1999 Fiscal Year Final Research Report Summary
The effects of nasal respiratory disturbance on sleep status, masticatory muscle function and mandibular posture
Project/Area Number |
10557198
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Research Category |
Grant-in-Aid for Scientific Research (B)
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Allocation Type | Single-year Grants |
Section | 展開研究 |
Research Field |
矯正・小児・社会系歯学
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Research Institution | Hiroshima University |
Principal Investigator |
MIYAMOTO Keisuke Hiroshima University, Dental Hospital, Assistant Professor, 歯学部・付属病院, 講師 (40229886)
|
Co-Investigator(Kenkyū-buntansha) |
UEDA Hiroshi, m. Hiroshima University, Dental Hospital, Research Associate, 歯学部・附属病院, 助手 (20304446)
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Project Period (FY) |
1998 – 1999
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Keywords | Sleep / Nasal respiration / Mandibular posture / Mouth opening / Obstructive sleep apnea / Masticatory muscle / Electromyography |
Research Abstract |
Nasal respiratory disturbance is thought to be related to the craniofacial morphogenesis. The aim of this study was to investigate the effects of nasal respiratory disturbance on sleep status, masticatory muscle function and mandibular posture. The vertical mandibular position was recorded intraorally using a magnet sensor at the same time as a standard sleep study in seven patients with obstuctive sleep apnea syndrome (OSAS), who had mild-to-moderate nasal obstruction. The percentage of total sleep time spent with mandibular opening greater than 5 mm was significantly larger (p < 0.001) in patients with OSAS (69.3 【minus-plus】 23.3%) compared with healthy adults without OSAS (11.1 【minus-plus】 11.6%). The stage of sleep effected the vertical mandibular posture during sleep in the supine position. On the other hand, it was found that sleep bruxism is rarely directly associated with apneas, but is rather related to the fragmented sleep. Activities of the masseter, temporal and digastric muscles were recorded for three hours during daytime with 30 children and 30 adults. Children exhibited longer duration of temporal muscle activity, whereas the masseter muscle presented longer duration of activity in adults. The activities of masseter and digastric muscles were significantly related with the vertical facial type in both children and adults. To investigate the bilateral balance of masticatory muscle activity under usual living condition, EMG recordings were performed for 15 normal controls and 15 patients with transverse craniofacial deformity during usual daily life. Asymmetry indices were significantly greater in patients during usual daytime and sleep for the anterior temporal muscle and significantly smaller during sleep for the masseter muscle as compared to the controls. Therefore, it was concluded that nasal respiratory disturbance may cause excessive mouth opening, induce frequent fragmentation of sleep and influence masticatory muscle activity during sleep.
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Research Products
(4 results)