Oral Biology Research, 2016; September 30, 40(3):134-142 Copyright c 2016, Oral Biology Research Institute DOI: 10.21851/obr.40.3.201609.134 Case Report ORAL BIOLOGY RESEARCH Orthodontic treatment using mini-tube appliances and customized resin domes using 3D CAD design Hye-In Kim, Sung-Hoon Lim *, and Sung-Nam Gang Department of Orthodontics, School of Dentistry, Chosun University, Gwangju 61452, Republic of Korea (Received Jul. 11, 2016; Revised version received Aug. 18, 2016; Accepted Aug. 29, 2016) ABSTRACT Mini-tube appliances can be used instead of orthodontic brackets and tubes. This mini-tube is a simple tube without a bonding base and bonded to the tooth by covering the tube with flowable resin. It is more esthetic and hygienic, although there is a limitation that only NiTi wires can be inserted into the mini-tube appliance. However, this mini-tube has no pre-adjusted in-and-out compensations, and therefore wire bending is required for finishing. This report describes a Class I crowding case treated with mini-tubes and customized resin domes using a virtual setup, 3-dimensional (3D) computer-aided design (CAD) and 3D printing. By this customization, wire bending or repositioning of mini-tubes was minimized, and treatment was performed with fewer adjustments and increased patient s comfort. KEY WORDS: Mini-tube appliance, Virtual setup, 3-dimensional (3D) computer-aided design (CAD), 3-dimensional (3D) printing, Class I crowding 서 론 스러운치료결과를얻었기에이를보고하고자한다. 많은환자들이교정치료시치료에소요되는기간과비용뿐만아니라, 브라켓부착에따른비심미성및불편감으로치료에부담을느끼는경우가많다. 이에따라브라켓을사용하지않는다양한치료방법이모색되어왔는데, 그중하나인 mini-tube 장치가전치부부분교정과재발증례의치료등에널리이용되고있다 [1]. 이장치는낮은 profile과작은부피감으로환자의불편감이적고위생관리가용이하며, 보다심미적이라는장점이있으나전체교정의경우마무리를위한 1st-order bend를부여한상태에서 mini-tube에호선을삽입하는것이어렵다는문제가있다. 이를보완하기위하여설측교정시사용하는 customized resin base와유사하게맞춤형교정장치를사용할수있는데, 본증례보고에서는디지털셋업을바탕으로치아별로다른두께를갖는 customized resin dome을형성하고 mini-tube를간접부착하여전체교정에적용함으로써만족 *Corresponding author: Sung-Hoon Lim Department of Orthodontics, School of Dentistry, Chosun University, 303 Pilmun-daero, Dong-gu, Gwangju 61452, Republic of Korea Tel.: +82-62-220-3870 E-mail: shlim@chosun.ac.kr 증례보고 진단 19세여자환자가 이가비뚤비뚤해요 라는주소로본원에내원하였다. 초진시안모사진에서골격적인대칭성은양호였으나하악전돌로인한오목한측모와 reverse smile arc가관찰되었다 (Fig. 1). 초진시구강내사진에서상악전치부의총생및얕은수직피개로좌우측절치는절단교합상태였고, 우측구치부의교합은양호하였으나좌측은하악견치의총생및원심경사와함께 III급경향의구치관계가관찰되었다. 구강위생상태는양호하였으나절단연부위에서전반적으로경도의저광화양상이관찰되었다 (Fig. 2). 초진시파노라마방사선사진에서하악양측견치의원심치관경사및상대적으로짧은상하악중절치의치근이관찰되었다 (Fig. 3). 측모두부계측방사선사진분석결과, 경도의하악골과성장으로인한중등도의골격성 III급부정교합으로진단되었으며하악전치의치축은정상범주에있었으나상악전치의치축은중등도로순측경사되어있었고심미선에대해상, - 134 -
Mini-tube appliances with customized resin domes using 3D CAD design Fig. 1. Pretreatment facial photographs. Fig. 2. Pretreatment intraoral photographs. Fig. 3. Pretreatment panoramic radiograph. 하순의 위치는 양호하였다(Fig. 4, Table 1). 치료계획 골격성 III급 부정교합으로 이상적인 안모개선을 위해서 Fig. 4. Preatreatment lateral cephalometric radiograph. 는 악교정 수술을 동반한 교정치료가 바람직하나 환자 본 인은 하악 전돌을 인지하지 못하는 상태로 발치와 수술 모 Pontedera, Italy) 소프트웨어를 사용하여 디지털 셋업을 실 두 부정적이었다. 따라서 치간삭제를 동반한 비발치 절충 시하였다(Fig. 5). 디지털 셋업이 완료된 모델을 3D CAD tool인 Geomagic 치료를 계획하였으며 치아의 상태 및 위생관리의 용이성 Design X (3D SYSTEMS, Rock Hill, SC, USA) 프로그램 을 고려하여 mini-tube를 이용하기로 하였다. 으로 import하여(fig. 6) 이상적인 호선의 위치를 먼저 설 치료과정 및 결과 정하고, 호선이 지나가는 치관의 중앙에 mini-tube를 수용 먼저 초진 모델을 스캔(SCANNER S600 ARTI, Zirkonzahn, 하면서 base 역할을 할 수 있는 customized resin dome을 Gais/South Tyrol, Italy)하여 바람직한 배열 및 교합을 형 디자인 하였다. 그런 다음, resin dome을 포함한 setup 모 성할 수 있도록 Maestro 3D Ortho Studio (AGE Solutions, 델에 0.5 mm의 thickness를 부여하여 shell을 형성한 후 호 - 135 -
Hye-In Kim, Sung-Hoon Lim, and Sung-Nam Gang Table 1. Results of a cephalometric analysis Measurement Norm Pretreatment Posttreatment SNA( ) 81.1 81.7** 81.9*** SNB( ) 78.0 83.2** 81.9*** ANB( ) 3.5-1.5** -0.03*** FMA( ) 29.6 21.1** 21.1*** U1 to SN( ) 105.3 119.1** 111.1*** U1 to FH( ) 113.8 131.0** 123.6*** FMIA( ) 56.8 69.3** 76.3*** IIA( ) 125.4 118.3** 132.7*** UL to E-Line(mm) -0.8-2.9** -3.4*** LL to E-Line(mm) 0.1 0.6** -0.3*** Wits -2.7-6.9** -5.4*** *>one standard deviation from the norm. **>two standard deviations from the norm. ***>three standard deviations from the norm. 선과모델을제거하여치아와 resin dome의음형을얻었다 (Fig. 7). 본증례에사용된 mini-tube는내경이 0.46 mm, 외경이 0.71 mm의 round tube(silver MTA, HUBIT, Uiwang, Korea) 로, 호선의두께를 mini-tube의외경에맞추어설계함으로써음형에형성된홀에 mini-tube가삽입될수있게하였고, resin dome의간접부착을위해 shell type의음형을 3D printer (D35, Prodways, Les Mureaux, France) 로출력하여 transfer jig로사용하기로하였다 (Fig. 8 and 9). Transfer jig를셋업모델상에설계한상태로출력했기때문에부정교합상태인환자의구강내로옮기기위하여 tray를치아별로절단한후석고모델에적합시켜양호한적합상태를먼저확인하고 (Fig. 10) mini-tube를 transfer jig에삽입하였다 (Fig. 11). 이때환자의구강내간접부착 Fig. 5. Completed digital setup. Fig. 6. Imported digital setup model. Fig. 7. Design of the customized resin domes and shell type transfer jig. - 136 -
Mini-tube appliances with customized resin domes using 3D CAD design Fig. 8. 3D Printed model of the upper shell type transfer jig. Fig. 9. 3D Printed model of the lower shell type transfer jig. Fig. 10. Shell type transfer jigs were placed on the pretreatment models to check the fitting and interferences between jigs. Fig 11. Inside view of transfer tray (left), inserted mini-tube in the hole of the tray (center) and mini-tubes (right). 시 jig의분리가용이하도록 mini-tube 삽입전 jig 내부의 resin dome 부위에 vaseline을먼저도포하였다. 하악에먼저장치를부착하였는데, 환자의구강내산부식및본딩제도포후 jig 내부의 resin dome 부위에 flowable resin (Z350 XT, 3M ESPE, MN, USA) 을주입하여간접부착을실시하였다. 3D printing된 shell은두께가얇고 brittle하기때문에 jig는쉽게제거가가능하다. 이때하악전치부의배열이양호한부위에서먼저 1.5 mm 치간삭제를실시한후에장치를부착하였고, 상악은 1개월 뒤에간접부착하고초기호선은.012" NiTi로배열을시작하였다 (Fig. 12 and 13). 치료 3개월째, 하악제2소구치의근심면까지치간삭제하여총 3.1 mm의공간을확보하였고상하악모두.016" NiTi를장착하였다 (Fig. 14). 치료 6개월째, 하악의치간삭제로수평피개가확보되어상악에서도제1소구치근심면까지총 2.5 mm의치간삭제를실시하였다. 상악전치부의정출을위해상악좌우중절치와우측측절치의 mini-tube를치은연쪽으로재부착하 - 137 -
Hye-In Kim, Sung-Hoon Lim, and Sung-Nam Gang Fig. 12..012'' NiTi archwire was inserted after lower indirect bonding of mini-tubes. Fig. 13..012'' NiTi archwire was inserted after upper indirect bonding of mini-tubes. Fig. 14. Patient after 3 months of treatment. Interproximal reproximation was performed onto lower dentition and.016'' NiTi archwires were inserted into both arches. Fig. 15. Patient after 6 months of treatment. Interproximal reproximation was performed onto upper dentition. - 138 -
Mini-tube appliances with customized resin domes using 3D CAD design Fig. 16. Patient after 10 months of treatment. Intermaxillary vertical elastic on right side and class III elastic on left side were instructed. Fig. 17. Posttreatment intraoral photographs. Fig. 18. Posttretment facial photographs. 였다. 이때현재배열상태의 in-and-out은그대로유지하였다 (Fig. 15). 치료 10개월째, 상하악의치간삭제를실시한공간이거의폐쇄되었고양호한수직피개가형성되었다. 긴밀한교합의형성과중심선의개선을위해우측은수직악간고무줄, 좌측은 III급악간고무줄을사용하도록지시하였다 (Fig. 16). 치료 12개월째, 양호한배열및교합이얻어져상하악 견치간고정식유지장치를부착하고치료를종결하였다 (Fig. 17 and 18). 상악에만 clear retainer를추가로사용하도록지시하였다. 치료전, 치료후및셋업모형중첩에서, 셋업시에는초진과유사한정도의수직피개를형성하였으나치료중전치부의정출을위해 mini-tube를재위치시켰고, 치간삭제를통한상악전치부의후방이동시설측경사를허용하여보다깊은수직피개교합이형성되었다 (Fig. 19). 모 - 139 -
Hye-In Kim, Sung-Hoon Lim, and Sung-Nam Gang Fig. 19. Superimposition of digital setup (blue), pretreatment (gray) and posttretment (white) models. Fig. 20. Superimposition of pretreatment (gray) and posttretment (white) models. Fig. 22. Superimposition of pretreatment (blue) and posttreatment (red) cephalometric radiographs. Fig. 21. Superimposition of digital setup (blue) and posttreatment (white) models. 든모형중첩은 third palatal rugae와 palatal vault를기준으로중첩 [2] 하였다. 치료전후의디지털스캔모형중첩에서, 상악은치간삭제를통해절치의전돌없이총생을해소하였고구치부의폭경변화는없었다. 하악역시치간삭제의결과로상당량의하악전치부후방이동이관찰되었다 (Fig. 20). Fig. 23. Posttreatment panoramic radiograph. 디지털셋업과치료후의모형중첩에서는셋업에비해상악중절치의근심회전이충분하지않았으며치간삭제로인하여치료후에상하악전치부가셋업시에계획하였 Fig. 24. Intraoral photographs obtained after 3 months of retention. - 140 -
Mini-tube appliances with customized resin domes using 3D CAD design 던것보다후방으로견인되었다 (Fig. 21). 치료전후의측모두부계측방사선사진중첩결과다소간의하악골후하방회전이있었고, 치간삭제의결과로상하악총생의해소와함께, 상하악전치가설측으로경사되어적절한수평피개교합이형성되었으며, 상악전치가정출되면서적절한수직피개교합이달성되었다 (Fig. 22, Table 1). 치료후파노라마방사선사진에서초진시원심으로치관경사되어있었던상악우측견치와하악견치의직립이관찰되었고, 짧고회전되어있었던상악중절치의치근이흡수소견없이양호하게배열되었다 (Fig. 23). Retention 3개월째, 양호한유지상태가관찰되었다 (Fig. 24). 고 찰 교정치료과정의불편감과브라켓의낮은심미성을개선하기위해브라켓이없는교정치료에대한많은연구와시도가있었다. 대표적으로가철성투명교정장치 [3,4] 와브라켓을단순화하여크기를최소화한 MTA(Mini-Tube Appliance)[1] 의사용이늘고있으며, soluble tube로 resin dome과호선사이의간극을형성하는 Aline tube[5] 도고안되었고, 유지장치의제작시에주로사용되는 multistranded wires 또는 NiTi wire를조절하여 active retainer로써치아를이동시키는다양한방법 [6-8] 들이소개된바있다. 각장치별로장단점과한계가존재하며아직은어떠한장치로도브라켓을완전히대체할수는없으나일부증례에서는이러한장치들도효과적으로사용될수있다. 본증례에서는 3 mm 길이의 mini-tube를사용하였고, 디지털셋업후 3D 소프트웨어상에서가상의호선을위치시켜 mini-tube의이상적인위치및두께를설정함으로써 1st order, 즉, in-and-out이조절될수있도록하였다. 이를통해 mini-tube의단점을보완하여이용범위를전체교정으로확대하였고, mini-tube의위치를수정하는빈도를줄일수있었다. Mini-tube를재위치시킬때에도호선이장착된상태의전반적으로양호한배열상에서치아이동이필요한만큼만호선을 deflection시켜 mini-tube를부착하는 forced positioning을적용함으로써필요한방향에국한하여치아를이동시킬수있었다. 그러나 mini-tube는여전히많은한계점이존재하는데, 디지털셋업을통해 mini-tube의이상적인위치를설정했다고하더라도복잡한기공과정및간접부착과정에서오차가발생할수있으며 sharp edge에서의 3D 스캐닝과프린팅의정밀성도개선해야할과제로생각된다. 또한디지털셋업부터 customized resin dome의설계, 그리고간접부착을위한술식까지, 본증례와같은방법을적용하기 위해서는준비과정에소요되는시간과노력이적지않아 minor crowding 증례에는비효율적이다. 뿐만아니라 mini-tube의경우삽입가능한호선의종류및두께의제한으로인하여악간고무줄의사용이어려우며, 레벨링및악궁형태의조절도어려운한계점이있으므로증례의선별에주의가필요하다. 본증례에서구치부의교합관계및중심선의개선을위하여좌측에 III급악간고무줄을사용하였는데, 약한힘으로단기간동안에만사용하였음에도불구하고상악좌측제1대구치의근심회전이발생하는문제가있었다. 또한 mini-tube에삽입가능한최대크기인.016 NiTi 호선을삽입한다하더라도회전의개선등이불충분한경우가있고, 이러한문제들로인하여재부착이필요하거나결국브라켓을부착해야하는경우가있다. 구치관계의개선이필요한경우에는브라켓을사용하는것이더효율적일수도있으나, 본증례와같이구치관계의개선이많이필요하지않고, 치아의탈회가우려되는경우 mini-tube를디지털셋업을통해부착하는것으로양호한결과를얻을수있다. 감사의글 이논문은 2014년도조선대학교학술연구비의지원을받아연구되었음. Conflict of Interest The authors declare that they have no competing interests. ORCID Hye-In Kim 0000-0003-0752-7473 Sung-Hoon Lim 0000-0003-4528-8514 Sung-Nam Gang 0000-0002-1608-9199 References 1. Hwang HS, Jeon HR, Kim SP, Kim WS, Lee GH. A new orthodontic appliance for rapid anterior alignment in adults; Mini-Tube Appliance (MTA). J Korean Dent Assoc 2011;49:398-409. 2. Jang I, Tanaka M, Koga Y, Iijima S, Yozgatian JH, Cha BK, Yoshida N. A novel method for the assessment of three-dimensional tooth movement during orthodontic - 141 -
Hye-In Kim, Sung-Hoon Lim, and Sung-Nam Gang treatment. Angle Orthod 2009;79:447-453. 3. Sheridan JJ, Armbruster P, Nguyen P, Pulitzer S. Tooth Movement with Essix Mounding. J Clin Orthod 2004; 38:435-441. 4. Boyd RL, Miller RJ, Vlaskalic V. The Invisalign system in adult orthodontics: mild crowding and space closure cases. J Clin Orthod 2000;34:203-212. 5. Kim TK. Bracket-Free Orthodontics. Seoul: Daehan Narae Publishing; 2015. 6. Musilli M. The Bracketless Fixed Orthodotics: Nine years of clinical experimentation. Prog Orthod 2008;9: 72-92. 7. Liou EJ, Chen LI, Huang CS. Nickel-titanium mandibualr bondedlingual 3-3 retainer: For permanent retention and solving relapse of mandibular anterior crowding. Am J Orthod Dentofacial Orthop 2001;119:443-449. doi: 10.1067/mod.2001.111397. 8. Anna M, Fabio C. Atlas of Bracketless Fixed Lingual Orthodontics basic concepts. Rho (Milan): Quintessenza Edizioni s.r.l.; 2015. - 142 -