DOI:10.5125/jkaoms.2010.36.5.375 Le Fort I 골절단술에서 posterior impaction의양과 occlusal plane angle, incisor inclination의변화관계에관한연구 김복주 김민구 김정한 김철훈동아대학교의료원치과학교실구강악안면외과 Abstract (J Korean Assoc Oral Maxillofac Surg 2010;36:375-9) Study about the relationship between the amount of posterior impaction and the change of occlusal plane angle and incisor inclination in Le Fort I osteotomy Bok-Joo Kim, Min-Gu Kim, Jung-Han Kim, Chul-Hoon Kim Department of Oral and Maxillofacial surgery, Department of Dentistry, Dong-A University Medical Center, Busan, Korea Introduction: In the management of dentofacial deformities, variable movement of the maxilla can be made possible by a Le Fort I osteotomy. Posterior impaction of the maxilla necessary for rotation of the maxillomandibular complex enhances the functions and esthetic results. In cases of posterior impaction of the maxilla, an increase in the figure of the occlusal plane angle and incisor inclination can occur. This study reports the relationship between the amount of posterior impaction and the change in the occlusal plane angle and incisor inclination in a Le Fort I osteotomy by preoperative and postoperative lateral cephalograms. Materials and Methods: Twenty patients who had undergone orthognathic surgery in Dong-A University Medical Center participated in this study. Lateral cephalometrics, within 3 weeks prior to surgery and 3 days after surgery, were used for analysis. Pre and postoperative measurements of the occlusal plane angle and incisal inclination based on the Frankfort horizontal (FH) plane were performed. X and Y were defined as the amount of vertical change in the upper incisor tip and the amount of vertical change in the upper first molar mesial cup tip through the operation. The amount of final posterior maxillary impaction was determined by subtracting Y from X, which is the difference in vertical height. According to the amount of posterior maxillary impaction, the change in the occlusal plane angle and incisal inclination was measured. Results: The average posterior maxillary impaction was 2.91 mm and the average change in the occlusal plane angle and incisal inclination was 6.54 after surgery. As a result, each mm of posterior maxillary impaction changed the occlusal plane angle and incisal inclination by 2.25. Statistically, there was high significance. Two cases were observed: one with the same amount of posterior maxillary impaction performed on both the right and left showing 2.20, and the other with a different amount of posterior maxillary impaction performed showing 2.35. In this case, there was no significance difference between the two cases. Conclusion: Each mm of posterior maxillary impaction changes the occlusal plane angle and incisal inclination by an average of 2.25. In posterior maxillary impaction, there was no significant difference in the amount of change in the occlusal plane angle and incisal inclination regardless of whether there was an equal amount of posterior maxillary impaction on both sides. This study is expected to help in the presurgical orthodontic preparation and presurgical treatment planning. Key words: Maxilla, Le Fort Osteotomy, Malocclusion, Impacted tooth, Incisor [paper submitted 2010. 7. 2 / revised 2010. 10. 15 / accepted 2010. 10. 20 ] Ⅰ. 서론 교정치료를동반한수술적방법으로상악골과하악골의골격적인부조화를가진환자의심미적, 기능적인면을회 김철훈 602-812 부산광역시서구동대신동 3 가 1 번지동아대학교의료원치과학교실구강악안면외과 Chul-Hoon Kim Department of Oral & Maxillofacial surgery, Department of Dentistry, Dong-A University Medical Center Dong dae shin-dong 3-1, Seo-gu, Busan, 602-812, Korea Tel: +82-51-240-5470 Fax: +82-51-241-5475 E-mail: bbp2000@hanmail.net * 본연구는동아대학교연구비지원에의해이루어졌음. 복시키기위한여러노력들이오랫동안시도되었으며, 근본적인골격적부조화를개선시키기위해 1900 년대에처음으로하악골절제술을통한하악골전돌증의치료가시도되었다 1. 악안면기형의외과적인처치에있어서하악골만을후방또는전방위치시키는것이일반적인방법으로시행할수있지만상하악의골격적인차이가심하거나상악전치부의치축의변화가필요한경우, 장안모를동반하여전체적인안모의길이의감소가필요한경우또는교합평면의변형이심한경우등에는상하악골의동시수술을시행하는경우가많다. 특히최근악골의부조화가있는환자에있어서기능적인개선뿐만아니라심미적인개선을함 375
J Korean Assoc Oral Maxillofac Surg 2010;36:375-9 께요구하는환자들이늘어감에따라, 양악수술의적응증이되는환자도꾸준히늘어나고있는실정이다. Epker와 Fish 2 는하악전돌증의경우에외과적으로교정해야하는양이전후방으로 12 mm 이상인경우에는양악수술을고려해야한다고하였고실제로하악전돌증환자 26명에대하여상하악골의동시이동술 (simultaneous mobilization) 을시행하여적절한기능적, 심미적인결과를얻을수있었음을보고하였다. 따라서, Le Fort I 골절단술을이용한상하악골의동시이동술은, 골격성제 III급부정교합을비롯한대부분의악안면기형의수정에사용하는수술로 3,4 광범위한수술에도불구하고술후합병증이적은편이며 5 악안면기형환자를한번에 3차원적으로교정가능하고안면골을보다적절한위치로이동시켜술후에더욱심미적일뿐만아니라술후교정도또한용이하게한다 6-8. 상하악골의동시이동술에서상악 posterior impaction의정의는상악의전방부보다후방부의상방이동이며, 다른말로상하악복합체의 clockwise rotation으로도표현한다. 상악 posterior impaction의효과는 Frankfort horizontal (FH) plane에대한occlusal plane angle의증가와 incisor inclination의감소를가져올수있고 chin 즉, pogonion point의후방이동을이끌어낼수있으며, 또한상하악복합체의 cranial base에대한관계를향상시킬수있고, 골격성 III급부정교합환자의악교정수술에서하악의후방이동량을증가시킴으로써심미적인개선에대한기대치를좀더높일수있다. Sarver 등 9 은 1993년 hypodivergent skeletal pattern 을가진환자에서 clockwise rotation을통해우수한안정성과심미적결과를얻었음을보고하였으며, Naini 등 10 은 2003년 differential maxillary impaction에서 maxillary incisor inclination을구하는공식을제시하였으나, 단점으로공식이복잡하여임상적적용에한계가있다. 따라서, 본연구는상악의후상방이동양에대한 occlusal plane angle, incisor inclination의임상적, 통계학적으로변화한수치를확인하여상악의 posterior impaction에의한교합평면및상악전치부치축의변화량을정량적으로확인해보고자한다. 1 명의환자는앵글씨분류에의한골격성 II 급부정교합으로단지상악 Le Fort I 골절단술만시행한후하악의 autorotation 만을시행하였고, 19 명은앵글씨분류에의한골격성 III 급부정교합으로양악의동시이동술을시행하였다. Le Fort I 골절단술을시행할경우 posterior impaction 과함께상악의다양한이동이가능한데, 단지 posterior impaction 만을시행한환자는 3 명이였으며나머지 17 명의환자는상악의 advancement, setback, leveling 등의이동을동반하여수술을시행하였다. 또한, 상악을후상방으로 rotation 시킬때 rotation 의 center 는 A-point 를기준으로하였다. 20 명의환자중좌우같은양의 posterior impaction 을시행한환자는 10 명이었고좌우다른양의 posterior impaction (differential posterior impaction) 을시행한환자또한 10 명이었다. 2. 연구방법 술전 3 주이내, 술후 3 일이내채득한측모방사선사진을분석에이용하였다. 얻어진방사선사진을교정용영상진단프로그램 (V-cephTM 4.0, Cyber-Med Inc., Seoul, Korea) 을이용하여 Fig. 1 과같이 6 개의계측점을설정하였다. 이때측정에대한신뢰도를평가하기위해처음계측후 10 일후동일한계측자가다시반복계측을하였다. 두번의계측을 Pearson 상관분석을이용해비교한결과반복측정시모든계측항목에서높은상관관계를나타내어, 검사와재검사측정치간의일치도가높음을알수있었다. 또한 tracing 후확대한상에서오차를수정하였으며이러한과정을통해술전과술후의 landmark 로 sella nasion (SN) plane 과 FH plane 이가동일하게표시되도록하였다. Ⅱ. 연구대상및방법 1. 연구대상 골격성 II, 또는 III 급부정교합으로진단받고술전교정을시행한뒤동아대학교의료원구강악안면외과학교실에서 1 명의숙련된의사에의해 2008 년 10 월부터 2009 년 6 월까지악교정수술을시행받은환자중에서 6 개월이상추적가능한환자로, 상악후상방이동을시행한환자 20 명을대상으로연구를시행하였다. 여성은 11 명남성은 9 명이었으며평균연령은 22 (18-31) 세였다. 20 례모두금속판을이용하여고정하였으며, 1 주간의악간고정이시행되었다. Fig. 1. Anatomic landmark used in this study. (S: sella, N: nasion, Po: porion, Or: orbitale, UM: upper fist molar mesial cusp tip, U1: upper incisor cusp tip) 376
Le Fort I 골절단술에서 posterior impaction 의양과 occlusal plane angle, incisor inclination 의변화관계에관한연구 Table 1. Average occlusal plane angle and incisal inclination in presurgical state Mean Range occlusal plane angle 7.2-1.75-12.24 incisal inclination 122.46 114.31-132.7 Fig. 2. Measuring parameters. (X: vertical change of upper incisor, Y: vertical change of upper first molar, Y-X: amount of posterior Mx. impaction) 술전및술후 FH plane 에대해 occlusal plane angle, incisal inclination 을측정하였으며, 술전, 술후상악전치 tip 의수직적높이변화량을 X 라하고, 상악제 1 대구치의 mesial cusp tip 의수직적변화량 Y 라고정하였으며 Y-X, 즉수직적높이차이를통해최종 posterior impaction 양을결정하였다.(Fig. 2) Table 2. Average amount of posterior impaction and average amount of change of occlusal plane angle, incisal inclination after surgery Amount Mean Range SD PI 2.91 0.26-7.75 1.78 OPA, II change 6.540.5-16 3.77 OPA, II change due to PI 2.25* 1.5-3.1 0.39 (PI: posterior impaction, OPA: occlusal plane angle, II: incisal inclination, *: Pearson's correlation coefficients, 0.969, P<0.01) Table 3. Average amount of change of occlusal plane angle, incisal inclination in same posterior impaction and differential posterior impaction Mean SD N P value Same posterior impaction 2.2 0.27 10 0.393* Differential posterior impaction 2.35 0.38 10 (*: Mann-Whitney U-test) 3. 통계분석 이번연구의주요목적은상악의 posterior impaction 의양에따른 occlusal plane angle, incisor inclination 의변화를알아보는것이다. 각각의환자에서 posterior impaction 의양을측정하고, 이에따른 occlusal plane angle, incisor inclination 의변화량을측정하여 posterior impaction 1 mm 당 occlusal plane angle, incisor inclination 의변화값의평균값을구하였으며이에관한유의성은 Pearson s correlation coefficients 을통해검정하였다. 좌우같은양및다른양의 posterior impaction 을시행하였을때 occlusal plane angle, incisal inclination 의변화값사이의유의성은 Mann-Whitney U-test 을통해검정하였다. 통계분석은 SPSS version 12.0 (SPSS Inc., Chicago, IL, USA) 을이용하였고유의수준은 P<0.05 에서검정하였다. Ⅲ. 결과 환자 20 명의술전평균 occlusal plane angle 은 7.2 이었으며가장낮은환자가 -1.75 로측정되었다. 술전평균상악중절치 incisal inclination 은 122.46 였다.(Table 1) 평균 posterior impaction 의양은 2.91 mm 이였으며최대치는상악전방부의 inferior positioning 을동반하여 posterior impaction 을시행한환자로 7.75 mm 였다. 술후평균 occlusal plane angle, incisal inclination 변화량은 6.54 이며, occlusal plane angle, incisal inclination 은상악의회전과함께변화하는수치이므로변화량은동일하였다.(Table 2) 결과적으로 posterior impaction 1 mm 당 occlusal plane angle, incisal inclination 변화량은 2.25 이였으며높은통계학적유의성을보이는것으로나타났다.(Pearson s correlation coefficients: 0.969, P<0.01) 한편, 좌우같은양및다른양의 posterior impaction 을시행하였을때 occlusal plane angle, incisal inclination 의변화를살펴본결과, 좌우같은양의 posterior impaction 에서는 2.20 이었으며, 좌우다른양의 posterior impaction 에서는 2.35 로두수치간에통계학적으로차이는없었다.(Table 3) Ⅳ. 고찰 Le FortⅠ 골절단술은 1864 년 Cheever 가비인두강의종괴절제를위한상악골의 down fracture 를최초로소개한이후, 1921 년 Wasmund 에의해안면기형의수정을위한상악골절단술로이용되었다. 그러나기술적인어려움등으로주로하악골수술만으로악안면기형을해결하다가, 1965 년경에이르러서야 Wilmar, Obwegeser, Bell 등에의해악안면기형의해결을위한상악골절단술의술후안정성이보고된이후보편화되었다. 양악수술의적응증으로첫째악골전후방의 skeletal 377
J Korean Assoc Oral Maxillofac Surg 2010;36:375-9 deformity 가전후방적으로 12 mm 이상인심한하악전돌증, 둘째수직상악골과다증 (vertical maxillary excess) 를동반한하악전돌증, 셋째수직상악골과소증 (vertical maxillary deficiency) 를동반한하악전돌증을들었다 11,12. 이러한적응증은최근에이르러서도적용되는기준이며근래에와서는수술기구와수술방법의발전그리고심미성을중시하는환자와교정의사들의요구가늘어나조금더복잡한양상으로상악의 3 차원적인이동이필요한경우가늘어나고있다. 양악동시수술에서 Le Fort I 골절단술시상악 posterior impaction 의적응증은상악교합평면이후방으로 canting 되어있는경우나 anterior open bite 의경우에좀더나은심미적인결과를얻기위해서시행하기도하며하악이동양의증가가필요할때적용가능하고또한, 골격성 III 급부정교합에서술전교정이불충분하여치성보상이부족한경우에도상악전치각도를증가시키기위해필요한경우가있다. 실제로약간의전치부개교를동반한골격성 III 급부정교합의양악수술에서교합평면자체를시계방향으로회전시켜주는상악의 posterior impaction 을동반하지않는다면후안면고경의증가로인한 pterygomasseteric sling 과 suprahyoid muscle group 의긴장을야기하여술후불안정을야기한다고보고된바가있다 13. 그와동반하여안면고경자체의감소가제한적으로이루어질수있으며이것은하악골의 chin 부위에서의 reduction genioplasty 를부가적으로시행해야할수도있는여지를남기게되는경우가있게된다. 또한, 상악골의후방부를올려서교합평면의경사도가증가하는시계방향의회전이그반대인경우인반시계방향의회전에비해유리하고이때하악골의 pogonion 부위의후상방이동으로인해서이부가돌출된 III 급부정교합의수술시부가적으로심미적인증진을가져올수있다고하였고 14,15, Swinnen 등 16 은전치부개교합을가진환자에서 Le Fort I 골절단술시 posterior impaction 을시행한결과술후안정성이높게나타났다고보고하였다. Le Fort I 상악골절단술시 posterior impaction 의비적응증으로는상악의후상방이동으로인해 occlusal plane angle 과 incisor inclination 이증가하며이미교합평면의경사가큰경우에만약 occlusal plane angle 이 temporal bone 의 articular eminence 의 inclination 보다커지게되면 canine guidance 와 incisal guidance 의상실및작업측과비작업측의구치부교합간섭을유발할수있고또한, 상악전치의설측경사로인한심미성상실, lip support 의부족으로인해 nosolabial angle 의증가를가져올수있다. 이상의내용을종합해볼때상악의 posterior impaction 은환자의심미개선과높은안정성을가진술식이며필연적으로 occlusal plane angle, incisal inclination 의변화를가져온다. 따라서 occlusal plane angle 과 incisor inclination 의증가에따른문제를예방하기위해술전 occlusal plane angle, incisal inclination 을고려하여 posterior impaction 의양을결정해야하며, 현재시행하는악교정수술의술전 surgical treatment objective (STO) 에서도상악골의이동양을결정하는기준으로상악절치의위치나각도를기준으로하는경우가많다. 하지만 posterior impaction 에따른 occlusal plane angle, incisal inclination 의변화량에대한임상적연구가부족한것은사실이며, 이는실제로술전 STO 를통한 paper surgery 를통해서어느정도상악절치의위치나각도의변화를예상가능하기때문일것이라생각한다. 그럼에도불구하고이번연구에서확인한상악의 posterior impaction 에따른 occlusal plane angle, incisal inclination 의변화량은술전교정치료의양을결정하는데도움이되리라생각한다. 특히술전교정단계에서골격성 III 급부정교합환자의증가되어있는상악 incisal inclination 을상악의 posterior impaction 을통해감소, 즉치성보상 (decompensation) 을시킬수있으므로술전교정시 incisal inclination 의양을결정하는데도움이된다. 또한상악의 posterior impaction 에따른 occlusal plane angle, incisal inclination 의변화량에임상적평균값을통해 model surgery 및수술중에일어날수있는 posterior impaction 양의오차에대해서상악절치의각도변화를수술중에도수치적으로예상할수있는자료가됨으로써능동적인대처가가능할것으로생각한다. 한편각각의환자에서 posterior impaction 의양에따른 occlusal plane angle, incisal inclination 의변화량의차이가생기는원인으로상악의전후방길이즉, 본연구에서측정한 central incisor 에서제 1 대구치사이의거리의차이가변수로작용한것으로생각한다. 각환자에서 central incisor 에서제 1 대구치사이의거리가다른원인으로술전교정시상악의발치교정의여부, 각환자의상악악궁크기, 악궁형태가있다. 따라서발치교정을시행한경우 central incisor 에서제 1 대구치사이의거리가짧아져상악의 posterior impaction 의양에따른 occlusal plane angle, incisal inclination 의변화량은증가할것이다. 좌우같은양및다른양의 posterior impaction 을시행하였을때 occlusal plane angle, incisal inclination 의변화결과에서두결과간에통계학적차이는없었다. 이는계측에있어서의오차때문이라생각하며조사한환자수가많았다면유의성이있었으리라생각한다. Ⅴ. 결론 본연구에서동아대학교의료원구강악안면외과학교실에서시행한 20 명의악교정수술환자에서상악골의 posterior impaction 의양에따른 occlusal plane angle, incisor inclination 변화량을계측한연구결과는다음과같다. 1. 상기연구를통해상악골의 posterior impaction 1 mm 당 occlusal plane angle 과 incisal inclination 은평균 2.25 의변화를보였다. 2. 상악의 posterior impaction 시좌우같은양과좌우다른양의수술을시행한경우에도 occlusal plane angle 과 378
Le Fort I 골절단술에서 posterior impaction 의양과 occlusal plane angle, incisor inclination 의변화관계에관한연구 incisal inclination 의변화량에는큰차이가없었다. 3. Occlusal plane angle, incisal inclination 변화량에미치는변수로고려되는것은각환자의 central incisor 에서제 1 대구치사이의거리즉, 상악의전후방길이의차이가변수로작용할것으로판단된다. 이연구의결과를통해 pre-surgical orthodontic preparation 과 pre-surgical treatment planning 에도움이되리라생각하며또한, posterior impaction 의양에따른 chin 의후방이동양에대한수치적인상관관계를파악한다면 treatment planning 에더욱도움이되리라여겨진다. References 1. Blair VP. Operations on the jaw bone and face: a study of etiology and pathological anatomy of developmental malrelations of the maxilla and mandible to each other and to facial outline and of their operative treatment when beyond the scope of the orthodontist. Surg Gynecol Obstet 1907;4:67-78. 2. Epker BN, Fish LC. The surgical orthodontic correction of class III skeletal open-bite. Am J orthod 1978;73:601-18. 3. Choi SW, Park HS, Cha IH. A study on accuracy of the maxillary repositioning in orthognathic surgery by the external measuring technique. J Korean Assoc Oral Maxillofac Surg 1996;22:537-43. 4. Rotter BE, Zeitler DL. Stability of the Le Fort Ⅰ maxillary osteotomy after rigid internal fixation. J Oral Maxillofac Surg 1999;57:1080-8; discussion 1089. 5. Moser K, Freihofer HP. Long-term experience with simultaneous movement of the upper and lower jaw. J Maxillofac Surg 1980;8: 271-7. 6. Choi BH, Yoon JH. Soft tissue changes associated with Le Fort I maxillary advancement. J Korean Assoc Oral Maxillofac Surg 1984;10:175-82. 7. Epker BN, Turvey T, Fish LC. Indication for simultaneous mobilization of the maxilla and mandible for the correction of dentofacial deformities. Oral Surg Oral Med Oral Pathol 1982;54:369-81. 8. Turvey TA. Simultaneous mobilization of the maxilla and mandible: surgical technique and results. J Oral Maxillofac Surg 1982;40:96-9. 9. Sarver DM, Weissman SM, Johnston MW. Diagnosis and treatment planning of hypodivergent skeletal pattern with clockwise occlusal plane rotation. Int J Adult Orthodon Orthognath Surg 1993;8:113-21. 10. Naini FB, Hunt NP, Moles DR. The relationship between maxillary length, differential maxillary impaction, and the change in maxillary incisor inclination. Am J Orthod Dentofacial Orthop 2003;124:526-9. 11. Turvey T, Hall DJ, Fish LC, Epker BN. Surgical-orthodontic treatment planning for simultaneous mobilization of the maxilla and mandible in the correction of dentofacial deformities. Oral Surg Oral Med Oral Pathol 1982;54:491-8. 12. Wolford LM, Chemello PD, Hilliard FW. Occlusal plane alteration in orthognathic surgery. J Oral Maxillofac Surg. 1993;51: 730-40. 13. Lee JH, Lee HJ. Stability of occlusal plane after Le Fort I maxillary osteotomy in patients with skeletal class III maloccusion. J Korean Assoc Oral Maxillofac Surg 1996;22:429-36. 14. Reyneke JP, Evans WG. Surgical manipulation of the occlusal plane. Int J Adult Orthodon Orthognath Surg 1990;5:99-110. 15. Reitzik M. Skeletal and dental changes after surgical correction of mandibular prognathism. J Oral surg 1980;38:109-16. 16. Swinnen K, Politis C, Willems G, de Bruyne I, Fieuws S, Heidbuchel K, et al. Skeletal and dento-alveolar stability after surgical orthodontic treatment of anterior open bite: a retrospective study. Eur J Orthod 2001;23:547-57. 379