI, clinically only grade IV tonsils are predictive of severe OSA. Pharyngeal tissue volume likely reflects body mass index rather than OSA.

Subregional pharyngeal changes after orthognathic surgery in skeletal Class III patients analyzed by convolutional neural networks-based segmentation

ObjectivesTo evaluate the accuracy of fully automatic segmentation of pharyngeal volume of interests (VOIs) before and after orthognathic surgery in skeletal Class III patients using a convolutional neural network (CNN) model and to investigate the clinical applicability of artificial intelligence for quantitative evaluation of treatment changes in pharyngeal VOIs. Methods310 cone-beam computed tomography (CBCT) images were divided into a training set (n = 150), validation set (n = 40), and test set (n = 120). The test datasets comprised matched pairs of pre- and post-treatment images of 60 skeletal Class III patients (mean age 23.1 ± 5.0 years; ANB<-2⁰) who underwent bimaxillary orthognathic surgery with orthodontic treatment. A 3D U-Net CNNs model was applied for fully automatic segmentation and measurement of subregional pharyngeal volumes of pre-treatment (T0) and post-treatment (T1) scans. The model's accuracy was compared to semi-automatic segmentation outcomes by humans using the dice similarity coefficient (DSC) and volume similarity (VS). The correlation between surgical skeletal changes and model accuracy was obtained. ResultsThe proposed model achieved high performance of subregional pharyngeal segmentation on both T0 and T1 images, representing a significant T1–T0 difference of DSC only in the nasopharynx. Region-specific differences amongst pharyngeal VOIs, which were observed at T0, disappeared on the T1 images. The decreased DSC of nasopharyngeal segmentation after treatment was weakly correlated with the amount of maxillary advancement. There was no correlation between the mandibular setback amount and model accuracy. ConclusionsThe proposed model offers fast and accurate subregional pharyngeal segmentation on both pre-treatment and post-treatment CBCT images in skeletal Class III patients. Clinical significanceWe elucidated the clinical applicability of the CNNs model to quantitatively evaluate subregional pharyngeal changes after surgical-orthodontic treatment, which offers a basis for developing a fully integrated multiclass CNNs model to predict pharyngeal responses after dentoskeletal treatments.

The dynamics of deglutition during head rotation using dynamic 320-row area detector computed tomography.

We aimed to elucidate the dynamics of deglutition during head rotation by acquiring 320-row area detector computed tomography (320-ADCT) images and analyzing deglutition during head rotation. This study included 11 patients experiencing globus pharyngeus. A 320-ADCT was used to acquire images in two types of viscosity (thin and thick), with the head rotated to the left. We measured the movement time of deglutition-related organs (soft palate, epiglottis, upper esophageal sphincter [UES], and true vocal cords) and pharyngeal volume (bolus ratio at the start of UES opening [Bolus ratio], pharyngeal volume contraction ratio [PVCR], and pharyngeal volume before swallowing [PVBS]). A two-way analysis of variance was performed for statistical analysis, and all items were compared for significant differences in terms of head rotation and viscosity. EZR was used for all statistical analyses (p-value <.05). Head rotation significantly accelerated the onset of epiglottis inversion and UES opening compared with no head rotation. The duration of epiglottis inversion with the thin viscosity fluid was significantly longer. The bolus ratio increased significantly with thick viscosity. There was no significant difference in viscosity and head rotation in terms of PVCR. PVBS increased significantly with head rotation. The significantly earlier start of epiglottis inversion and UES opening due to head rotation could be caused by: (1) swallowing center; (2) pharyngeal volume; and (3) pharyngeal contraction force. Thus, we plan to further analyze swallowing with head rotation by combining swallowing CT with manometry and examine its relationship with pharyngeal contraction force. 3b.

Reliability of parental reporting of child snoring in children referred for obstructive sleep apnea.

Despite the high number of studies based on subjective reports of snoring, self-reported snoring has hardly been validated at all. As there is no "gold-standard" for objective snoring measurements, studies must evaluate whether the presence of snoring based on parental judgement is linked to objective measurements of nasal and/or pharyngeal obstruction in children referred for obstructive sleep apnea. A total of 146 children (median age 11 years) underwent polysomnography (with snoring recording using nasal cannula signal), acoustic rhinometry and pharyngometry, while their parents filled out the Spruyt-Gozal questionnaire assessing both frequency and loudness of subjective snoring. Three categories were further differentiated (null, low and high) for both frequency and loudness. The apnea-hypopnea index was significantly different in the three groups for both frequency (p=0.04) and loudness (p=0.01) of subjective snoring. Children in the low or high groups (frequency or loudness), compared with those in the null group, experienced a decline in both pharyngeal (sitting and supine positions) and nasopharyngeal (supine position) volumes (frequency, pharynx sitting: p=0.03; supine: 0.005 and nasopharynx: p=0.002; loudness, p=0.03; p=0.007 and p=0.03; three group comparisons). Objective snoring frequency during the night obtained with cannula was weakly related to loudness of subjective snoring but not to subjective snoring frequency during the week, and was biased by nasal obstruction. In conclusion, our study showed that parental assessment of snoring is related to a reduction in both pharyngeal and nasopharyngeal volumes in snorers, arguing for the adequacy of their evaluation of both snoring frequency and loudness.

Development and validation of moderate to severe obstructive sleep apnea screening test (ColTon) in a pediatric population

ObjectiveDevelopment and validation of a machine learning algorithm to predict moderate to severe obstructive sleep apnea syndrome (OSAS) in otherwise healthy children. DesignMultivariable logistic regression and cforest algorithm of a large cross-sectional data set of children with sleep-disordered breathing. SettingAn university pediatric sleep centre. ParticipantsChildren underwent clinical examination, acoustic rhinometry and pharyngometry, and surveying through parental sleep questionnaires, allowing the recording of 14 predictors that have been associated with OSAS. The dataset was nonrandomly split into a training (development) versus test (external validation) set (2:1 ratio) based on the time of the polysomnography. We followed the TRIPOD checklist. ResultsWe included 336 children in the analysis: 220 in the training set (median age [25th–75th percentile]: 10.6 years [7.4; 13.5], z-score of BMI: 1.96 [0.73; 2.50], 89 girls) and 116 in the test set (10.3 years [7.8; 13.0], z-score of BMI: 1.89 [0.61; 2.46], 51 girls). The prevalence of moderate to severe OSAS was 106/336 (32%). A machine learning algorithm using the cforest with pharyngeal collapsibility (pharyngeal volume reduction from sitting to supine position measured by pharyngometry) and tonsillar hypertrophy (Brodsky scale), constituting the ColTon index, as predictors yielded an area under the curve of 0.89, 95% confidence interval [0.85–0.93]. The ColTon index had an accuracy of 76%, sensitivity of 63%, specificity of 81%, negative predictive value of 84%, and positive predictive value of 59% on the validation set. ConclusionA cforest classifier allows valid predictions for moderate to severe OSAS in mostly obese, otherwise healthy children.