Cephalometric changes in adult pharyngeal morphology

Cephalometric changes in pharyngeal airway dimensions after functional treatment with twin block versus myobrace appliances in developing skeletal class II patients: a randomized clinical trial

BACKGROUND

Several appliances have been used for correction of developing skeletal Class II, including different myofunctional appliances as Twin block (TB)as well as the new pre-fabricated Myobrace (MB) appliance. However, the effects of these devices on the pharyngeal airways have not been compared in the literature. Thus, the aim of this study was to compare the effects of two Class II correction appliances; TB and MB on the sagittal pharyngeal airway dimension (SPAD), including the nasopharyngeal airway area (NPAA), the oropharyngeal airway area (OPAA), and the laryngopharyngeal airway area (LPAA).

METHODS

This is a two parallel arms randomized comparative clinical trial. Twenty-six children of 9-12 years with Skeletal Class II malocclusion due to mandibular deficiency and normal maxillary growth as confirmed by lateral cephalometric X-ray readings (ANB angle > 4° and SNB angle < 78) and Cervical vertebral maturational index (CVMI) 1 or 2 were randomly assigned into two equal groups. Group I: TB, Group II: MB (prefabricated functional appliance, Myofunctional Research Co., Australia). Lateral cephalograms were taken for all patients in both groups before treatment (T1) and after treatment (6 months later) (T2). The primary aim was to assess pre and post treatment changes in the SPAD in each group, and compare between the two study groups. The secondary aim was to evaluate the sagittal skeletal measurements such as the SNA, SNB, ANB, Wits appraisal, as well as vertical skeletal measurements represented by the Frankfurt-mandibular plane angle (FMA) measured pre- and post-treatment. The independent samples t-test was used to compare the two study groups, and the mean difference and 95% confidence intervals (CI) were computed. The paired samples t-test was used to compare various parameters between T1 and T2 within each group. The cutoff for significance was p-value < 0.05. Data were analyzed using IBM SPSS for Windows (Version 26.0).

RESULTS

By Comparing changes in airway measurements within each group, it was found that NPAA, OPAA, and LPAA increased significantly after treatment within each group of MB and TB. TB group showed significantly higher mean difference (T2-T1) in both NPAA and OPAA than MB group with 28.39 (± 56.75) and 40.46 (± 52.16) respectively. The increase in LPAA values was not statistically significant at (T2-T1) between both groups. Regarding skeletal changes, there was a significant increase in the SNB values between T1 and T2 within each group with 2.82 (± 3.32) for MB group and 3.79 (± 3.06) for TB group Moreover, there was a significant decrease in the ANB values between T1 and T2 within each group by 2.42 (± 2.70) for MB group and 3.06 (± 1.14) for TB group. Similarly, there was a significant decrease in the ANB values between T1 and T2 within each group by -2.13 (± 0.62) for MB group and - 2.46 (± 0.72) for TB group. No significant differences were found between both groups in SNA, SNB, ANB and Wits appraisal at p = 0.06, p = 0.45, p = 0.43 and p = 0.22 respectively. FMA did not show significant difference between T1 and T2 within each group, nor showed a significant mean difference between both groups at T2-T1.

CONCLUSIONS

TB was more effective than MB in improving the upper (NPAA) and middle (OPAA) airways, while no difference was found regarding the lower airway (LPAA). Both TB and MB reduced the severity of developing skeletal class II due to mandibular retrognathism by forward posturing of the mandible. Thus, patients with airway problems would benefit more from TB than MB.

Evaluation of effects of removable functional orthodontic apparatus on the upper airway size by cephalometric films

OBJECTIVE

Respiration is a vital functional process that has effects on normal craniofacial development. Since the upper airway formations and dentofacial structures are adjacent to each other, the interaction between them is possible. The aim of this study is to evaluate the effects of removable functional appliances used in the treatment of patients with mandibular and maxillary growth retardation-stenosis in Class I, Class II, and Class III malocclusion on the upper airway.

MATERIALS AND METHODS

Thirty two patients were studied in the study. The patients were divided into 4 groups according to treatment modalities. Maxillary expansion device group (Group A), Twinblock-Monoblock group (Group B), Face mask group (Group C), and Chincup group (Group D). The upper airway size in the lateral cephalometric images of the patients before orthodontic treatment with removable functional appliances (T0) and the upper airway size in the lateral cephalometric images taken after the end of the orthodontic treatment with the removable functional appliances (T1) were retrospectively compared.

RESULT

Most upper airway size increased after orthodontic treatment (T1) in the individuals who received orthodontic treatment with A, B, C, and D type removable functional appliances compared to pre-treatment (T0). When the changes in upper airway size pre-treatment (T0) and post-treatment (T1) were compared, the change in upper airway size according to treatment groups was found to be statistically different (p <0.05).

CONCLUSION

Since a large part of the upper airway is located in the craniofacial complex, orthodontists also examine the airway for diagnosis and planning and can regulate the airway in case of occlusion that has occurred or may occur. This puts orthodontists in an important place to intervene when complications occur or may develop in the upper airway. By determining the effects of removable functional appliances on the airways, airway problems that may be experienced at an early age can be prevented.

Effects of surgical mandibular advancement on the upper airways of adult class II patients: A systematic review with meta-analysis

AIM

To systematically review the effects of surgical mandibular advancement (SMA) regarding changes of the upper airways in adult patients with skeletal Class II malocclusion.

MATERIALS AND METHODS

Five electronic databases were searched up to April 2020. Human studies focusing on the morphology and dimension of the upper airways after SMA were included. 'Quality assessment for Before-After (Pre-Post) Studies' was used to assess the risk of bias of the individual studies. Standard mean differences (SMD) with 95% confidence intervals (CI) were calculated for random effect model meta-analysis. The certainty of evidence was assessed using the GRADE tool.

RESULTS

Twenty cohort studies of only treated patients without control group were eligible for qualitative synthesis, of which 17 were used for quantitative synthesis. Very low certainty of evidence indicated that SMA resulted in significant increase of the volume and of the smallest cross-sectional area (SMC) of the nasopharynx (volume SMD: 1.43, CI: 0.62, 2.24, P = .001, I²  = 87.8%; SMC SMD: 1.53, CI: 0.59, 2.47, P = .001, I²  = 90.5%) and oropharynx (volume SMD: 1.36, CI: 0.37,2.35, P = .007, I²  = 92.1%; SMC SMD: 1.21, CI: 0.11,2.32, P = .032, I²  = 93.1%). Significant augmentation of the distances between the posterior pharynx wall and the uvala (SMD: 0.73, CI: 0.46,0.98, P < .001, I²  = 72.7%), the posterior border of the tongue (SMD: 0.52, CI: 0.21,0.84, P = .001; I² : 60.5%), the gonion (SMD: 1.24, CI: 0.56,1.91, P < .001; I²  = 88.8%) and the epiglottis (SMD: 0.40, CI: 0.06,0.74, P = .033; I²  = 84.8%) were observed.

CONCLUSIONS

Weak evidence suggests enlargement of the upper airways of adult Class II subjects following SMA, with major increases in the oropharynx.

Pharyngeal airway, hyoid bone, and soft palate changes after Class II treatment with Twin-block and Forsus appliances during the postpeak growth period

INTRODUCTION

This study aimed to compare cephalometrically the pharyngeal airway, hyoid bone, and soft palate (SP) changes after Class II malocclusion treatments using Twin-block (TWB) and Forsus Fatigue Resistant Device (FFRD) (3M Unitek Corp, 3M Dental Products, Monrovia, Calif) during the postpeak growth period.

METHODS

Forty-two patients with Class II malocclusion treated during the postpeak growth period were randomly and retrospectively included in this study. These patients were divided into 2 treatment groups: TWB and FFRD. The skeletal, dental, pharyngeal airway, hyoid bone position, and SP measurements were obtained from the lateral cephalometric radiographs taken at the beginning and at the end of the treatment. Paired-samples and independent-samples t tests were used for the intragroup and intergroup comparisons, respectively.

RESULTS

In the TWB group, the SNB (°), Md1-NB (mm), Md1-NB (°), and McNamara upper and lower pharyngeal airway dimensions significantly increased, whereas the ANB (°), AD1-Ba (mm), AD2-H (mm), adenoidal nasopharyngeal area, and SP angle decreased (P < 0.05). In the FFRD group, the SNB (°), Md1-NB (mm), Md1-NB (°), Ptm-Ba (mm), and McNamara upper airway dimensions significantly increased, whereas the ANB (°), AD2-H (mm), and interincisor angle decreased (P < 0.05). Moreover, there were statistically significant differences in the Md1-NB angles and SP thicknesses between the 2 groups (P < 0.05).

CONCLUSIONS

The effects of TWB and FFRD treatment on the airway during the postpeak growth period were similar. However, the FFRD caused a greater mandibular incisor protrusion.

Upper airway morphological changes in obstructive sleep apnoea: effect of age on pharyngeal anatomy

OBJECTIVE

To evaluate the upper airway morphology changes associated with ageing in adult Chinese patients with obstructive sleep apnoea.

METHODS

A total of 124 male patients diagnosed with obstructive sleep apnoea by overnight polysomnography, who underwent upper airway computed tomography, were enrolled. The linear dimensions, cross-sectional area and volume of the upper airway region and the surrounding bony frame were measured. The association between ageing and upper airway morphology was analysed.

RESULTS

Soft palate length, minimum cross-sectional area of the retroglossal region, lateral dimensions at the minimum cross-sectional area of the retropalatal and retroglossal regions, nasopharyngeal volume, and average cross-sectional area of the nasopharyngeal region were found to significantly increase with ageing in all patients, while the upper airway shape flattened with ageing. The volume of the retropalatal region increased with ageing among the patients with a body mass index of less than 24 kg/m2. The volume of parapharyngeal fat pad increased with ageing among patients with a body mass index greater than 28 kg/m2.

CONCLUSION

A number of dimensional, cross-sectional and volumetric parameters of the pharynx increased with age, indicating that non-anatomical factors may play a more important role in the pathogenesis of obstructive sleep apnoea in aged patients.

Dynamical Changes of Mandible and Upper Airway After Mandibular Distraction Osteogenesis in Pierre Robin Sequence

OBJECTIVE

To present the dynamical evaluation of mandible and upper airway size among Chinese infant patients following mandibular distraction osteogenesis in a short-term follow-up and compare predistraction measurements with a normal age- and sex-matched control.

METHODS

All the patients have undergone the computed tomography (CT) scan before mandibular distraction osteogenesis (T0), at the end of the distraction phase (T1), and 3 months after the end of the distraction phase before the distractor removal (T2). A CT analyzing computer software MIMICS was utilized to analyze the anatomic variables of upper airway size and mandible size. All analysis was based on a significance level of 0.05.

RESULTS

Eight patients with Pierre Robin sequence differed mainly in the mandibular body length and the minimum anteroposterior dimension of the retroglossal airway from the control. After mandibular distraction osteogenesis, the mandibular body length and the ramus height both increased significantly, the ramus height also increased after 3 months of consolidation. Only small increase in the airway dimension of the retroglossal area at T2 was observed compared with T1.

CONCLUSION

Mandibular distraction osteogenesis is an effective modality in treating Pierre Robin sequence. Compared with normal control, the main difference may be the length of mandibular body and the area of the retroglossal airway. There may not be an increase in the diameter of airway and the length of mandibular body after 3 months of growth and development in Pierre Robin sequence. Individual surgical plan should be made to gain a better prognosis.

Analysis of the middle region of the pharynx in adolescents with different anteroposterior craniofacial skeletal patterns

Objective:

To assess the volume and morphology of the middle region of the pharynx (MRP) in adolescents with different anteroposterior craniofacial skeletal patterns.

Methods:

One hundred twenty-six patients (56 male and 70 female), who had cone-beam computed tomography (CBCT) within their records, were selected for this cross-sectional study. Participants were classified, according to their ANB angle value, in Class I (1^o ≤ ANB ≤ 3^o), Class II (ANB > 3^o) and Class III (ANB < 1^o). The total volume (tV), minimum axial area (AxMin) and morphology of the MRP and its subdivisions - velopharynx (VP) and oropharynx (OP) - were characterized by CBCT and 3-dimensional image reconstruction software. Intergroup comparisons were performed by ANOVA and Tukey post-hoc tests. Correlations between tV and Axmin with the ANB angle values were tested using linear regression analysis, considering sex as covariable.

Results:

Statistically significant difference between groups were observed in tV only for the VP region; Class II individuals presented significantly lower tV (6863.75 ± 2627.20 mm³) than Class III subjects (9011.62 ± 3442.56 mm³) (p< 0.05). No significant differences were observed between groups for any other variable assessed, neither in MRP nor in the OP region (p> 0.05). A significant negative correlation was evidenced between tV and Axmin and the ANB angle values; sexual dimorphism was observed for some variables.

Conclusions:

Class II subjects have smaller tV in the VP region. tV and Axmin tend to decrease in all evaluated regions when the ANB angle values increase.

Nasality Changes With Age in Normal Korean-Speaking Adults

Objectives

This study was performed to investigate the effects of aging on nasality and the influence of age-related changes in nasal cavity volume and nasal patency on nasality.

Methods

A total of 180 healthy Korean-speaking adult volunteers, who had no nasal or voice-related complaints, were enrolled in this study. Nasometry, acoustic rhinometry, and rhinomanometry were performed to obtain the nasalance score, nasal cavity volume, and nasal resistance, respectively. Changes in these parameters with age were analyzed.

Results

Nasal cavity volume increased significantly, and nasal resistance decreased significantly, with age. The nasalance scores for the nasal passage and oronasal passage decreased significantly with age, while there were no age-related changes in nasalance scores for the oral passage.

Conclusion

Nasalance scores for the passages containing nasal consonants decreased with age although significant increases were observed in nasal cavity volume and nasal patency with age. Therefore, the age-related decreases in nasalance scores may result from factors other than changes in the nasal cavity.

A Novel Approach to Determine the Prevalence of Type of Soft Palate Using Digital Intraoral Impression

Aim

To determine the prevalence of type of soft palate in targeted population.

Materials and Methods

Using computer technology in dentistry, intraoral digital scanner, and 3D analysis software tool, study was conducted. 100 patients selected from the outpatient clinics were divided into two groups based on the ages of 20–40 years and 41–60 years with equal ratio of males and females. Each selected patient's maxillary arch was scanned with intraoral scanner; images so obtained were sectioned in anteroposterior cross section and with the 3D analysis software; the angulation between hard and soft palate was determined.

Results

The prevalence of type II soft palate (angulation between hard and soft palate is between 10 and 45 degrees) was highest, 60% in group 1 and 44% in group 2. The difference between genders was statistically significant with p value <0.05 in both the groups, although females had higher angulation compared to the males in all classes of both groups.

Conclusions

In targeted population of Aseer Province, Saudi Arabia, the prevalence of type II soft palate was more common, with higher soft palate angulation among females. The advanced age had no effect in the type of soft palate in the region.

Effect of Clark's twin-block appliance (CTB) and non-extraction fixed mechano-therapy on the pharyngeal dimensions of growing children

Introduction:

Narrow airway dimensions due to mandibular deficiency can predispose an individual to severe respiratory distress. Hence, treatment with mandibular advancement devices at an early age might help improving the pharyngeal passage and reduce the risk of respiratory difficulties. Therefore, the aim of the current study was to evaluate the mean changes in the pharyngeal dimensions of children with mandibular deficiency treated with Clark's twin-block appliance (CTB) followed by fixed orthodontic treatment.

Methods:

Orthodontic records of 42 children with mandibular deficiency were selected. Records comprised three lateral cephalograms taken at the start of CTB treatment, after CTB removal and at the end of fixed appliance treatment, and were compared with 32 controls from the Bolton-Brush study. Friedman test was used to compare pre-treatment, mid-treatment and post-treatment pharyngeal dimensions. Wilcoxon signed rank test was used to compare the airway between pre-treatment and post follow-up controls. Mann-Whitney U test was applied to compare the mean changes in pharyngeal dimensions between treatment group and controls from T₂ to T₀. Post-hoc Dunnet T3 test was used for multiple comparisons of treatment outcomes after CTB and fixed appliances, taking a p-value of ≤ 0.05 as statistically significant.

Results:

Superior pharyngeal space (p < 0.001) and upper airway thickness (p = 0.035) were significantly increased after CTB, and the change in superior pharyngeal space remained stable after fixed mechano-therapy.

Conclusion:

CTB can have a positive effect in improving pharyngeal space and the resultant increase in airway remains stable on an average of two and a half years.

Difficult airway management in a patient with a thin mandible

A 47-year-old woman was referred for surgical treatment of osteomyelitis of the mandible. She had already undergone three previous surgeries. Pre-anesthetic airway evaluation predicted a difficult airway, due to the thin, retro-positioned mandible, tongue, and atrophic changes in the lips and soft tissue. We inserted packing gauzes in the buccal mucosa for easier mask fitting and ventilation. During direct laryngoscopic intubation with a nasotracheal tube (NTT), fracture of a thin mandible can easily occur. Therefore, we used a fiberoptic bronchoscope to insert the NTT. After surgery, we performed a tongue-tie to protect against airway obstruction caused by the backward movement of the tongue during recovery. The patient recovered without any complications. We determined the status of the patient precisely and consequently performed thorough preparations for the surgery, allowing the patient to be anesthetized safely and recover after surgery. Careful assessment of the patient and airway prior to surgery is necessary.

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

Purpose

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

Materials and Methods

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

Results

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

Conclusion

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

Upper airway changes following single-step or stepwise advancement using the Functional Mandibular Advancer

OBJECTIVES

Purpose of the present study was to determine and compare possible changes in the dimensions of the pharyngeal airway, morphology of the soft palate, and position of the tongue and hyoid bone after single-step or stepwise mandibular advancement using the Functional Mandibular Advancer (FMA).

PATIENTS AND METHODS

The sample included 51 peak-pubertal Class II subjects. In all, 34 patients were allocated to two groups using matched randomization: a single-step mandibular advancement group (SSG) and a stepwise mandibular advancement group (SWG). Both groups were treated with FMA followed by fixed appliance therapy; the remaining 17 subjects who underwent only fixed appliance therapy constituted the control group (CG). The study was conducted using pre- and posttreatment lateral cephalometric radiographs. Data were analyzed by paired t test, one-way analysis of variance, and Pearson's correlation coefficient.

RESULT

In the SWG and SSG, although increases in nasopharyngeal airway dimensions were not significant compared with those in the CG, enlargements in the oropharyngeal airway dimensions at the level of the soft palate tip and behind the tongue, and decreases in soft palate angulation, were significant. Tongue height increased significantly only in the SWG. Compared with the CG, while forward movement of the hyoid was more prominent in SSG and SWG, the change in the vertical movement of the hyoid was not significant. No significant difference between SWG and SSG was observed in pharyngeal airway, soft palate, tongue or hyoid measurements.

CONCLUSIONS

The mode of mandibular advancement in FMA treatment did not significantly affect changes in the pharyngeal airway, soft palate, tongue, and hyoid bone.

Three-dimensional analyses of palatal morphology and its relation to upper airway area in obstructive sleep apnea

OBJECTIVE

To evaluate the relationship between palatal morphology and pharyngeal airway morphology in patients who have obstructive sleep apnea (OSA) and compare with a nonsnoring and nonapneic control group.

MATERIALS AND METHODS

Three-dimensional maxillary dental cast measurements from 25 OSA patients (6 women, 19 men) with a mean age of 41.5 (4.8) years, and 25 control group participants (14 women, 11 men) without any symptom of OSA with a mean age of 38.3 (3.7) were correlated with an analysis of pharyngeal area evaluated with lateral cephalograms. Intermolar and intercanine widths and palatal volumes were calculated on the dental casts, and the upper airway area measurements were performed on lateral cephalograms.

RESULTS

OSA patients had smaller oropharyngeal volume and upper airway when compared with controls (P < .001). Palatal area measurements were significantly smaller in OSA (P < .001). OSA patients had significantly narrower maxilla with smaller intermolar and intercanine widths (P < .001). A positive correlation was found between the palatal morphology and pharyngeal dimensions.

CONCLUSIONS

A significant correlation exists between palatal morphology and pharyngeal airway.

Cephalometric oropharynx and oral cavity analysis in Chiari malformation Type I: a retrospective case-control study

OBJECTIVE Traditionally, Chiari malformation Type I has been related to downward herniation of the cerebellar tonsils as a consequence of an underdeveloped posterior cranial fossa. Although the common symptoms of Chiari malformation Type I are occipital headaches, cervical pain, dizziness, paresthesia, and sensory loss, patients often report symptoms related to pharyngeal dysfunction such as choking, regurgitation, dysphagia, aspiration, chronic cough, and sleep disorders. In addition, tracheal intubation is often difficult in these patients. The purpose of this study was to analyze the morphological features of the oropharynx and oral cavity in patients with Chiari malformation Type I to help identify underlying anatomical anomalies leading to these debilitating symptoms. METHODS Seventy-six adult patients with symptomatic Chiari malformation Type I with cerebellar tonsillar descent greater than 5 mm below the foramen magnum and a small posterior cranial fossa and 49 sex-matched controls were selected to perform a retrospective case-control MRI-based morphometric study in a tertiary hospital. Eleven linear and areal parameters of the oropharyngeal cavity on midsagittal T1-weighted MRI were measured and the average values between patients and control cohorts were compared. Correlations between variables showing or approaching statistical significance in these structures and posterior cranial fossa measurements related with the occipital bone were sought. RESULTS Significant differences were detected for several oropharynx and oral cavity measures in the patient cohort, primarily involving the length and thickness of the soft palate (p = 9.5E-05 and p = 3.0E-03, respectively). A statistically significant (p < 0.01) moderate correlation between some of these variables and posterior cranial fossa parameters was observed. CONCLUSIONS The existence of structural oropharyngeal and oral cavity anomalies in patients with Chiari malformation Type I was confirmed, which may contribute to the frequent occurrence of respiratory and deglutitory complications and sleep disorders in this syndrome.

A Focus on Variation in Morphology of Soft Palate Using Cone-Beam Computed Tomography with Assessment of Need's Ratio in Central Madhya Pradesh Population

INTRODUCTION

Soft palate is an anatomical structure that helps in modifying the quality of voice and to breathe while swallowing. Through the variants and shapes of the soft palate, we can assess the age and gender of an individual.

AIM

The aim of the present study was to investigate the variation in morphology of soft palate and to find its association with the Need's ratio, Velar Length (VL), Velar Width (VW) and Pharyngeal Depth (PD), in age groups and gender using CBCT in Central Madhya Pradesh population.

MATERIALS AND METHODS

The study sample consisted of 121 CBCT scans of individuals aged between 15 to 45 years. These scans were retrieved from the Department of Oral Radiology. The velar morphology on CBCT was examined and grouped into six types. The results obtained were subjected to a statistical analysis to find the association between variants of the soft palate with gender and different age groups. ANOVA and Z-test were used for statistical analysis. The p≤0.05 was considered as significant while p≤0.001 was considered as highly significant.

RESULTS

The most frequent type of soft palate was rat tail shaped. The mean VL and VW values were significantly higher in males while PD and Need's ratio were higher among females, insignificantly associated with the types of soft palate. A significant association was observed between the mean VL and VW with various age groups, showing an increase in values with an increase in age.

CONCLUSION

A variation in morphology of soft palate plays an important role in the assessment of velopharyngeal closure and in diagnosing obstructive sleep apnoea individuals.

Computed tomography cephalometric and upper airway measurements in patients with OSA and erectile dysfunction

PURPOSE

Erectile dysfunction (ED) has been linked to obstructive sleep apnea (OSA). This study used computed tomography (CT) to identify cephalometric and upper airway anatomic features in patients with OSA that correlate with the presence of ED.

METHODS

In this prospective study, 20 CT cephalometric and upper airway measurements, most commonly associated with OSA, were analyzed in 53 age- and BMI-matched consecutive eligible subjects. Twenty-two were diagnosed with OSA and ED (OSA+/ED+), 17 with OSA without ED (OSA+/ED-), and 14 without OSA and ED (OSA-/ED-) serving as a control group.

RESULTS

Although OSA+/ED+ did not differentiate significantly in CT measurements from OSA+/ED-, they showed more alterations when compared to OSA-/ED-, which included narrower bony oropharynx, longer soft palate and uvula (PNS-P), and narrower retropalatal and retrolingual airway diameter (p < 0.05). Binary forward stepwise model analysis showed that PNS-P was the only significant variable in the predictive model for ED in patients with OSA (OR = 1.129, 95 % CI = 1.0005-1.268, p = 0.041). In the OSA+/ED+ group, PNS-P correlated with the percentage of total sleep time with oxygen saturation <90 % (r = 0.61, p < 0.01) and was the only determinant in the relevant predictive model (n = 22, model R = 0.612, adjusted R (2) = 0.337, F = 10.167, p < 0.005).

CONCLUSIONS

Characteristics of the craniofacial and upper airway structures suggest that a longer soft palate and uvula may be important risk factors for the concurrence of ED in patients with OSA. Only OSA+/ED+ showed significant narrowing in the retropalatal, retrolingual, and bony oropharynx level when compared with BMI-matched OSA-/ED-.

Lateral teleradiography of the head as a diagnostic tool used to predict obstructive sleep apnea

OBJECTIVES

To (1) assess the relationship between obstructive sleep apnea (OSA) and craniofacial, pharyngeal anatomy and (2) to submit the recommendations for clinicians for increasing the sensitivity in the diagnostics of OSA.

METHODS

A review of the relevant literature linking OSA in adults with cephalometric analysis was performed. In total, 11 articles with similar procedural criteria were selected. The data were analysed using the Comprehensive Meta-Analysis Software (Biostat Inc., Englewood, NJ) and Statistica 12.0 (StatSoft Inc., Dell Software, Tulsa, OK).

RESULTS

Adults with OSA did not show statistically significant differences in the sagittal and vertical skeletal planes in comparison with the controls (p > 0.05). The patients with OSA had soft palate length, width and area increased accordingly by 4.21, 1.99 mm and 0.86 cm(2), tongue area increased by 2.02 cm(2), the upper posterior pharyngeal space (SPAS) and lower posterior pharyngeal space reduced accordingly by 4.53 and 1.32 mm, mandibular plane to the hyoid bone (MP-H) distance increased by 4.14 mm compared with the controls (p < 0.05). The SPAS parameter of the patients with OSA did not show statistically significant differences between the studies, with the mean value being 5.69 mm.

CONCLUSIONS

Analysed cephalometric data totally supported the concept of soft-tissue abnormalities in subjects with OSA, skeletal-only halfway; MP-H and SPAS being the most reliable parameters. Increased MP-H may serve as a predictor when differentiating normal subjects and patients with OSA. Reduced SPAS width could be a prognostic parameter for suspecting OSA. These two values should be kept in mind by dentists and can also be used as a simple auxiliary method by physicians; nevertheless, it is still underestimated and more studies are needed.

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.

Comparative analysis of upper airway volume with lateral cephalograms and cone-beam computed tomography

INTRODUCTION

In this study, we aimed to evaluate the adenoidal nasopharyngeal ratio (ANR) on lateral cephalograms by assessing upper airway volumes using cone-beam computed tomography (CBCT) images as the validation method.

METHODS

Fifty-five patients were included in the study, and it was essential that the lateral cephalograms and CBCT images taken at their examinations were not more than 1 week apart. There were 32 subjects in group A (age ≤15 years) and 23 subjects in group B (age >15 years). The ANR was measured on the lateral cephalograms. The area and volumetric measurements of the nasopharynx and the total upper airway were obtained from CBCT images. Repeated measurements of the ANR and airway volume were performed on 10 subjects by 2 observers.

RESULTS

Group A had a higher correlation (r = -0.78) between the ANR and the nasopharynx volume than did group B (r = -0.57). The ANR had a weak correlation with the total upper airway volume (group A, r = -0.48; group B, r = -0.32). Both measurements made on lateral cephalograms and CBCT were highly reproducible in terms of intraobserver and interobserver agreement.

CONCLUSIONS

Based on our results, the measurement of the ANR on lateral cephalograms can be used as an initial screening method to estimate the nasopharynx volumes of younger patients (age ≤15 years).

Cephalometric and anthropometric data of obstructive apnea in different age groups

INTRODUCTION

Patients with obstructive sleep apnea syndrome usually present with changes in upper airway morphology and/or body fat distribution, which may occur throughout life and increase the severity of obstructive sleep apnea syndrome with age.

OBJECTIVE

To correlate cephalometric and anthropometric measures with obstructive sleep apnea syndrome severity in different age groups.

METHODS

A retrospective study of cephalometric and anthropometric measures of 102 patients with obstructive sleep apnea syndrome was analyzed. Patients were divided into three age groups (≥20 and <40 years, ≥40 and <60 years, and ≥60 years). Pearson's correlation was performed for these measures with the apnea-hypopnea index in the full sample, and subsequently by age group.

RESULTS

The cephalometric measures MP-H (distance between the mandibular plane and the hyoid bone) and PNS-P (distance between the posterior nasal spine and the tip of the soft palate) and the neck and waist circumferences showed a statistically significant correlation with apnea-hypopnea index in both the full sample and in the ≥40 and <60 years age group. These variables did not show any significant correlation with the other two age groups (<40 and ≥60 years).

CONCLUSION

Cephalometric measurements MP-H and PNS-P and cervical and waist circumferences correlated with obstructive sleep apnea syndrome severity in patients in the ≥40 and <60 age group.

A 2-year follow-up of changes after bimaxillary surgery in patients with mandibular prognathism: 3-dimensional analysis of pharyngeal airway volume and hyoid bone position

PURPOSE

The aims of this study were to use 3-dimensional cone-beam computed tomography (CBCT) to evaluate how the upper airway and hyoid bone position changed after orthognathic surgery in patients with skeletal Class III malocclusions and to analyze the relations among upper airway changes, the change in the position of the hyoid bone, and postsurgical stability.

MATERIALS AND METHODS

CBCT scans were obtained from 15 patients with mandibular prognathism before surgery (T0), 6 months after surgery (T1), 1 year after surgery (T2), and 2 years after surgery (T3). Positional displacement of the hyoid bone was assessed using the coordinates at T0, T1, T2, and T3. In addition, the volume of each patient's pharyngeal airway was measured. Differences in CBCT scans at the established time points were determined by the Wilcoxon signed rank test. The Spearman correlation coefficient was used to determine the relations among changes in hyoid bone position, airway volume, and skeletal reference points.

RESULTS

The hyoid bone moved backward at 6 months after surgery (T0 to T1), and the total volume of the pharyngeal airway was considerably decreased at the same time points. At 1 year after surgery (T1 to T2), although the hyoid moved more posteriorly and the total volume of the pharyngeal airway was decreased, the changes were not major. At 2 years after surgery, the hyoid bone moved anteriorly and the size of the upper pharyngeal airway was increased (T2 to T3).

CONCLUSION

The hyoid bone moved posteriorly and the pharyngeal airway volume was decreased at 6 months after bimaxillary surgery. These measurements had a tendency to recover at 2 years postoperatively. The decrease in pharyngeal airway volume was not correlated with positional changes of the hyoid bone.

The relationship between upper airways and craniofacial morphology studied in 3D. A CBCT study

OBJECTIVES

To assess whether morphology and dimension of the upper airway differ between patients characterized by various craniofacial morphology.

SETTING AND SAMPLE POPULATION

Ninety young adult patients from the Postgraduate Clinic, Section of Orthodontics, Department of Dentistry, Health, Aarhus University, Denmark, with no obvious signs of respiratory diseases and no previous adeno-tonsillectomy procedures. Thirty patients were characterized as Class I (-0.5 < ANB < 4.5), 30 as Class II (ANB > 4.5), and 30 as Class III (ANB < -0.5).

MATERIAL AND METHODS

Cone-beam computed tomography (CBCT) scans obtained in a supine position for all patients. Cephalometric landmarks were identified in 3D. Sagittal and transversal dimensions, cross sections, and partial and total volumes of the upper airway were correlated with the cephalometric measurements in all three planes of space. The cross-sectional minimal area of the upper airway was assessed as well.

RESULTS

No statistical significant relationships between dimension and morphology of upper airways and skeletal malocclusion were found.

CONCLUSION

Differences in craniofacial morphology as identified by the sagittal jaw relationship were not correlated with variation in upper airway volumes. A clinical significant relation was detected between minimal area and total upper airway volume.

Correlation of morphological variants of the soft palate and Need's ratio in normal individuals: A digital cephalometric study

Purpose

The present study was aimed to investigate the variation of soft palate morphology in different age and gender groups. The correlations of radiographic velar length (VL), velar width (VW), pharyngeal depth (PD), and Need's ratio with soft palate variants were also studied in the North Indian subpopulation.

Materials and Methods

The study sample consisted of 300 subjects aged between 15 and 45 (mean: 31.32) years. The velar morphology on lateral cephalograms was examined and grouped into six types. The results obtained were subjected to a statistical analysis to find the correlation between variants of the soft palate with gender and different age groups.

Results

The most frequent type of soft palate was leaf shaped (48.7%), and the least common was crook shaped (3.0%) among both the genders and various age groups, showing a significant correlation. The mean VL, VW, and PD values were significantly higher in males and significantly correlated with the types of soft palate. A significant correlation was observed between the mean VL, VW, PD, and Need's ratio with various age groups, showing an inconsistent pattern with an increase in age. The types of soft palate, gender, and Need's ratio were also significantly correlated, with an overall higher mean value of the Need's ratio among female subjects and the S-shaped soft palate.

Conclusion

The knowledge of a varied spectrum of velar morphology and the variants of the soft palate help in a better understanding of the velopharyngeal closure and craniofacial anomalies.

CBCT evaluation of the upper airway morphological changes in growing patients of class II division 1 malocclusion with mandibular retrusion using twin block appliance: a comparative research

Objective

The purpose of this study was to evaluate the morphological changes of upper airway after Twin Block (TB) treatment in growing patients with Class II division 1 malocclusion and mandibular retrusion compared with untreated Class II patients by cone beam computed tomography (CBCT).

Materials and Methods

Thirty growing patients who have completed TB treatment were recruited into TB group. The control group (n = 30) was selected from the patients with the same diagnosis and without TB treatment. CBCT scans of the pre-treatment (T1) and post-treatment (T2) data of TB group and control data were collected. After three-dimensional (3D) reconstruction and registration of T1 and T2 data, the morphological changes of upper airway during TB treatment were measured. The statistical differences between T1 and T2 data of TB group as well as T2 and control data were accessed by t-test.

Results

During the TB treatment, the mandible moved advanced by 3.52±2.14 mm in the horizontal direction and 3.77±2.10 mm in the vertical direction. The hyoid bone was in a more forward and inferior place. The upper airway showed a significant enlargement in nasopharynx, oropharynx and hypopharynx. In addition, the nasopharynx turned more circular, and the oropharynx became more elliptic in transverse shape. However, the transverse shape of the hypopharynx showed no significant difference. After comparison between T2 and control data, only the horizontal movement of the hyoid bone, the volumetric expansion of the oropharynx and hypopharynx, and changes of the oropharyngeal transverse shape showed significant difference.

Conclusion

Compared to the untreated Class II patients, the upper airway of growing patients with Class II division 1 malocclusion and mandibular retrusion showed a significant enlargement in the oropharynx and hypopharynx as well as a more elliptic transverse shape in the oropharynx, and the hyoid bone moved to an anterior position after TB treatment.

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.

Comparison of cone-beam computed tomography incidental findings between patients with moderate/severe obstructive sleep apnea and mild obstructive sleep apnea/healthy patients

OBJECTIVE

The objective of this study was to compare the incidental radiographic findings in the maxillofacial structures and the pharyngeal airway between subjects with moderate/severe obstructive sleep apnea (OSA) and mild OSA/healthy subjects using cone-beam computed tomography (CBCT) scans.

STUDY DESIGN

A total of 53 subjects with moderate/severe OSA (with a Respiratory Disturbance Index [RDI] ≥ 15 events/h) and 33 mild OSA/healthy subjects (RDI < 15), based on ambulatory somnographic assessment, were recruited. Supine CBCTs were taken and sent for radiological report. The incidental findings were compared between the 2 groups.

RESULTS

Moderate/severe subjects had larger prevalence of conchae bullosa, hypertrophic turbinates, hypertrophic tonsils, elongated or posteriorly placed soft palate, narrower airway, enlarged tongue, and focal calcifications, although no significant differences were found.

CONCLUSIONS

CBCT is useful in identifying maxillofacial and airway anomalies that could interfere with normal breathing; however, no significant difference was found in prevalence of incidental findings between subjects with moderate/severe OSA and mild OSA/healthy subjects. Further studies are necessary to generalize our results.

Changes in the upper and lower pharyngeal airway spaces associated with rapid maxillary expansion

Objectives. The primary objectives of this retrospective study were first to compare the upper and lower pharyngeal airway spaces between orthodontic patients with and without maxillary constriction and second to evaluate the effect of rapid maxillary expansion (RME) on these airway spaces. A secondary objective was to compare the mode of breathing between groups. Materials and Methods. The experimental (RME) group consisted of 30 patients (mean age, 14.2 ± 1.3 years, 16 boys and 14 girls) with maxillary constriction who were treated with hyrax-type RME. The control group comprised the records of age- and gender matched patients (mean age, 13.8 ± 1.5 years, 16 boys and 14 girls) with no maxillary constriction but requiring nonextraction comprehensive orthodontic treatment. Cephalometric measurements in the sagittal dimension of upper and lower airway spaces for the initial and final records were recorded. Mode of breathing and length of treatment were also compared. Results. The sagittal dimension of the upper airway increased significantly in the RME group (mean = 1.3 mm) compared to the control group (mean = 0.5 mm), P = 0.016. However, there was no significant difference in the lower pharyngeal airway measurement between the RME group (mean = 0.2) and the control group (mean = 0.4), P = 0.30. There was no significant difference with respect to mode of breathing between the two groups (P = 0.79). Conclusion. Rapid maxillary expansion (RME) during orthodontic treatment may have a positive effect on the upper pharyngeal airway, with no significant change on the lower pharyngeal airway.

Measurements of normal upper airway assessed by 3-dimensional computed tomography in Chinese children and adolescents

OBJECTIVE

To establish normative data of upper airway dimensions in Chinese children and adolescents by age and sex.

METHODS

CT-scans of 281 Chinese children and adolescents (140 girls, 141 boys) aged from 6 to 18 years (yr) were selected among the patients who visited in Department of Oral and Maxillofacial Surgery from September 2009 to August 2010. Child was defined as 6-12 yr, and adolescent as 13-18 yr. All the subjects were divided into 4 groups according to age as 6-9, 10-12, 13-15 and 16-18. The upper airway was divided into four distinct anatomic regions: the nasopharynx, the palatopharynx, the glossopharynx and the epiglottic region. Using 3-dimension image processing software, the minimal cross-sectional area with its sagittal diameter and transversal diameter, length and volume of upper airway segmentations were measured.

RESULTS

There was no difference in all parameters of segmentations between genders in children. In adolescents the differences of airway parameters were evident between genders. Male adolescents' upper airway were bigger and longer than female's. Volumes and lengths of segmentations were increased with age in male and female respectively.

CONCLUSIONS

Norms for upper airway in Chinese children and adolescents assessed by 3-D reconstruction computed tomography have been established. Volume and other dimension of upper airway are increased with age. Significant sex dimorphisms in upper airway dimension are evident in adolescents.

Airway volume for different dentofacial skeletal patterns

INTRODUCTION

Our objective was to evaluate the nasal passage (NP) and oropharyngeal (OP) volumes of patients with different dentofacial skeletal patterns.

METHODS

The study sample consisted of 140 patients (70 boys, 70 girls), divided into 3 groups as Class I (1 ≤ ANB ≤ 3), Class II (ANB > 3), and Class III (ANB < 1), and then further divided into 4 groups as SNA angle ≥ 80°, SNA angle <80°, SNB angle ≥78°, and SNB angle < 78° to evaluate how the positional changes in the maxilla and the mandible affect the OP and NP variables. Differences between groups were determined by using the Kruskal-Wallis test. Correlations between the variables were tested with the Spearman correlation coefficient. The linear multiple regression test was applied to create a model for the airway volumes separately.

RESULTS

The OP volume of the Class II subjects (n = 50) was significantly lower when compared with that of the Class I (n = 46) and Class III subjects (n = 44). The only statistically significant difference for NP volume was observed between the Class I and Class II groups. The mean OP airway volume of subjects with retruded mandibular positions was statistically significantly smaller when compared with the subjects with higher SNB angles. The area of the most constricted region at the base of the tongue (minAx) had a high potential in explaining the OP volume, whereas the NP volume models were not as successful as the OP counterpart. However, minAx was also entered into the NP volume equations as an explanatory variable.

CONCLUSIONS

The OP airway volumes of Class II patients were smaller when compared with Class I and Class III patients. It was observed that mandibular position with respect to cranial base had an effect on the OP airway volume. The only significant difference for the NP volume was between the Class I and Class II groups, with a smaller volume observed for the Class II group.

Orofacial airway dimensions in subjects with Class I malocclusion and different growth patterns

OBJECTIVE

To test the null hypotheses that there are no significant differences in craniofacial structures and orofacial airway dimensions in subjects with Class I malocclusion and different growth patterns.

MATERIALS AND METHODS

Lateral cephalometric radiographs of 31 low angle (mean age, 14.0 ± 2.0 years; range, 10.3-16.5 years), 40 high angle (mean age, 12.7 ± 1.6 years; range, 10.1-16.2 years), and 33 normal growth (mean age, 13.9 ± 1.3 years; range, 11.2-16.8 years) subjects with Class I malocclusion were examined. In total, 34 measurements (27 craniofacial and 7 orofacial airways) were evaluated. Groups were constituted according to the SN-MP angle. Group differences were analyzed with analysis of variance (ANOVA) and the Tukey test, at the P < .05 level.

RESULTS

According to ANOVA, only 5 of the 27 craniofacial measurements showed no statistically significant differences among different growth patterns. For orofacial airway measurements, statistically significant differences were found in nasopharyngeal airway space (P < .01), palatal tongue space (P < .05), upper posterior airway space (PAS) (P < .05), and tongue gap (P < .001). No statistically significant orofacial airway differences were determined between low angle and normal growth subjects. High angle subjects had a larger tongue gap than those with normal and low angles (P < .01). Additionally, nasopharyngeal airway space (P < .01) and upper PAS (P < .05) measurements were larger and palatal tongue space (P < .05) was narrower in low angle than in high angle subjects.

CONCLUSIONS

The null hypotheses were rejected. Significant differences in craniofacial morphology and orofacial airway dimensions of Class I subjects with different growth patterns were identified.

Interaction between otorhinolaryngology and orthodontics: correlation between the nasopharyngeal airway and the craniofacial complex

In terms of pathophysiology, an anatomically narrow airway is a predisposing factor for obstruction of the upper respiratory tract. The correlation between the nasopharyngeal airway and the craniofacial structures is discussed in this context. Thus a mutual interaction between the pharynx and the mandibular position was demonstrated, whereby the transverse dimension of the nasopharynx was significantly larger in patients with prognathism than in patients with retrognathism. The influence of chronic obstruction of the nasal airway on craniofacial development was also discussed. The form-and-function interaction, which ought to explain the causal relationship between nasal obstruction and craniofacial growth, appears to be of a multifactorial rather than a one-dimensional, linear nature. It is not disputed, however, that expanding the maxilla improves not only nasal volume and nasal flow, but also the subjective sensation of patients, although it is not possible to make a prognostic statement about the extent of this improvement because of the differing reactions of individuals. Orthodontic appliances for advancing the mandible can also be successfully used in the treatment of mild obstructive sleep apnea syndrome. This treatment method should be considered particularly for patients who are unwilling to undergo or cannot tolerate CPAP (continuous positive airway pressure) treatment.

Craniofacial changes after 2 years of nasal continuous positive airway pressure use in patients with obstructive sleep apnea

BACKGROUND

Many patients with obstructive sleep apnea (OSA) use nasal continuous positive airway pressure (nCPAP) as a first-line therapy. Previous studies have reported midfacial hypoplasia in children using nCPAP. The aim of this study is to assess the craniofacial changes in adult subjects with OSA after nCPAP use.

METHODS

Forty-six Japanese subjects who used nCPAP for a minimum of 2 years had both a baseline and a follow-up cephalometric radiograph taken. These two radiographs were analyzed, and changes in craniofacial structures were assessed. The cephalometric measurements evaluated were related to face height, interarch relationship, and tooth position.

RESULTS

Most of the patients with OSA were men (89.1%), and the mean baseline values for age, BMI, and apnea-hypopnea index (AHI) were 56.3 ± 13.4 years, 26.8 ± 5.6 kg/m(2), and 42.0 ± 18.6/h. The average duration of nCPAP use was 35.0 ± 6.7 months. After nCPAP use, cephalometric variables demonstrated a significant retrusion of the anterior maxilla, a decrease in maxillary-mandibular discrepancy, a setback of the supramentale and chin positions, a retroclination of maxillary incisors, and a decrease of convexity. However, significant correlations between the craniofacial changes, demographic variables, or the duration of nCPAP use could not be identified. None of the patients self-reported any permanent change of occlusion or facial profile.

CONCLUSION

The use of an nCPAP machine for > 2 years may change craniofacial form by reducing maxillary and mandibular prominence and/or by altering the relationship between the dental arches.

Soft palate length and upper airway relationship in OSA and non-OSA subjects

BACKGROUND

The narrowest area of the airway between the posterior nasal opening and the epiglottis is usually located in the retro palatal area. Many consider this the most likely site of airway obstruction during an obstructive sleep apnea (OSA) event. The aim of this study was to investigate the differences in soft palate and airway length between OSA and non-OSA patients.

METHODS

In this study, we analyzed the ratio of the soft palate and the upper airway length in 45 consecutive patients. Twenty-five had an Apnea-Hypoapnea Index of more than five events per hour and were classified in the OSA group (male, 19; female, 6). These patients were compared with 20 normal controls (male, 12; female, 8). Controls who complained of snoring did have sleep studies (n=5). The other fifteen controls were clinically asymptomatic and did not have sleep studies. Medical computed tomography scans were taken to determine the length of the upper airway and the soft palate length measured in the midsagittal image.

RESULTS

Soft palate length was significantly larger in OSA patients compared to controls (p=0.009), and in men compared to women (p=0.002). However, there were no differences in airway length. The soft palate length, as a percent of oropharyngeal airway length, was significantly larger in OSA patients compared to controls (p= <0.0001) and in men compared to women (p=0.02). Soft palate length increases significantly with age by 0.3 mm per year in males (after adjustment for body mass index (BMI) and OSA). Soft palate length as a percent of airway length is larger in OSA patients and increases significantly with BMI in males only after adjusting for age.

CONCLUSION

In this study, OSA patients had a longer soft palate in proportion to their oropharyngeal airway compared to controls as well as men compared to women. This proportion could be used for identifying patients at risk for OSA in combination with age.

Three-dimensional cephalometric study of upper airway space in skeletal class II and III healthy patients

Because the pharynx and the dentofacial structures have close relationship, a mutual interaction can be expected to occur between them. The literature presents skeletal malocclusion as etiology for airway morphology changes and/or vice versa. The present three-dimensional cephalometric study from computed tomography scans was carried out to investigate upper airway space in normal nasal breathing patients presenting skeletal pattern of classes II and III. In addition, the statistical analysis was done according to gender criterion. The results revealed that the majority of the airway measurements have not been affected by type of malocclusion. The three-dimensional technology used in this study also allowed the volume and surface area calculations, and no statistical significance was found. The retroglossal width and posterior nasal cavity height mean were larger in males than females in the class II group, but volume and cross-section area were not statistically significant. However, in class III group, although the differences in linear and angular measures means were not significant, the retropalatal volume and retroglossal volume and cross-section area were larger in males. The authors highlight that the evaluation of upper airway space should be an integral part of diagnosis and treatment planning to achieve functional balance and stability of the results.

Can facial type be used to predict changes in hyoid bone position with age? A perspective based on longitudinal data

INTRODUCTION

Low positioning of the hyoid bone is associated with the unique human ability of speech, but it might also predispose the airway to collapse. The low position of the hyoid bone has been studied in adults with sleep apnea. However, information on age-related changes in hyoid bone position in the general adult population is sparse.

METHODS

We used pairs of lateral cephalometric radiographs taken 15 years apart to assess vertical changes over time in hyoid position in 163 normal white men (ages, 30-72 years).

RESULTS AND CONCLUSIONS

Significant changes in hyoid bone position were independent of age or obesity but were related to facial type, as classified by the steepness of the lower margin of the mandible. Changes in hyoid position over time were significant in dolichofacial subjects but not in brachyfacial subjects. This finding might be particularly important because a low hyoid bone with a brachial face appears to be a morphologic characteristic of nonobese patients with severe obstructive sleep apnea.

Morphological variety of the soft palate in normal individuals: a digital cephalometric study

OBJECTIVES

The literature describes the morphology of the soft palate as being of only one kind and ignores its diversity, but in our clinical work we discovered that the morphology of the soft palate has a variable presentation on lateral cephalometry. The aim of our study was to investigate the variation of the velar morphology.

METHODS

In this study, the sample comprised 200 normal subjects whose ages ranged from 5-48 years (mean 19.37 years). The morphology of the soft palate on lateral cephalometry was examined and classified into six types. The dimensional differences of the soft palate between each pair of types and the differences in proportion to different age and gender groups were also studied.

RESULTS

The morphology of the soft palate was classified into six types. There was a significant difference between the pre-adult and adult groups and also between male and female groups in proportion to velar type. The velar length in Type 3 was significantly shorter than in all other types apart from Type 6. However, there was no significant difference between any two of the other 5 types.

CONCLUSIONS

The soft palate has variable radiographic appearances on lateral cephalometry. The classification system and statistical findings here may help the research of velopharyngeal closure in cleft palate individuals, and aetiological study of obstructive sleep apnoea syndrome and other conditions.

Gender- and age-based differences in computerized tomographic measurements of the orophaynx

OBJECTIVE

Our aim was to examine the influence of aging and body mass index (BMI) on the oropharynx configuration in male and female Japanese patients.

STUDY DESIGN

This study examined the computerized tomography (CT) images of 19 man and 19 women, group matched for age and BMI. The airway and the soft tissue volumes between the posterior nasal spine and top of the epiglottis were compared.

RESULTS

The patients' height, total oropharynx length (TOL), and lower oropharynx lengths and volume measurements (soft tissue and airway) demonstrated statistically significant gender differences. Men consistently had larger TOL and volumes than women. In men, TOL changed with age, and age was a significant predictor of lower oropharynx length. In men, the upper oropharynx soft tissue volume decreased significantly with age and lower oropharynx soft tissue volume increased significantly with age. In women, no significant relationship was identified.

CONCLUSION

The airway lengthens with aging in males and we speculate that it becomes more collapsible, which in turn could contribute to obstructive sleep apnea.