Changes in shape of upper airway during titrated mandibular advancement: a magnetic resonance imaging study
Gao, X-Mei.; Otsuka, R.; Ono, T.; Honda, E-ichi.; Sasaki, T.; Kuroda, T.
Zhonghua Er Bi Yan Hou Tou Jing Wai Ke Za Zhi 40(2): 137-140
2005
ISSN/ISBN: 1673-0860 PMID: 16429736 Document Number: 584689
To examine adaptive changes in the shape of the upper airway during titrated mandibular advancement. Furthermore, to understand the mechanism of mandible-adjustable therapy to improve the ventilation. Fourteen non-apnea participated in the study. A custom-made oral device was used to keep the mandible in titrated advancement at 0% (F0), 50% (F50), 75% (F75), 100% (F100) of the maximum advancement. Magnetic resonance imaging was used to investigate the difference in the shape of upper-airway in these 4 positions. Changes in the anteroposterior direction (AP), lateral direction (Lat) and its ratio (AP/Lat) were calculated, which were transformed into the percentage of the original ones. The dose-dependent decrease of AP/Lat was found when the mandible was advanced (P = 0.0001). Lateral change rate in percentage increased by degrees (P = 0.0023), while the increase of anteroposterior change rate in percentage showed no statistical significance. The shape of upper airway tended to be less round. The enlargement of upper airway during titrated mandibular advancement was mainly the result of enlargement in lateral direction.