A cephalometric comparative study of the soft tissue airway dimensions in persons with hyperdivergent and normodivergent facial patterns

Is there any correlation between otitis media and dental malocclusion in children? A systematic review

PURPOSE

This study aims to evaluate whether there is a correlation between otitis and dental malocclusions.

METHODS

Electronic databases were searched for observational studies published until July 2021 without language or time restrictions.

PROSPERO

CRD42021270760. Observational studies on children with and without OM and/or malocclusion were included. After removing duplicates and excluding not-eligible articles, two reviewers screened relevant articles independently. Two reviewers independently extracted data and assessed data quality and validity through the Newcastle-Ottawa Scale (NOS) quality assessment tool for non-randomized studies.

RESULTS

Five studies met the selection inclusion criteria and were included in the studies for a total of 499 patients. Three studies investigated the relationship between malocclusion and otitis media, while the remaining two studies analyzed the inverse relationship and one of them considered eustachian tube dysfunction as a proxy of OM. An association between malocclusion and otitis media and vice versa emerged, although with relevant limitations.

CONCLUSION

There is some evidence that there is an association between otitis and malocclusion; however, it is not yet possible to establish a definitive correlation.

Evaluation of pharyngeal airway space after orthodontic extraction treatment in class II malocclusion integrating with the subjective sleep quality assessment

Orthodontic treatment with premolar extractions is typically used to relieve dental crowding and retract anterior teeth for lip profile improvement. The aim of the study is to compare the changes in regional pharyngeal airway space (PAS) after orthodontic treatment with Class II malocclusion and to identify the correlations between questionnaire results and PAS dimensions after orthodontic treatment. In this retrospective cohort study, 79 consecutive patients were divided into normodivergent nonextraction, normodivergent extraction, and hyperdivergent extraction groups. Serial lateral cephalograms were used to evaluate the patients' PASs and hyoid bone positions. The Pittsburgh Sleep Quality Index and STOP-Bang questionnaire were used for sleep quality evaluation and obstructive sleep apnea (OSA) risk assessment, respectively, after treatment. The greatest airway reduction was observed in hyperdivergent extraction group. However, the changes in PAS and hyoid positions did not differ significantly among three groups. According to questionnaire results, all three groups had high sleep quality and low risk of OSA, with no significant intergroup differences. Moreover, pretreatment-to-posttreatment changes in PAS were not correlated with sleep quality or risk of OSA. Orthodontic retraction with premolar extractions nither exhibit significant reduction in airway dimensions nor increase their risk of OSA.

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

OBJECTIVES

This study aimed to determine the three-dimensional (3D) correlation between maxillomandibular complex parameters and pharyngeal airway dimensions in different sagittal and vertical malocclusions.

METHODS

This retrospective cross-sectional study included the CBCT scans of 368 patients with a mean age of 23.81 ± 3.01 years. The patients were classified into three groups (skeletal Class I, II, and III). Each class group was divided into three subgroups based on vertical growth patterns (hypo-, normo-, and hyperdivergent). The maxillomandibular complex was evaluated in the three planes using 16 skeletal measurements. Naso-, oro-, hypo-, and total pharyngeal airway spaces were assessed in terms of width, volume, surface area, and minimum constricted area (MCA). Two-way ANOVA followed by the Bonferroni post-hoc test were used.

RESULTS

The nasopharyngeal airway space was significantly lowest regarding sagittal and lateral widths in the skeletal Class III patients, the lowest volume and surface area were in hyperdivergent patients, and MCA was the highest in Class II and hypodivergent patients. The oro- and hypopharyngeal sagittal width, volume, surface area, and MCA were the lowest in the hyperdivergent patients, and oropharyngeal lateral width and hypopharyngeal sagittal width were the highest in skeletal Class III. The total pharyngeal volume, surface area, and MCA were the lowest in the hyperdivergent patients, and skeletal Class II patients had the lowest MCA.

CONCLUSIONS

The pharyngeal airway dimensions differ with various sagittal and vertical malocclusions. These differences could apply to diagnosis, treatment planning, and possible changes following orthodontic/orthopedic or surgical treatment.

Temporomandibular Joint and Otitis Media: A Narrative Review of Implications in Etiopathogenesis and Treatment

Otitis media (OM) and its recurring (rAOM), effusive (OME), and chronic forms, represent a frequent clinical challenge. The middle ear, the mandible, and the temporomandibular joint (TMJ) share several embryological and anatomical connections. Despite that, the role of mandibular malposition and TMJ dysfunction is frequently overlooked in the management of otitis media. In this narrative review, we present current evidence supporting the etiopathogenetic role of a dysfunctional stomatognathic system in the onset of OM and the effectiveness of orthognathic treatment in preventing rAOM and OME. In particular, a focus on the influence of TMJ on Eustachian tube function is provided.

Study of pharyngeal airway morphology with CBCT: Benefits of four premolar extraction orthodontic treatments

BACKGROUND AND AIM

Four premolars extractions are routine procedures for correction of malocclusion, but will inevitably lead to a reduction of tongue space, whether this will weaken the pharyngeal airway remains a controversy.

PATIENTS AND METHODS

Cone-beam computed tomography (CBCT) radiographs of 80 patients who completed four premolar extraction orthodontic treatments were collected and divided into three anteroposterior skeletal groups according to the ANB (angle subspinale to nasion to supramentale) value. Linear, angular, cross-sectional area, and volumetric dimensions of the pharyngeal airway were measured using Dolphin Imaging 11.9 software. One-way analysis of variance and Pearson's correlation coefficient test were performed to assess the intergroup comparisons. Treatment changes were evaluated with two-sample t-tests.

RESULTS

In intergroup comparisons, vertical linear and cross-sectional area differences were identified in S-Go/N-Me, VD1, VD1/N-Me, VD2/N-Me, AA, OAA and OMINI (p<0.05), while other measurements showed no significant differences. Angle2, the tilting degree of the pharyngeal airway, showed a positive correlation with ANB (p<0.05). As for the treatment changes, a significant increase was found in the pharyngeal airway in the Class I group (OUA p<0.05, VD1 p<0.001, VD2 p<0.05) and Class II group (VD1 p<0.001. VD2, p<0.05), and inversely, a significant decrease was found in the pharyngeal airway in the Class III group (OAA p<0.05, OMINI p<0.05, OUA p<0.05). No volumetric difference was identified. Interestingly, regarding the preoperative pharyngeal airway size, values trended to the mean value significantly.

CONCLUSION

Four premolar extraction orthodontic treatments did not affect the pharyngeal airway volume except for the vertical liner and cross-sectional area dimensions. The trend of the gold standard suggested a positive influence of four premolar extraction orthodontic treatments.

A 3D CBCT Analysis of Airway and Cephalometric Values in Patients Diagnosed with Juvenile Idiopathic Arthritis Compared to a Control Group

Introduction: The temporomandibular joint (TMJ) is affected in 30–45% of juvenile idiopathic arthritis (JIA) patients, with all JIA subtypes at risk for TMJ involvement. JIA patients with TMJ involvement may present with altered craniofacial morphology, including micrognathia, mandibular retrognathia, a hyperdivergent mandibular plane angle, and skeletal anterior open bite. These features are also commonly present and associated with non-JIA pediatric patients with obstructive sleep apnea (OSA). Materials and Methods: The study was comprised of a group of 32 JIA patients and a group of 32 healthy control subjects. CBCT images were taken for all patients and were imported into Dolphin Imaging software. The Dolphin Imaging was used to measure the upper airway volumes and the most constricted cross-sectional areas of each patient. Cephalometric images were rendered from the CBCT data for each patient, and the following cephalometric values were identified: SNA angle, SNB angle, ANB angle, anterior facial height (AFH), posterior facial height (PFH), mandibular plane angle (SN-MP), FMA (FH-MP), overjet (OJ), and overbite (OB). Airway volumes, the most constricted cross-sectional area values, and cephalometric values were compared between the JIA and control groups. Results: For airway values, statistically significant differences were seen in the nasopharynx airway volume (p = 0.004), total upper airway volume (p = 0.013), and the most constricted cross-sectional area (p = 0.026). The oropharynx airway volume was not statistically significant (p = 0.051). For cephalometric values, only the posterior facial height showed a statistically significant difference (p = 0.024). Conclusions: There was a significant difference in airway dimensions in the JIA patients as compared to the control patients. In addition, the posterior facial dimensions seem to be affected in JIA patients. The ODDs ratio analysis further corroborated the findings that were significant.

Evaluation and Correlation Between Pharyngeal Space, Mandible, and Tongue in Two Different Facial Patterns

Introduction:

Respiratory function has a direct relationship with the pharyngeal airway dimension and mandibular morphology. The objective of the present study was to compare and correlate pharyngeal airway, mandibular morphology, and tongue position in hyperdivergent and normodivergent patterns using standard cephalometric radiographs.

Materials and Methods:

A total of 130 individuals with age 13 to 19 years, with no craniofacial skeletal abnormalities, were taken. The individuals were divided into 2 groups based on their Frankfort mandibular angle (FMA). Group I consist of 65 hyperdivergent individuals (34 males, 31 females) with FMA >28. Group II consisted of 65 normodivergent individuals (28 males, 37 females) with FMA >25 to <28. For statistical analysis, variables were analyzed by unpaired t-test, with P value <.05. Correlation between the pharyngeal space and the other variables was analyzed with the Pearson correlation test.

Results:

Upper pharyngeal airway space in hyperdivergent growth pattern exhibited a significant negative correlation with ramus width (r = −0.02 and P = .028). Gonial angle showed a statistically significant inverse correlation with lower pharyngeal airway space (r = −0.398 and P = .029). A-point-nasion-B-point (ANB), saddle angle, posterior tongue space, tongue gap, and pharyngeal airway among normodivergent subjects, showed a statistically significant negative correlation.

Conclusion:

The present study showed a significant relationship between pharyngeal airway space, craniofacial morphology, and tongue position suggesting that narrower airway space may be a causative factor for altered dentofacial skeletal patterns. Reduced ramus width, lowered tongue, and narrower posterior pharyngeal wall might be a balancing mechanism set for morphological imbalance in hyperdivergent pattern.

Elastodontic Therapy of Hyperdivergent Class II Patients Using AMCOP® Devices: A Retrospective Study

Background: The management of a hyperdivergent growth pattern is one of the most challenging in orthodontics and different treatments are advocated. The present study analyses the effectiveness of elastodontic therapy with AMCOP® devices in treating children with hyperdivergent class II malocclusion and the effect on the upper airway patency. Methods: The study group included 21 patients (10 males and 11 females, mean age 8.22 ± 1.17 years) with a hyperdivergent growth and a class II malocclusion treated with AMCOP® devices. Cephalometric analysis was performed before treatment (T0) and after treatment (T1). Results: After treatment, the cephalometric analysis revealed a correction of the class II malocclusion and a modification of the growth pattern with a divergence reduction. The improvement of the upper airway space was also observed. Conclusion: The elastodontic therapy effectively corrected hyperdivergent class II malocclusion in growing patients over a short period.

A Wi-Fi-Based Mask-Type Laryngoscope for Telediagnosis During the COVID-19 Pandemic: Instrument Validation Study

Background

Owing to the COVID-19 pandemic, social distancing has become mandatory. Wireless endoscopy in contactless examinations promises to protect health care workers and reduce viral spread.

Objective

This study aimed to introduce a contactless endoscopic diagnosis system using a wireless endoscope resembling a mask.

Methods

The Wi-Fi–based contactless mask endoscopy system comprises a disposable endoscope and a controller. First, the effective force applied by the tip during insertion was evaluated in a simple transoral model consisting of a force sensor on a simulated oropharynx wall. Second, the delay in video streaming was evaluated by comparing the frame rate and delays between a movement and its image over direct and Wi-Fi connections. Third, the system was applied to a detailed laryngopharyngeal tract phantom.

Results

The smartphone-controlled wireless endoscopy system was successfully evaluated. The mean, maximum, and minimum collision forces against the wall of the transoral model were 296 mN (30 gf), 363 mN (37 gf), and 235 mN (24 gf), respectively. The delay resulting from the wireless connection was 0.72 seconds. Using the phantom, an inexperienced user took around 1 minute to orient the endoscope to a desired area via the app.

Conclusions

Device articulation does not pose a significant risk of laryngopharyngeal wall penetration, and latency does not significantly impede its use. Contactless wireless video streaming was successful within the access point range regardless of the presence of walls. The mask endoscope can be controlled and articulated wirelessly, minimizing contact between patients and device operators. By minimizing contact, the device can protect health care workers from infectious viruses like the coronavirus.

Geometric morphometric analysis of growth patterns among facial types

Introduction:

Extreme patterns of vertical facial divergence are of great importance to clinicians because of their association with dental malocclusion and functional problems of the orofacial complex. Understanding the growth patterns associated with vertical facial divergence is critical for clinicians to provide optimal treatment. This study evaluates and compares growth patterns from childhood to adulthood among 3 classifications of vertical facial divergence using longitudinal, lateral cephalograms from the Craniofacial Growth Consortium Study.

Methods:

Participants (183 females, 188 males) were classified into 1 of 3 facial types on the basis of their adult mandibular plane angle (MPA): hyperdivergent (MPA >39°; n = 40), normodivergent (28° ≤ MPA ≤ 39°; n = 216), and hypodivergent (MPA <28°; n = 115). Each individual had 5 cephalograms between ages 6 and 20 years. A set of 36 cephalometric landmarks were digitized on each cephalogram. Landmark configurations were superimposed to align 5 homologous landmarks of the anterior cranial base and scaled to unit centroid size. Growth trajectories were calculated using multivariate regression for each facial type and sex combination.

Results:

Divergent growth trajectories were identified among facial types, finding more similarities in normodivergent and hypodivergent growth patterns than either share with the hyperdivergent group. Through the use of geometric morphometric methods, new patterns of facial growth related to vertical facial divergence were identified. Hyperdivergent growth exhibits a downward rotation of the maxillomandibular complex relative to the anterior cranial base, in addition to the increased relative growth of the lower anterior face. Conversely, normodivergent and hypodivergent groups exhibit stable positioning of the maxilla relative to the anterior cranial base, with the forward rotation of the mandible. Furthermore, the hyperdivergent maxilla and mandible become relatively shorter and posteriorly positioned with age compared with the other groups.

Conclusions:

This study demonstrates how hyperdivergent growth, particularly restricted growth and positioning of the maxilla, results in a higher potential risk for Class II malocclusion. Future work will investigate growth patterns within each classification of facial divergence.

Effect of extraction treatment on upper airway dimensions in patients with bimaxillary skeletal protrusion relative to their vertical skeletal pattern

Objective

To investigate dimensional changes in regional pharyngeal airway spaces after premolar extraction in bimaxillary skeletal protrusion (BSP) patients according to vertical skeletal pattern, and to further identify dentoskeletal risk factors to predict posttreatment pharyngeal changes.

Methods

Fifty-five adults showing BSP treated with microimplant anchorage after four premolar extractions were included in this retrospective study. The subjects were divided into two groups according to the mandibular plane steepness hyperdivergent (Frankfort horizontal plane to mandibular plane [FH-MP] ≥ 30) and nonhyperdivergent groups (FH-MP < 30). The control group consisted of 20 untreated adults with skeletal Class I normodivergent pattern and favorable profile. Treatment changes in cephalometric variables were evaluated and compared. The association between posttreatment changes in the dentoskeletal and upper airway variables were analyzed using linear regression analysis.

Results

The BSP patients showed no significant decrease in the pharyngeal dimensions to the lower level in comparison with controls, except for middle airway space (MAS, p < 0.01). The upper airway variable representing greater decrease in the hyperdivergent group than in the nonhyperdivergent group was the MAS (p < 0.01). Posttreatment changes in FH-MP had negative correlation with changes in MAS (β = –0.42, p < 0.01) and inferior airway space (β = –0.52, p < 0.01) as a result of multivariable regression analysis adjusted for sagittal skeletal relationship.

Conclusions

Decreased pharyngeal dimensions after treatment in BSP patients showed no significant difference from the normal range of pharyngeal dimensions. However, the glossopharyngeal airway space may be susceptible to treatment when vertical dimension increased in hyperdivergent BSP patients.

Craniofacial and airway morphology of individuals with oculoauriculovertebral spectrum

OBJECTIVES

The objectives of this study were to characterize the craniofacial and airway morphology of oculo-auriculo-vertebral spectrum (OAVS) individuals using computed tomography (CT) examination.

SETTING AND SAMPLE POPULATION

This sample included individuals in the age range from 5 to 14 years, consisted of a group of 18 OAVS individuals (12 females and 6 males), Pruzansky-Kaban¹ IIB and III and by a paired control group matched by age and sex for comparison of morphometric and airway variables.

MATERIALS AND METHODS

Through the CT examination, airway analysis was performed using Dolphin Imaging® Software, and seven morphometric measurements were performed to evaluate craniofacial morphology by Materialize Mimics® Software. To compare airway and morphometric variables, the control group was used. Student's t test and Mann-Whitney U test were performed to compare differences between the groups.

RESULTS

Statistically significant differences were showed between the control and OAVS groups for the variables: total airway (TA) area, volume and MAA, RP area, RP volume, RP MAA, RG volume, RG MAA, total posterior height diff, Md incl and y-axis asymmetry. Pearson and Spearman's correlation showed mostly moderate correlations between Mand Occlusal canting AS with TA area and RP volume, Ax-Gn with TA area and Hy-C3 with TA volume.

CONCLUSIONS

The OAVS's airway was altered and worse than the control group. Our results suggest that the contralateral side of OAVS individuals is unaffected; however, longitudinal assessments are needed to confirm it. Hyoid bone and postural measures play an important role in interpreting airway features of individuals with and without OAVS.

Pharyngeal airway and hyoid bone position changes of skeletal anchored Forsus Fatigue Resistant Device and activator appliances

OBJECTIVES

To evaluate the effects of miniplate anchored Forsus Fatigue Resistant Device (MAF) and activator treatments in the pharyngeal airway dimensions and hyoid bone position.

MATERIALS AND METHODS

Thirty-eight patients with mandibular retrusion who were treated with either MAF or activator were selected retrospectively and compared with an untreated control group. The data of 114 lateral cephalograms, comprising those taken before treatment (T1) and at the end of functional treatment (T2), were evaluated with regard to their linear, angular, and area measurements.

RESULTS

The mandibular length increased and the hyoid bone moved forward with both treatments (P < 0.05). The horizontal change in the hyoid bone position with MAF treatment was correlated with changes in the point B and ANB angle. Increases of 1.8 mm, 1.4 mm, and 1.8 mm in the pharyngeal airway dimensions were obtained at the levels of the second, third, and fourth cervical vertebra, respectively, with the MAF treatment. On the other hand, an increase of 1.9 mm was found at the level of the fourth cervical vertebra with the activator treatment. The greatest vertical movement in the Menton and the highest increase in the oropharyngeal area were observed in the MAF group (P < 0.05).

CONCLUSION

Both the MAF and activator treatments caused favorable maxillomandibular changes; however, the MAF treatment provided a greater increase in the oropharyngeal area according to both the increase in mandibular length and the change in the vertical position of the mandible.

CLINICAL RELEVANCE

Functional appliances were found to be useful in increasing the pharyngeal airway dimensions in the short-term. The skeletal anchored fixed functional appliance caused a greater increase in the oropharyngeal airway area that may be beneficial for Class II patients who carry a risk of having respiratory problems.

Assessment of airway dimensions in skeletal Class I malocclusion patients with various vertical facial patterns: A cephalometric study in a sample of the Saudi population

OBJECTIVE

To compare airway widths among skeletal Class I malocclusion patients with different vertical facial patterns.

MATERIAL AND METHODS

A total of 103 lateral cephalograms of skeletal Class I patients (mean age of 20 ± 2.3 years) with no history of orthodontic treatment, trauma, facial syndromes, or nasopharyngeal dysfunction were included. Based on the Frankfort-mandibular plane angle measurements, the sample was divided into three groups: low-angle, high-angle, and normal-angle groups. Upper and lower pharyngeal airway widths were measured as described by McNamara. The analysis of variance test was performed to compare the means of groups. Pairwise comparisons were performed using Tukey's post-hoc test. Differences were considered statistically significant at P < 0.05.

RESULTS

ANOVA showed a significant mean difference between the groups for both the upper and lower airway widths with P values of 0.011 and 0.003, respectively. Tukey Pairwise comparisons showed the upper airway width to be significantly narrower in the high-angle group compared to the normal-angle (P = 0.021) and low-angle groups (P = 0.013). Furthermore, the lower airway width in the high angle group was significantly narrower than the normal angle (P = 0.020) and low-angle groups (P = 0.017). There were no statistically significant differences between normal and low angle groups.

CONCLUSIONS

The upper and lower pharyngeal widths in the Class I high-angle group were significantly narrower than those in the normal-angle and low-angle groups.

Effects of clear aligner therapy for Class II malocclusion on upper airway morphology and daytime sleepiness in adults: A case series

INTRODUCTION

To evaluate the effects of clear aligner therapy (CAT) on the upper airway dimensions and on daytime sleepiness in adults with dentoskeletal Class II malocclusion.

METHODS

This study was conducted from August 2017 to February 2019. Inclusion criteria were healthy adults≥18years old, Angle Class II division 1 malocclusion, first-molar relationship of end-to-end or greater, overjet<10mm, and presenting for multi-arch comprehensive orthodontic treatment with aligners. Treatment mechanics included mandibular dentoalveolar advancement with Class II elastics without maxillary sequential distalization programmed into aligners. Post-treatment changes in dentoskeletal and upper airway dimensions were assessed using CBCT images. The treatment effect on daytime sleepiness was evaluated using an Epworth Sleepiness Scale (ESS).

RESULTS

Eight subjects were included in this pilot study (mean age at treatment initiation=44.6years [SD=15.3]). The mean treatment duration was 12.2months (SD=3.4). No statistically significant treatment changes were observed in upper airway dimensions or dentoskeletal cephalometric analyses. Subjects with excessive daytime sleepiness at pre-treatment reported an improvement post-treatment, but no significant difference in the mean ESS score was found.

CONCLUSION

Treatment of Class II division 1 malocclusion in adults by mandibular dentoalveolar advancement using CAT has no statistically significant effects on the airway and dentoskeletal measurements, or daytime sleepiness.

Cephalometric Evaluation of the Upper Airway in Different Skeletal Classifications of Jaws

BACKGROUND

Respiratory system is an important section in development of maxillofacial components and many studies indicated its effect on normal growth of the jaws. The aim of this study is to evaluate upper airway in different skeletal classifications of jaws in lateral cephalogram and its relation to age and gender.

MATERIALS AND METHODS

Study samples were 105 digital cephalometric radiographies, 72 females and 33 males. Lateral cephalograms were hand traced and based on Stainer analysis, there were 30 samples in Class I, 30 samples in Class II and 45 samples in Class III subgroup. Vertical linear measurements, horizontal linear measurements, and angular measurement, proportions and space measurements of the airway in the Cephalograms were analyzed by AutoCAD software.

RESULTS

Data were analyzed using SPSS software version 20. Two horizontal linear measurement (the hypo pharyngeal airway depth, the nasopharyngeal airway depth) and one space measurement (soft palate space) were significantly different in skeletal classes. Vertical and horizontal linear measurements in the 3 groups were increased significantly in men rather than women. The developmental age of groups showed some significant differences.

CONCLUSION

Upper airway dimension is different in different skeletal classes, developmental ages, and gender.

Pharyngeal airway spaces in different skeletal malocclusions: a CBCT 3D assessment

Objective: To three-dimensionally evaluate the upper pharyngeal airway spaces in adults with different anteroposterior and vertical skeletal malocclusions.Methods: In this retrospective study, three-dimensional airway volume and the minimum constricted areas of 120 adults were measured from cone beam computed tomography volume scans. The sample was divided into skeletal Class I and Class II and subdivided into average and long face malocclusions in each skeletal Class. Airway volumes of the naso-, palato-, and glossopharynx, and the minimum constricted area were measured and compared.Results: Skeletal Class II reduced glossopharyngeal airway volume and larger total minimum constricted area in average faces and more nasal minimum constricted area in long faces. Skeletal Class II with long face significantly increased palatopharyngeal and glossopharyngeal airway volumes as well as larger palatopharyngeal minimum constricted area (p < 0.05).Conclusion: This paper found a likely association between jaw skeletal classification and airway dimensions.

Breathing mode influence on craniofacial development and head posture

OBJECTIVE

The incidence of abnormal breathing and its consequences on craniofacial development is increasing, and is not limited to children with adenoid faces. The objective of this study was to evaluate the cephalometric differences in craniofacial structures and head posture between nasal breathing and oral breathing children and teenagers with a normal facial growth pattern.

METHOD

Ninety-eight 7-16 year-old patients with a normal facial growth pattern were clinically and radiographically evaluated. They were classified as either nasal breathing or oral breathing patients according to the predominant mode of breathing through clinical and historical evaluation, and breathing respiratory rate predomination as quantified by an airflow sensor. They were divided in two age groups (G1: 7-9) (G2: 10-16) to account for normal age-related facial growth.

RESULTS

Oral breathing children (8.0±0.7 years) showed less nasopharyngeal cross-sectional dimension (MPP) (p=0.030), whereas other structures were similar to their nasal breathing counterparts (7.6±0.9 years). However, oral breathing teenagers (12.3±2.0 years) exhibited a greater palate length (ANS-PNS) (p=0.049), a higher vertical dimension in the lower anterior face (Xi-ANS-Pm) (p=0.015), and a lower position of the hyoid bone with respect to the mandibular plane (H-MP) (p=0.017) than their nasal breathing counterparts (12.5±1.9 years). No statistically significant differences were found in head posture.

CONCLUSION

Even in individuals with a normal facial growth pattern, when compared with nasal breathing individuals, oral breathing children present differences in airway dimensions. Among adolescents, these dissimilarities include structures in the facial development and hyoid bone position.

Assessment of upper airways measurements in patients with mandibular skeletal Class II malocclusion

Objective:

Mandibular Class II malocclusions seem to interfere in upper airways measurements. The aim of this study was to assess the upper airways measurements of patients with skeletal Class II malocclusion in order to investigate the association between these measurements and the position and length of the mandible as well as mandibular growth trend, comparing the Class II group with a Class I one.

Methods:

A total of 80 lateral cephalograms from 80 individuals aged between 10 and 17 years old were assessed. Forty radiographs of Class I malocclusion individuals were matched by age with forty radiographs of individuals with mandibular Class II malocclusion. McNamara Jr., Ricketts, Downs and Jarabak's measurements were used for cephalometric evaluation. Data were submitted to descriptive and inferential statistical analysis by means of SPSS 20.0 statistical package. Student's t-test, Pearson correlation and intraclass correlation coefficient were used. A 95% confidence interval and 5% significance level were adopted to interpret the results.

Results:

There were differences between groups. Oropharynx and nasopharynx sizes as well as mandibular position and length were found to be reduced in Class II individuals. There was a statistically significant positive correlation between the size of the oropharynx and Xi-Pm, Co-Gn and SNB measurements. In addition, the size of the nasopharynx was found to be correlated with Xi-Pm, Co-Gn, facial depth, SNB, facial axis and FMA.

Conclusion:

Individuals with mandibular Class II malocclusion were shown to have upper airways measurements diminished. There was a correlation between mandibular length and position and the size of oropharynx and nasopharynx.

Comparison of the Changes in Hyoid Bone Position in Subjects with Normodivergent and Hyperdivergent Growth Patterns: A Cephalometric Study

Objective

The aim of this study is to test the hypothesis that there is no difference in hyoid bone position among individuals with different growth patterns before and after treatment.

Materials and Methods

Pre- and post-treatment lateral cephalogram of forty Class I adults in the age group of 20–27 years were grouped. All the cases were treated with the first premolar extraction in all quadrants. Based on the growth pattern of the face, individuals were divided into: (1) Group 1 (n = 20): Normodivergent, i.e., FH/MP angle smaller than 30.5° (20 patients). (2) Group 2 (n = 20): Hyperdivergent, i.e., FH/MP angle larger than 30.5° (20 patients). Lateral cephalograms were traced and analyzed manually for evaluation of hyoid bone position. Patients in both groups were treated with preadjusted appliances. Pre- and post-treatment lateral cephalograms were traced, and variables were compared using paired t-test, and the relationship between dentofacial variables, growth pattern, and the hyoid bone position was analyzed using Karl Pearson’s correlation coefficient method. The changes of hyoid position after treatment were compared using t-test.

Results

The data were analyzed by Kolmogorov–Smirnov and paired t-test. Karl Pearson’s correlation coefficient test was performed to determine whether there was an association between the changes of hyoid and growth pattern. Following retraction of incisors, statistically significant correlation was observed in the pre- and post-treatment values of dentofacial structures and hyoid bone, but no significant correlation was found in position of the hyoid bone in the normodivergent and hyperdivergent groups. In both the groups, hyoid bone moved in an inferior and posterior direction after orthodontic treatment.

Conclusion

No change was seen in position of the hyoid bone in normodivergent and hyperdivergent groups.

Upper airway asymmetry in skeletal Class III malocclusions with mandibular deviation

The purpose of this study was to investigate the relationship between bilateral differences of upper airway and mandibular morphologic patterns in subjects with skeletal Class III mandibular deviation. 47 skeletal Class III (ANB < 0°) adult patients with and without mandibular deviation were divided into 2 groups. Bilateral differences of minimum cross-sectional area, mean cross-sectional area, volume of subdivisions (nasopharynx, palatopharynx, glossopharynx, hypopharynx) were assessed paired t test. Stepwise linear regression analysis and Pearson correlation coefficients were computed between a significant pair of upper airway variables and a pair of mandibular deviation variables to examine the quantitative relationship between the upper airway asymmetry and mandibular deviation. The mean cross-sectional area and the volume of palatopharynx on the deviated side in mandibular deviated group was significantly smaller than non-deviated side. The asymmetry index of the palatopharyngeal volume showed significant correlations with CRA asymmetry (r = 0.49) and Ramus asymmetry (r = 0.54). However, in the glossopharyngeal and hypopharyngeal segment, the mandibular deviated group showed significant asymmetry, characterized by larger mean cross-sectional area and volume in deviated side. The asymmetry index of the glossopharyngeal volume and hypopharyngeal volume showed significant correlations with CRA asymmetry (r = 0.42), Me-s (r = 0.72) and Me-s (r = 0.67) respectively.

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

The present study was aimed to investigate the relationship of the upper airway size and craniofacial structures in 3 dimensions in growing children of skeletal Class III. Forty-seven children (19 boys and 28 girls, 9.6 ± 1.3 years of age, range 8.0-12.4 years) were selected. Twenty-three children with normal vertical development were divided into groups of insufficient maxilla and overdeveloped mandible for the airway comparison between different sagittal skeletal patterns. Thirty-two children with the same sagittal development were divided into groups of low angle, normal angle, and high angle for the comparison between different vertical skeletal developments. The upper airway and craniofacial structures were measured in cone beam computed tomography images using DOLPHIN 11.7 software. Mann-Whitney U test and Kruskal-Wallis test were used to analyze the airway differences between groups. Spearman correlated analysis was done between the upper airway size and the craniofacial pattern in the transverse dimension. The results showed that the nasopharynx was the only affected airway part between groups of insufficient maxilla and overdeveloped mandible (P <0.05). The high angle group showed smaller upper airway compared with the groups of normal angle and low angle (P <0.05). The skeletal transverse dimension was correlated with the height of velopharynx, hypopharynx, and total airway with small gender differences.

Craniofacial skeletal pattern: is it really correlated with the degree of adenoid obstruction?

OBJECTIVE

The aim of this study was to compare the cephalometric pattern of children with and without adenoid obstruction.

METHODS

The sample comprised 100 children aged between four and 14 years old, both males and females, subjected to cephalometric examination for sagittal and vertical skeletal analysis. The sample also underwent nasofiberendoscopic examination intended to objectively assess the degree of adenoid obstruction.

RESULTS

The individuals presented tendencies towards vertical craniofacial growth, convex profile and mandibular retrusion. However, there were no differences between obstructive and non-obstructive patients concerning all cephalometric variables. Correlations between skeletal parameters and the percentage of adenoid obstruction were either low or not significant.

CONCLUSIONS

Results suggest that specific craniofacial patterns, such as Class II and hyperdivergency, might not be associated with adenoid hypertrophy.

Upper and lower pharyngeal airway space in West-Tamil Nadu population

Aim:

To compare the upper and lower pharyngeal airway (LPA) width in Class II malocclusion patients with low, average, and high vertical growth patterns.

Study Design:

Cross-sectional analytical study.

Materials and Methods:

Pretreatment lateral cephalometric films of 90 Class II subjects were used to measure the upper and LPAs. The inclusion criteria were subjects of West-Tamil Nadu, aged between 14 and 25 years, only skeletal Class II subjects of either gender and no pharyngeal pathology at initial visit. The sample comprised a total of 90 Class II subjects divided into three groups according to the vertical facial pattern: Normodivergent (n = 30), hypodivergent (n = 30), and hyperdivergent (n = 30). The assessment of upper and LPAs was done according to McNamara's airway analysis.

Statistical Analysis:

The intergroup comparison of the upper and LPAs was performed with one-way analysis of variance and the Tukey test was used to compare among the various vertical patterns.

Results:

Skeletal Class II subjects with hyperdivergent facial pattern showed statistically significant narrow upper pharyngeal width when compared to normodivergent and hypodivergent facial patterns. No statistically significant difference was found in the lower pharyngeal width in all three vertical facial growth patterns.

Conclusion:

Subjects with Class II malocclusions and hyperdivergent growth pattern have significantly narrow upper pharyngeal airway space when compared to other two vertical patterns. Narrow pharyngeal airway space is one of the predisposing factors for mouth breathing and obstructive sleep apnea.

Soft tissue airway dimensions and craniocervical posture in subjects with different growth patterns

OBJECTIVE

To compare the dimensions of the nasopharynx and oropharynx of subjects with different growth patterns and to determine whether any correlation exists with their craniocervical posture.

MATERIALS AND METHODS

Cephalometric radiograph of 60 subjects (16-25 years old), taken in natural head position, were divided into three groups according to the mandibular plane angle: hypodivergent (SN/MP <26°), normodivergent (SN/MP 26°-38°), and hyperdivergent (SN/MP <38°). Correlations were calculated between nasopharyngeal area, oropharyngeal area, and craniocervical posture. Continuous variables were compared by one-way analysis of variance, and the significance of mean difference between the groups was done by the Tukey post hoc test. A value of P < .05 was considered statistically significant.

RESULTS

Patients in the hyperdivergent group were found to have significantly smaller nasopharyngeal and oropharyngeal areas than the other groups (P < .001 and P < .05, respectively). Similarly, the oropharyngeal area in the normodivergent group was significantly smaller than that in the hypodivergent group (P < .05). However, no significant differences were found in the nasopharyngeal area between the hypodivergent and normodivergent groups and between the hyperdivergent and normodivergent groups (P > .05). Reduced pharyngeal airways were typically seen in patients with a large craniocervical angle and a large mandibular inclination.

CONCLUSIONS

Smaller nasopharyngeal and oropharyngeal airways were seen in connection with a large craniocervical and a large mandibular inclination. We therefore suggest that the vertical skeletal pattern may be one of the factors that contribute to nasopharyngeal and oropharyngeal obstruction.

A comparative study of the pharyngeal airway space, measured with cone beam computed tomography, between patients with different craniofacial morphologies

PURPOSE

The present study aims to determine any existing association between airway dimensions, measured with cone beam computed tomography (CBCT), and the different patient craniofacial morphologies.

MATERIAL AND METHODS

Sixty CBCT (Dental Picasso Master 3D) images, from patients treated at the Orthodontics Master at Valencia University were selected. The program InVivoDental 5.1 was used to visualize sections, analyze three-dimensional images, and perform airway measurements in the three planes of the space. Intra- and interobserver error methods were recorded. After that, measurements at three different levels of the airway (upper, medium, lower) were taken, in both the anteroposterior and transversal directions of the airway space. The area (mm(2)) of the airway space at the three levels was also measured.

RESULTS

In the anteroposterior airway measurements, there were differences between the measurements by level. The magnitude of these differences depended on the skeletal pattern of the individual. In the transversal airway measurements and in the area airway measurements, there were no differences according to the skeletal pattern. However, in the transversal direction, measurements in the lower level were significantly higher than in the superior level in all cases. When measuring the area, significantly higher measurements in the upper level were recorded. The homogeneity between medium and lower levels decreased gradually from class I to class III subjects.

CONCLUSIONS

No statistically significant results were observed that related the anteroposterior and vertical skeletal craniofacial morphology with airway dimensions, although some specific associations have been detected for certain airway levels or for pattern combinations.

Effects of reverse headgear on pharyngeal airway in patients with different vertical craniofacial features

The aim of this study was to investigate the effects of reverse headgear (RH) on pharyngeal airway morphology in two groups of Class III patients with different vertical craniofacial features in comparison with an untreated Class III group. Seventeen subjects (9 males, 8 females; mean age 11.3 ± 0.98 years) with optimum vertical growth and 17 subjects (10 males, 7 females, mean age 11.5 ± 1.1 years) with a vertical growth pattern treated with a removable intra-oral appliance and a Delaire type facemask were included. An untreated Class III control group of 11 subjects (8 males, 3 females, mean age 9.1 ± 1.1 years) was included to compare the treated groups. The paired t-test for intragroup and one-way ANOVA for intergroup comparisons were performed. The relationships between changes in the craniofacial morphology and airway were assessed by Spearman correlation analysis. The airway dimensions at the adenoid side and soft palate were increased in the treatment groups compared to the control group (p < 0.05). The nasopharyngeal area demonstrated a significant difference in normodivergent and control subjects (p < 0.05). No significant difference was found in the airway morphology due to different vertical features. The effect of RH treatment on the sagittal airway dimensions revealed no significant difference between different vertical craniofacial features in the short term.

The effect of teeth extraction for orthodontic treatment on the upper airway: a systematic review

PURPOSE

The purpose of this study was to evaluate the effect of teeth extraction for orthodontic treatment on the upper airway.

METHODS

Relevant trials assessing the effect of orthodontic extractions on the upper airway were retrieved electronically through PubMed, Embase, Medline, Web of Knowledge, and the Cochrane Library. The processes of literature search, selection, quality assessment, and data extraction were performed by two authors independently.

RESULTS

Seven articles were included in this systematic review. They were categorized into three groups according to their indications for extractions, namely anteroposterior discrepancy (group 1), crowding (group 2), and unspecified indications (group 3). In group 1, enrolled patients were diagnosed with class I bimaxillary protrusion and had four first premolars extracted, with a significant decrease in upper airway dimension. In group 2, increase in the upper airway dimension was reported in patients who were diagnosed with class I crowding and four first premolars extracted. In group 3, all patients were adolescents and no significant change in the upper airway dimension was observed.

CONCLUSIONS

Currently, it is difficult to draw evidence-based conclusions because of the exceeding heterogeneity among included studies, and more qualified trials are required to provide reliable evidence. Extractions followed by large retraction of the anterior teeth in adult bimaxillary protrusion cases could possibly lead to narrowing of the upper airway. Mesial movement of the molars appeared to increase the posterior space for the tongue and enlarge the upper airway dimensions. Although the effect of teeth extraction on upper airway dimension seems to be related to indications for extraction, accepted scientific evidence is still insufficient owing to the limited number of included studies. The relationship between the upper airway size and the respiratory function has not been demonstrated. While there may be a decrease in the upper airway volume, there is no evidence that this would turn an airway more collapsible. None of the studies assessed in this review had actual functional assessment of breathing. Additional qualified trials are necessary to verify reliability.

Effects of twin-block appliance on the anatomy of pharyngeal airway passage (PAP) in class II malocclusion subjects

Background

The use of functional appliances for the correction of retrognathic mandible is very common in orthodontics. Similar appliances known as oral appliances are also frequently used in adults for the treatment of mild to moderate obstructive sleep apnea (OSA). Many studies have reported improvement of pharyngeal airway passage (PAP) dimensions following functional appliance therapy in children and oral appliance therapy in adults. There is only one study in the literature that discussed the effect of oral appliance therapy on posterior pharyngeal wall thickness (PPWT) among subjects with OSA. The effect of functional appliance therapy on PPWT has never been investigated. Thus the present study was conducted to evaluate the effects of twin-block appliance on pharyngeal airway passage (PAP) dimensions and posterior pharyngeal wall thickness (PPWT) in class II malocclusion subjects with retrognathic mandibles.

Methods

Thirty-eight class II malocclusion subjects in the age range of 8 to 14 years with mandibular retrusion were divided into a treatment (n = 20) and control (n = 18) group. Mandibular retrusion in the treatment group subjects was corrected by twin-block appliance. The effect of twin-block appliance on PAP and PPWT dimensions were evaluated from lateral cephalograms recorded prior-to and after 6 months of appliance therapy in the treatment group subjects and the changes were compared with the changes in the control group subjects. Student’s t-test was used for statistical analysis; P-value of 0.05 was considered a statistically significant level.

Results

The depth of the oropharynx was increased significantly in the treatment group subjects (P < 0.001) as compared to the control group subjects (P < 0.05). The depth of the hypopharynx increased significantly in treatment group subjects (P < 0.01). The PPWT at the level of the nasopharynx, oropharynx, and hypopharynx were maintained in the treatment group subjects; whereas in control group subjects, the PPWT was further reduced although the changes were not statistically significant.

Conclusions

Correction of mandibular retrusion by twin-block appliance in class II malocclusion subjects increased the PAP dimensions and maintained the pre-treatment thickness of posterior pharyngeal wall.

Cephalometric study of the upper airways and dentoalveolar height in open bite patients

Open bite is related to various etiological factors and, in many cases, is difficult to diagnose. The present study is aimed at evaluating, through cephalometric analysis, the dimensions of the upper airways and dentoalveolar heights in open bite (OB) patients versus normal overbite patients. The relationship between the width of the upper airways and the lack of overbite is also studied, in order to differentiate between dental open bite (DOB) and skeletal open bite (SOB).

MATERIALS AND METHODS

Eighty X-rays were selected from files of orthodontic patients to form the control sample (n=40) and open bite sample (n=40). Dimensions of the upper airways and dentoalveolar heights were measured in both samples, using 16 linear measurements, two angle values and one ratio.

RESULTS

In OB patients, anteroposterior narrowing of the upper airways, mainly in the nasopharynx and oropharynx, was observed, together with forward displacement of the hyoid bone and increased maxillary and mandibular dentoalveolar heights, and anterior facial height. In SOB, the overbite was more negative and facial growth was more clockwise-oriented than in DOB. Greater narrowing of the airways in the anteroposterior orientation was also noted. In DOB, there was evidence of muscular adaptation, as shown by increased values of the hyoid bone displacement to a more anterior and lower position, and increased values of the vertical dimensions of the airways. An increase in posterior facial height was also observed allowing anterior rotation of the mandible.

CONCLUSION

The results suggest that the airway's dimensions reflect a tendency to open bite. The variable vertical airway length (Val) and the position of the hyoid bone allow the adaptive potential of these individuals to be determined and make the treatment of open bites more predictable.

The influence of craniofacial morphology on the upper airway dimensions

Objective: 

To evaluate the influence of craniofacial morphology on the upper airway dimensions in healthy adult subjects.

Materials and Methods: 

The records of 276 healthy 17- to 27-year-old patients were extracted from the cone-beam computed tomography image database of the Institute of Stomatology, Riga Stradins University. Dolphin 11.7 software was used to evaluate craniofacial anatomy and semiautomatic segmentation of the upper airway. Measurements of oropharyngeal airway volume (OPV), minimal cross-sectional area (CSAmin), and nasopharyngeal airway volume (NPV) were obtained. The presence of adenoid tissues was recorded. Associations between variables were analyzed by Spearman's correlation coefficients, and multivariate linear regression analysis was used to identify factors that had a possible influence on upper airway dimensions.

Results: 

The following factors were identified as influencing the variability of NPV (23%): SNA angle, gender, and presence of adenoids. Statistically significant, although weak, correlations were found between SNB angle and OPV (r  =  0.144, P &lt; .05) and CSAmin (r  =  0.182, P &lt; .01).

Conclusion: 

The results suggest that craniofacial morphology alone does not have a significant influence on upper airway dimensions.

Cephalometric evaluation of tongue position and airway remodelling in children treated with swallowing occlusal contact intercept appliance (S.O.C.I.A.)

INTRODUCTION

Facial growth changes the position of the jaws (in particular vertical position of the maxilla and antero-posterior position of the mandible) and may, in turn, modify the position of the tongue and the hyoid bone, thus, generating modifications of the upper airway space. In the present paper, effects on upper airway space and tongue position of a new functional appliance, the swallowing occlusal contact intercept appliance (SOCIA) have been investigated.

MATERIALS AND METHODS

Retrospective cephaolmetric study of twenty-four children (mean age 9.46±1.60) with hyperdivergent Class II malocclusion with mandibular retrusion and atypical deglutition, was performed on radiographs taken before and after 24 months treatment with "SOCIA" appliance. The variables considered in this study, and analysed by means of a Paired t-test with a 5% level of significance, included the distance between the base of epiglottis (EB) and the tip of the tongue (TT), the distance from the tongue dorsum to EB-TT (TGH), the distance between the posterior nasal spine PNS and EB (VAL), SPAS, MAS and IAS (i.e. superior, medium and inferior pharyngeal airspace width).

RESULTS

Our findings showed a significant increase in tongue length (TT-EB) and tongue height (TGH); thus, confirming the reposition of the tongue from a lower posture to its physiological position onto the palatal spot. These modifications of the tongue posture had effects on the upper airway space. The most important modifications were observed in SPAS, with a significant 5.9 mm increase. Some increase was found also for MAS (0.83 mm) and IAS (1.1 mm) but without statistical significance. A significant increase (7.75 mm) was also found for VAL, probably as a result of the augmentation of posterior facial height.

CONCLUSIONS

SOCIA appliance is capable to improve tongue position and the superior posterior airway space, and, consequently, to improve deglutition, phonation and respiratory function.

Comparison of pharyngeal airway volume among different vertical skeletal patterns: a cone-beam computed tomography study

OBJECTIVE

To test the null hypothesis that there are no significant differences in pharyngeal airway volumes among adult patients with different vertical skeletal patterns and a clinically normal sagittal skeletal pattern using cone-beam computed tomography (CBCT).

MATERIAL AND METHODS

The study sample consisted of 100 adult patients (45 men and 55 women; mean age  =  24.0 ± 5.3 years) with a normal sagittal skeletal pattern divided into three groups according to the vertical skeletal patterns: high angle (32 patients: 15 women and 17 men), low angle (34 patients: 14 women and 20 men), and normal angle (34 patients: 16 women and 18 men) groups. Nasopharyngeal, oropharyngeal, and total airway volumes of patients in all vertical groups were calculated. Group differences were analyzed using one-way analysis of variance and post hoc Tukey tests.

RESULTS

Nasopharyngeal airway volume in the high-angle group (mean  =  6067.9 ± 1693.9 mm(3)) was significantly lower than that of the low- and normal-angle groups (P < .01). Oropharyngeal airway volume was highest in the low-angle group (mean  =  15,957.6 ± 6817.2 mm(3)) and significantly decreased in the control (mean  =  11,826.1 ± 4831.9 mm(3); P  =  .008) and high angle (mean  =  10,869.1 ± 4084.1 mm(3); P  =  .001) groups. Total airway volume was highest in the low-angle group (mean  =  24,261.6 ± 8470.1 mm(3)) and lowest in the high-angle group (mean  =  16,937.0 ± 5027.4 mm(3); P < .001).

CONCLUSION

The null hypothesis was rejected. Significant differences were found in pharyngeal airway volumes among different skeletal vertical patterns.

Effects of first premolar extraction on airway dimensions in young adolescents: A retrospective cephalometric appraisal

OBJECTIVE

To evaluate the upper airway dimensions in adolescents treated for bimaxillary proclination with first premolar extraction.

MATERIALS AND METHODS

A retrospective cephalometric evaluation was carried out on the available pre and post orthodontic treatment records of 150 patients (12-18 years of age) who had bimaxillary proclination and were treated with fixed orthodontic therapy. Cephalometric landmarks for sagittal airway measurements and hyoid bone were identified; linear and angular measurements were obtained. Descriptive statistics using paired t-test was used to assess changes in pre and post treatment values and Pearson's correlation coefficient was calculated to evaluate the reliability of observations. The method error calculations were performed using the Dahlberg formula.

RESULTS

It was observed that the mean values of nasopharyngeal dimension and Total Airway Length (TAL) showed no statistically significant difference in pre and post treatment groups. All other airway and hyoid parameters showed statistically significant difference. Pearson's correlation coefficient showed statistically significant correlations in all the airway and hyoid parameters.

CONCLUSIONS

In the present study, the nasopharyngeal dimension and TAL were not found to be directly affected by the retraction of anterior teeth, This can be attributed to the fact that nasopharyngeal dimension and TAL are not under direct influence of tongue position. The other findings also indicated direct correlation of tongue position to oropharynx and hypopharynx. Consequently, we emphasize clinically relevant anatomic risk factors that should be given prime importance and serious consideration on the decision whether to extract or not in growing patients.

A three dimensional study of upper airway in adult skeletal Class II patients with different vertical growth patterns

OBJECTIVE

The study was performed to compare the 3D pharyngeal airway dimensions in adult skeletal Class II patients with different vertical growth patterns (low, normal, and high angle) and to investigate whether the upper airway dimensions of untreated skeletal Class II adults were affected by vertical skeletal variables.

METHODS

Cone-beam computed tomography (CBCT) records of 64 untreated adult skeletal Class II patients (34 male and 30 female) were collected to evaluate the pharyngeal airway dimensions. Subjects were divided into three subgroups according to the GoGn-SN angle (low angle, normal angle or high angle). All subgroups were matched for sex. ANOVA and SNK-q tests were used to identify differences within and among groups (p<0.05). Coefficient of product-moment correlation (Pearson correlation coefficient) was used to analyze the association between pharyngeal airway dimensions and vertical growth patterns.

RESULTS

The results showed that pharyngeal airway measurements were statistically significantly less (p<0.05) in high angle group as compared to normal angle or low angle group.

CONCLUSIONS

Adult skeletal Class II subjects with vertical growth patterns have significantly narrower pharyngeal airways than those with normal or horizontal growth patterns, confirming an association between pharyngeal airway measurements and a vertical skeletal pattern.

Three-dimensional evaluation of upper airway in patients with different anteroposterior skeletal patterns

OBJECTIVES

To investigate variability in the upper airway of subjects with different anteroposterior skeletal patterns by evaluating the volume and the most constricted cross-sectional area of the pharyngeal airway and defining correlations between the different variables.

MATERIAL AND METHODS

The study sample consisted of 60 patients (29 boys, 31 girls) divided into three groups: Class I (1 ≤ ANB ≤ 3), Class II (ANB>3), and Class III (ANB<1), to evaluate how the jaw relationship affects the airway volume and the most constricted cross-sectional area (Min-CSA). Differences between groups were determined using the Tukey-Kramer test. Correlations between variables were tested using Pearson's correlation coefficient.

RESULTS

The volume and the Min-CSA of the pharyngeal airway (PA) were significantly related to anteroposterior skeletal patterns (p < 0.05). The nasopharyngeal airway (NA) volume of Class I and Class III subjects was significantly larger than that of Class II subjects (p < 0.05). The Min-CSA and the length of PA were significantly related to the volume of PA (p < 0.05). The site and the size of the Min-CSA varied among the three groups.

CONCLUSIONS

The volume and the most constricted cross-sectional area of the airway varied with different anteroposterior skeletal patterns. The NA volume of Class I and Class III subjects was significantly larger than that of patients with a Class II skeletal pattern.

Short-term pharyngeal airway changes after mandibular advancement surgery in adult Class II-Patients--a three-dimensional retrospective study

The purpose of this study was to investigate volume changes in posterior airway space (PAS) after bilateral mandibular advancement surgery. Measurements were taken based on three-dimensional (3D) records available for a large and homogeneous cohort of patients. Pre- and postoperative CBCT scans of 102 adult patients with Class II dysgnathia were visualized and analyzed using 3D software (Mimics® Innovation Suite 14.1; Materialise, Leuven, Belgium). The PAS was divided into three segments by three planes parallel and one plane perpendicular to the Frankfort horizontal plane. Total volume, partial volumes, and cross-sectional areas were calculated from the pre- and postoperative scans. Dahlberg coefficients were obtained to verify each parameter for the measurements' reliability. The statistical significance of the changes observed was analyzed by Wilcoxon's rank-sum test. Highly significant (p=0.000) increases in total posterior airway volume (+32.0%) were noted as an effect of mandibular advancement surgery, amounting to 45.6% in the lower PAS third compared to 38.8% in the middle and 12.5% in the upper PAS third. We also obtained highly significant (p=0.000) increases in all the cross-sectional areas investigated, amounting to 48.5% on the soft-palate level compared to 21.6% on the level of the epiglottis tip, and 14.6% on the hard-palate level. These results demonstrate that bilateral mandibular advancement surgery in Class II-Patients leads to significant increases in PAS volume and significant widening of the narrower sites inside the pharynx.