The impacts of open-mouth breathing on upper airway space in obstructive sleep apnea: 3-D MDCT analysis.
Open-mouth breathing during sleep is a risk factor for obstructive sleep apnea (OSA) and is associated with increased disease severity and upper airway collapsibility. The aim of this study was to investigate the effect of open-mouth breathing on the upper airway space in patients with OSA using three-dimensional multi-detector computed tomography (3-D MDCT). The study design included a case-control study with planned data collection. The study was performed at a tertiary medical center. 3-D MDCT analysis was conducted on 52 patients with OSA under two experimental conditions: mouth closed and mouth open. Under these conditions, we measured the minimal cross-sectional area of the retropalatal and retroglossal regions (mXSA-RP, mXSA-RG), as well as the upper airway length (UAL), defined as the vertical dimension from hard palate to hyoid. We also computed the volume of the upper airway space by 3-D reconstruction of both conditions. When the mouth was open, mXSA-RP and mXSA-RG significantly decreased and the UAL significantly increased, irrespective of the severity of OSA. However, between the closed- and open-mouth states, there was no significant change in upper airway volume at any severity of OSA. Results suggest that the more elongated and narrow upper airway during open-mouth breathing may aggravate the collapsibility of the upper airway and, thus, negatively affect OSA severity.
Department of Otorhinolaryngology-Head and Neck Surgery, Korea University College of Medicine, Seoul, Korea.
Eun Joong
EJ
Kim
Ji Ho
JH
Choi
Kang Woo
KW
Kim
Tae Hoon
TH
Kim
Sang Hag
SH
Lee
Heung Man
HM
Lee
Chol
C
Shin
Ki Yeol
KY
Lee
Seung Hoon
SH
Lee
D000293:Adolescent; D000328:Adult; D000368:Aged; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006928:Hyoid Bone / Q000000981:diagnostic imaging / Q000503:physiopathology; D021621:Imaging, Three-Dimensional; D008297:Male; D008875:Middle Aged; D009058:Mouth Breathing / Q000000981:diagnostic imaging* / Q000209:etiology / Q000503:physiopathology; D017286:Polysomnography; D012119:Respiration; D012189:Retrospective Studies; D020181:Sleep Apnea, Obstructive / Q000150:complications / Q000000981:diagnostic imaging* / Q000503:physiopathology; D014057:Tomography, X-Ray Computed / Q000379:methods*; D055815:Young Adult