Developmental changes of pharyngeal airway structures from young to adult persons

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.

Cephalometric appraisal of the effects of orthodontic treatment on total airway dimensions in adolescents

Aim

This retrospective study was performed to rule out any jeopardizing effect of extraction therapy of four first premolars on airway at any level of its anatomic course.

Materials and methods

Lateral cephalograms of 50 adolescent patients divided into two groups of 25 each, based on orthodontic treatment by first premolar extraction as group I and without extraction as group II, were selected for the study. 13 angular and 11 linear measurements were compared pre-and post-treatment via statistical analyses using SPSS (Version 17.5, SPSS, Chicago) software. Paired 't' tests were used to assess the variability. P-value < 0.05 was considered to be statistically significant.

Results

Comparison of angular parameters showed that the average percentage (%) change in SNA, SNB, ANB, IMPA, FMA, saddle, articulare, gonial, total angle and hyoid did not differ significantly across two study groups (P > 0.05), but values of UI/LI, UI/NA, LI/NB, differed significantly among both groups. Similarly, linear parameters showed that the average % change in nasopharyngeal airway space (NAS) and width of soft palate differed significantly across two study groups (P-value<0.05), whereas the average % change in posterior airway space (PAS), hypopharyngeal airway space (HAS), hyoid distance and length of tongue did not differ significantly (P-value>0.05). However, no significant differences were observed during intragroup and intergroup comparisons of the combined angular and linear measurements of both groups.

Conclusions

Present study showed no significant change on airway after therapeutic orthodontic tooth movement with or without extraction treatment.

Assessment of the Airway Characteristics in Children with Cleft Lip and Palate using Cone Beam Computed Tomography

OBJECTIVE

The aim of our study is to use cone beam computed tomography (CBCT) to assess the dimensional changes in the nasopharyngeal soft-tissue characteristics in children of Indian origin with repaired cleft lip and palate (CLP) and to compare the results with patients with ideal occlusion.

MATERIALS AND METHODS

A sample of 20 children (10 girls, 10 boys) with repaired CLP was selected. Cone beam computed tomography scans were taken to measure the nasopharyngeal airway changes in terms of linear measurements and sagittal cross-sectional areas. Error analysis was performed to prevent systematic or random errors. Independent means t-tests and Pearson correlation analysis were used to evaluate sex differences and the correlations among the variables.

RESULTS

Nasopharyngeal soft-tissue characteristics were different in the control and the study groups. Subjects with repaired CLP had lesser lower aerial width, lower adenoidal width and lower airway width. The upper airway width was also significantly lesser. The retropalatal and the total airway area were significantly greater in the control group.

CONCLUSION

The narrow pharyngeal airway in patients with CLP might result in functional impairment of breathing in patients. Further investigations are necessary to clarify the relationship between pharyngeal structure and airway function in patients with CLP. How to cite this article: Agarwal A, Marwah N. Assessment of the Airway Characteristics in Children with Cleft Lip and Palate using Cone Beam Computed Tomography. Int J Clin Pediatr Dent 2016;9(1):5-9.

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.

Mandibular morphology and pharyngeal airway space: A cephalometric study

Introduction

Mandibular retrognathism is considered to be the most important risk factor for upper airway obstruction.

Aim

This cross-sectional study intended to examine the relationship between craniofacial morphology and the pharyngeal airway space (PAS) in patients with mandibular retrognathism and mandibular prognathism, when compared to normal subjects. The study also analyzed the influence of mandibular morphology on pharyngeal length (PL).

Materials and Methods

The PAS was assessed in 92 females (age 15-30 years) further divided into three groups - Group 1- normal mandible (76°≤ SNB ≤82°; n = 31); Group 2-mandibular retrognathism (SNB <76°; n = 31); Group 3-Mandibular prognathism (SNB >82°; n = 30). All subjects were examined by lateral cephalometry with head position standardized using an inclinometer. Craniocervical angulation, uvula length, thickness and angulation were compared among different groups.

Results

The results showed no statistically significant difference in the pharyngeal airway between the three groups. Measurements of PL showed statistically significant higher values for retrognathic mandible group than normal and prognathic mandible group.

Conclusion

There is no significant difference between PAS between patients with mandibular retrognathism, normal mandible and mandibular prognathism. Mandibular retrognathism patients show a significantly higher uvula angulation than patients with mandibular prognathism. Craniocervical angulation showed maximum value in retrognathic mandible group followed by normal and prognathic mandible group respectively. Mean PL for retrognathic mandible patients was significantly higher than prognathic mandible patients.

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.

Three-dimensional analysis of the pharyngeal airway morphology in growing Japanese girls with and without cleft lip and palate

INTRODUCTION

We evaluated the 3-dimensional craniofacial skeletal and pharyngeal airway morphology in growing patients with and without cleft lip and palate.

METHODS

Our juvenile subjects consisted of 34 girls (ages, 9-12 years); 15 had cleft lip and palate, and 19 did not. The adolescent subjects consisted of 32 girls (ages, 13-17 years); 14 had cleft lip and palate, and 18 did not. Each subject was examined with cone-beam computed tomography. The dimensions of the craniofacial skeleton and pharyngeal airway were measured. The Scheffé method of multiple comparisons was used to identify relationships among skeletal and pharyngeal variables.

RESULTS

The pharyngeal airway and mandibular size variables did not differ significantly between the juvenile and adolescent cleft lip and palate groups. Significant differences were observed between each cleft lip and palate group and its corresponding control group. FHN-A, FHN-B, FH-NA, FH-NB, and Co-Me were significantly smaller in the cleft lip and palate groups than in the corresponding control groups. Anteroposterior and lateral widths, heights, and volumes of the superior oropharyngeal airway were significantly smaller in the adolescent cleft lip and palate group than in the adolescent controls.

CONCLUSIONS

The mandible and the oropharyngeal airway were larger in the adolescent controls than in the juvenile controls without cleft lip and palate, but there were no significant differences between the adolescent and juvenile patients with cleft lip and palate.

Sagittal mandibular development effects on the dimensions of the awake pharyngeal airway passage

OBJECTIVE

To test the hypothesis that sagittal mandibular development has no effects on the dimensions of the awake pharyngeal airway passage.

MATERIALS AND METHODS

Ninety-one subjects (age 15-25 years) with a normal vertical growth pattern of the mandible, normally positioned maxilla, and various sagittal mandibular developments were divided into three groups based on the sagittal mandibular development. Group I included 37 subjects who had a normally positioned mandible (76 degrees < or = angle between 'S,' 'N,' and 'B'; it represents the antero-posterior position of the maxilla in relation to the anterior cranial base [SNB] < or = 82 degrees ), Group II included 31 subjects in whom the mandible was retrognathic (SNB < 76 degrees ), and Group III included 23 subjects in whom the mandible was prognathic (SNB > 82 degrees ) in relation to the anterior cranial base. Lateral cephalograms were traced manually to evaluate the pharyngeal airway passage.

RESULTS

The length of the soft palate was significantly smaller in mandibular prognathism subjects than in subjects with mandibular retrognathism (P < .01). The thickness of the soft palate was significantly greater among subjects with mandibular prognathism than in subjects with normal (P < .01) and retrognathic (P < .001) mandibular development. The sagittal mandibular development had no effect on the dimensions of the nasopharyngeal and hypopharyngeal airway passage. The depth of the oropharynx was comparable among the subjects with normal and retrognathic mandibles but was greater (P < .001) among subjects with mandibular prognathism.

CONCLUSIONS

The hypothesis is rejected. Sagittal mandibular development had significant effects on the dimensions of the awake pharyngeal airway passage.