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

Oropharyngeal complex differences related to sex and occlusal factors in adolescents aged 12-17 years

OBJECTIVE

To investigate oropharyngeal complex differences related to sex and occlusal factors in adolescents.

METHODS

A cross-sectional study was conducted with 108 patients aged 12-17 years. The oropharyngeal complex was evaluated by imaging exams. Occlusal variables included molar relationship, facial growth pattern, maxilla shape, tooth loss, anterior crossbite, and anterior open bite. Statistical analysis included independent t-test, Mann-Whitney, ANOVA, and Kruskal-Wallis tests. The significance level was 5%.

RESULTS

There were increases of the tongue measurement (p = 0.026) and the hyoid approach at the base of the mandible among boys (p = 0.016) and the distance from the hyoid at the base of the mandible among girls (p = 0.039). There was shortening of the soft palate measurements (p = 0.003 and p = 0.007) and tongue (p = 0.018) among adolescents with an anterior crossbite.

CONCLUSION

Findings suggest sex, age, and anterior crossbite can be related to oropharyngeal morphology.

Anatomic development of the upper airway during the first five years of life: A three-dimensional imaging study

PURPOSE

Normative data on the growth and development of the upper airway across the sexes is needed for the diagnosis and treatment of congenital and acquired respiratory anomalies and to gain insight on developmental changes in speech acoustics and disorders with craniofacial anomalies.

METHODS

The growth of the upper airway in children ages birth to 5 years, as compared to adults, was quantified using an imaging database with computed tomography studies from typically developing individuals. Methodological criteria for scan inclusion and airway measurements included: head position, histogram-based airway segmentation, anatomic landmark placement, and development of a semi-automatic centerline for data extraction. A comprehensive set of 2D and 3D supra- and sub-glottal measurements from the choanae to tracheal opening were obtained including: naso-oro-laryngo-pharynx subregion volume and length, each subregion's superior and inferior cross-sectional-area, and antero-posterior and transverse/width distances.

RESULTS

Growth of the upper airway during the first 5 years of life was more pronounced in the vertical and transverse/lateral dimensions than in the antero-posterior dimension. By age 5 years, females have larger pharyngeal measurement than males. Prepubertal sex-differences were identified in the subglottal region.

CONCLUSIONS

Our findings demonstrate the importance of studying the growth of the upper airway in 3D. As the lumen length increases, its shape changes, becoming increasingly elliptical during the first 5 years of life. This study also emphasizes the importance of methodological considerations for both image acquisition and data extraction, as well as the use of consistent anatomic structures in defining pharyngeal regions.

Do simultaneous mandibular advancement and temporomandibular joint prosthesis impact the upper airway in TMJ ankylosis patients?

Background

Ankylosis of the temporomandibular joint (TMJ) is a pathological disorder which results in patients’ limited or even complete failure of mouth opening. When TMJ ankylosis occurs during the growing age, moderate to severe micrognathia might be the proposed scenario of such cases, accompanied by obstructive sleep apnea and hypopnea syndrome (OSAHS). TMJ reconstruction using total TMJ prostheses with mandibular advancement (MA) can simultaneously improve the function and aesthetic profile of such patients. The purpose of this study was to determine whether the upper airway can be improved after TMJ reconstruction with total TMJ prostheses combined with or without MA in TMJ ankylosis patients.

Methods

Fourteen patients with pre-(T1) and post-(T2) operative CT scans were included. Patients were divided into two groups according to the operation with or without MA (MA/WoMA). The changes of the upper airway and jaw bones were comparatively analyzed within and between the two groups.

Results

In MA Group, the volume of the total upper airway (Vt) and palatopharynx (V1), together with the surface area (SA) of the total upper airway (SAt) and palatopharynx (SA1) increased significantly after the operation by 41.4%, 43.2%, 36.3% and 36.6%, respectively. In WoMA Group, V1, SAt and SA1 increased significantly by 21.0%, 19.0% and 23.1% following surgery. The changes of Point B (P<0.01), Y-axis angle (P<0.01), SNB (P<0.01), and ANB (P<0.01) were significantly greater in MA Group than in WoMA Group. Comparing both groups, the maxilla, and mandible were more backward in MA Group than in WoMA group before the operation, but there was no significant difference of the final position of the maxilla and mandible after the operation between both groups.

Conclusions

Release of TMJ ankylosis and condylar reconstruction using total joint prostheses simultaneously with MA could significantly improve the total volume and other various parameters of the upper airway, while, only the dimension of the palatopharynx increased in cases without MA.

Airways cephalometric norms from a sample of Caucasian Children

Background

The diagnosis of the respiratory pattern and the analysis of airway dimension using lateral cephalometric radiographs include the study of the adenoid region, free air space of the nasopharynx and oropharynx, soft palate and posterior part of the tongue. The objective of this study is to identify the airways cephalometric norms from a sample of Caucasian children, in relation to gender, age and type of malocclusion.

Material and Methods

A total of 480 patients of both sexes were included in the study, the age ranged between 6-12 years. The radiographic records were analyzed using the Nemoceph® 11.3.0 software and the diagnosis of skeletal class was performed using the Steiner analysis. The cephalometric measurements used for the study were PNS-AD1, AD1-Ba, PNS-Ba, Ptm-Ba, PNS-H and the upper and lower airways according to McNamara analysis. The comparative analysis was performed using only upper and lower airways variables.

Results

The mean values for each variable in the total sample were 23.2 mm (PNS-Ad1), 24.7 mm (Ad1-Ba), 47.6 mm (PNS-Ba), 45.7 mm (Ptm-Ba), 30.0 mm (PNS-H), 9.3 mm (upper airway) and 11.5 mm (lower airway). According to gender, all variables were greater in the boys group except for the lower airway. In relation to age, the mean values increased with age except for the lower airway and the AD1-Ba variables. In patients with skeletal Class I greater dimensions of the upper and lower airways were observed.

Conclusions

In this Caucasian sample, it has been observed a tendency of minor airway dimensions in patients with skeletal Class II, lower age range female gender. It has been observed only significant differences between age and skeletal class for lower airways variable and, in relation to upper airways variable the results were significant in relation to age.

Key words:Child development, Diagnostic XRay, Cephalometry, Respiratory system diagnostic imaging.

Craniofacial and Upper Airway Development in Patients With Treacher Collins Syndrome

ABSTRACT

This study evaluated age-associated morphology changes in the cranial base, facial development, and upper airway of patients with Treacher Collins syndrome (TCS). A total of 33 preoperative computed tomographic images (TCS, n = 14; control, n = 19) were included in the study and divided into three age-related subgroups (2-6 years, 7-18 years, and older than 18 years). Linear, angular cephalometric measurements and upper airway volumes were collected. All measurements were analyzed using ProPlan CMF software (version 3.0; Materialize, Leuven, Belgium). The association between aging and upper airway morphology was analyzed. Compared to control subjects, TCS patients had a smaller cranial base, maxilla, and nose; they also had reduced upper airway volume compared to control subjects. The observed differences were most significant in patients between the ages of 7 and 18 years. This study used computed tomography-based three-dimensional analyses to provide a detailed description of age-related changes that occur in craniofacial measurements and upper airway volumes in children, adolescents, and young adult patients with TCS in China. These data can be used to evaluate individual patients with TCS and to select treatment to improve the growth of the craniofacial region.

Does overweight affect the sagittal dimension of the posterior airway space in a non-OSAS population? A case control study

OBJECTIVE

The null hypothesis was that, in a non-obstructive sleep apnea syndrome population, overweight do not reduce the antero-posterior dimension of the posterior airway space.

MATERIALS AND METHODS

The author retrospectively reviewed the records of subjects evaluated at the Maxillofacial Surgery Unit, Department of Neurosciences, University of Padova Medical School, Padova, Italy, from 2016 to 2018. Only patients with complete demographic, anthropological and CBCT dataset were enrolled. OSAS patient were also ruled-out. Enrolled patients were divided into overweight (28 cases) and non-overweight (32 controls) groups according to the patient's Body Mass Index. Each two-dimensional cephalometric radiography obtained from the cone-beam computer tomography dataset was evaluated in order to measure linear and angular distances between standardized cephalometric landmarks. The two-sample t-test was the statistical test applied to compare the case and control data.

RESULTS

There were no statistical differences between the two study groups for any of the evaluated variables: the null hypothesis was accepted.

CONCLUSION

This study showed that in a non-obstructive sleep-apnea population, overweight and class I obesity does not influence the airway space in the antero-posterior dimension. Further investigation should focus on categorized overweight-obese population. Accurate and reliable protocol for tridimensional airways assessment should be implemented.

Three-dimensional assessment of pharyngeal volume and cross-sectional area in Chinese infants and preschool children

OBJECTIVE

The cross-sectional area (CSA) and the volume of the pharyngeal airway normative reference data aren't established, although they are closely associated with the pathogenesis of obstructive sleep apnea syndrome (OSAS) in infants and preschool children. Our objective is to measure the cross-sectional area (CSA) and volume of pharyngeal airway subregions and investigate the effects of age and sex in infants and preschool children using computerized tomography (CT).

METHODS

After applying strict inclusion criteria, 57 infants and preschool children (27 females, 30 males) aged from 1 day to 72 months who underwent maxillofacial CT scans due to trauma were selected. The sample was stratified into three age groups (1 day-24 months, 25-48 months, and 49-72 months). The CSA and the volume of the naso-, palato-, glosso-, and laryngopharyngeal airway were calculated using a 3-dimensional image processing software. Linear regression analysis was performed to express the effect of age, height, and weight. One-way analysis of covariance with height as a covariate was used to analyze the statistical significance of the difference between males and females within each age group.

RESULTS

The CSA and volume of all pharyngeal airway subregions increased with age, height, and weight (P < 0.05) in children under 6 years old. Multiple linear regression analysis showed an age effect, identified in all measurements (P < 0.001), whereas no height or weight effect were found. There were no differences in any measurements between males and females within each age group.

CONCLUSION

The normative reference data of CSA and volume of pharyngeal airway subregions were established after applying strict inclusion and exclusion criteria in infants and preschool children. Results may be useful in screening and assist in the timely diagnosis and management of pediatric OSAS.

A clinical prediction rule to identify difficult intubation in children with Robin sequence requiring mandibular distraction osteogenesis based on craniofacial CT measures

BACKGROUND

Airway management is challenging in children with Robin sequence (RS) requiring mandibular distraction osteogenesis (MDO). We derived and validated a prediction rule to identify difficult intubation before MDO for children with RS based on craniofacial computed tomography (CT) images.

METHOD

This was a retrospective study of 69 children with RS requiring MDO from November 2016 to June 2018. Multiple CT imaging parameters and baseline characteristic (sex, age, gestational age, body mass index [BMI]) were compared between children with normal and difficult intubation according to Cormack-Lehane classification. A clinical prediction rule was established to identify difficult intubation using group differences in CT parameters (eleven distances, six angles, one section cross-sectional area, and three segment volumes) and clinicodemographic characteristics. Predictive accuracy was evaluated by receiver operating characteristic (ROC) curve analysis.

RESULTS

The overall incidence of difficult intubation was 56.52%, and there was no significant difference in sex ratio, age, weight, height, BMI, or gestational age between groups. The distance between the root of the tongue and posterior pharyngeal wall was significantly shorter, the bilateral mandibular angle shallower, and the cross-sectional area at the epiglottis tip smaller in the difficult intubation group. A clinical prediction rule based on airway cross-sectional area at the tip of the epiglottis was established. Area > 36.97 mm² predicted difficult intubation while area < 36.97 mm² predicted normal intubation with 100% sensitivity, 62.5% specificity, 78.6% positive predictive value, and 100% negative predictive value (area under the ROC curve = 0.8125).

CONCLUSION

Computed tomography measures can objectively evaluate upper airway morphology in patients with RS for prediction of difficult intubation. If validated in a larger series, the measures identified could be incorporated into airway assessment tools to guide treatment decisions. This was a retrospective study and was granted permission to access and use these medical records by the ethics committee of Guangzhou Women and Children's Medical Center.

TRIALS REGISTRATION

Registration No. ChiCTR1800018252, NaZhang, Sept 7 2018.

Comparison of the effects of rapid maxillary expansion and alternate rapid maxillary expansion and constriction protocols followed by facemask therapy

Objective

The aim of this retrospective study was to evaluate and compare the changes in the pharyngeal airway (PA), maxillary sinus volume, and skeletal parameters after rapid maxillary expansion (RME) and alternate rapid maxillary expansion and constriction (Alt-RAMEC) followed by facemask (FM) therapy.

Methods

The records of 40 patients with skeletal Class III malocclusion due to maxillary retrognathism were collected, and the patients were assigned into two groups. The first group comprised 8 male and 12 female patients (mean age, 10.0 ± 1.1 years) treated using RME/FM for an average of 10 months. The second group comprised 10 male and 10 female patients (mean age, 9.64 ± 1.3 years) treated using Alt-RAMEC/FM for an average of 12 months. Cone-beam computed tomography images acquired before (T0) and after treatment (T1) were evaluated.

Results

Regarding the skeletal effects, significant differences between the groups were the increase in ANS-HRP (perpendicular distance of ANS to the horizontal reference plane, 0.99 mm, p <0.05) in the Alt-RAMEC/FM group and the decrease in PP-SN (palatal plane to Sella-Nasion plane, 0.93°, p < 0.05) in the RME/FM group. Maxillary sinus volumes increased significantly in both the groups, and the increase was statistically significantly higher in the Alt-RAMEC/FM group. Although no significant intergroup differences were observed in PA volumes, both lower (1,011.19 mm³) and total (1,601.21 mm³), PA volume increased significantly in the Alt-RAMEC/FM group.

Conclusions

The different expansion devices and protocols used with FM therapy do not seem to affect the forward movement of the maxilla and PA volumes. In contrast, the increase in maxillary sinus volume was greater in the Alt-RAMEC/FM protocol.

Three-dimensional study of the upper airway in different skeletal Class II malocclusion patterns

OBJECTIVES

To characterize upper airway volume and morphology in patients with different skeletal patterns of Class II malocclusion compared to Class I.

MATERIALS AND METHODS

A total of 197 individuals who had cone-beam computed tomography were allocated into groups according to ANB, SNA, and SNB angles (Class I, Class II maxillary protrusion, Class II mandibular retrusion), each subdivided into hypodivergent, normal, and hyperdivergent. Nasopharynx (NP), oropharynx (OP), and hypopharynx (HP) were assessed with three-dimensional image reconstruction software.

RESULTS

Intergroup comparison did not detect significant differences in volume and morphology of NP, OP, and HP. The males displayed larger OP and HP volume than the females. Positive correlations between age and NP, OP, HP volume and between craniocervical angle and OP and HP volume were observed. Linear regression analysis detected a tendency for OP and HP volume to increase as maxillary and mandibular length increased.

CONCLUSIONS

Upper airway volume and morphology were similar in different skeletal patterns of Class II malocclusion. Actual upper and lower jaw lengths were more closely related to upper airway volume and morphology than the angles that reflected their position relative to the cranial base.

Upper Airway Computed Tomography Measures and Receipt of Tracheotomy in Infants With Robin Sequence

IMPORTANCE

Airway management in infants with Robin sequence is challenging. Objective upper airway measures associated with severe airway compromise requiring tracheotomy are needed to guide decision making.

OBJECTIVES

To define objective upper airway measures in infants with Robin sequence from craniofacial computed tomography (CT) and to identify those measures in Robin sequence associated with tracheotomy.

DESIGN, SETTING, AND PARTICIPANTS

A cohort study (2003 to 2014, over 1-year follow-up) of 37 infants with Robin sequence evaluated for surgical management and 37 selected age- and sex-matched controls without a craniofacial condition conducted in a pediatric institution's craniofacial center.

MAIN OUTCOMES AND MEASURES

Define and compare CT-generated upper airway measures in these groups: infants with Robin sequence vs controls, and infants with Robin sequence with vs without tracheotomy. A negative difference signifies lower values for the Robin sequence and tracheotomy groups. Clinical data collected included age and height at time of CT scan, sex, tracheotomy presence, associated syndrome, and laboratory indicators of hypoventilation and hypoxemia. To evaluate interrater reliability, 2 raters performed each measurement in the Robin sequence group.

RESULTS

In 74 infants, 17 of 28 measures were different between infants with Robin sequence and those in the control group. Tracheotomy was performed in 14 of 37 (38%) infants with Robin sequence. Infants with tracheotomy more commonly had associated syndromes (12 of 14 [86%] vs 11 of 23 [48%]) and a history of hypoventilation and hypoxemia (13 of 14 [93%] vs 15 of 23 [65%]). Five of the 11 measures associated with tracheotomy were reliable and simpler to measure with the following mean differences (95% CIs) between groups: tongue length, 0.87 (0.26 to 1.48); tongue position relative to palate, 0.83 (0.22 to 1.45); mandibular total length, -0.8 (-1.42 to -0.19); gonial angle, 0.71 (0.08 to 1.34); and inferior pogonial angle, 0.66 (0.02 to 1.29). Using a receiver operating characteristic analysis, a composite score of these 5 measures for predicting tracheotomy risk yielded an area under the curve of 0.83 and achieved 86% sensitivity and 74% specificity.

CONCLUSIONS AND RELEVANCE

Computed tomography measures quantifying tongue position and mandibular configuration can identify infants with Robin sequence, and importantly, differentiate those who have severe upper airway compromise requiring tracheotomy. Following validation, these measures can be used for objective upper airway assessment and for expediting clinical decision-making in these challenging cases for which no such tools currently exist.

Linear dimensions of normal upper airway structure by magnetic resonance imaging in Chinese Han infants and preschool children

OBJECTIVES

To establish normative data of upper airway structure in Chinese Han infants and preschool children.

METHODS

Magnetic resonance imaging (MRI) scans of 521 Chinese Han infants and preschool children (225 girls, 296 boys) aged from 1 day to 72 months were selected from the children who underwent head MRI at the Capital Institute of Pediatrics Affiliated Children Hospital, Beijing, China. No subjects had sleep-disordered breathing or associated conditions that may have affected the upper airway anatomy. The upper airway dimensions and surrounding soft tissue sizes were measured along the mid-sagittal and axial images.

RESULTS

On images from the mid-sagittal image, the normative values of the following were obtained for all age group: thickness of the adenoid and nasopharyngeal area, length and thickness of the soft palate, length and height of the tongue, length of upper airway, distance between the mental spine and clivus, and the adenoid oblique width, soft palate oblique width, and tongue oblique width along the mental spine-clivus line. Normative values of the mean tonsillar width and intertonsillar space on the axial images were also obtained. There were no differences in any measurements between boys and girls in either infants or preschool children. Older children had larger airway dimensions, as expected.

CONCLUSION

Normative values for upper airway structure in Chinese Han infants and preschool children assessed by MRI were established. The upper airway dimension and surrounding soft tissues size, including soft palate, adenoid, tongue, and tonsils, were increased with age. There were no gender differences during the first six years of life. These data may prove useful when studying airway disease in Chinese Han children.

Analogue simulation of pharyngeal airflow response to Twin Block treatment in growing patients with Class II(1) and mandibular retrognathia

The flow dynamics of respiratory airflow is the basic factor that influences the ventilation function of the upper airway. This research aimed to investigate the pharyngeal flow field characteristics after Twin Block (TB) treatment in growing patients with Class II(1) and mandibular retrognathia by computation fluid dynamics (CFD) simulation. Cone beam computed tomography (CBCT) scans of patients who have completed TB treatment (n = 30) and about to accept TB treatment (n = 30) were reconstructed. After CFD simulation, correlations between the pharyngeal pressure drop and morphological parameters were further analyzed. During inspiration, we found that the pressure minimum occurred in the hypopharynx, while the maximum pressure drop and velocity was located in the oropharynx. After TB treatment, the oropharynx and hypopharynx showed significant differences in airflow features, and the most obvious change was observed in the oropharynx. A significant correlation was discovered between the change amount of oropharyngeal pressure drop and volume (r = 0.694, p = 0.001), mean cross-sectional area (r = 0.859, p = 0.000), and ratio of the minimum and mean cross-sectional area (r = 0.898, p = 0.000) of the oropharynx. Our research suggested that the pharyngeal airflow characteristics response positively to mandibular advancement with the enlargement in volume, cross-sectional area and more uniform oropharyngeal area distribution.

Three-Dimensional Evaluation of the Upper Airway Morphological Changes in Growing Patients with Skeletal Class III Malocclusion Treated by Protraction Headgear and Rapid Palatal Expansion: A Comparative Research

Objective

The aim of this study was to evaluate the morphological changes of upper airway after protraction headgear and rapid maxillary expansion (PE) treatment in growing patients with Class III malocclusion and maxillary skeletal deficiency compared with untreated Class III patients by cone-beam computed tomography (CBCT).

Methods

Thirty growing patients who have completed PE therapy were included in PE group. The control group (n = 30) was selected from the growing untreated patients with the same diagnosis. The CBCT scans of the pre-treatment (T1) and post-treatment (T2) of PE group and the control group were collected. Reconstruction and registration of the 3D models of T1 and T2 were completed. By comparing the data obtained from T1, T2 and control group, the morphological changes of the upper airway during the PE treatment were evaluated.

Results

Comparing with the data from T1 group, the subspinale (A) of maxilla and the upper incisor (UI) of the T2 group were moved in the anterior direction. The gnathion (Gn) of mandible was moved in the posterior-inferior direction. The displacement of the hyoid bone as well as the length and width of dental arch showed significant difference. The volume and mean cross-sectional area of nasopharynx, velopharynx and glossopharynx region showed significant difference. The largest anteroposterior/the largest lateral (AP/LR) ratios of the velopharynx and glossopharynx were increased, but the AP/LR ratio of the hypopharynx was decreased. In addition, the length and width of the maxillary dental arch, the displacement of the hyoid bone, the volume of nasopharynx and velopharynx, and the AP/LR ratio of the hypopharynx and velopharynx showed significant difference between the data from control and T2 group.

Conclusion

The PE treatment of Class Ⅲ malocclusion with maxillary skeletal hypoplasia leads to a significant increase in the volume of nasopharynx and velopharynx.

Gender-related difference in the upper airway dimensions and hyoid bone position in Chinese Han children and adolescents aged 6-18 years using cone beam computed tomography

OBJECTIVE

To investigate the gender-related differences in upper airway dimensions and hyoid bone position in Chinese Han children and adolescents (6-18 years) using cone-beam computed tomography (CBCT).

MATERIALS AND METHODS

CBCT-scans of 119 boys and 135 girls were selected and divided into four groups (group 1: 6-9 years; group 2: 10-12 years; group 3: 13-15 years; group 4: 16-18 years). The airway dimensions including the cross-sectional area (CSA), anteroposterior (AP) and lateral (LAT) width, length (L), mean CSA and volume (VOL) of upper airway segmentations and hyoid bone position including 11 linear and three angular measurements were investigated using Materialism's interactive medical image control system (MIMICS) 16.01 software. Gender-related differences were analyzed by two independent sample t-tests.

RESULTS

No gender-related difference was found in values of the facial morphology, airway dimensions and hyoid bone position for group 1 (p > 0.05). The children and adolescents in groups 2, 3 and 4 showed significant gender-related differences in the measurement results of facial morphology, airway dimensions and hyoid bone positions (p < 0.05). What's more, the measurement values of boys were obviously larger than those of girls except some measurements in group 2.

CONCLUSIONS

The measurements of airway dimensions and hyoid bone positions have gender-related differences in children and adolescents aged 10-18 years. These results could be taken into consideration during orthodontic diagnosis and treatment.

Cephalometric norms for the upper airway of 12-year-old Chinese children

Objective

To establish cephalometric norms for the upper airway of 12-year-old Chinese children, and to assess these norms with regard to gender, age, ethnicity and other craniofacial structures.

Methods

Lateral cephalograms were obtained from a random sample of 425 12-year-old Chinese children (224 boys and 201 girls) to establish the Chinese norms, and from a matched group of 108 12-year-old Caucasian children (61 boys and 47 girls) as an ethnic comparison. Published data on the upper airway norms of Chinese adults were used to make age comparisons. Nine upper airway and 14 craniofacial variables were measured.

Results

Chinese boys tended to have a thicker soft palate (P = 0.008), and less depth in the retropalatal (P = 0.011), retroglossal (P = 0.034) and hypopharyngeal (P < 0.001) pharynx than Chinese girls, whereas no gender dimorphism was found in Caucasian children. Ethnic differences were found in the depth of the retroglossal oropharynx in both genders and the position of the hyoid bone in boys. Compared with Chinese adults, the overall size of the upper airway in Chinese children was smaller. The mandibular body length and the craniocervical inclination were found to be statistically significantly, albeit weakly correlated with upper airway variables.

Conclusions

Cephalometric norms for the upper airway of Chinese 12-year-old children were established, indicating gender-specific differences, and some ethnic differences were found in comparison with those of 12-year-old Caucasian children. An association between the mandibular body length and the craniocervical inclination with upper airway variables was also noticeable.

Three-dimensional alterations in pharyngeal airway and maxillary sinus volumes in Class III maxillary deficiency subjects undergoing orthopedic facemask treatment

OBJECTIVE

To assess short-term alterations in the volume of pharyngeal airway space and maxillary sinuses associated with rapid maxillary expansion (RME) and facemask (FM) use in growing Class III maxillary-deficient patients.

MATERIALS AND METHODS

Twenty-two patients (14 girls, eight boys) treated with the RME/FM and having pretreatment and posttreatment cone beam-computed tomographic scans were identified from the archives of the Marmara University, Department of Orthodontics. According to the protraction force that was used, they were divided into two groups: a group with 400 g protraction force (12 subjects) and a group with 800 g protraction force (10 subjects). Mean age for the study group was 10 years. All patients were diagnosed with normal/low vertical growth pattern, maxillary deficiency, and normal mandible. No control group was available for this study. For each patient, a hyrax expansion screw with acrylic cap splint was constructed and RME was performed for 10 days. On the seventh day, protraction with a FM started.

RESULTS

The results showed a statistically significant increase in the volume of maxillary sinuses after treatment, which was related to the growth. On the other hand, the increase in the volume of pharyngeal airway was not statistically significant.

CONCLUSIONS

RME/FM treatment did not affect at all the volume of maxillary sinuses and actually inhibited the normal expected increase of the volume of the pharynx when compared with a control group comprising normal individuals.