著者

大木 淳

出版者

九州歯科学会

雑誌

九州歯科学会雑誌 (ISSN:03686833)

巻号頁・発行日

vol.36, no.1, pp.212-227, 1982

被引用文献数

2

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In orthodontics, mouth-breathing is cited as one of the causes of maxillary protrusion, for it is considered that the pressure balance among the lips, cheeks, tongue, and intraoral air pressures which determine the tooth position and the dental arch form changes by mouth-breathing. However, this belief has not been experimentally demonstrated sufficiently. Therefore, differences in pressures by the soft tissues between normal breathing and mouth-breathing and the effects of these differences on the dental arch form were examined. For this purpose, nine subjects with normal occlusion were measured for the following pressures during a 30-minute period of normal breathing at rest and during the same duration of experimental mouth-breathing : the lip and tongue pressures at the upper right central incisor ; the cheek and tongue pressure at the upper right second premolar ; and the intraoral air pressures at the labial side of the upper right central incisor (the labial region), at the central palate (the palatal region) and at the buccal side of the upper right second premolar (the buccal region). The results were as follow : 1. With the change in the mode of breathing, between normal and experimental mouth-breathing at rest (30-minute period), the time pressure integral of the lip pressure at the upper right central incisor decreased significantly in mouth-breathing. The oral negative pressures at the labial region and the palatal region also decreased significantly. 2. Positive correlation was recognized between the lip pressure at the upper central incisor and the negative pressure of the labial region, between the tongue pressure at the same side and the negative pressure of the palatal region and between the cheek pressure at the upper second premolar and the negative pressure of the buccal region. 3. At the upper central incisor, a relative increase in the tongue pressure as against the lip pressure was observed during mouth-breathing in eight of the nine subjects. At the upper second premolars, a relative increase in the tongue pressure as against the cheek pressure was observed in seven of the nine subjects. However, the degree of the increase was less as compared with the upper central incisor. The foregoings are suggestive of the possibility that mouth-breathing may cause labial inclination of the upper incisors.

著者

横内 陽子 橋本 伸哉 伊藤 伸哉 大木 淳之

出版者

独立行政法人国立環境研究所

雑誌

特定領域研究

巻号頁・発行日

2006

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海洋から大気中に放出されるハロカーボンについてグローバルな大気観測および北西太平洋と南北インド洋における海水中ハロカーボン連続観測によってそれらの分布と変動を明らかにした。また、植物プランクトンの培養実験により、ハロカーボンがクリプト藻やラン藻の培養後期(減少期)に生成されることを示し、さらに、海産性微細藻類の生物学的なヨウ化メチルの生成機構がハライドイオン・チオールメチルトランスフェラーゼ(HTMT)反応に起因することを明らかにすると共に遺伝子の単離にも成功した。