利用核磁共振影像檢視下顎前突裝置治療 阻塞性睡眠呼吸中止症病患的有效機制和原理

Abstract

研究目的:根據過去文獻，下顎前突裝置可以有效治療睡眠呼吸中止症，然而治療上還是存很多個體上的差異，作用的機制也尚未全部釐清。過去研究發現口內裝置的效應主要是令帆咽區的側壁開展(左右)，然而此現象和下顎移動的方向(前後)並不一致。在很多失敗案例上看到，除了側壁未明顯開展，下顎前突時前後徑也有減少的現象。是否有其他因素(例如:舌頭)導致下顎前突帶來的前後徑開展效益被抵銷甚至塌陷，需要進一步探討。本研究將利用核磁共振造影(magnetic resonance imaging ,MRI)取得配戴口內裝置前後的影像，來進一分析”舌支撐設計對舌頭形狀變化的影響”以及”舌頭形狀變化對臨床治療反應的的可能機制”。 研究方法:本研究納入了29名輕度至重度的睡眠呼吸中止症病患，並使用舌支持式下顎前突裝置(TMAD)進行治療。並以睡眠多功能檢查儀(PSG)報告評估治療成效。並利用核磁共振影像，對舌骨位置、舌頭型態、軟腭型態、以及上呼吸道空間進行分析評估。 結果:使用TMAD後和基期時相比，舌骨位置明顯提升(p=0.000)。舌體形態方面:頦結節以上舌體高度減少及(p=0.000 )，頦結節往後到舌背最遠距離增加(p=0.000)，舌骨往前到舌尖距離減少(p=0.000)。呼吸道的改變上：最小截面積明顯增加(p=0.049)，軟顎後區域體積明顯增加(p=0.015)。 依照成效分為反應組(responder)和不反應組(non-responder)的話，反應組有偏向二級咬合的骨性結構，且其舌前高度明顯較高(p=0.026)。在增加最窄截面積以及總體積的效益上，比不反應組來的明顯。(最小截面積:64.19%±128.63% VS 0.11%±55.37%, p=0.044；總體積:13.79%±17.39% VS-2.13%±26.77%, P=0.043 ) 結論:本研究使用了系統性的方式，評估了TMAD對舌頭以及其他上呼吸道周邊組織的效應。發現在下顎前突裝置提供舌支持結構下，舌頭形狀在下顎突動作後仍然會有變化。因為構成舌頭的數條肌肉，在前突時也會有不同程度的收縮和放鬆，並非完全是增加口空間後，舌背失去支持所造成的陷落。使用TMAD後，舌體前端高度會減少，後端高度沒有明顯變化。舌骨往前到舌尖的距離減少，頦結節往後到舌背的距離增加。比較沒有舌前端抬起，舌背往後塌陷的狀態。且前端高度減少較少的患者，可能因為重心保留在更前方的位置，對維持呼吸道的開展有比較明顯的效益。此外由失敗案例分析上發現，上呼吸道最窄捷橫截面積在下顎前突後縮小，側壁未明顯開展，且前後徑明顯縮短，同時也發現舌體後上半部後移壓迫呼吸道的現象，然而須注意，本研究有樣本數、族群等、患者檢查狀態方面的受限，未來需納繼續入更多的受試者，來達到更有力的實證。

Purpose:Mandibular advancement device (MAD) can effectively treat obstructive sleep apnea (OSA); however,treatment response is variable, and the mechanisms behind differences in treatment outcomes has still not been fully clarified. The change of tongue reaction at jaw protrusion may play an important role for dimension change of airway ,but this issues are seldom discussed.The aims of this study were (1) to assess the effects of tongue-backing mandible advancement device,TMAD) on tongue shape and (2) to compare tongue shape changes with TMAD between treatment responders and nonresponders. Methods:Twenty-eight adults with symptomatic mild to severe OSA were included. A custom-made mandible advancement device(TMD) was provided to patients, and treatment outcome was determined by polysomnography (PSG). Two dimensional tongue measurements were evaluated on mid-saggital slice form MRI image without and with TMAD in situ. Tongue measurements of anterior lenth(TAL), posteriorlength(TPL),anterior height(TAH),posterior height(TPH) and area(TA) were collected. Surrounding structure,including hyoid bone position(MP-H),length(PL), thichness(PT) and area(PA) of palate and minimal cross section area(Amin),length,volumn of upper airway were also measured . Results: There were significant anatomic changes in MP-H (decreased,p=0.000),TAL(decreased ,p=0.000),TPL(increased,p=0.000),TAH (decreased,p=0.000),Amin(increased, p=0.049), volumn of veolopharynx (increased,p=0.015) with insertion of MAS .Responders showed a greater increase in Amin (64.19%±128.63% VS 0.11%±55.37%, p=0.044) and totoal upper airway volomn (13.79%±17.39% VS -2.13%±26.77%,P=0.043 )with MAS in situ compared to nonresponders. Conclusion: This study reports a systematically evaluate the effects of TMAD on tongue shape using MRI as well as assessment of adjacent hyoid bone,soft palate and upper airway structures without and with MAS treatment for OSA. Our finding suggests that Although TMAD try to given more support to tongue.The change of tongue shape is still significant after jaw protrusion .It can be not only attributed to jaw protrusion-induced oral cavity changes but also potentially reflex changes of tongue muscle. TMAD responders showed large ATH without TMAD ,and less decrease in ATH with TMAD in situ.Futher more TMAD responder shows better performance in terms of increasing minimal cross section area and volumn of upper airway. Whether differences in alteration of tongue with TMAD explain differences in treatment response needs further investigation.