대한구강내과학회지 Vol. 30, No. 4, 2005 교합조건및이악물기힘의변화가하악의비틀림회전운동에미치는영향 원광대학교치과대학구강내과학교실및원광치의학연구소 이갈이나이악물기시근활성, 하악의이동, 악관절에가해지는부하, 그리고교합에미치는영향등에대한연구는많았으나하악운동에미치는영향에대해서는연구가적었다. 따라서측두하악장애의주요한기여요인으로간주되는이악물기나강한씹기에의해나타나는하악의미세한운동양태에대해서는더많은연구가수행될필요가있으며, 이에본연구에서는하악의비틀림회전운동을중심으로이악물기및강한씹기의영향을조사하였다. 저작계이상이없는건강한남자 14 명을선정하여교합고경및형태의변화와수의적이악물기수준의차이가이악물기및씹기운동시나타나는하악의비틀림회전운동 (torque rotational movement) 에미치는영향을조사하였다. 각교합조건과이악물기힘에서의씹기운동은먼저나무젓가락 ( 분리기 ) 이없는한번의이악물기와나무젓가락을구치부에위치시킨상태에서두번에걸친씹는운동등세번의하악운동으로구성되었다. 본연구의결론은다음과같다. 1. 좌측으로씹을때와우측으로씹을때간에전두면및시상면상운동거리는두가지이악물기힘모두에서차이가없었으나하악의운동속도는다른양상을보여강한이악물기에서는차이가없었으나약한이악물기에서는좌측으로씹을때우측에비해속도가다소빠른경향을보였다. 이때하악의비틀림회전운동각은두가지이악물기모두에서전두면상차이는거의없었으나수평면상각도에서는씹는측에따라차이가있는경향을보였다. 2. 이악물기힘의차이는전두면및시상면상운동거리와속도에영향을미쳐강한씹기에서약한씹기에비해측정치가크게나타났으며하악의비틀림회전운동각역시강한씹기에서수평면상운동각이다소증가된양상을보였다. 3. 전두면및시상면상개구거리는교합조건에따른차이를보였는데, 즉웨이퍼나레진블록등교합고경이높은교합형태일수록운동거리가감소하였으며, 이때강한씹기에서는운동속도역시유사한양상으로감소하였다. 그러나하악의비틀림회전운동각은전두면및수평면모두에서교합조건에따른차이를거의나타내지않았다. 4. 세번의씹는운동에서분리기가없는경우에비해있는경우에서대체로전두면상회전운동각을제외한나머지하악의비틀림회전운동량은모두증가하는양상을보였다. 그러나이때각교합형태간동일항목의비교에서는전두면상회전운동거리가이악물기힘에따른차이를보여약한이악물기에서유의한변화를나타내었다. 이상의연구를통해하악비틀림회전운동의전체적인양상은관찰면에따라다르게나타나이악물기힘에따른차이는전두면에비해수평면상측정치가더많이변화되는모습을보였으나교합조건에따른양상은관찰면간차이를보이지않았다. 한편이악물기및씹는운동각각에서의하악비틀림회전운동량은교합조건이나이악물기힘에관계없이대체로분리기씹기에의해수평면상회전운동량의변화가전두면상측정치에비해더유의하게나타났다. 주제어 : 이악물기, 강한씹기, 하악의비틀림회전운동 교신저자 : 한경수원광대학교치과대학구강내과학교실전북익산시신용동 344-2 E-mail: ksshan@wonkwang.ac.kr 원고접수일 : 2005-09-10 심사완료일 : 2005-12-12 Ⅰ. 서론 측두하악장애는저작계기능장애와구강안면동통이단독으로, 또는함께나타날수있는장애로서이질적장애들의복합체로규정할수있다. 측두하악장애를가진환자들은전형적으로저작근이나악관절의통 411
증및하악운동의부조화나개구제한과같은악기능과하악운동의변화를호소하고있으며, 이러한증상에더하여두통, 이통, 현기증, 이명등을나타내기도한다 1,2). 측두하악장애의원인요소로간주되는것은다양하나여전히일치된견해가없으며그결과외상, 교합이상, 스트레스, 이상기능등이주로거론되고있는데, 이중에서최근들어더많은주목을받는것이이상기능 (parafunction) 이다 3-8). 흔히구강악습관으로일컬어지는이상기능활동에는이갈이, 이악물기, 볼이나혀를씹거나손가락을빠는행위, 습관성의좋지못한자세, 직업관련행동, 단단한물체를씹거나껌을장시간씹는행위등이포함될수있는데일반적으로볼때각개인의생리적내성한계내에서일어나는이상기능활동은일상적으로흔하며또한대부분저작계내여러조직에손상을일으키지않으나그한계를넘어서는경우에는문제를발생시키게된다 9-12). 이러한악습관중에서특히많이연구되어온것으로이갈이나이악물기를들수있겠는데 13-18), 이들이저작계에미치는영향이나측두하악장애와의관련성에대해 Egermark-Eriksson 등 19) 은어린이에대한조사에서대상자의 20% 정도에서기능장애의제증상과관련이있었다고하였으며, Haggerty 등 20) 은정상인에비해측두하악장애환자에서최대수준이하 (submaximal) 의치아접촉을유지하는시간이더길다고하였으며, Glaros 등 21) 은실험참가자의 25% 에서이악물기가측두하악장애의근막동통이나악관절동통을초래하기에충분한증상을발현하였다고하였다. 이갈이나이악물기시근활성에대해서도많은연구가있어왔으며 22-28), Okeson 9), Ito 등 29), Rassouli 등 30) 은이갈이나이악물기에의해거상근활성이증가하면서결과적으로하악의미약한이동을초래하고그것은이어서악관절에가해지는부하량에영향을미친다고하였다. 그러나이때좌, 우양측이동시에균등하게치아접촉을하는경우그러한하악의이동량이최소로될수있다고하면서국소적인치아상실, 편측성교합간섭, 그리고실험적인추축장치의장착등은턱을비틀어지게하는효과가있다고하였다. 이와유사하게 Takenami 등 31) 은지속적인절치부이악물기에의해측두하악관절내전방관절강의폭이유의하게줄었다고보고하였다. 교합에관련된영향으로는김등 32) 은최대이악물 기에서습관적이악물기에비해교합접촉의수와지속시간이증가한다고하였고, Korioth 등 33), Kumagai 등 34) 은교합력의분포에대해보고하면서이악물기의힘이증가할수록전체교합력중구치부에서의교합력은상대적으로증가하나전치부에서의교합력은상대적으로감소한다고하였으며, 이악물기시의교합접촉의면적을연구한 Gurdsapsri 등 35) 도이와유사한결과로이악물기의힘이증가할수록구치부의교합면적은증가하나전치부의교합면적은오히려감소한다고보고하였다. 이처럼이갈이나이악물기의영향에대해다각적으로연구되어왔으나하악운동에미치는영향에대해서는연구가적었다. 최근측정장비의발달에의해점차이에대한연구가진행되고있는데, Yamazaki 등 36) 은이악물기에의해하악의수평이동은거의없는반면수직상승이나타났다고하였고, Miura 등 37) 은상악구치는구개측및치근단방향으로, 이에반해하악구치는설측및치근단방향으로변위가있다고하였으며, Baba 등 38) 은교합면에올린레진블록의양태에따라하악의이동양태가달라편측성블록인경우에는이악물기로하악이반대측으로상승하였고, 소구치부에양측성인블록인경우구치부의강한상승이있었으나대구치부에양측성인경우는유의한이동이없었다고보고하였다. 그러나측두하악장애의주요한기여요인으로간주되는이악물기나강한씹기에의해나타나는하악의미세한운동양태에대해서는더많은연구가수행될필요가있으며, 이에본연구에서는하악운동의미세한변화를다각적으로관찰, 측정할수있는 BioPak 시스템을이용하여몇가지교합고경과형태및수의적이악물기힘의정도에따른실험적이악물기및씹기에서변화되는하악의비틀림회전운동의양태를규명하고자하였으며, 그결과다소의지견을얻었기에보고하고자한다. 1. 연구대상 Ⅱ. 연구대상및방법 저작계이상이없는건강한남자 14 명을선정하여실험을진행하였다. 이들의평균연령은 25.5±2.1 세이었으며, 신장은평균 173.4±3.9 cm, 체중은 69.7±8.4 kg으로계측되었다. 412
교합조건및이악물기힘의변화가하악의비틀림회전운동에미치는영향 2. 연구방법 1 교합조건의형성교합형태및고경의변화가하악의비틀림회전운동 (torque rotational movement) 에미치는영향을알기위하여세가지의교합조건을설정하였다. 첫째는자연치열, 다음으로웨이퍼장착, 그리고마지막으로웨이퍼에레진블록을추가로올린형태등으로하였다. 이러한교합형태하에서고경의변화를위해먼저자연치열에서이악물기및씹기 (biting) 를하고다음으로치열모형에 2 mm두께의아크릴레진판 (plate) 을압착시켜형성한웨이퍼 (wafer) 를상, 하악치열에모두장착하여고경이평균 3.6 mm증가된상태에서, 마지막으로상, 하악웨이퍼의좌, 우측대구치부에편평한형태의높이 5 mm레진블록을추가로올려자연치열에비해약 14 mm정도고경이증가된상태에서이악물기및씹기를시행하였다. 2 이악물기힘의발휘두가지수준의이악물기힘을발휘하여이악물기및나무젓가락씹기에서의교근의근활성을측정하였다. 이를위해 BioPak R system(bioresearch Inc., USA) 의 BioEMG를사용하였으며, 좌, 우측교근중앙부의피부에전극을부착하였다. 이악물기및씹기시의힘의발휘는교근의근활성을기준으로하였는데먼저교근이최대수의적수축 (maximum voluntary contraction) 을보이는이악물기를시행하여그때의근활성을최대 ( 강한 ) 씹기에서의측정치로하고, 다음으로교근의근활성이최대수의적수축의 50% 정도인상태로이악물기를시행하여절반 ( 약한 ) 씹기에서의측정치로하였다. 이러한측정을각각좌측과우측별로실시하였으며, 하악의비틀림회전운동양태를측정하기전에대상자에게각수준의이악물기에서근활성이재현될수있도록나무젓가락 ( 분리기, 5x5 mm ) 을씹는훈련을반복시켰다. 3 하악비틀림회전운동의측정비틀림회전운동의측정은동일한 BioPak 시스템의 BioEGN 을사용하였으며, 측정을위해하악절치부순면에측정용자석을부착하였다. 비틀림회전운동의측정을위한각교합조건및이악물기힘에서의 1 회의씹기운동은한번의이악물기와두번의씹는운동으로구성되어실시되었는데, 우선하악안정위를취하게하고그위치를각씹기운동에서의기준 위치로정한다음먼저나무젓가락이없는강한이악물기를하도록하였다. 이어서자연스러운개, 폐구운동을하면서구치부에위치시킨나무젓가락을강하게씹는운동을하도록하였으며, 다시개, 폐구운동을하여역시나무젓가락을강하게씹는세번째운동을하였다. 이러한과정을약한씹기에서도동일하게반복하였고각교합조건및이악물기힘에서의씹기운동은 2 회반복, 실시하여그평균을측정치로하였으며, 이때각씹기운동이끝난후 5 분간의휴식을취한후다음의씹기운동을실시하였다. 씹기운동에서관찰한항목으로는먼저한번의이악물기와두번의씹기로구성된운동전체의양상을분석하기위하여전두면상개구거리, 시상면상개구거리및후방이동거리, 수평면상좌, 우측운동거리, 개, 폐구시하악운동의속도, 그리고전두면과수평면상비틀림운동량등을기록하였으며, 다음으로한번의이악물기와두번의씹는운동에서각각의비틀림회전운동양상을분석하기위하여전두면과수평면상비틀림운동량을운동각과운동거리, 그리고운동방향으로나누어기록하였다. 4 통계처리수집된자료의분석과통계처리를위해서는 SPSS R 윈도우 (ver. 10.0) 프로그램을사용하였으며, 각각의통계검정에서이악물기힘의크기및좌측과우측씹기운동간비교에는 t- 검정을, 세가지교합조건간비교와각교합조건에서비틀림회전운동량의비교에는일원분산분석 (ANOVA) 검정을이용하였다. Ⅲ. 연구결과 강한씹기를시행한경우장치의장착여부나형태와관계없이전반적으로좌, 우측씹기간에는유의한차이가나타나지않았다 (Table 1). 자연치열에서전두면상개구거리는우측으로강한씹기를시행한경우 33.6 mm, 좌측으로강한씹기를시행한경우 33.2 mm로나타나거의동일한운동량을기록하였다. 이러한양상은장치를장착한경우에서도거의같게나타났으며, 아울러시상면상후방이동거리 (sagittal posterior) 나개구거리 (slant) 에서도유사한모습을보였다. 그러나전두면상개구거리나시상면상개구거리등은자연치열인경우보다웨이퍼를장착한경우감소하고여기에레진블록을올려장치를더높인경우더욱감소하는양상을보인반면시상면상후방이 413
동거리의경우에는자연치열에서 17 mm정도이던것이장치의장착으로다소감소하는경향을보였으나장치의형태간에는거의차이가없었다. 수평면상이동거리는씹는측에따라각각좌, 우측으로치우치는양상을보일수밖에없겠는데장치가없는자연치열에서는씹는측으로의운동량이분명하여좌우측간에유의한차이를보이는반면웨이퍼를장착한경우는그러한현상이다소덜분명해져경향만을보이게되고, 높이가더올려진블록장치에서는좌측으로씹을때와우측으로씹을때의양상이일관되지않은모습을보이고있다. 여기서주목되는것은우측으로씹을때의저작측인우측이동거리는장치로인해교합이높아짐에따라감소하는양이많은반면좌측으로씹을때의좌측이동거리는비록유의하기는하지만감소하는양이우측에비해상대적으로적게나타났다. 개구와폐구운동간의속도비교에서는전반적으로항상개구운동에서빠른경향을보였으며, 상호간에부분적으로는유의한차이를보이기도하였으나자연치열및장치를장착한경우에일관되는양상을보이지는않았다. 그러나이때개, 폐구운동모두에서의속도는전두면상개구거리나시상면상개구거리의경우와마찬가지로자연치열에서가장빠르고다음이웨이퍼장착, 그리고블록을올린장치에서가장느린순서로관찰되었으며, 이러한양상은좌, 우측에걸쳐대체로유의한차이를보였다. 하악운동시전치부에서기록된비틀림운동량의각도는전두면상에서좌측이올라가는경우자연치열이나웨이퍼에서는 4 도내외를보였으나블록을올린장치에서는 3 도내외로나타나대체로교합이높아질수록감소되는경향을보였다. 그러나이러한모습은우측이올라가는경우에서는거의나타나지않았다. 이때자연치열에서는각각좌측과우측으로의비틀림운동각이매우유사하였으나장치를장착한경우에서는자연치열에비해운동각이감소하거나좌, 우측씹기간에차이가있는경향을보였다. 또한좌우측운동각의합계는우측으로씹을경우교합이높아지면서감소하는양상을보였으나 (p<0.05) 좌측으로씹을경우에는유의한차이를나타내지않았다. 수평면상비틀림운동각은전두면상운동각에비해좌, 우측씹기간에차이가나타나우측으로씹을때좌측이전방으로나오는각은자연치열이나장치장착모두에서유의하게크거나그러한경향을보였으나반면좌측으로씹을때우측이전방으로나오는 양상은그러하지못하였다 (Table 1). 이때좌우측운동각의합계는전두면상비틀림운동각의경우와유사하게나타나우측으로씹을경우교합이높아지면서감소하는양상을보였으나 (p<0.05) 좌측으로씹을경우에는유의한차이를나타내지않았다. 이악물기시근활성수준을절반정도로하여씹기를한경우에서도최대로강한씹기를시행한경우와마찬가지로전두면상개구거리를비롯한시상면상개구거리와후방이동거리등모든운동범위가좌, 우측씹기간에유의한차이를나타내지않았으며, 자연치열보다장치를장착한경우에서, 그리고블록을올린경우에서더욱운동거리가감소하는양상역시강한씹기를시행한경우와마찬가지로나타났다 (Table 2). 또한수평면상운동거리역시강한씹기를시행한경우와마찬가지로자연치열에서는각각의씹는쪽으로하악이유의하게이동하였으나웨이퍼및블록을올린장치에서는유의한차이가없이다만그러한경향을보이면서전반적으로모든교합형태에서강한씹기를한경우에비해좌우측간측정치의차이가감소하였다. 전두면상비틀림운동각역시강한씹기를시행한경우와마찬가지로우측으로씹거나좌측으로씹거나에관계없이좌측으로올라가는각도가우측으로올라가는각도에비해큰경향을보였으나강한씹기를시행한경우보다일관성이더낮았으며이러한양상은수평면상비틀림운동각에서도유사하게나타나전체적인경향은강한씹기를시행한경우와유사하나좌우측간의차이는더감소한결과를보였다. 강한씹기를한경우와그수축력의절반정도로씹기를한경우를각각좌, 우측별로비교한결과전두면상개구거리와시상면상개구거리, 그리고후방이동거리에서는대체로우측으로씹기를한경우에서좌측에비해차이가더현저하게나타났다. 그러나수평면상이동거리는씹는힘간에대체로차이를보이지않았으며, 특히우측으로씹는경우저작측인우측에서는좌측으로씹는경우의저작측인좌측에비해더욱차이를보이지않았다 (Table 3, 4). 개, 폐구운동속도는자연치열에서는좌, 우측모두강한씹기에서절반정도로씹기에비해속도가빠른것으로나타났으나장치를장착한두가지경우에서는비록그러한경향은일관되게나타났으나유의한차이는부분적으로나타났다. 전두면상및수평면상을통틀어비틀림운동각의차이에대한조사에서는우측으로씹은경우에서좌 414
교합조건및이악물기힘의변화가하악의비틀림회전운동에미치는영향 Table 1. Mean value of each component of mandibular movement with maximum voluntary contraction(mvc) in natural dentition in wafer in block mounted right biting left biting sig. right biting left biting sig. right biting left biting sig. opening( mm ) 33.6 ± 4.5 33.2 ± 5.2 NS 28.0 ± 4.7 28.8 ± 6.1 NS 20.6 ± 5.4 20.8 ± 5.4 NS sagittal slant 38.1 ± 5.9 37.2 ± 6.2 NS 32.0 ± 5.7 32.6 ± 6.8 NS 25.4 ± 7.0 25.2 ± 6.9 NS distance ( mm ) posterior 17.8 ± 4.4 16.6 ± 3.7 NS 14.3 ± 5.1 14.1 ± 4.1 NS 14.2 ± 5.3 13.4 ± 4.9 NS horizontal distance( mm ) velocity ( mm /s) right 8.8 ± 3.5 5.1 ± 3.0 *** 7.0 ± 3.8 5.1 ± 2.8 4.9 ± 2.5 4.4 ± 2.7 NS left 1.8 ± 1.6 5.4 ± 2.1 *** 3.1 ± 2.9 4.7 ± 1.6 1.8 ± 1.9 3.3 ± 1.9 ** opening 220.5 ± 59.6 206.8 ± 44.0 NS 176.7 ± 54.4 177.4 ± 46.8 NS 142.2 ± 42.9 155.2 ± 51.2 NS closing 160.6 ± 57.2 180.2 ± 75.3 NS 152.4 ± 47.0 165.6 ± 61.7 NS 136.4 ± 45.9 119.6 ± 42.4 NS left up 4.0 ± 1.5 4.0 ± 2.1 NS 4.4 ± 1.9 3.7 ± 2.6 NS 2.9 ± 1.7 3.2 ± 1.6 NS right up 2.8 ± 2.2 2.8 ± 1.5 NS 2.2 ± 1.4 2.9 ± 1.1 2.1 ± 1.4 2.6 ± 1.2 NS horizontal right fwd 1.3 ± 0.9 2.3 ± 1.8 NS 1.7 ± 1.1 2.3 ± 1.3 NS 1.4 ± 1.0 3.4 ± 1.8 ** left fwd 8.3 ± 4.0 5.5 ± 3.9 *** 7.7 ± 4.1 5.2 ± 2.4 ** 5.1 ± 2.4 3.9 ± 2.4 fwd : forward NS : not significant, : p<0.1, ** : p<0.01, *** : p<0.001 Table 2. Mean value of each component of mandibular movement with 50% of maximum voluntary contraction in natural dentition in wafer in block mounted right biting left biting sig. right biting left biting sig. right biting left biting sig. opening( mm ) 28.3 ± 4.2 27.3 ± 8.5 NS 24.5 ± 5.6 26.7 ± 7.3 NS 18.3 ± 4.8 18.2 ± 4.4 NS sagittal distance( mm ) slant 31.3 ± 4.8 31.3 ± 9.5 NS 27.5 ± 6.5 30.0 ± 8.1 NS 21.9 ± 5.8 22.2 ± 5.8 NS posterior 11.5 ± 4.1 12.0 ± 4.2 NS 11.1 ± 4.6 12.1 ± 4.2 NS 11.4 ± 3.6 11.2 ± 3.2 NS horizontal right 8.6 ± 3.2 5.7 ± 3.7 * 7.1 ± 2.6 6.5 ± 3.6 NS 4.9 ± 2.2 5.2 ± 2.5 NS distance ( mm ) left 2.3 ± 2.1 4.6 ± 2.0 *** 2.5 ± 1.8 3.6 ± 2.2 NS 3.1 ± 2.4 1.7 ± 1.3 velocity ( mm /s) opening 150.4 ± 29.0 171.4 ± 49.4 157.7 ± 48.9 155.1 ± 49.6 NS 132.4 ± 45.0 133.8 ± 36.6 NS closing 122.1 ± 34.4 143.9 ± 52.8 124.2 ± 42.4 145.4 ± 55.2 99.2 ± 34.7 116.4 ± 47.5 * left up 4.2 ± 1.3 3.3 ± 1.8 NS 3.6 ± 1.2 3.5 ± 2.3 NS 3.3 ± 1.1 2.9 ± 1.7 NS right up 2.1 ± 1.9 2.7 ± 1.1 NS 2.0 ± 1.4 3.3 ± 1.5 * 2.4 ± 1.9 2.2 ± 1.2 NS horizontal right fwd 1.2 ± 0.9 1.6 ± 0.8 NS 1.1 ± 0.9 1.6 ± 1.1 NS 1.7 ± 1.2 2.5 ± 1.4 left fwd 7.0 ± 3.0 4.9 ± 2.2 ** 5.8 ± 4.3 4.7 ± 2.4 NS 5.0 ± 2.3 3.9 ± 2.4 * fwd : forward NS : not significant, : p<0.1, * : p<0.05, ** : p<0.01, *** : p<0.001 415
Table 3. Mean value at maximum voluntary contraction(mvc) and 50% of MVC in right side biting in natural dentition in wafer in block mounted maximum half sig. maximum half sig. maximum half sig. opening( mm ) 33.6 ± 4.5 28.3 ± 4.2 *** 28.0 ± 4.7 24.5 ± 5.6 *** 20.6 ± 5.4 18.3 ± 4.8 * sagittal distance( mm ) horizontal distance( mm ) velocity ( mm /s) horizontal slant 38.1 ± 5.9 31.3 ± 4.8 *** 32.0 ± 5.7 27.5 ± 6.5 *** 25.4 ± 7.0 21.9 ± 5.8 * posterior 17.8 ± 4.4 12.3 ± 3.1 *** 14.3 ± 5.1 11.1 ± 4.6 *** 14.2 ± 5.3 11.4 ± 3.6 * right 8.8 ± 3.5 8.6 ± 3.2 NS 7.0 ± 3.8 7.1 ± 2.6 NS 4.9 ± 2.5 4.9 ± 2.2 NS left 1.8 ± 1.6 2.3 ± 2.1 NS 3.1 ± 2.9 2.5 ± 1.8 NS 1.7 ± 1.9 3.1 ± 2.4 ** opening 220.5 ± 59.6 150.4 ± 29.0 *** 176.7 ± 54.4 157.7 ± 48.9 NS 142.2 ± 42.9 132.4 ± 45.0 NS closing 160.6 ± 57.2 122.1 ± 34.4 * 152.4 ± 47.0 124.2 ± 42.4 ** 136.4 ± 45.9 99.3 ± 34.7 ** left up 4.0 ± 1.5 4.2 ± 1.3 NS 4.4 ± 1.9 3.6 ± 1.2 * 2.9 ± 1.7 3.3 ± 1.1 NS right up 2.8 ± 2.2 2.1 ± 1.9 2.2 ± 1.4 2.0 ± 1.4 NS 2.1 ± 1.4 2.4 ± 1.9 NS right fwd 1.3 ± 0.9 1.2 ± 0.9 NS 1.7 ± 1.1 1.1 ± 0.9 * 1.4 ± 1.0 1.7 ± 1.2 NS left fwd 8.3 ± 4.0 7.0 ± 3.0 * 7.7 ± 4.1 5.8 ± 4.3 * 5.1 ± 2.4 5.0 ± 2.3 NS fwd : forward NS : not significant, : p<0.1, * : p<0.05, ** : p<0.01, *** : p<0.001 Table 4. Mean value at maximum voluntary contraction(mvc) and 50% of MVC in left side biting in natural dentition in wafer in block mounted maximum half sig. maximum half sig. maximum half sig. opening( mm ) 33.2 ± 5.2 27.3 ± 8.5 ** 28.8 ± 6.1 26.7 ± 7.3 * 20.8 ± 5.4 18.2 ± 4.4 * sagittal slant 37.2 ± 6.2 31.3 ± 9.5 * 32.6 ± 6.8 30.0 ± 8.1 * 25.2 ± 6.9 22.2 ± 5.8 distance( mm ) posterior 15.7 ± 4.9 12.0 ± 4.2 *** 14.1 ± 4.1 12.1 ± 4.2 13.4 ± 4.9 11.2 ± 3.2 NS horizontal right 5.1 ± 3.0 5.7 ± 3.7 NS 5.1 ± 2.8 6.5 ± 3.6 4.4 ± 2.7 5.2 ± 2.5 NS distance( mm ) left 5.4 ± 2.1 4.6 ± 2.0 4.7 ± 1.6 3.6 ± 2.2 NS 3.3 ± 1.9 1.7 ± 1.3 * velocity ( mm /s) horizontal opening 206.8 ± 44.0 171.4 ± 49.4 * 177.4 ± 46.8 155.1 ± 49.6 ** 155.2 ± 51.2 133.8 ± 36.6 closing 180.2 ± 75.8 143.9 ± 52.8 * 165.6 ± 61.7 145.4 ± 55.2 * 119.6 ± 42.4 116.4 ± 47.5 NS left up 4.0 ± 2.1 3.3 ± 1.8 NS 3.7 ± 2.6 3.5 ± 2.30 NS 3.2 ± 1.6 2.9 ± 1.7 NS right up 2.8 ± 1.5 2.7 ± 1.1 NS 2.9 ± 1.1 3.3 ± 1.5 NS 2.6 ± 1.2 2.2 ± 1.2 NS right fwd 2.3 ± 1.8 1.6 ± 0.8 NS 2.3 ± 1.3 1.6 ± 1.1 3.4 ± 1.8 2.5 ± 1.4 ** left fwd 5.5 ± 3.9 4.9 ± 2.2 NS 5.2 ± 2.4 4.7 ± 2.4 NS 3.9 ± 2.4 3.9 ± 2.4 NS fwd : forward NS : not significant, : p<0.1, * : p<0.05, ** : p<0.01, *** : p<0.001 416
교합조건및이악물기힘의변화가하악의비틀림회전운동에미치는영향 측으로씹은경우에비해강한씹기에서의비틀림운동각이절반정도로씹기에서의운동각보다큰경우가더자주나타났으며, 전체적으로볼때강한씹기에서하악의비틀림회전운동량이큰경향을보였다. 한편비틀림운동각의관찰에서주목되는현상은전두면상운동각의합에비해수평면상운동각의합이전반적으로큰경향을보이는것으로자연치열과웨이퍼, 그리고블록을올린장치등세가지교합형태모두에서특히우측으로강한씹기를한경우유의하게큰양상을보였다. 자연치열과두가지장치를장착하였을때의차이를비교한결과최대로강한씹기와절반정도의약한씹기모두에서전두면상개구거리와시상면상개구거리에서자연치열에서운동거리가가장길고다음이웨이퍼장착시, 그리고블록을올린장치를장착한경우에서운동범위가가장적은양상을보였으며이러한모습은좌, 우측에관계없이동일하였다 (Table 5, 6). 이러한결과는수평면상운동거리에서도유사하게나타나우측으로씹은경우우측에서, 좌측으로씹은경우좌측에서유의한차이를보이며일 관되게나타났다. 그러나시상면상후방이동거리는어느경우에서도유의한차이를보이지않았다. 그러나이러한양상과달리운동속도에서는씹는힘의차이가분명하게나타나강한씹기에서는개, 폐구운동모두에서대체로자연치열에서가장빠르고블록을올린장치에서가장느린양상을보였으나절반정도로씹기에서는어느경우에서도유의한차이를보이지않았다. 전두면상및수평면상비틀림운동각은강한씹기에서나절반정도로씹기모두에서대부분의경우장치장착에따른차이를보이지않았다. 그러나각평면상의좌, 우측운동각을합친경우에서는다소다르게나타나좌측으로씹기를한경우에서는여전히차이가없었으나우측으로씹기를한경우에서는유의한차이를보였다 (p<0.05). 이악물기 1 회및 2 회의씹기등세번의씹는운동으로이루어진각조건의운동에서나무젓가락인분리기가있는경우와그렇지않은경우, 즉높이의차와더불어분리기로인한상, 하악간의균등하지못한접촉이하악의비틀림회전운동에어떠한영향을 Table 5. Difference among three occlusal conditions with maximum voluntary contraction(mvc) in natural dentition right biting in wafer in block mounted sig. in natural dentition left biting in wafer in block mounted opening( mm ) 33.6 ± 4.5 28.0 ± 4.7 20.6 ± 5.4 *** 33.2 ± 5.2 28.8 ± 6.1 20.8 ± 5.4 *** sig. sagittal distance( mm ) horizontal distance( mm ) velocity ( mm /s) slant 38.1 ± 5.9 32.0 ± 5.7 25.4 ± 7.0 *** 37.2 ± 6.2 32.6 ± 6.8 25.2 ± 6.9 *** posterior 17.8 ± 4.4 14.3 ± 5.1 14.2 ± 5.3 NS 15.7 ± 4.9 14.1 ± 4.1 13.4 ± 4.9 NS right 8.8 ± 3.5 7.0 ± 3.8 4.9 ± 2.5 ** 5.1 ± 3.0 5.1 ± 2.8 4.4 ± 2.7 NS left 1.8 ± 1.6 3.1 ± 2.9 1.7 ± 1.9 NS 5.4 ± 2.1 4.7 ± 1.6 3.3 ± 1.9 * opening 220.5 ± 59.6 176.7 ± 54.4 142.2 ± 42.9 *** 206.8 ± 44.0 177.4 ± 46.8 155.2 ± 51.2 * closing 160.6 ± 57.2 152.4 ± 47.0 136.4 ± 45.9 NS 180.2 ± 75.8 165.6 ± 61.7 119.6 ± 42.4 * left up 4.0 ± 1.5 4.4 ± 1.9 2.9 ± 1.7 4.0 ± 2.1 3.7 ± 2.6 3.2 ± 1.6 NS right up 2.8 ± 2.2 2.2 ± 1.4 2.1 ± 1.4 NS 2.8 ± 1.5 2.9 ± 1.1 2.6 ± 1.2 NS horizontal right fwd 1.3 ± 0.9 1.7 ± 1.1 1.4 ± 1.0 NS 2.3 ± 1.8 2.3 ± 1.3 3.4 ± 1.8 NS left fwd 8.3 ± 4.0 7.7 ± 4.1 5.1 ± 2.4 * 5.5 ± 3.9 5.2 ± 2.4 3.9 ± 2.4 NS fwd : forward NS : not significant, : p<0.1, * : p<0.05, ** : p<0.01, *** : p<0.001 417
Table 6. Difference among three occlusal conditions with 50% of maximum voluntary contraction in natural dentition right biting in wafer in block mounted sig. in natural dentition left biting in wafer in block mounted opening( mm ) 28.3 ± 4.2 24.5 ± 5.6 18.3 ± 4.8 *** 27.3 ± 8.5 26.7 ± 7.3 18.2 ± 4.4 ** sagittal slant 31.3 ± 4.8 27.5 ± 6.5 21.9 ± 5.8 *** 31.3 ± 9.5 30.0 ± 8.1 22.2 ± 5.8 ** distance( mm ) posterior 11.5 ± 4.0 11.1 ± 4.6 11.4 ± 3.6 NS 12.0 ± 4.2 12.1 ± 4.2 11.2 ± 3.2 NS horizontal right 8.6 ± 3.2 7.1 ± 2.6 4.9 ± 2.2 ** 5.7 ± 3.7 6.5 ± 3.6 5.2 ± 2.5 NS distance( mm ) left 2.3 ± 2.0 2.5 ± 1.8 3.1 ± 2.4 NS 4.6 ± 2.0 3.6 ± 2.2 1.7 ± 1.3 *** velocity opening 150.4 ± 29.0 157.7 ± 48.9 132.4 ± 45.0 NS 171.4 ± 49.4 155.1 ± 49.6 133.8 ± 36.6 NS ( mm /s) closing 122.0 ± 34.4 124.2 ± 42.4 99.3 ± 34.7 NS 143.9 ± 52.8 145.4 ± 55.2 116.4 ± 47.5 NS left up 4.2 ± 1.3 3.6 ± 1.2 3.3 ± 1.1 NS 3.3 ± 1.8 3.5 ± 2.3 2.9 ± 1.7 NS right up 2.1 ± 1.9 2.0 ± 1.4 2.4 ± 1.9 NS 2.7 ± 1.1 3.3 ± 1.5 2.2 ± 1.2 NS horizontal right fwd 1.2 ± 0.9 1.1 ± 0.9 1.7 ± 1.2 NS 1.6 ± 0.8 1.6 ± 1.1 2.5 ± 1.4 left fwd 7.0 ± 3.0 6.5 ± 3.1 5.0 ± 2.3 NS 4.9 ± 2.2 4.7 ± 2.4 3.9 ± 2.4 NS fwd : forward NS : not significant, : p<0.1, * : p<0.05, ** : p<0.01, *** : p<0.001 sig. Table 7. Mean value of mandibular torque rotational movement by stick biting in three occlusal conditions with maximum voluntary contraction(mvc) in natural dentition horiz. in wafer horiz. in block mounted sig. (naturalwaferblock) horiz. horiz. right biting left biting without stick with stick1 with stick2 sig. without stick with stick1 with stick2 sig. angle -0.5 ± 0.5 1.0 ± 1.0 1.4 ± 1.5 * -0.4 ± 0.3 1.1 ± 0.8 1.2 ± 1.1 *** dist. -0.4 ± 0.5 1.0 ± 0.8 1.3 ± 1.2 ** -0.4 ± 0.3 1.0 ± 0.7 1.1 ± 0.9 *** angle -0.7 ± 0.6 1.2 ± 0.9 1.3 ± 0.9 *** -0.7 ± 0.5 1.2 ± 1.1 1.4 ± 1.2 ** dist. -0.6 ± 0.5 1.1 ± 0.8 1.2 ± 0.8 *** -0.6 ± 0.5 1.0 ± 0.9 1.2 ± 1.0 ** angle -1.2 ± 1.5 0.4 ± 1.5 0.1 ± 1.8 NS -1.1 ± 1.1 0.4 ± 2.2 0.3 ± 2.1 NS dist. -1.1 ± 1.3 0.9 ± 1.0 1.2 ± 0.9 * -1.0 ± 1.0 1.3 ± 1.3 1.3 ± 1.3 * angle -0.6 ± 0.5 1.6 ± 0.9 1.1 ± 1.0 *** -1.0 ± 1.1 1.9 ± 1.4 1.4 ± 1.1 ** dist. -0.5 ± 0.5 1.4 ± 0.8 1.0 ± 0.8 *** -0.8 ± 1.0 1.7 ± 1.2 1.2 ± 0.9 ** angle -1.0 ± 0.7 0.6 ± 1.8 0.3 ± 2.0 NS -1.0 ± 0.8 1.3 ± 1.6 0.7 ± 1.7 dist. -0.8 ± 0.6 1.4 ± 0.9 1.3 ± 1.0 *** -0.9 ± 0.7 1.4 ± 1.2 1.2 ± 1.0 ** angle -0.6 ± 0.6 1.6 ± 1.4 1.9 ± 1.1 *** -0.8 ± 0.5 1.3 ± 1.2 1.7 ± 1.2 ** dist. -0.5 ± 0.6 1.4 ± 1.2 1.6 ± 1.0 *** -0.7 ± 0.5 1.1 ± 1.0 1.5 ± 1.0 ** angle NS NS NS NS NS dist. NS NS NS NS NS angle NS NS NS NS NS NS dist. NS NS NS NS NS NS - means move backward or upward from the reference position, "+" means opposite direction horiz. : horizontal, : rotation, dist. : distance( mm ) NS : not significant, : p<0.1, * : p<0.05, ** : p<0.01, *** : p<0.001 418
교합조건및이악물기힘의변화가하악의비틀림회전운동에미치는영향 미치는지조사한결과강하게씹는경우자연치열의좌, 우측모두에서이악물기에의해안정위에서보다후상방으로이동한하악위가첫번째분리기씹기에의해전두면상및수평면상비틀림회전운동량이모두증가하면서전하방으로이동하였고, 이때두번째분리기씹기에의해더욱전하방으로이동하는양상을보였으며, 이러한양상은절반정도로씹는경우에서도거의유사하였다 (Table 7, 8). 웨이퍼를장착하거나블록을올린장치를장착한경우에서는자연치열에서보였던일관된변화의경향이거의나타나지않았으며, 다만부분적으로볼때블록을올린장치에서는수평면상비틀림회전운동량이자연치열의경우와유사하게분리기씹기에의해점차증가되는양상을, 그리고웨이퍼장치에서는수평면상비틀림회전운동량이이와달리분리기를처음씹을때가장크고두번째로분리기를씹는경우에서는비틀림운동량이감소하는경향을보였다. 한편절반정도로씹은경우에는웨이퍼장치에서와 블록을올린장치모두에서수평면상비틀림회전운동량이좌측의경우는유의하게, 그리고우측의경우는경향을보이면서분리기를씹는경우에서분리기없이장치를악물기하는경우보다비틀림운동량이증가하는모습을나타내었다. 종합해보면분리기없이악물기를한후이어지는두번의분리기씹기를통해시행된각조건하에서의씹기운동에서나타난비틀림회전운동의전체적인모습은교합조건이나이악물기수준의차이에관계없이수평면상비틀림운동각의합이전두면상운동각의합에비해큰경향을보였다. 이와는달리 3 회에걸친각각의씹는운동을개별적으로분석한결과에서는자연치열과달리장치를장착한경우에서전두면상비틀림운동량은분리기의영향이유의하지않았던반면수평면상비틀림회전운동량은비록전체적이지는않았으나부분적인유의성을보여분리기의영향을더많이받는것으로보였으며, 이때두평면상운동량은상호간에유의한차이를나타내지않았다. Table 8. Mean value of mandibular torque rotational movement by stick biting in three occlusal conditions with 50% of maximum voluntary contraction(mvc) in natural dentition in wafer in block mounted sig. (naturalwaferblock) right biting left biting without stick with stick1 with stick2 sig. without stick with stick1 with stick2 sig. angle -0.4 ± 0.4 0.6 ± 1.0 0.8 ± 1.6 NS -0.4 ± 0.2 0.9 ± 0.9 0.9 ± 1.0 ** dist. -0.3 ± 0.3 0.8 ± 0.6 1.0 ± 1.2 ** -0.3 ± 0.2 0.9 ± 0.7 0.8 ± 0.8 *** horiz. angle -0.7 ± 0.5 1.0 ± 0.6 1.1 ± 0.9 ** -0.4 ± 0.4 1.3 ± 0.7 1.4 ± 0.9 *** dist. -0.5 ± 0.4 0.8 ± 0.5 0.9 ± 0.8 ** -0.3 ± 0.3 1.2 ± 0.6 1.2 ± 0.8 *** horiz. horiz. horiz. angle -0.8 ± 0.8 0.5 ± 1.0 0.8 ± 0.9 NS -1.1 ± 0.9 0.3 ± 2.4 0.3 ± 2.3 NS dist. -0.7 ± 0.7 0.8 ± 0.6 0.9 ± 0.5 * -1.3 ± 1.1 1.7 ± 1.2 1.7 ± 1.0 *** angle -0.5 ± 0.4 0.7 ± 0.6 0.9 ± 0.5 ** -0.6 ± 0.6 1.6 ± 1.3 1.6 ± 1.0 *** dist. -0.4 ± 0.4 0.6 ± 0.5 0.8 ± 0.5 ** -0.5 ± 0.5 1.4 ± 1.1 1.4 ± 0.9 *** angle -1.4 ± 1.2 0.4 ± 1.8 1.0 ± 1.8 NS -1.1 ± 1.2 1.1 ± 1.4 0.8 ± 1.4 dist. -1.2 ± 1.0 1.2 ± 1.0 1.4 ± 1.1 ** -0.9 ± 1.0 1.2 ± 1.0 1.0 ± 1.1 * angle -0.7 ± 0.8 1.2 ± 1.1 1.1 ± 0.9 ** -0.5 ± 0.5 1.4 ± 0.9 1.3 ± 1.2 *** dist. -0.6 ± 0.7 1.0 ± 0.9 1.0 ± 0.8 ** -0.5 ± 0.5 1.2 ± 0.8 1.1 ± 1.0 *** angle ** NS NS * NS NS dist. * ** * * *** *** angle NS NS NS NS NS NS dist. NS NS NS NS NS NS - means move backward or upward from the reference position, "+" means opposite direction horiz. : horizontal, : rotation, dist. : distance( mm ) NS : not significant, : p<0.1, * : p<0.05, ** : p<0.01, *** : p<0.001 419
Ⅳ. 총괄및고찰 측두하악장애의다양한원인요소를찾아내어사전에예방을하거나또는치료초기부터적절히제거내지차단할수있다면최근들어더욱복잡한양태로발현되는측두하악장애의관리에크게유익할것이다. 또한치료수요를제대로파악하고그에효과적으로부응하기위한대비책을세울수있다면치의학분야의한계를넘어주요한만성통증의하나로인식되기시작하는측두하악장애로인한사회적손실을상당히줄일수있을것이다. 그결과특별히이러한논리를표면적으로제시하지는않았지만측두하악장애의발현과지속, 그리고치료예후에관련되는요인들을규명하며치료결과를예측하고자하는노력들이꾸준히진행되어왔다. 물론이러한노력을가로막는커다란요인중의하나는측두하악장애가지니는자체적인문제로장애가상당수사람들에서는일과성이거나자기한정성인양상을보인다는특징을빼놓을수없다 39). 그로인해, 예를들어당뇨병이나고혈압과같이국가적인차원에서대비책을강구해야할필요성을얻지못하게되고따라서개인적인치료차원에서머물게되다보니측두하악장애의진단과치료및사후관리에이르는전과정에걸쳐진료수혜자인환자들에게올바른진료서비스를제공하지못하고있는것이현실적인문제라고할수있다. 그러나다른연구는시간적경과로볼때일시적인증상의호전이있을수있으나결국에는장기적인악화의길로들어서 40), 2.5 년후의추적조사결과증상이있음에도치료를받지않았던악관절내장환자의 1/3~1/4 에서여전히증상이존재하였다고보고하였으며 41), 또한일부의환자에서는악관절면의병적변화가결국통증과심각한하악의위치이상을초래하였다고하였다 42). 이러한현상에대해 Brooke 등 43) 은추적조사기간을길게잡을경우대부분환자에서악화되는것이일반적이며따라서치료받지않을경우결국만성통증으로이행될것이라고추정하는것이더합리적일것이라고하였다. 이처럼측두하악장애가여러원인에의해발생하게되면일부환자에게는완전한치유가쉽지않은문제가될수있으므로각각의가능한원인에대한다각적인연구는매우필요한과제가되고있다. 측두하악장애의치료수요에대해보고한 Kirveskari 44) 는촉진시압통을가진사람들이그렇지않은사람들에 비해결국치료를필요로하는비율이높으며, 여기에이악물기습관을함께가지고있을경우는더욱유의하게차이를보인다고하였으나이악물기만을가진경우는그렇지않은사람에비해유의하지는않으나치료요구의경향이강하다고하였다. 이와같이이악물기는여전히측두하악장애의발현과치료수요에서중요한부분을차지하고있다. 본연구에서이용한강한씹기에서의이악물기힘은수의적이악물기로교근의활성이최대가될때의교합력을말하며, 약한씹기에서의이악물기힘은최대근활성의 50% 수준에서의교합력으로, 이를이용한이유로 Thompson 등 45) 은최대보다적은 (submaximal) 수축력의수의적이악물기를연습한후최대교합력이증가되고교합력당근활성은감소하며, 피로저항성역시유의하게증가됨을보였다고하였으며, Kiliaridis 등 46) 도체계적인씹기 (chewing) 연습을통해교합력이상당히개선되었다고하여적절한이악물기연습이저작근의근력을강화시키는데도움이될수도있음을시사한보고에근거하였다. 이때 Thompson 등 45) 이실시한최대보다적은수준의근수축력은최대수축력의 50~75% 로본연구에서는이중 50% 로결정하였다. 이수준을얼마로정하는가는 Hagberg 등 47) 및 Kumagai 등 48) 의연구에서보고된바와같이근활성, 교합접촉의수, 교합력, 접촉면적등어느것을조사하든지간에수축력이 20% 에서 100% 에이르는동안수축력과단일기울기의직선적관계라기보다는대체로측정된수축력의단계마다기울기가변화된양태를보이고있어연구방법을고안하는과정에서그다지큰요인은아니라고생각되었다. 다만수축력이너무적을경우현실적으로처방될수있는운동요법도되지못하고아울러하악의위치변화에미치는영향도미미할것이므로결과적으로이악물기의영향을제대로나타내지못할것으로판단되어본연구에서는 50% 로약한이악물기수준을정하였다. 하악의운동은분류기준에따라다양하게구분된다. 일반적으로운동범위에서는한계운동이나습관운동으로, 관찰부위에서는절치부운동이나과두운동으로, 운동양태에서는회전운동이나활주운동으로, 기능구분에서는단순개폐구운동이나저작운동으로, 그리고조직에대한건강도에서는기능운동이나이상기능운동으로구별된다. 그러나어느형태의운동이든간에한번의하악운동에는이러한여러기준에의해구분될수있는운동양상이다양하게포함되어있 420
교합조건및이악물기힘의변화가하악의비틀림회전운동에미치는영향 으므로현실적으로는그중에서어느특정한면을대상으로하거나기준을중심으로하여하악운동을연구하여왔다. 이갈이나이악물기시의하악운동에대한연구가드문이유의하나는하악과두의회전운동및활주운동에의해나타나는하악의전체적인운동양태는정상인이나측두하악장애환자에서나름대로정상적이거나장애에따른특징적모습을나타내는반면개구량이거의없는이갈이나이악물기에서는통상적인관찰방법으로는미세한과두운동의양태나운동량을측정하기어려운제약이있기때문이다. 그러나점차측정도구나장비의발달이진행되면서본연구에서와같이하악의절치부에부착된자석의비틀림회전운동등을근거로하여하악의전체적인움직임과운동량을추정할수있게되었으며, 그결과이악물기에의해야기되는하악의사소한운동양태를관찰, 분석하게되었다. 하악의비틀림회전운동이란현실적으로대부분의하악운동이순수회전운동이아니고어느형태로는하악와내에서활주운동을하게되며, 따라서하악이움직일때순수한수평및수직운동을할수없으며양측과두의움직임이상이함으로해서결과적으로전체적으로볼때는하악체가비틀림회전력을받는운동을하게되는양태에근거해붙여진이름으로이러한측정방법을최초로도입한 BioPak 시스템을이용할경우기준이되는하악위에서새로운하악위로하악이이동하는방향과각도및거리등을측정할수있다. 한 49) 이하악의비틀림회전운동에대해국내최초로보고한이래다수의연구가수행되어졌다 50-55). 그러나대부분이측두하악장애환자에서관절잡음의발생이나과두걸림에의한변화, 그리고하악의각종운동이나교합장치에따른차이에대해비틀림회전운동량의변화를보고한것으로서본연구에서의이악물기나씹기운동이비틀림회전운동량에미치는영향에대한연구결과를평면적으로단순비교하기에어려움이있다. 또비틀림회전운동양태를관찰하는데있어두가지프로그램이이용되는데이때서로다른프로그램으로관찰, 분석한경우에도역시연구결과의단순비교는의미가없다. 이러한결과가초래된것은비틀림회전운동에대한다각적연구나유용한연구결과가적어이운동에대한평가가지니는진단학적가치가확립되지못하고따라서연구자들의공통된견해가확립되어있지않기때문으로생각 되었다. 개구량이큰발음운동에서의비틀림회전운동량을관찰한김등 53) 은교합장치의장착여부에관계없이측두하악장애환자군에서정상대조군에비해전두면및수평면상비틀림회전운동량이크게나타났다고하면서이때같은군내에서는장치장착에의해유의한차이가나타나지않았다고하였다. 본연구에서도장치의장착이나형태, 그리고이악물기의수준에관계없이거의모든경우에서전두면및수평면상비틀림회전운동량에유의한차이를보이지않아기준이되는하악위를설정한이후에는단순히장치의장착만으로비틀림회전운동량이거의변화되지않음을나타내었다. 그러나김등 53) 은장치의장착이전두면상개구거리및시상면상개구거리에도영향을미치지않는것으로보고한반면본연구에서는교합고경이높은장치로갈수록이들거리가유의하게줄어드는양상을보여상이한결과를나타내었는데이는아마도자연치열에서전두면상개구거리가 7 mm정도인발음운동에비해본연구에서의이악물기에이어지는자연스런씹기운동시 30 mm를넘는개구량은상대적으로매우큰것으로간주될수있으며, 따라서장치의효과가반영되었던것으로판단하였다. 비틀림회전운동에대한교합접촉의효과를배제하기위하여상, 하악에판토그라프용클러치를장착하고관찰한한등 52) 은클러치의장착으로전방및양측방으로의운동시수직적개구량은유의하게증가한반면정중개구로를따르는개구운동의개구량은오히려감소하는경향을보였다고하면서그러나이때개구량과는반대로전두면및수평면상의비틀림회전운동량은클러치의장착으로전방및양측방으로의운동에서거의변화를보이지않은반면정중개구운동에서는증가되는양상을보였다고하였다. 이에대해씹기에서의개구운동만을조사한본연구에서는장치의장착으로정중개구량은감소하였으나전두면및수평면상비틀림회전운동량은유의한차이가거의없어다소상이한결과를나타내었는데이는아마도개구량에있어서는클러치의장착이나본연구에서웨이퍼나추가로레진블록을올린장치의장착이나에관계없이하악운동시불편감을초래하였기때문으로보이나비틀림회전운동에있어서는한등 52) 의연구는개구운동이위주인반면본연구에서는이악물기와씹기등의강한폐구운동이포함되어있기때문으로간주되었다. 421
최대로이악물기를할때와절반정도로이악물기를할때전두면및수평면상비틀림회전운동량에차이를보였는데대체로강한씹기를할경우이동량이큰경향을보였다. 이로부터당연한결과지만악관절에가해지는부하를줄이기위해서는부드러운음식을먹거나이악물기, 씹기등의악습관를피해야할것이다. 연구결과표로제시하지는않았으나자연치열이나장치를장착한경우나모두에서전두면및수평면상비틀림운동량과이들평면에서의개구거리와는아무런상관관계를발견할수없었다. 또한이악물기시근활성이나당시의교합력과도아무런상관성이없어비틀림운동량의속성에대해보다많은연구가필요할것으로사료되었다. 이는이악물기및씹는운동으로구성된한번의씹기운동을전체적으로보면개구거리나운동속도의차이가전두면및수평면상비틀림운동량에별다른영향을미치지못하였으나 (Table 5, 6), 반면각각의씹는운동을개별적으로분석하여비교한경우에서는분리기를씹는것에의해, 즉교합의높이나씹는힘의크기, 방향등에의해유의한차이가있는결과를보였기때문이다 (Table 7, 8). 하악의비틀림회전운동은모든하악운동에서항상일어나는현상으로현재까지는운동량이나운동방향만을관찰하고있지만앞으로는보다발전된장비를이용하여강한교합접촉시나또는개, 폐구운동시의비틀림회전운동으로하악과두를포함한상, 하악의모든부분이각각받는부하량이나부하의방향을측정할수도있을것이다. 그때가되면본연구에서개구량이증가되는하악위에서의비틀림회전운동량이이악물기나씹는운동과같은폐구에근접한하악위의그것에비해비틀림회전운동량자체는많지만조직에가해지는부하량이나부하의방향에서는오히려나쁜영향이덜할것이라는현재의예상을확인하게될수도있을것이다. 따라서본연구결과미흡하였던점을규명하기위해서나보다발전된측정장비의출현을위해서라도비틀림회전운동에대한관심과연구는계속되어야할것이다. Ⅴ. 결론 저작계이상이없는건강한남자 14 명을선정하여교합고경및형태의변화와수의적이악물기수준의차이가이악물기및씹기운동시나타나는하악의비틀림회전운동 (torque rotational movement) 에미 치는영향을조사하기위하여연구를시행하였다. 교합양태의변화는세가지교합조건으로부여하였는데첫째는자연치열, 다음으로고경이평균 3.6 mm정도증가된상태의상, 하악웨이퍼장착, 그리고마지막으로웨이퍼의구치부에레진블록을추가로올려자연치열에비해약 14 mm의고경이증가된상태등으로하였다. 수의적이악물기힘은두가지로부여하여교근이최대수의적수축 (maximum voluntary contraction) 을보이는근활성에서의이악물기및씹기운동을최대 ( 강한 ) 씹기로하고, 교근근활성이최대수의적수축의 50% 인경우에서의것을절반 ( 약한 ) 씹기로하였다. 근활성의측정에는 BioPak R 시스템의 BioEMG 를사용하였고, 하악의비틀림회전운동을관찰하기위하여는동일한 BioPak 시스템의 BioEGN 을사용하였다. 각교합조건과이악물기힘에서의씹기운동은먼저나무젓가락 ( 분리기 ) 이없는한번의이악물기와나무젓가락을구치부에위치시킨상태에서두번에걸친씹는운동등세번의하악운동으로구성되었다. 분석항목은전두면상개구거리, 시상면상개구거리및후방이동거리, 수평면상좌, 우측거리, 개, 폐구시하악운동속도, 그리고전두면과수평면상의비틀림운동량등이었으며, 수집된자료는 SPSS R 윈도우 (ver. 10.0) 프로그램을사용하여분석, 처리하였다. 본연구의결론은다음과같다. 1. 좌측으로씹을때와우측으로씹을때간에전두면및시상면상운동거리는두가지이악물기힘모두에서차이가없었으나하악의운동속도는다른양상을보여강한이악물기에서는차이가없었으나약한이악물기에서는좌측으로씹을때우측에비해속도가다소빠른경향을보였다. 이때하악의비틀림회전운동각은두가지이악물기모두에서전두면상차이는거의없었으나수평면상각도에서는씹는측에따라차이가있는경향을보였다. 2. 이악물기힘의차이는전두면및시상면상운동거리와속도에영향을미쳐강한씹기에서약한씹기에비해측정치가크게나타났으며하악의비틀림회전운동각역시강한씹기에서수평면상운동각이다소증가된양상을보였다. 3. 전두면및시상면상개구거리는교합조건에따른차이를보였는데, 즉웨이퍼나레진블록등교합고경이높은교합형태일수록운동거리가감소하였 422
교합조건및이악물기힘의변화가하악의비틀림회전운동에미치는영향 으며, 이때강한씹기에서는운동속도역시유사한양상으로감소하였다. 그러나하악의비틀림회전운동각은전두면및수평면모두에서교합조건에따른차이를거의나타내지않았다. 4. 세번의씹는운동에서분리기가없는경우에비해있는경우에서대체로전두면상회전운동각을제외한나머지하악의비틀림회전운동량은모두증가하는양상을보였다. 그러나이때각교합형태간동일항목의비교에서는전두면상회전운동거리가이악물기힘에따른차이를보여약한이악물기에서유의한변화를나타내었다. 이상의연구를통해 3 회의개, 폐구운동으로구성된 1 회의씹기운동에서하악비틀림회전운동의전체적인양상은관찰면에따라다르게나타나이악물기힘에따른차이는전두면에비해수평면상측정치가더많이변화되는모습을보였으나교합조건에따른양상은관찰면간차이를보이지않았다. 한편이악물기및씹는운동각각에서의하악비틀림회전운동량은교합조건이나이악물기힘에관계없이대체로분리기씹기에의해수평면상회전운동량의변화가전두면상측정치에비해더유의하게나타났다. 참고문헌 1. Glaros AG, Glass EG. Temporomandibular disorders. In Gatchel RJ and Blanchard B(Eds.), Psychophysiological Disorders. Washington DC, 1993, American Psychological Association, 299-356. 2. Glaros AG, Burton E. Parafuctional clenching, pain, and effort in temporomandibular disorders. J Behav Med, 2004;27(1):91-100. 3. Clark GT, Tsukiyama Y, Baba K, Watanabe T. Sixty-eight years of experimental occlusal interference studies : What have we learned?. J Prosthet Dent, 1999;82:704-713. 4. Laskin DM. Etiology of the pain-dysfunction syndrome. J Am Dent Assoc, 1969;79;147-153. 5. Flor H, Birbaumer N, Schulte W, Roos R. Stressrelated electromyographic responses in patients with chronic temporomandibular pain. Pain, 1991;46:145 152. 6. Intrieri RC, Jones GE, Alcorn ID. Masseter muscle hyperactivity and myofascial pain dysfunction syndrome: A relationship under stress. J Behav Med, 1994;17:479-500. 7. Christensen LV. Progressive jaw muscle fatigue of experimental tooth clenching in man. J Oral Rehabil, 1981;8;413-420. 8. Clark GT, Adler RC, Lee JJ. Jaw pain and tenderness levels during and after repeated sustained maximum voluntary protrusion. Pain, 1991;45:17 22. 9. Okeson JP. Management of temporomadibular disorders. 5ed, Singapore, 2003, Elsevier, 151-183. 10. Molin C, Carlsson GE, Friling B, Hedegard B. Frequency of symptoms of mandibular dysfunction in young swedish men. J Oral Rehabil, 1976;3:9-17. 11. Ingervall B, Mohlin B, Thilander B. Prevalence of symptom of functional disturbances of the masticatory system in swedish men. J Oral Rehabil, 1980;7: 185-193. 12. Nilner M. Prevlence of functional disturbances and disease of the stomatognathic system in 15 to 18 years olds. Swed Dent J, 1981;5:189-197. 13. Lobbezoo F, Lavigne GJ. Do bruxism and temporomandibular disorders have a cause-and-effect relationship?. J Orofac Pain, 1997;11:15-23. 14. Ahlberg J, Rantala M, Savolainen A, Suvinen T, Nissinen M, Sarna S, Lindholm H, Könönen M. Reported bruxism and stress experience. Comm Dent Oral Epidemiol, 2002;30:405-412. 15. Rugh JD, Robbins JW. Oral habit disorders. In: Ingersoll BD, ed. Behavioural aspects in dentistry. New York, 1982, Appleton-Century-Crofts, 179-194. 16. Ciancaglini R, Gherlone EF, Radaelli G. The relationship of bruxism with craniofacial pain and symptoms from the masticatory system in the adult population. J Oral Rehabil, 2001;28:842 848. 17. Gavish A, Halachmi M, Winocur E, Gazit E. Oral habits and their association with signs and symptoms of temporomandibular disorders in adolescent girls. J Oral Rehabil, 2000;27:22-32. 18. Sari S, Sonmez H. Investigation of the relationship between oral parafunctions and temporomandibular joint dysfunction in Turkish children with mixed and permanent dentition. J Oral Rehabil, 2002;29:108 112. 19. Egermark-Eriksson I, Carlsson GE, Ingervll B. Prevalence of dysfunction and orofacial parafunction in 7-,11-and 15-year-old swedish children. Eur J Orthod, 1981;3:163-170. 20. Haggerty C, Glaro AG, Glass EG. Ecological momentary assessment of parafunctional clenching in temporomandibular disorder. J Dent Res, 2000;79: 605-611. 21. Glaros AG, Forbes M, Shanker J, Glass EG. Effect of parafunctional clenching on temporomandibular 423
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교합조건및이악물기힘의변화가하악의비틀림회전운동에미치는영향 analysis of electromyographic activity of masticatory muscles versus bite force. Scand J Dent Res, 1985;93:396-402. 48. Kumagai H, Suzuki T, Hamada T et al. Occlusal force distribution on the dental arch during various levels of clenching. J Oral Rehabil, 1999;26:932-935. 49. 한경수. Biopak 을이용한하악의회전운동에관한연구. 대한구강내과학회지, 1994;19:193-203. 50. 한경수, 이유미. 하악의회전운동량과과로의형태에관한연구. 대한구강내과학회지, 1996;21:369-382. 51. 이유미, 한경수, 허문일. 하악의비틀림회전운동에영향을미치는요인. 대한구강내과학회지, 1998;23:143-155. 52. 한경수, 이규미, 허문일. 클러치의장착이하악의비틀림회전운동에미치는영향. 대한구강내과학회지, 1999; 24:207-217. 53. 김문규, 한경수, 김종영, 양근영. 교합장치가발음시하악위및하악의비틀림회전운동에미치는영향, 대한구강내과학회지, 2001;26:59-73. 54. Kim K, Kim HS, Kim YK, Chung SC. A study on the rotational torque movement of mandible in patients with TMJ closed lock. Cranio, 1999;17:189-195. 55. 소종섭, 이경호, 정성창. 악관절음환자의하악비틀림회전운동에관한연구. 대한구강내과학회지, 1999;24: 455-466. - ABSTRACT - Effects of Occlusal Condition and Clenching Force on the Mandibular Torque Rotational Movement Min-Jung Oh, D.D.S.,M.S.D., Kyung-Soo Han, D.D.S.,M.S.D.,Ph.D Dept. of Oral Medicine, Wonkwang University School of Dentistry, and Wonkwang Dental Research Institute The purpose of this study was to investigate the effects of occlusal condition and clenching level on the mandibular torque rotational movement. For this study, healthy 14 men without any symptoms and signs of temporomandibular disorders were selected. Mandibular torque rotational movement was observed in each circumstance of combination of three occlusal conditions such as natural dentition, with wafer of 3.6 mm thickness, and wafer with resin stop of 14 mm thickness total during hard biting of bite stick at maximum voluntary contraction(mvc) and 50% of MVC level of surface EMG activity of masseter muscle. Electromyographic activity and mandibular torque rotational movement were observed using BioEMG and BioEGN in BioPak R system. Each biting movement in each circumstance was composed of clenching one time and hard biting of wooden stick two times. The observed items were opening distance, velocity and amount of torque rotational movement in mandibular movement, and the data were statistically processed with SPSS R windows (ver.10.0). The results of this study were as follows: 1. There were no differences in the mandibular movement distance between those value in both biting sides, and between those in both clenching forces, but the mandibular velocity showed a different results by clenching force. For the amount of torque rotational movement, there were no difference in the value of the plane but some significant difference was in the value of the horizontal plane by biting side. 2. The mandibular movement distance and the mandibular velocity in both planes were higher by maximum voluntary contraction than those by half maximum voluntary contraction, and amount of torque rotational movement in the horizontal plane was also increased by maximum voluntary contraction. 3. The opening distance in both planes were decreased with the increase of vertical dimension of occlusion, namely, by the occlusal appliances, and this pattern was also showed in the mandibular velocity in case of hard biting by maximum voluntary contraction. However, the amount of torque rotational movement were not different by the increase of vertical dimension of occlusion. 425
4. The value of angle and distance of the torque rotational movement in the hard biting of wooden stick were generally higher than those in the clenching without wooden stick in both planes without regard to occlusal conditions and/or clenching forces. Key words : Clenching, Hard biting, Mandibular torque rotational movement 426