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

Tianhu Wang,Jinlong Zhao,Jinwu Chen,Fang Yang,Zhenhua Yang,Yongming Li,Mingye Zhang,Heinz Fehrenbach

doi:10.1371/journal.pone.0095544

Abstract

ObjectiveThe study was performed to compare the 3D pharyngeal airway dimensions in adult skeletal Class II patients with different vertical growth patterns (low, normal, and high angle) and to investigate whether the upper airway dimensions of untreated skeletal Class II adults were affected by vertical skeletal variables.MethodsCone-beam computed tomography (CBCT) records of 64 untreated adult skeletal Class II patients (34 male and 30 female) were collected to evaluate the pharyngeal airway dimensions. Subjects were divided into three subgroups according to the GoGn-SN angle (low angle, normal angle or high angle). All subgroups were matched for sex. ANOVA and SNK - q tests were used to identify differences within and among groups (p<0.05). Coefficient of product-moment correlation (Pearson correlation coefficient) was used to analyze the association between pharyngeal airway dimensions and vertical growth patterns.ResultsThe results showed that pharyngeal airway measurements were statistically significantly less (p<0.05) in high angle group as compared to normal angle or low angle group.ConclusionsAdult skeletal Class II subjects with vertical growth patterns have significantly narrower pharyngeal airways than those with normal or horizontal growth patterns, confirming an association between pharyngeal airway measurements and a vertical skeletal pattern.

Highlights

Obstructive sleep apnea (OSA) is a common respiratory sleep disorder characterized by snoring and episodes of breathing cessation during sleep despite respiratory effort, which is rarely observed in young subjects
A reduction in pharyngeal space is a clinical observation commonly reported in OSA patients; until now, the precise mechanism of upper airway occlusion remains under debate [1]
The aims of our present study were (1) to compare the 3D pharyngeal airway dimensions in adult skeletal Class II patients with different vertical growth patterns and (2) to investigate whether the upper airway dimensions of untreated skeletal Class II adults were affected by vertical skeletal variables

Summary

Introduction

Obstructive sleep apnea (OSA) is a common respiratory sleep disorder characterized by snoring and episodes of breathing cessation during sleep despite respiratory effort, which is rarely observed in young subjects. A reduction in pharyngeal space is a clinical observation commonly reported in OSA patients; until now, the precise mechanism of upper airway occlusion remains under debate [1]. Previous studies of OSA from different samples have shown an association between craniofacial skeletal morphology and upper airway dimensions in OSA patients [2]. It has been reported that Class II malocclusions and vertical growth patterns are anatomic predisposing factors for the obstruction of the pharyngeal airways [3,4,5,6,7]. When compared to healthy patients with normal occlusions and growth patterns, or Class I malocclusions, healthy patients with Class II malocclusions and vertical growth patterns might have narrower airway passages

Methods

Results

Conclusion