Nasopharyngeal Airway Volume Research Articles

Comparative Assessment of Pharyngeal Airway Dimensions in Skeletal Class I, II, and III Emirati Subjects: A Cone Beam Computed Tomography Study.

The aim of the current study was to evaluate the pharyngeal airway dimensions of individuals with different skeletal patterns in a cohort of the Emirati population. The specific aim was to assess the relationship between pharyngeal airway dimensions and anterior facial height in relation to different skeletal patterns. This retrospective study was conducted on a sample of 103 CBCT scans of adult Emirati subjects categorized into three groups according to their skeletal classification as indicated by the ANB angle: Class I (n = 35), Class II (n = 46), and Class III (n = 22). All CBCT scans were taken using an i-CAT CBCT imaging machine (Imaging Sciences, Hatfield, PA, USA). The age range of the patients was 19 to 68 years (62 women and 41 men). ANOVA, t-tests, Kruskal-Wallis, and Mann-Whitney tests were employed for comparing means among groups. The correlation coefficient was used to evaluate the association between variables. A p-value of less than 0.05 was considered statistically significant. This study revealed significant associations between various airway parameters and cephalometric measurements. Positive correlations were observed between nasal cavity volume and nasopharynx volume, as well as anterior facial height. Oropharynx volume exhibited positive correlations with hypopharynx volume and total airway volume, and negative correlations with overjet, ANB angle, and patient age. Hypopharynx volume correlated positively with total airway volume and the most constricted area of the airway (MCA). Total airway volume showed positive correlations with MCA and anterior facial height. MCA had negative correlations with ANB angle and patient age. Nasopharynx volume was significantly larger in the skeletal Class I group than in the Class II or Class III groups, while the other airway parameters showed no significant differences among the groups (p > 0.05). Several airway parameters showed a correlation with anterior facial height among the different skeletal patterns. Nasopharyngeal airway volume was significantly larger in the skeletal Class I group than in Class II and III groups in the studied sample.

Three-dimensional assessment of the nasopharyngeal airway in Down syndrome during the mixed dentition period: a case-control study.

In this retrospective case-control study, we aimed to evaluate the nasopharyngeal airway volume of children with Down syndrome (DS) and compare the results with those of control participants well matched for sex and age. Fifteen children with DS (mean age = 9.43 ± 0.38 years; 8 boys, 7 girls) and 15 control participants (mean age = 9.51 ± 0.40 years; 8 boys, 7 girls) were enrolled. The nasopharyngeal airway volume and the cross-sectional morphology were measured with cone-beam computed tomography taken for orthodontic treatment. All measurements were assessed by analysis of covariance (ANCOVA) using Bonferroni post hoc pairwise comparison tests. Covariates were body height and body weight, and the ANB angle and the mandibular plane angle. Significance was set at P < .0019. Nasal airway, superior airway, and total airway volumes of DS participants were significantly smaller than those of the control participants in ANCOVA results adjusted for ANB angle and mandibular plane angle (P = .000). In ANCOVA results adjusted for body height and body weight, no statistically significant differences in the volume measurements were found. The results indicate that the nasopharyngeal airway volume differs between children with and without DS and that the airway volume tends to be smaller in DS children than in children without DS.

MSCT 3D Analysis of Nasopharyngeal Airway After Le Fort I Maxillary Setback Surgeries.

In recent years, maxillary Le Fort I osteotomy setback has been widely applied in correcting maxilla prognathism. In the meantime, airway considerations have attracted more and more attention. The aim of this research was to observe the alteration of nasopharyngeal airway indexes after maxilla setback and offer evidence for the effectiveness and safety of maxillary Le Fort I setback surgeries. As for a retrospective cross-sectional study, 40 patients diagnosed with maxilla prognathism and undergoing maxillary setback surgeries were enrolled. They were grouped by the type of maxillary setback operations as group A (integral maxillary setback, n=19) and group B (segmental maxillary setback, n=21). Multislice computed tomography data were collected 1 week before (T0) and more than 3 months (T1) after surgery. 3D reconstruction and evaluation of the pharyngeal airway were conducted to analyze nasopharyngeal airway index variation before and after surgery and the difference between group A and group B. Preoperative and postoperative nasopharyngeal airway volume showed no statistical significance in group A (P=0.872) and group B (P=0.169) as well as other indexes of the nasopharynx. The comparison of postoperative airway changes between group A and group B also showed no significant difference. Both integral and segmental maxillary Le Fort I osteotomy setbacks have slight impact on nasopharyngeal airway dimensions and are safe within a specific setback range.

Assessment of maximal inspiratory and expiratory pressures in skeletal Class II patients with different growth patterns.

To evaluate maximal inspiratory (MIP) and expiratory (MEP) pressures, which are reflective of respiratory muscle strength, in skeletal Class II patients with different growth patterns (horizontal, average, and vertical) and to correlate those with airway dimension. Patients with a Class II skeletal base seeking orthodontic treatment were assigned to the following groups: average, horizontal, and vertical growth pattern. The control group (n = 14) comprised patients with a Class I skeletal base and average growth pattern. Airway dimensions were obtained using cone-beam computed tomography scans, and a spirometer with a pressure transducer was used for assessment of MIP and MEP. Routine spirometry for assessment of lung function was also performed. No significant differences were found in maximal inspiratory and expiratory pressures for the study groups in comparison with the control group. Class I patients had significantly greater oropharyngeal and nasopharyngeal airway volumes compared with the study groups. No significant difference in minimal cross-section area of the airway was observed among groups. A weak positive correlation between maximal inspiratory pressure and airway volume was observed. Although Class I patients displayed significantly greater oropharyngeal and nasopharyngeal airway volumes, there was no significant difference in respiratory muscle strength or airway function between Class II patients with different growth patterns and the Class I control group. The findings underscore the significance of exploring factors beyond craniofacial growth patterns that may contribute to sleep-related breathing disorders.

Short-term outcomes in the upper airway with tooth-bone-borne vs bone-borne rapid maxillary expanders

BackgroundThis study compared the area and minimal section of the nasal cavity, nasopharynx, oropharynx, and hypopharynx in cases treated with different methods of microimplant-assisted expansion.MethodsBased on a pilot study to calculate the sample size, 30 patients with transverse maxillary deficiency over 14 years of age were retrospectively selected. These patients had received two different types of microimplant-assisted maxillary expansion treatment (MARPE and BAME). The patient underwent Cone-Beam computed tomography (CBCT) before and after treatment (mean time 1.5 months) with MARPE or BAME and upper airway measurements (volume and minimum cross-sectional area) were taken to assess upper airways changes and compare changes between the groups. A paired sample t-test was performed to evaluate the T0-T1 change of airway measurements obtained with MARPE and BAME, and a student t-test to compare changes in airway measurements between MARPE and BAME.ResultsThis investigation shows a statistically significant increase in total nasopharyngeal airway volume (0.59 ± 1.42 cm3; p < 0.01), total oropharyngeal airway volume (3.83 ± 7.53 cm3; p < 0.01) and minimum oropharyngeal cross-section (53.23 ± 126.46 mm2; p < 0.05) in all cases treated with micro-screw assisted expansion. The minimal cross-sectional area of the oropharynx ((79.12 ± 142.28 mm2; p < 0.05) and hypopharynx (59.87 ± 89.79 mm2; p < 0.05) showed significant changes for cases treated with BAME. As for the comparison between cases treated with MARPE and BAME, no differences in upper airway changes have been observed, except for the minimum cross-sectional area of the nasal cavity, which increases for MARPE (52.05 ± 132.91 mm2) and decreases for BAME (-34.10 ± 90.85 mm2).ConclusionsA significant increase in total area and minimal section at the level of nasopharynx and oropharynx was observed in cases treated with BAME. Regarding the comparison of MARPE and BAME treatments, no differences were found in the total airway volume and minimal section in upper airway except for the minimum cross section of the nasal cavity that increases for MARPE and decreases for BAME.

Genetic Subtypes of Apert Syndrome Are Associated With Differences in Airway Morphology and Early Upper Airway Obstruction.

Apert syndrome is predominantly caused by 2 paternally inherited gain-of-function mutations in the FGFR2 gene, Pro253Arg, and Ser252Trp. Studies comparing phenotypic features between these 2 mutations have established differences in syndactyly severity and incidence of cleft palate. Obstructive sleep apnea can be debilitating in a subset of patients with Apert syndrome, yet is not well understood. This study aims to determine whether FGFR2 mutations impart differential effects on airway physiology and morphology. Patients with Apert syndrome and confirmatory molecular testing were reviewed for polysomnography, nasal endoscopy, microlaryngoscopy and bronchoscopy, and computed tomography imaging. Obstructive apnea-hypopnea index and oxygen saturation nadir, nasal airway volumes, choanal cross-sectional area, and midfacial cephalometric dimensions were compared across mutation types. Twenty-four patients (13 Ser252Trp, 11 Pro253Arg) were included. Severe obstructive sleep apnea (obstructive apnea-hypopnea index>10) occurred in 8 (62%) patients with Ser252Trp mutations compared with 1 (9%) patient with Pro253Arg mutations ( P =0.009). Computed tomography imaging at 1 year of age demonstrated that nasopharyngeal airway volumes were 5302±1076mm 3 in the Ser252Trp group and 6832±1414mm 3 in the Pro253Arg group ( P =0.041). Maxillary length (anterior nasal spine-posterior nasal spine, P =0.026) and basion-anterior nasal spine ( P =0.007) were shorter in patients with Ser252Trp mutations. The findings suggest that the Ser252Trp mutation in Apert syndrome is associated with higher severity obstructive sleep apnea and decreased nasopharyngeal airway volume. Heightened clinical awareness of these associations may inform treatment planning and family counseling.

Application of U-Net network in automatic image segmentation of adenoid and airway of nasopharynx

Objective:To explore the effect of fully automatic image segmentation of adenoid and nasopharyngeal airway by deep learning model based on U-Net network. Methods:From March 2021 to March 2022, 240 children underwent cone beam computed tomography（CBCT） in the Department of Otolaryngology, Head and Neck Surgery, General Hospital of Shenzhen University. 52 of them were selected for manual labeling of nasopharynx airway and adenoid, and then were trained and verified by the deep learning model. After applying the model to the remaining data, compare the differences between conventional two-dimensional indicators and deep learning three-dimensional indicators in 240 datasets. Results:For the 52 cases of modeling and training data sets, there was no significant difference between the prediction results of deep learning and the manual labeling results of doctors（P>0.05）. The model evaluation index of nasopharyngeal airway volume: Mean Intersection over Union（MIOU） s （86.32±0.54）%; Dice Similarity Coefficient（DSC）: （92.91±0.23）%; Accuracy: （95.92±0.25）%; Precision: （91.93±0.14）%; and the model evaluation index of Adenoid volume: MIOU: （86.28±0.61）%; DSC: （92.88±0.17）%; Accuracy: （95.90±0.29）%; Precision: （92.30±0.23）%. There was a positive correlation between the two-dimensional index A/N and the three-dimensional index AV/（AV+NAV） in 240 children of different age groups（P<0.05）, and the correlation coefficient of 9-13 years old was 0.74. Conclusion:The deep learning model based on U-Net network has a good effect on the automatic image segmentation of adenoid and nasopharynx airway, and has high application value. The model has a certain generalization ability.

Comparison of changes in the nasal cavity, pharyngeal airway, and maxillary sinus volumes after expansion and maxillary protraction with two protocols: Rapid palatal expansion versus alternate rapid maxillary expansion and constriction.

To evaluate and compare a series of volume changes in the nasal cavity (NC), nasopharynx, oropharynx, and maxillary sinuses (MS) in growing Class III patients after either rapid palatal expansion (RPE) or alternate rapid maxillary expansion and constriction (Alt-RAMEC) followed by facemask (FM) therapy, by using conebeam computed tomography (CBCT). Forty growing Class III patients were retrospectively selected and divided into two matched groups: RPE/FM (14 females, 6 males; mean age, 9.66 ± 1.23 years) and Alt-RAMEC/FM groups (14 females, 6 males; mean age, 10.28 ± 1.45 years). The anteroposterior and vertical displacements of Point A, the volumes of the NC, nasopharyngeal, oropharyngeal, and MS were measured at different time points: pretreatment (T1), postexpansion (T2), and postprotraction (T3). Both groups demonstrated significant maxilla advancement (by 1.3 mm) during expansion, with a statistically significant intergroup difference during protraction (RPE/FM, 1.1 mm; Alt-RAMEC/FM, 2.4 mm; p < 0.05) and throughout the treatment (RPE/FM, 2.4 mm; Alt-RAMEC/FM, 3.7 mm; p < 0.05). NC and nasopharyngeal airway volumes increased significantly in both groups after expansion, protraction, and treatment. The oropharyngeal and MS volumes increased in both groups after protraction and post-treatment. However, no volumetric differences were observed between the two groups. There was no significant difference in airway volume changes, including NC, nasopharyngeal, oropharyngeal airway, and MS, between RPE/FM and Alt-RAMEC/FM groups at different time points. Although there was significantly more forward movement after protraction in the Alt-RAMEC/FM group, the difference was deemed too small to be clinically relevant.

A 3-Dimensional Evaluation of the Effects of Unilateral Vertical Mandibular Distraction Osteogenesis on Airway Volume Among Patients With Hemifacial Microsomia.

The aim of this study was to evaluate the volumetric airway changes using three-dimensional images following unilateral vertical mandibular distraction osteogenesis (uVMD) among patients with hemifacial microsomia (HFM). This retrospective study analyzed cone-beam computed tomography (CBCT) scans of patients with HFM at three different timepoints; pretreatment (T0), posttreatment (T1), and at least 6 months post-distraction (T2). The individuals underwent uVMD between December 2018-Januaray 2021. The nasopharyngeal (NP) volume, oropharyngeal (OP) volume, and the area of maximum constriction (MC) were measured. Wilcoxon signed-rank test was used to compare the airway volumes between T0-T1, T1-T2, and T0-T2. Five patients met the inclusion criteria (mean age = 10.4 years; 1 female, 4 males). Intraclass correlation analysis showed excellent interrater reliability (r > .86, P < .001). Posttreatment, the OP airway volume exhibited a significant mean increase of 56% (P = .043) from T0 to T1, but decreased from T1-T2 by 13%. Likewise, the total airway volume presented with a significant mean increase of 48% between T0-T1 (P = .044), and a decrease of 7% from T1-T2. The changes in the NP airway volume and area of MC were not statistically significant (P > .05), but an increase in the mean values were observed. Surgical intervention with uVMD may significantly increase the OP airway volume and the total airway volume among patients with HFM immediately after distraction. However, the statistical significance diminished after six months post-consolidation, but the mean percent change may remain of clinical significance. The NP volume did not seem to show significant changes in response to uVMD.

A Three-dimensional Analysis of Nasopharyngeal Airway Characteristics in Subjects with Cleidocranial Dysplasia: A CBCT Study.

Children with congenital or acquired craniofacial abnormalities exhibit an array of dental abnormalities like supernumerary teeth, failure of permanent teeth eruption, decreased alveolar bone height, etc. These subjects undergo complex corrective surgeries to improve esthetics and functional derangements, predisposing them to risks of obstructive sleep apnea due to airway obstruction. The various corrective or therapeutic procedures done might lead to airway complications in these children. The study designed was for retrospective evaluation and comparison of the nasopharyngeal (NP) characteristics and assessment of the airway volume three-dimensionally in normal vs cleidocranial subjects. Cone-beam computed tomography (CBCT) scans of nine subjects with cleidocranial dysplasia (CCD) were compared with the control sample, and matched for age and sex. A 3D-DOCTOR software by Able Software Corporation was used to calculate the volumetric measurements. The correlation and differences among the values were assessed using an independent t-test and Pearson analysis. The values of lower airway width, upper adenoid width, McNamara upper pharynx, retroglossal area, and total pharyngeal area were found to be reduced in the cleidocranial subjects. The NP airway volume and total airway volume also significantly decreased. Cleidocranial dysplasia (CCD) being a rare genetic disorder, we could find only nine established cases. Hence our study can be called a pilot study but may work to establish a database of any sort of skeletal and dental anomaly with possible specific respiratory characteristics affecting airway. Chaturvedi S, Chaturvedi Y, Chowdhary S, et al. A Three-dimensional Analysis of Nasopharyngeal Airway Characteristics in Subjects with Cleidocranial Dysplasia: A CBCT Study. Int J Clin Pediatr Dent 2022;15(5):520-524.

Analysis of maxillary arch morphology and its relationship with upper airway in mouth breathing subjects with different sagittal growth patterns

ObjectiveThis three-dimensional cone beam computed tomography(CBCT) study assessed pharyngeal airway and maxillary arch in mouth breathing subjects with different skeletal classifications and analyzed the factors associated with the upper airway morphological variations in mouth breathing (MB) and nasal breathing (NB) subjects. MethodsOne hundred and five subjects (52 MB and 53 NB children), divided into three skeletal groups: Class I (1° ≤ ANB° ≤ 5°), Class II (ANB° >5°), and Class III (ANB°<1°). An independent t-test and one-way ANOVA test were utilized in the group analysis of normal distributed data. The linear multiple regression test was applied to create a model for the airway volumes based on the maxillary arch parameters in different skeletal groups. ResultsIn three skeletal groups, NB individuals had greater oropharyngeal airway volume (OPV) and total pharyngeal airway volume (TPV) than MB. Maxillary arch parameters of intermolar width (IMW), intercanine width (ICW), and maxillary width of canines (MWC) were larger in NB participants than in MB subjects. In the MB group, we discovered that Class II individuals had lower NPV (nasopharyngeal airway volume) than Class I and Class III. MWC was lower in Class II subjects compared to Class I and Class III in both the NB and MB groups. ConclusionNB individuals had greater pharyngeal airway and maxillary arch parameters than MB subjects. Our model equation revealed that the inter-molar width (IMW) and palatal area (PA) parameters were the strongest predictors of total pharyngeal airway volume (TPV) in the skeletal Class II and Class I groups.

Three-Dimensional Analyses of Postoperative Effects of Surgically Assisted Rapid Palatal Expansion (SARPE) on the Soft Tissue of the Midface Region and the Upper Airway Space Using Stereophotogrammetry and Cone Beam Computed Tomography (CBCT).

Surgically assisted rapid palatal expansion (SARPE) is an established method to treat transverse maxillary hypoplasia in skeletally mature adult patients. SARPE affects the surrounding soft tissue. In addition, effects on the airway and breathing have been described. Aim of this study was to assess the effects of SARPE on the nasal soft tissue and the upper airway by means of three-dimensional stereophotogrammetry and cone beam computed tomography (CBCT). This retrospective study used preoperative and postoperative cone beam computed tomography (CBCT) scans and three-dimensional stereophotogrammetry. Ten skeletally adult patients (4 male, 6 female; mean age 27.68 years) with transverse maxillary hypoplasia were included. Patients had undergone SARPE procedure, performed by the same surgical team using the same technique. Nasal soft tissue changes were analyzed, using three-dimensional stereophotogrammetry records taken preoperatively (t0) and at the postoperative checkup appointment (t1). The upper airway was assessed using CBCT scans for surgical planning (t0) and the first scan taken after SARPE (t1). In stereophotogrammetry, it was shown that only a few soft tissue nasal parameters increased significantly and SARPE leads to mainly clinically irrelevant changes in nasal soft tissue. In CBCT, only a significant increase in nasopharyngeal airway volume was found. Results were in alignment with literature. The effects of SARPE on the nasal soft tissue are mostly statistically insignificant and clinically irrelevant. Airway volume significantly increased in the nasopharyngeal area. Further research on SARPE effects should be conducted to reinforce SARPE as a treatment option for sleep apnea patients.

Comparison of Nasopharyngeal Airway Volume in Cleft Lip and Palate Patients With Normal Individuals Using Cone Beam Computed Tomography.

This study aimed to compare nasopharyngeal airway volume in cleft lip and palate patients with normal individuals using Cone Beam Computed Tomography (CBCT). In this cross-sectional study, 40 CBCT scans of 9 to 12-years-old patients were enrolled and divided into 3 groups: normal individuals (n=16), unilateral cleft lip and palate (UCLP, n=14) and bilateral cleft lip and palate patients (BCLP, n=10). Superior and middle pharyngeal airway volumes and nasal width were measured and compared between 3 groups. ANOVA and χ 2 tests were used for statistical comparison. P <0.05 was considered significant. Superior airway volume was not significantly different between the 3 groups ( P =0.36). However, there was a significant difference between the 3 groups regarding middle pharyngeal volume ( P =0.49) and nasal width ( P =0.021). There was not a significant difference in the upper and middle pharyngeal volume and also nasal width between the 2 sexes. Considering different dimensions of evaluation of the pharyngeal airway volume of cleft lip and palate patients, the evaluation of airway volume is essential during orthodontic or orthognathic surgical treatments that expand or protect the maxilla.

Three-dimensional evaluation of pharyngeal airway and maxillary arch in mouth and nasal breathing children with skeletal Class I and II

ObjectiveThis study aimed to investigate whether the subjects with mouth breathing (MB) or nasal breathing (NB) with different sagittal skeletal patterns showed different maxillary arch and pharyngeal airway characteristics.MethodsCone-beam computed tomography scans from 70 children aged 10 to 12 years with sagittal skeletal Classes I and II were used to measure the pharyngeal airway, maxillary width, palatal area, and height. The independent t-test and the Mann–Whitney U test were used for the intragroup analysis of pharyngeal airway and maxillary arch parameters.ResultsIn the Skeletal Class I group, nasopharyngeal airway volume (P < 0.01), oropharyngeal airway volume (OPV), and total pharyngeal airway volume (TPV) (all P < 0.001) were significantly greater in subjects with NB than in those with MB. Furthermore, intermolar width, maxillary width at the molars, intercanine width, maxillary width at the canines, and palatal area were significantly larger in subjects with NB than in those with MB (all P < 0.001). In the Skeletal Class II group, OPV, TPV (both P < 0.05) were significantly greater in subjects with NB than in those with MB. No significant differences in pharyngeal airway parameters in the MB group between subjects with Skeletal Class I and those with Skeletal Class II.ConclusionRegardless of sagittal Skeletal Class I or II, the pharyngeal airway and maxillary arch in children with MB differ from those with NB. However, the pharyngeal airway was not significantly different between Skeletal Class I and II in children with MB.

Evaluating the changes in nasal airway volume and nasal airflow after surgically assisted rapid maxillary expansion

This study aims to compare the changes in the nasal airway volume and nasal airflow using acoustic rhinometry (AR), rhinomanometry (RMN), and dental volumetric tomography (DVT) after surgically assisted rapid maxillary expansion (SARME). Our study consists of 13 adults, 3 male and 10 female patients, aged between 15 and 26, with completed skeletal development. In our study, DVT imaging was obtained twice, preoperation and 3 months after expansion. AR and RMN measurements were recorded, and Visual Analog Score (VAS) and Nasal Obstruction Symptom Evaluation (NOSE)Scale surveys were scored at preoperation and 3 months after expansion. Nasopharyngeal-oropharyngeal airway volume and areas were calculated using the Romexis 3.8.3.R (Planmeca,Helsinki, Finland) and Nemotec V2019 (Madrid, Spain) software programs. IBM SPSS Statistics 22 (SPSS IBM, Armonk, New York) was used for statistical analysis. Comparing the preoperation and postexpansion measurements by both software programs revealed a statistically significant increase in the nasopharyngeal airway volume. No statistically significant change was observed in the oropharyngeal airway volume. Furthermore, we found a statistically significant increase in VAS but a significant decrease in NOSE. According to our findings, nasal airway volume increased after SARME, and although there was no significant change in nasal resistance, patients' quality of life increased significantly.

Three-dimensional assessment of airway volumes in patients with unilateral cleft lip and palate

BackgroundConsidering the adverse consequences of respiratory insufficiency in cleft lip and palate (CLP) patients, this study aimed to assess the pharyngeal airway dimensions in 9–12-year-old patients with unilateral CLP. This historical cohort evaluated the cone-beam computed tomography (CBCT) scans of 30 patients with non-syndromic unilateral CLP between 9 and 12 years and 30 age- and sex-matched non-cleft controls. Three-dimensional (3D) images were reconstructed by the Mimics software, and the nasopharyngeal, oropharyngeal, and total airway volumes, as well as the minimal cross-sectional area of the airway (minAx), and posterior airway length (PAL) were all measured in the sagittal plane. Data were analyzed by the Student’s t test.ResultsThe oropharyngeal and the total airway volumes, as well as the minAx and PAL in CLP patients, were significantly smaller than the corresponding values in the control group (P < 0.05). Despite smaller nasopharyngeal airway volume in CLP patients than controls, this difference was not statistically significant (P > 0.05).ConclusionsNine- to twelve-year-old non-syndromic unilateral CLP patients have smaller pharyngeal airway dimensions than non-cleft controls, and are therefore at higher risk of respiratory insufficiency.

RELATION BETWEEN SAGITTAL POSITION OF THE MANDIBLE AND PHARYNGEAL AIRWAY VOLUME IN ADULTS USING CONE BEAM COMPUTED TOMOGRAPHY

Introduction: Many authors have discussed the relationship between craniofacial morphology and pharyngeal airway spaces in different malocclusions and skeletal patterns. So the aim of this work was to study the relation between sagittal position of the mandible and pharyngeal airway volume in adults using CBCT. Materials And Methods:Twentyone CBCT radiographs were collected from the archive of Radiology Department at Suez Canal University and were divided into 3 groups according to the measured SNB angle. Group 1 normal mandibular position, group 2 retrognathic mandible and group 3 prognathic mandible. Dolphin 3D imaging software was used to measure the airway volume for all the radiographs. Nasopharyngeal, oropharyngeal, hypopharyngeal and total pharyngeal airway volumes were measured for all the radiographs. F-test (ANOVA) was used for comparison between groups and Tukey test for pairwise comparisons. Correlations between variables were tested using PearsonÂ’s correlation coefficient. Results: there was statistically significant difference in the mean total pharyngeal airway volume and oropharyngeal airway volumes between the three groups. Nasopharyngeal airway volume and hypopharyngeal airway volume had non-significant difference between groups. There was a significant positive correlation between total pharyngeal airway volume (mm3) and SNB angle. Conclusion: Pharyngeal airway volume differs with different sagittal positions of the mandible. Pharyngeal airway volume decreases with mandibular retrognathism and increases with mandibular prognathism.

Miniscrew-assisted rapid palatal expander (MARPE) therapeutic results: A review

Background: One of the most common maxillary abnormalities is transverse deficiency, which can be a contributory factor in malocclusions. There are some evidence of successful non-surgical treatment of this type of discrepancy after puberty by using maxillary expansion techniques. The Miniscrew-assisted rapid palatal expander (MARPE) method is a newly introduced method that has attracted the interest of many orthodontists. This study aimed to evaluate the therapeutic results of this technique in a systematic review. Method: In this study, various databases including PubMed, Scopus, and ISI (Web of science) were queried with proper keywords, provided by PICO strategy of research, from 1980 to December 2020. Relevant articles were collected with restrictions on the English language. The full text of papers with all inclusion criteria was assessed. The therapeutic outcomes of MARPE were evaluated in the selected studies. Results: A total of 14 studies were included in the systematic review. Totally, 5 case report studies, 8 retrospective studies, and 1 case series study were reviewed. Cone-beam computed tomography was used as an outcome measure in all studies. In all reviewed studies, maxillary expansion occurred with high success rates in patients. Moreover, respiratory characteristics were also assessed in two studies measuring respiratory muscle strength, airflow and nasal and nasopharyngeal airway volume, showing benefits of MARPE. A study also examined three-dimensional soft tissue stereophotogrammetry. Based on these studies, the indication for using this method was a maxillary transverse deficiency as well as upper and lower arches crowding. No serious complications were reported in any of the reviewed studies. However, most studies did not perform long-term follow-ups and the age range of the subjects was mainly between 12 and 24 years. MARPE has been suggested as a treatment modality for correction of maxillary transverse deficiency in young adults but patients under the age of 14 may also benefit from this treatment in special conditions. Conclusion: A general review of the results of studies showed the high efficiency of MARPE technique in correcting maxillary transverse deficiency.

Three-dimensional changes of the upper airway in patients with Class II malocclusion treated with functional appliances: a systematic review and meta-analysis.

To evaluate the three-dimensional (3D) changes of the upper airway in patients with Class II malocclusion treated with functional appliances (FAs). A comprehensive search of seven electronic databases was conducted from the date of inception to 12 July 2020. Manual search was also performed in relevant Chinese and English periodicals. Prospective and retrospective studies evaluating the 3D airway changes after FAs applied on growing patients with skeletal Class II malocclusion were included. Risk of bias assessment of each included study was performed referring to ROBINS-I. The effects of FAs on upper airway were evaluated by meta-analysis using STATA software. The outcome variables were the changes of oropharyngeal airway volumes (OAVs), nasopharyngeal airway volumes (NAVs), minimum cross-sectional area (MCA) and antero-posterior position of hyoid bone (HB). The overall quality of evidence for each outcome was rated based on Grading of Recommendations Assessment, Development and Evaluation recommendations. Nine studies were ultimately included in the systematic review and five were included and analyzed in meta-analysis. The results indicated that the pooled mean differences among these studies were 2162.80 [95 per cent confidence interval (CI): 1264.97, 3060.62), 382.20 (95 per cent CI: 140.95, 623.44), 59.91 (95 per cent CI: 41.45, 78.38), and 0.63 (95 per cent CI: -1.97, 3.23) for changes of OAVs, NAVs, MCA, and antero-posterior position of HB, respectively. Weak evidence suggests that FAs can increase OAVs, NAVs, and MCA in growing patients with Class II malocclusion. Weak evidence also suggests that antero-posterior position of HB cannot be affected by FAs. Further studies are necessary to assess the stability of its effect on the upper airway in the long term. The review protocol was not registered prior to the study.

Growth patterns of the airway in Crouzon syndrome patients with different types of cranial vault suture synostosis

The severity of obstructive respiratory difficulty varies among affected Crouzon syndrome patients. The aim of this study was to investigate the correlation between the restricted airway volume in Crouzon syndrome and the associated type of cranial vault suture synostosis. Computed tomography scans of 68 unoperated Crouzon syndrome patients and 89 control subjects were subgrouped into four types: type I, bilateral coronal synostosis; type II, sagittal synostosis; type III, pansynostosis; type IV, perpendicular combinations of synostoses. Measurements were made using Mimics software. Of type I Crouzon patients, 42% had a restricted nasal airway (P=0.002), while the pharyngeal airway volume was not significantly reduced. Type II Crouzon patients grew normal segmental airway volumes. Crouzon patients of type III developed simultaneously reduced nasal and pharyngeal airway volumes in infancy, by 38% (P=0.034) and 51% (P=0.014), respectively. However, the nasal airway achieved a normal volume by 2 years of age without any intervention, while the pharyngeal airway remained significantly reduced up to 6 years of age, by 42% (P=0.013), compared to controls. Type IV Crouzon patients developed a reduced nasal airway volume (32%, P=0.048) and a non-significant restricted pharyngeal airway (18%, P=0.325). Airway compromise in Crouzon syndrome is variable when associated with different craniosynostosis fusion patterns. Type II (sagittal synostosis) Crouzon patients grew a normal nasopharyngeal airway volume. Those with types I (bicoronal synostosis) and IV (perpendicular synostoses) had significantly restricted nasal airways and a tendency towards a reduced pharyngeal volume. Type III (pansynostosis) Crouzon infants had the worst restriction of both airways, although there was some improvement with age.