Obstructive sleep apnea patients with the oral appliance experience pharyngeal size and shape changes in three dimensions.
Pharyngeal size and shape differences between pre- and posttrials of a mandible-protruding oral appliance were investigated using cine computerized tomography (CT). Fourteen patients diagnosed with obstructive sleep apnea whose apnea-hypopnea index was higher than 5 and arousal index higher than 20 underwent a second overnight sleep study to evaluate the effectiveness of the oral appliance. Three-dimensional changes in pharyngeal shape measured on cross-sectional CT images during two respiratory cycles after oral appliance delivery were estimated by three variables: (1) lateral dimension, (2) anterior-posterior dimension, and (3) cross-sectional area at five vertical levels. Apnea indices improved significantly when the appliance was used. During apnea, measurements at retropalatal and retroglossal levels decreased most. However, the cross-sectional area of these levels appeared to increase significantly (P < .05) with the appliance in place during wakefulness. The oral appliance appears to enlarge the pharynx to a greater degree in the lateral than in the sagittal plane at the retropalatal and retroglossal levels of the pharynx, suggesting a mechanism for the effectiveness of oral appliances that protrude the mandible.
Kyung
Seung Hyun
SH
Sungkyunkwan University School of Medicine, Seoul, South Korea.
Park
Young-Chel
YC
Pae
Eung-Kwon
EK
D002508:Cephalometry; D002933:Cineradiography; D045422:Continuous Positive Airway Pressure; D005260:Female; D006801:Humans; D008297:Male; D019186:Mandibular Advancement / Q000295:instrumentation*; D008875:Middle Aged; D017090:Occlusal Splints; D010614:Pharynx / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D017286:Polysomnography; D020181:Sleep Apnea, Obstructive / Q000628:therapy*; D014057:Tomography, X-Ray Computed / Q000379:methods