Stabilita chirurgickeâ counter-clockwise rotace dolnõâ cï elisti Stability of surgical counter-clockwise rotation of the mandible

Transcription

1 ORTODONCIE rocïnõâk19 Stabilita chirurgickeâ counter-clockwise rotace dolnõâ cï elisti Stability of surgical counter-clockwise rotation of the mandible *MUDr. Lusine Samsonyan, *MUDr. Hana TycovaÂ, *MUDr. Josef KucÏ era, **RNDr. JaromõÂr BeÏ laâ cï ek, CSc., ***MUDr. et MUDr. Rene Folta n, PhD., FEBOMFS *Ortodonticke oddeï lenõâ, Stomatologicka klinika1. LF UK avfn v Praze *Department of Orthodontics, Clinic of Stomatology, 1st Medical Faculty of Charles University in Prague ** OddeÏ lenõâ biomedicõânskeâ statistiky prïi U stavu Biofyziky 1. LF UK v Praze ** Department of Biomedical Statistics, Institute of Biophysics, 1st Medical Faculty of Charles University in Prague *** OddeÏ lenõâ maxilofaciaâ lnõâ chirurgie, Stomatologicka klinika1. LF UK avfn v Praze *** Department of Maxillofacial Surgery, Clinic of Stomatology, 1st Medical Faculty of Charles University in Prague Souhrn Jednou z mozï nostõâ chirurgickeâ leâ cï by otevrïeneâ ho skusu je chirurgickaâ counter-clockwise rotace dolnõâ cï elisti nebo maxilo-mandibulaâ rnõâho komplexu. CõÂlem teâ to studie bylo posoudit stabilitu vyâ sledkuê chirurgickeâ terapie otevrïeneâ ho skusu pomocõâ sagitaâ lnõâ osteotomie veï tve dolnõâ cï elisti s counter-clockwise rotacõâ okluznõâ roviny a zjistit, zda je stabilita CCW rotace dolnõâ cï elisti ovlivneï naâ pocï tem desticï ek (minidlah) rigidnõâ osteosynteâ zy v dolnõâ cï e- listi. Soubor zahrnoval 26 pacientuê, kterïõâ podstoupili CCW rotaci hornõâ i dolnõâ cï elisti. Bylo porovnaâvaâ no 8 kefalometrickych parametruê ve trïech cï asovyâ ch obdobõâch - po ortodontickeâ dekompenzaci vady (T0), maximaâ lneï sedm dnõâ po chirurgickeâ korekci (T1) a minimaâ lneï jeden rok po chirurgickeâ m zaâ kroku (T2). Po vyhodnocenõâ vyâ sledkuê meïrïenõâ jsme dospeïlikzaâveï ru, zïe stabilita CCW rotace dolnõâ cï elisti nenõâ zaâ vislaâ na pocï tu pouzïityâ ch minidlah (Ortodoncie 2010, 19, cï. 4, str ). Abstract One of the possible approaches to surgical treatment of anterior open-bite is the counter-clockwise rotation of the mandible or the whole maxillo-facial complex. The aim of this study was to evaluate stability of sagittal osteotomy of the mandiblar ramus and counter-clockwise rotation of the occlusal plane and find out whether the stability of CCW rotation is affected by the number of miniplates of rigid osteosynthesis in the mandible. Our sample comprised 26 patients who underwent CCW rotation of both upper and lower jaw. A total of 8 cephalometric parameters were compared in 3 time periods - after the orthodontic decompensation of the anomaly (T0), maximum 7 days after surgical treatment (T1), and at least 1 year after surgery (T2). Evaluation of results leads us to the conclusion that the stability of CCW rotation of the mandible is not affected by the number of miniplates used (Ortodoncie 2010, 19, No. 4, p ). KlõÂcÏ ovaâ slova: otevrïenyâ skus, chirurgickaâ counter-clockwise rotace, minidlahy, stabilita. Key Words: open bite, surgical counter-clockwise rotation, miniplates, stability redakce@orthodont-cz.cz 27

2 rocïnõâk19 ORTODONCIE U vod V etiologii skeletaâ lnõâho otevrïeneâ ho skusu je zanejcï asteï jsï õâ prïõâcï inu povazï ovaâ naneprïõâznivaâ ruê stovaâ rotace cï elistõâ nebo nadmeï rnaâ erupce lateraâ lnõâch uâ sekuê chrupu. PrÏi analyâ ze kefalometrickeâ ho snõâmku jsou za znaâ mky skeletaâ lnõâho otevrïeneâ ho skusu nejcï asteï ji oznacï ovaâ ny kraâ tkaâ veï tev dolnõâ cï elisti arotace distaâ lnõâ cï aâ sti hornõâ cï elisti smeï rem kaudaâ lnõâm. Obatyto faktory vedou k rotaci dolnõâ cï elisti doluê adozadu. TõÂm se zveïtsï uje prïednõâ vyâsï kaoblicï eje, v neï kteryâch prïõâpadech dochaâ zõâ k oddaâ lenõâ frontaâ lnõâch zubuê avzniku otevrïeneâ ho skusu. Pacient zõâskaâvaâ charakteristickyâ vzhled tzv. dlouheâ ho oblicï eje (syndrom dlouheâ ho oblicï eje neboli ¹long-faceª) [1, 2]. U speï sï naâ leâ cï baskeletaâ lnõâho otevrïeneâ ho skusu v pruêbeïhuruê stu vyzï aduje prïedevsï õâm korekci rotace distaâ lnõâ cï aâ sti hornõâ cï elisti aomezovaâ nõâ erupce zubuê postrannõâho uâ seku. U teïzïkyâch vad tohoto typu nenõâcï asto mozïneâ dosaâ hnout uspokojiveâ ho funkcï nõâho aestetickeâ ho vyâ sledku pouze pomocõâ ortodontickeâ leâ cï by. Redukce prïednõâ oblicï ejoveâ vyâsïky auâ pravu rotace cï elistõâ u dospeï leâ ho pacienta se skeletaâ lnõâm otevrïenyâ m skusem lze cï asto dosaâ hnout jen pomocõâ chirurgickeâ intervence [1, 3]. Pla novaâ nõâ ortodonticko-chirurgickeâ leâ cï by by meï lo byât zalozï eno nejen nazmeïneï postavenõâ cï elistõâvuêcïibaâzi lebnõâ avuêcï i sobeï navzaâ jem, ale takeâ nazlepsï enõâ pacientovavzhledu anastabiliteï vyâsledkuê leâcï by [4]. JednõÂm z chirurgickyâch zaâ krokuê, kteryâ se provaâdõâ kuâ praveï otevrïeneâ ho skusu u dospeïleâ ho pacienta, je sagitaâ lnõâ osteotomie veï tve dolnõâ cï elisti. Sagita lnõâ osteotomii dolnõâ cï elisti (Bilateral Sagittal Split Osteotomy, daâ le jen BSSO) poprveâ popsal Obwegeser v roce 1957 [5]. Od teâ doby prosï latato chirurgickaâ technika cï etnyâ mi modifikacemi. Epkerova modifikace sagitaâ lnõâ osteotomie mandibuly jako jedinaâ umozïnï uje CCW rotaci dolnõâ cï elisti [6]. Podstatou operace je oboustranneâ sagitaâ lnõâ rozsïteï penõâ veï tvõâ dolnõâ cï elisti od oblasti mezi incisura semilunaris a foramen mandibulae azï do krajiny cï elistnõâho uâ hlu. Tato Epkerova modifikace BSSO umozïnï uje nejen posun dolnõâ cï elisti doprïedu adozadu, ale soucï asneï i jejõâ rotaci. Posun doprïedu v kombinaci s CCW rotacõâ lze s vyâhodou pouzï õât u pacientuê s velkyâm uâ hlem mandibulaâ rnõâ linie, s malou a posteriorneï ulozïenou dolnõâ cï elistõâ. NeÏ kterïõâ autorïi [2, 7, 8, 9, 10] uvaâdõâ,zïe monomaxilaâ rnõâ CCW rotace mandibuly nenõâ vhodnou metodou terapie otevrïeneâ ho skusu, ato prïedevsï õâm kvuê li sï patneâ stabiliteï vyâ konu. Uda vajõâ, zï e prïi tomto zaâ kroku dochaâ zõâ k napõânaâ nõâ pterygomasseterickeâ smycï ky, atoto napeï tõâ je pozdeï ji prïõâcï inou recidivy. NicmeÂneÏ dalsï õâ modifikace chirurgickeâ techniky avyâ voj osteosyntetickyâ ch materiaâ luê, naprïõâklad pouzï itõâ rigidnõâ fixace kostnõâch uâ lomkuê,vyârazneï zlepsï ily stabilitu tohoto vyâkonu [3,11,12]. Introduction The unfavourable growth rotation of the mandible and excessive eruption of lateral teeth is often regarded as one the most frequent causes of skeletal open bite. Among the most common cephalometric characteristics of skeletal open bite belong short mandibular ramus and rotation of the distal part of the maxilla in caudal direction. Both of these factors result in the downward and posterior rotation of the mandible. This leads to the increased anterior facial height, in some cases anterior teeth fail to compensate for increasing hyperdivergency and an anterior open bite forms. This often results in typical facial appearance, so-called ¹long face syndromeª. [1, 2] Successful treatment of skeletal open bite during growth requires correction of maxillary plane rotation and restriction of eruption of posterior teeth. However, in more severe cases it is impossible to achieve a satisfactory functional and esthetic result with the orthodontic treatment only. In adult patients with skeletal open bite the reduction of anterior facial height and adjustment of the unfavourable jaw rotation may be achieved only by means of surgical intervention [1, 3]. The planning of combined orthodontic-surgical therapy should be based not only on the desired improvement of the jaw position relative to the base of the skull and relative to each other, treatment should be aimed also at improvement of facial esthetics and stability of the results achieved during the therapy [4]. One of the surgical approaches used for correction of skeletal open bite in adults is sagittal osteotomy of the mandibular ramus. Bilateral sagittal split osteotomy (BSSO) was first described by Obwegeser in 1957 [5]. The method has undergone a number of modifications since that time. Epker's modification of BSSO is the only one allowing the CCW rotation of the mandible [6]. The principle of the operation is bilateral sagittal split of mandibular ramus from the area between incisura semilunaris and foramen mandibulae to the area of mandibular angle. Epker's modification of BSSO does not only allow to move the distal segment in forward and backward direction, but at the same time allows also rotation of the segment. The anterior movement together with CCW rotation may be used in high angle patients with a hypoplastic and/or posteriorly positioned mandible. Some authors [2, 7, 8, 9, 10] report that monomaxillary CCW rotation of the mandible is not an appropriate approach to the open bite deformities, due to insufficient stability of the result. They suggest that during the intervention the pterygomasseteric sling is being stretched, and that the subsequent tension makes the result prone to relapse. Nevertheless, new modifications of the approach as well as the development of redakce@orthodont-cz.cz

3 ORTODONCIE rocïnõâk19 U bimaxilaâ rnõâch zaâ krokuê,prïi terapii pacientuê se skeletaâ lnõâm otevrïenyâ m skusem, mnohdy provaâ dõâme soucï asneï takeâ posun distaâ lnõâ cï aâ sti hornõâ cï elisti smeï rem kraniaâ lnõâm (distaâ lnõâ impakce maxily), cï õâmzï se napeï tõâ pterygomasseterickeâ smycï ky vyâ razneï zredukuje. Bimaxila rnõâ CCW korekce otevrïeneâ ho skusu je povazïovaâ nazavyâkon s veïtsï õâ stabilitou [2, 13]. Proffit et al. [14] leâ cï bu skeletaâ lnõâho otevrïeneâ ho skusu impakcõâ hornõâ cï elisti aprïedsunutõâm dolnõâ cï elisti u II.trÏõÂd povazï uje za vyâ kon stabilnõâ jen s pouzï itõâm rigidnõâ fixace. Bimaxila rnõâ CCW rotace s sebou prïinaâsï õâ kromeï stability takeâ dalsïõâ vyâ hody. Poskytuje naâ m veï tsï õâ mozï nost ovlivnit estetiku oblicï eje pacienta a prïinaâ sï õâ vyâ razneï jsï õâ zkraâ cenõâ prïednõâ oblicï ejoveâ vyâ sï ky. U pacientuê s vyâ raznyâ m daâ snï ovyâ m uâ smeï vem nejen v lateraâ lnõâm uâ seku, ale takeâ ve frontaâlnõâm uâ seku, zlepsï õâ bimaxilaâ rnõâ zaâ krok s impakcõâ hornõâ cï elisti v celeâ m rozsahu vyâznamneï estetiku uâ smeïvupacienta. DalsÏõ vyâhodou CCW rotace je zveïtsï enõâ pruêchodnosti hornõâch cest dyâ chacõâch a zlepsï enõâ dechovyâ ch parametruê. Dle Mehraet al. [15] prïedsunutõâ a CCW rotace maxilo-mandibulaâ rnõâho komplexu zveï tsï õâ orofaryngeaâ lnõâ prostor retropalatinaâ lneï, retroglosaâ lneï a v oblasti nosohltanu. U III. skeletaâ lnõâ trïõâdy musõâme velmi pecï liveï volit druh operacï nõâho vyâ konu. PrÏi provedenõâ prosteâ ho zasunutõâ dolnõâ cï elisti vzad (set-back) u skeletaâ lnõâ III. trïõâdy, hrozõâ nebezpecï õâ zmensï enõâ hornõâch cest dyâ chacõâch. Folta n et al. [16] publikovali data, podle kteryâch prïi tomto zpuê sobu operace dochaâzõâ ke zhorsï enõâ dechovyâ ch parametruê ve spaâ nku. Proto tento zaâ krok provaâ dõâme veïtsï inou v raâ mci bimaxilaâ rnõâ operace, prïi ktereâ posun hornõâ cï elisti doprïedu umozï nõâ proveâ st zasunutõâ mandibuly v mensï õâm rozsahu. Bimaxila rnõâ operace s CCW rotacõâ maâ narozdõâl od prosteâho zasunutõâ dolnõâ cï elisti vzad u pacientuê se III. skeletaâ lnõâ trïõâdou daleko mensï õâ negativnõâ vliv na hornõâ cesty dyâchacõâ [16]. PodobnyÂm vyâ vojem, jakyâ m se vyvõâjelaoperacï nõâ technika, a jakyâ m postupneï za cï aly v teâ to indikaci prïevlaâ dat bimaxilaâ rnõâ vyâ kony, vyvõâjely se takeâ osteosyntetickeâ materiaâ ly, ktereâ vyâ razneï zlepsï ily stabilitu teâ to operace. Na nasï em pracovisï ti je dnes standardneï pouzï õâvaâ narigidnõâ osteosynteâ zave formeï titanovyâ ch minidlah. V literaturïe se setkaâ vaâ me s otaâ zkou, zdastabilita BSSO s CCW rotacõâ u pacientuê se skeletaâ lnõâm otevrïenyâm skusem zaâ visõâ napocï tu pouzï ityâch minidlah. CõÂlem nasï õâ studie bylo proveïrïit praâveï tuto otaâ zku. Materia l a metodika Do teâ to studie bylo zahrnuto celkem 26 pacientuê s otevrïenyâm skusem - 17 zï en a9 muzïuê. Pacienti byli rozdeï leni do dvou skupin podle pocï tu desticï ek rigidnõâ osteosynteâ zy. Skupina1 (13 pacientuê)meï lasegmenty dolnõâ cï elisti zdlahovaâ ny 1 desticï kou nakazïdeâ straneï, skupina2 (13 pacientuê)meï lasegmenty zdlahovaâny 2 new osteosynthetic materials (e.g. rigid fixation of bone fragments) improved the stability of results [3, 11, 12]. In bimaxillary surgical treatment of patients with skeletal open bite, movement of distal part of maxilla in cranial direction (distal maxillary impaction) is often performed at the same time. This significantly reduces the tension in pterygomasseteric sling. Bimaxillary correction of the open bite is considered to be the method with improved stability [2, 13]. Proffit et al. [14] considers the treatment of skeletal open bite by maxillary impaction and advancement of the mandible in Class II patients to be stable only when rigid fixation is used. Bimaxillary CCW rotation brings about other advantages. It gives us a greater possibility to influence esthetic results and allows to achieve a more distinct shortening of anterior facial height. In patients with gummy smile both in lateral and frontal segment, impaction of the upper jaw improves the esthetics of patient's smile. Another advantage of CCW rotation is seen in better passage of the upper airways and improved breathing parameters. According to Mehr et al. [15] the advancement and CCW rotation of maxillomandibular complex results in increased oropharyngeal area retropalatally, retroglossally, and in the area of nasopharynx. In skeletal Class III patients attention must be paid to chosing the right type of surgery. Mandibular set-back in skeletal Class III patients may lead to reduction of the upper airways. Folta n et al. [16] show that mandibular set-back results in worsening of breathing parameters during sleep. Therefore, mandibular set-back is almost always performed as a part of bimaxillary intervention, when the maxillary advancement allows for smaller mandible set-back. Bimaxillary approach with CCW rotation has smaller adverse effects on the upper airways [16]. The development of surgical techniques and growing number of bimaxillary interventions has been accompanied by development of osteosynthetic materials that improved the stability of treatment. In our department, rigid osteosynthesis using titanium miniplates became a routine. In the articles published in literature we often encounter a question, whether the stability of BSSO with CCW rotation in patients with skeletal open bite is related to the number of miniplates applied. To answer the question was also the purpose of this study. Material and methods The sample included 26 patients with open bite - 17 females and 9 males. The sample was divided into two groups according to the number of rigid miniplates. In Group 1 (13 patients) segments of the mandible were splinted with one miniplate on each side. In Group 2 (13 patients) segments of the mandible were splinted redakce@orthodont-cz.cz 29

4 rocïnõâk19 ORTODONCIE desticï kami na kazïdeâ straneï.vsï ichni jedinci v souboru byli dospeï lõâ bõâleâ rasy. VsÏ ichni pacienti podstoupili bimaxilaâ rnõâ operaci. Na hornõâ cï elisti bylaprovedenaimpakce, a to bud' v celeâ m rozsahu nebo pouze v jejõâ distaâ lnõâ cï aâ sti. U neï kteryâ ch pacientuê bylaoperace na hornõâ cï elisti provedenasegmentaâ lneï v linii Le Fort I. Nadolnõ cï elisti bylaprovedenaepkerovamodifikace sagitaâ lnõâ osteotomie veï tve a jejõâ CCW rotace. U 5 pacientuê byl proveden distaâ lnõâ posun (set-back) dolnõâ cï e- listi, u ostatnõâch pacientuê bylo provedeno prïedsunutõâ dolnõâ cï elisti (advancement) s CCW rotacõâ. Pro zlepsï enõâ estetiky oblicï eje bylau 18 pacientuê provedenagenioplastika. Navza jem bylaporovnaâ vaâ nastabilitaccw rotace dolnõâ cï elisti mezi skupinou pacientuê s jednou minidlahou (skupina 1) a skupinou pacientuê se dveïma minidlahami (skupina 2). with two miniplates on each side. All patients were adult individuals of caucasian origin. All patients underwent bimaxillary surgery. Total or partial impaction was performed in the maxilla. In some patients segmental Le Fort I maxillary osteotomy was performed. Epker's modification of sagittal ramus osteotomy was performed in the mandible, followed by CCW rotation. In 5 patients, set-back of the mandible was performed; in the remaining patients, advancement of the mandible and CCW rotation were done. To improve esthetic results genioplasty was carried out in 18 patients. The stability of the mandibular CCW rotation was compared between the patients with 1 miniplate (Group 1) and those with 2 miniplates (Group 2). Cephalograms were done after the orthodontic decompensation of the anomaly (T0), up to 7 days after Obr. 1. PouzÏ iteâ kefalometrickeâ body alinie Fig. 1. Cephalometric points nad lines N (Nasion) - strïed sutura nasofrontalis, middle of sutura nasofrontalis S(Sella) - strïed anatomickeâ Sella Turcica, middle of anatomic Sella Turcica Go (Gonion) - konstruovanyâ bod, pruê secï õâk tecï ny k dolnõâmu okraji corpus mandibulae z bodu Menton a tecï ny k zadnõâmu okraji ramus mandibulae z bodu Articulare, a constructed point, intersection of atangent to the lower margin of the mandibular body from Menton and a tangent to the posterior margin of the mandibular ramus from Articulare Me (Menton) - nejnizïsï õâ bod nakonturïe symfyâzy dolnõâ cï elisti, the lowest point on the contour of the mandibular symphysis Is (Incisale Superius) - incizaâ lnõâ hrana hornõâho centraâ lnõâho rïezaâ ku, incisal edge of the upper central incisor Ii (Incisale Inferius) - incizaâ lnõâ hrana dolnõâho centraâ lnõâho rïezaâ ku, incisal edge of the lower central incisor ML (Mandibula rnõâ linie, Mandibular Plane) - spojnice boduê Me ago, connecting line between Me and Go NL (Naza lnõâ linie) - spojnice boduê spina nasalis anterior (Spa) a spina nasalis posterior (Spp), connecting line between spina nasalis anterior (Spa) and spina nasalis posterior (Spp) HP (Horizontal plane) - horizontaâ lnõâ referencï nõâ linie - linie prolozï enaâ z bodu N (Nasion) svõârajõâcõâ uâ hel 7 s liniõâ Sella - Nasion, horizontal reference line - line from N (Nasion) constructed at an angle of 7 to the Sella-Nasion line LOP (Lower occlusal plane) - rovinaprolozï enaâ bodem 1 mm apikaâ lneï od inciznõâ hrany dolnõâho centraâ lnõâho rïezaâ ku amezihrbolkovou ryâhou dolnõâho prvnõâho molaâ ru, plane going through a point 1 mm apically from the incisal edge of lower central incisor and the intercuspal fossaof lower first molar UFH (mm) - hornõâ prïednõâ oblicï ejovaâ vyâsï ka-prïõâmaâ vzdaâ lenost Nasion a Spina nasalis anterior, upper facial height - distance between Nasion and Spina nasalis anterior Linea rnõâ parametry, Linear parameters: OB (mm) - hloubkaskusu - meï rïeno z Incisale Superius a Incisale Inferius nakolmici k horizontaâ lnõâ referencï nõâ linii (HP - horizontal plane), overbite - measured from Incisale Superius and Incisale Inferius on the perpendicular to the horizontal reference line (HP - horizontal plane) LFH - dolnõâ prïednõâ oblicï ejovaâ vyâsï ka-prïõâmaâ vzdaâ lenost Spina nasalis anterior a Menton, lower anterior facial height -distance between Spina nasalis anterior and Menton [17] U hloveâ rozmeï ry, Angular measurements: Go - Goniovy uâ hel svõâranyâ tecï nou k dolnõâmu okraji angulus mandibulae z bodu Menton a tecï nou k zadnõâmu okraji angulus mandibulae z bodu Artikulare, gonion angle - angle formed by a tangent to the lower edge of angulus mandibulae from Menton and a tangent to the posterior edge of angulus mandibulae from Articulare HPML - uâ hel, kteryâ svõâraâ mandibulaâ rnõâ linie (ML) s horizontaâ lnõâ rovinou (HP), angle between mandibular line (ML) and horizontal plane (HP) NLML -uâ hel mezi baâ zõâ hornõâ (NL) adolnõâ cï elisti (ML), angle between the upper jaw (NL) and the mandibular plane (ML) LOP (Lower occlusal plane angle) - uâ hel mezi dolnõâ okluznõâ rovinou (LOP) ahorizontaâ lnõâ rovinou (HP), angle between the lower occlusal plane (LOP) and horizontal plane (HP) [18] Indexy, indexes: SGo/NMe x 100% - pomeï r zadnõâ a prïednõâ oblicï ejoveâ vyâsï ky, proportion between posterior and anterior facial height UFH/LFH x 100% - pomeï r hornõâ adolnõâ oblicï ejoveâ vyâsï ky, proportion between upper and lower facial height redakce@orthodont-cz.cz

5 ORTODONCIE rocïnõâk19 Kefalometricke snõâmky byly zhotoveny po ortodontickeâ dekompenzaci vady (T0), maximaâ lneï 7 dnõâ po operaci (T1) a minimaâ lneï 1 rok po chirurgickeâ m zaâkroku (T2). Kefalometricke snõâmky byly zhotoveny na stomatologickeâ klinice 1. LF UK avfn v Praze av neïkolikaprivaâ tnõâch praxõâch. VsÏ echny snõâmky byly prïekreslovaâ ny jednou osobou naprosveï tlovacõâ skrïõânce na acetaâ tovyâ papõâr. Na kefalometrickyâ ch snõâmcõâch bylo hodnoceno celkem 8 parametruê, z toho 2 lineaâ rnõâ parametry, 4 uâ hloveâ parametry a 2 pomeï rneâ indexy. (Obr. 1) Vzhledem k tomu, zï e snõâmky byly zõâskaânyzruê znyâch zdrojuê, byl nakazïdeâ m snõâmku podle meï rïõâtkakefalostatu stanoven koeficient zveï tsï enõâ. Linea rnõâ parametery byly tõâmto koeficientem vynaâ sobeny tak, aby vyâslednaâ hodnotaodpovõâdalaskutecïneâ velikosti. Ze studie byly vyloucï eny snõâmky necï itelneâ, bez meï rïõâtka asnõâmky, ktereâ neodpovõâdaly vyâsï e uvedenyâm cï asovyâm pozïadavkuê m jejich zhotovenõâ. Statisticke zpracovaâ nõâ vyâ sledkuê bylo provedeno s vyuzï itõâm moduluê GLM anpar TESTS (Kolmogorov-SmirnovuÊ v test pro oveï rïenõâ prïedpokladuê o normaâ l- nõâm rozdeï lenõâ vstupnõâch promeï nnyâ ch). Byly zkoumaâ ny zmeï ny jednotlivyâch parametruê. RozdõÂl mezi cï asy T0 at1 vyjadrïuje operacï nõâ zmeï nu arozdõâl mezi cï asy T1 at2 prïõâpadnou recidivu. Recidiva operacï nõâho posunu u jednotlivyâ ch promeï nnyâ ch bylav raâ mci jednotlivyâ ch skupin testovaâ napomocõâ testuê mnohonaâ sobneâ ho porovnaâvaâ nõâ (LSD - least significant difference). K porovnaâ vaâ nõâ obou testovanyâ ch skupin navzaâ jem byl pouzï it dvouvyâbeï rovyâ T test. Bylo oveïrïovaâ no, zdase recidiva operacï nõâho posunu mezi skupinou 1 askupinou 2 statisticky vyâ znamneï lisï õâ. VsÏ echny statistickeâ testy byly provedeny prïi hladineï vyâznamnosti p = 0,05. Vy sledky U skupiny pacientuê s 1 minidlahou (skupina 1) v cïase T0-T1 dosï lo ke zmensï enõâ gonioveâho uâ hlu v pruêmeïru o 4,9. VcÏ ase T1-T2 se goniovyâ uâ hel zmensï il o 0,4. U skupiny pacientuê se 2 minidlahami (skupina 2) se vcï ase T0-T1 goniovyâ uâ hel zmensï il o 5,4. VcÏ ase T1- T2 dosï lo k recidiveï, kteraâ vzniklazveï tsï enõâm uâ hlu o 1,9. Testy mnohonaâ sobneâ ho porovnaâ vaâ nõâ bylo prokaâ zaâ no, zï e recidivavelicï iny Go je statisticky nevyâznamnaâ pro skupinu pacientuê s 1 minidlahou i pro skupinu pacientuê se 2 minidlahami. Statisticky nevyâznamnaâ recidiva nastala takeâ u velicï in SGo/NMe, UFH/LFH, LFH. RecidivavelicÏ iny HS bylau skupiny pacientuê s 1 minidlahou statisticky vyâ znamnaâ (p = 0,005) acï inõâ 24 % operacï nõâho posunu. U skupiny se 2 minidlahami nebyla recidiva statisticky vyâ znamnaâ. RecidivavelicÏ iny LOP je statisticky nevyâ znamnaâ pro skupinu pacientuê s 1 minidlahou. Pro skupinu pacientuê s 2 minidlahami je recidiva velicï iny LOP statisticky vyâznamnaâ (p=0,017) acï inõâ 29 % operacï nõâho posunu. surgery (T1), and at least 1 year after surgery (T2). Cephalograms were done at the Clinic of Stomatology, 1st Medical Faculty of Charles University in Prague, and in several private offices. All cephalograms were manually traced by one person on acetate paper. A total of 8 parameters were evaluated in cephalograms - 2 linear, 4 angular, and 2 indexes (Fig. 1). As the cephalograms came from different sources, the magnification coefficient was calculated in each cephalogram according to the scale of cephalostat. Linear parameters were multiplied by the coefficient so that the resulting value corresponded to the real size. Cephalograms that were illegible, lacked the scale, or did not meet the time criteria, were excluded from the study. The results were processed with the use of modules GLM and NPAR TESTS (Kolmogorov-Smirnov test to verify the normal distribution of variables). Changes of cephalometric variables were evaluated. The difference between T0 and T1 represents the surgical change, while the difference between T1 and T2 represents the relapse. The significance of relapse was tested in individual variables with multiple comparisons tests (LSD - least significant difference). To compare the difference between the two groups atwo-sample t-test was used. We tested whether the relapse after the surgery in Group 1 is significantly different from the relaps in Group 2. All the tests were performed at the level of statistical significance of Results In Group 1 (1 miniplate) gonion angle decreased by 4.9 on average between T0-T1; between T1-T2 gonion angle decreased by 0.4. In Group 2 (2 miniplates) gonion angle decreased by 5.4 between T0-T1. Between T1-T2 relapse occurred and the angle increased by 1.9. Tests of multiple comparison proved that the relapse of Go is not statistically significant in both Group 1 and Group 2. We found no statistically significant relapse in parameters SGo/NMe, UFH/LFH, LFH. The relapse of overbite was statistically significant in Group 1, and represented 24% of the change gained during the operation. No statistically significant relapse was found in Group 2. The relapse of LOP is not statistically significant in Group 1. However, we found statistically significant relaps in Group 2 (p=0.017), which represents 29% of the change performed during the operation. In parameters HP/ML and NL/ML the relapse was statistically significant in both groups of patients. In case of HP/ML the relapse represented 43% of the change in Group 1, and 29% in Group 2. In parameter NL/ML the relapse reached 31% in Group 1 and 35% in Group 2 (Table 1). redakce@orthodont-cz.cz 31

6 rocïnõâk19 ORTODONCIE Tab. 1: Velikost operacï nõâho posunu a recidiva. OperacÏ nõâ recidivav procentech. Table 1: The amount of surgical displacement and relapse. Surgical relapse in percentage. T0-T1 = operacï nõâ posun (surgical displacement); T1-T2 = recidiva(relapse); * p < 0.05; ** p < 0.01; *** p < 0.001; n.s. p > 0.05 Test statistics: multiple comparison (Least significance difference) U velicï in HP/ML anl/ml bylaproklaâ zaâ nastatisticky signifikantnõâ recidiva u obou skupin pacientuê. U velicï iny HP/ML recidivaoperacï nõâho posunu u pacientuê s 1 minidlahou cï inõâ 43 %, au pacientuê se 2 minidlahami 29 %. U velicï iny NL/ML recidivaoperacï nõâho posunu u pacientuê s 1 minidlahou cï inõâ 31 %, u pacientuê se 2 minidlahami cï inõâ 35 % (Tab. 1). RecidivaoperacÏ nõâho posunu mezi skupinou pacientuê s 1 minidlahou a skupinou pacientuê se 2 minidlahami pro testovaneâ velicï iny signifikantneï nelisïõâ (Tab. 2). Diskuse Chirurgicka CCW rotace dolnõâ cï elisti nebo maxilomandibulaâ rnõâho kompexu je jednou z mozï nostõâ leâ cï by otevrïeneâ ho skusu. Prova dõâ se nejen pro zlepsï enõâ funkce chrupu, ale takeâ vyâ znamneï prïispõâvaâ ke zlepsï enõâ estetiky oblicï eje u pacientuê se syndromem dlouheâho oblicï eje. Stabilitu monomaxilaâ rnõâho zaâ kroku popisuje ve sveâ studii Lim [8], kteryâ povazï uje CCW rotaci dolnõâ cï elisti zastabilnõâ vyâ kon pro korekci skeletaâ lnõâho otevrïeneâ ho skusu. Naopak Mobarak et al. [9] u pacientuê sprïedsu- nutõâm dolnõâ cï elisti ajejõâ CCW rotacõâ dospeï likzaâveï ru, zïe stabilitu tohoto zaâ kroku nelze spolehliveï prïedpoveï deï t, anemeï l by se pro leâcï bu skeletaâ lnõâho otevrïeneâ ho skusu pouzï õâvat. Abbaszadeh [19] retrospektivneï stanovil dlouhodobou stabilitu CCW rotace maxilo-mandibulaâ rnõâho komplexu u 30 pacientuê se II. skeletaâ lnõâ trïõâdou apovazï uje CCW rotaci maxilo-mandibulaâ rnõâho komplexu zastabilnõâ vyâ kon. Chemello et al. [20] udaâ vajõâ, zï e CCW rotace maxilo-mandibulaâ rnõâho komplexu je stabilnõâ vyâ kon u pacientuê se zdravyâ mi temporomandibulaâ rnõâmi klouby. Nicme neï Arnett atamborello [21] prokaâ zali, zï e remodelace a resorpce kloubnõâ hlavice, Tab. 2: RozdõÂl v recidiveï mezi skupinou pacientuê s 1 minidlahou a skupinou pacientuê se 2 minidlahami u jednotlivyâch testovanyâch velicï in. Table 2: Difference in amount of relapse in different tested parameters between the group of patients with one miniplate and two miniplates t-test * p < 0.05;, n.s. p > 0.05 We found no significant difference between Group 1 and Group 2 in relapse after surgery (Table 2). Discussion Surgical CCW rotation of the mandible or maxillomandibular complex is one of the approaches to the treatment of open bite. The method not only improves the function of dentition, but also contributes to the esthetic result in patients with long-face syndrome. In his work, Lim [8] discusses the stability of the monomaxillary intervention. He considers CCW rotation of the mandible a stable technique of skeletal open bite correction. On the other hand, Mobarak et al. [9] state that the stability is rather unpredictable in patients with the advancement of the mandible and its CCW rotation, and does not recommend this approach as a method for open bite treatment. Abbaszadeh [19] in his retrospective study reports along-time stability of CCW rotation of maxillo-mandibular complex in 30 patients with skeletal Class II, and considers the approach sta redakce@orthodont-cz.cz

7 ORTODONCIE rocïnõâk19 atõâm zpuê sobenaâ recidivapo prïedsunutõâ dolnõâ cï elisti (bez CCW rotace), muêzï e nastat jak u pacientuê s patologickyâmi zmeï nami na kloubu, tak u pacientuê se zdravyâmi klouby. Co se tyâkaâ fixace kosteïnyâchuâ lomkuê, je zrïejmeâ zïeazï s vyâ vojem rigidnõâ osteosynteâ zy muê zï eme prïedpoklaâ da t lepsï õâ stabilitu vyâ konu [7,20,21]. VeÏ tsï inaliteratury porovnaâvaâ ruê zneâ druhy rigidnõâ osteosynteâ zy, zejmeâ nabikortikaâ lnõâ sï rouby, minidlahy s monokortikaâ lnõâmõâ sï rouby cï i biodegradabilnõâ materiaâ ly. Reitzik et al. [22] shledali, zï e klõâcï ovou uâ lohu pro stabilitu osteotomie veï tve dolnõâ cï elisti je pouzï itõâ rigidnõâ osteosynteâ zy. Jako rigidnõâ osteosynteâ zajsou nejcï asteï ji pouzïõâvaâ ny minidlahy, a to bud' 1 nebo 2 minidlahy na kazï dou stranu. Arnett [13] u CCW rotace dolnõâ cï elisti pro dosazïenõâ lepsï õâ stability doporucï uje pouzï itõâ 2-3 minidlah. V literaturïe toto tvrzenõâ nenõâ ale proveï rïeno apublikovaâ no. CõÂlem studie bylo prokaâ zat, zda pocï et pouzï ityâch minidlah v dolnõâ cï elisti muê zï e ovlivnit stabilitu CCW rotace maxilo-mandibulaâ rnõâho komplexu. U gonioveâ ho uâ hlu u skupiny pacientuê s 1 minidlahou (skupina 1) dosïlo vcï ase T1-T2 ke zmensï enõâ tohoto uâ hlu, tedy k dalsïõâmu zvyâ razneï nõâ ve smeï ru operacï nõâho posunu. U pacientuê, u kteryâch byly pouzïity 2 minidlahy (skupina 2), bylo naopak zaznamenaâ no zveï tsï enõâ gonioveâ ho uâ hlu, ktereâ prïedstavuje statisticky signifikantnõâ pooperacïnõâ recidivu. Tento vyâ sledek je do jisteâ mõâry paradoxnõâ, nebot' jsme ocï ekaâ vali, zïe fixace 2 minidlahami prïinese stabilneï jsï õâ vyâ sledek amensï õâ pooperacï nõâ recidivu. Po statistickeâ m zpracovaâ nõâ dat teâ to studie se ukaâ zalo, zï e stabilita vyâsledkuê nezaâ visõâ napocï tu pouzï ityâch minidlah. Vy sledky teâ to studie mohou byâ t ovlivneï ny prïedevsï õâm nehomogennõâ skupinou pacientuê ajejich malyâm pocï tem. PouzÏ ityâ vzorek 26 pacientuê obsahoval jak muzïe,takzïeny. Vzhledem k tomu, zï e v obou zkoumanyâ ch skupinaâ ch pacientuê bylaprïõâtomnaobeï pohlavõâ, nebrala tato studie v uâ vahu zaâ vislost recidivy napohlavõâ pacientuê. DalsÏõÂmu skalõâm bylo, zï e ve studii nebyla rozlisï ovaâ naskeletaâ lnõâ trïõâda. V obou skupinaâ ch byli nerovnomeï rneï zastoupeni pacienti s II. skeletaâ lnõâ trïõâdou apacienti se III. skeletaâ lnõâ trïõâdou. NepochybneÏ urcï itou roli hraje prïõâtomnost nebo neprïõâtomnost skeletaâ lnõâ fixace v pooperacï nõâm ortodontickeâ m doleâ cï enõâ, atakeâ nestejnyâ cï as po ukoncï enõâ ortodontickeâ leâcï by. Tuto studii je nutno povazï ovat pouze za pilotnõâ studii, kteraâ bude nadaâ le rozsï irïovaâ na. K overïenõâ dlouhodobeâ stability bude trïebashromaâ zï dit vetsï õâ pocï et pacientuê s delsï õâ dobou po sejmutõâ fixnõâho aparaâ tu. Pro stanovenõâ skeletaâ lnõâ prïõâcï iny recidivy by nepochybneï vyâ razneï pomohlo CT vysï etrïenõâ kloubnõâ hlavice. ZajõÂmave vyâ sledky by mohlo prïineâ st meï rïenõâ zmeï ny deâ lky veï tve dolnõâ cï elisti zpuê sobeneâ resorptivnõâmi pochody nakloubnõâ hlavici. ble. Chemello et al. [20] concluded that CCW rotation of maxillo-mandibular complex is stable in patients with healthy temporomandibular joints. Nevertheless, Arnett and Tamborello [21] proved that remodelling and resorption of the condyle followed by relapse after mandibular advancement (without CCW rotation) may occur both in patients with pathological as well as healthy joints. A greater stability may be expected with the development of rigid osteosynthesis [7,20,21]. Majority of published studies compared different types of rigid oesteosynthesis, e.g. bicortical screws, miniplates with monocortical screws, or biodegradable materials. Reitzik et al. [22] found that use of rigid osteosynthesis is the key factor for stability of mandibular ramus osteotomy. Miniplates are most frequently use for rigid osteosynthesis, either one or two on each side. Arnett [13] recommends use of 2-3 miniplates in order to achieve a better stability of CCW rotation. However, this assumption has not been yet proved or discussed in literature. The aim of our study was to find out whether the number of miniplates used in the mandible contributes to the stability of CCW rotation. In Group 1 the gonion angle decreased between T1-T2, i.e. the direction of surgical movement was even more pronounced. On the contrary, in Group 2 the gonion angle increased, i.e. statistically significant relapse after the intervention occurred. This is paradoxical as we expected that the fixation with 2 miniplates would lead to a more stable result and less relapse. Our data showed that stability of the results is not related to the number of miniplates applied. However, our results may be biased, because group of patients was not homogenous and sample size was relatively small. The sample of patients involved both men and women in both groups. The purpose of the study did was not to find a relationship between relapse and sexual dimorphism. Another source of bias in this study is unequal distribution of skeletal classes. There were patients with skeletal Class II and skeletal Class III in both groups. Presence or absence of skeletal fixation during postoperative orthodontic treatment plays also a potential role in stability, as well as different period after debonding of orthodontic appliances. The study should be considered apilot study. To verify the long-term stability it would be necessary to collect a larger number of patients and take into account also longer period after the removal of fixed appliance. To establish the underlying skeletal cause of relaps, CT examination of mandibular condyle would be highly beneficial. Interesting results may be obtained by measuring changes in length of mandibular ramus caused by resorptive processes in the condyle. redakce@orthodont-cz.cz 33

8 rocïnõâk19 ORTODONCIE ZaÂveÏr Tato praâ ce se zabyâvala srovnaâvaâ nõâm mõâry recidivy operacï nõâho posunu dolnõâ cï elisti s CCW rotacõâ jeden rok po chirurgickeâmzaâ kroku mezi skupinou pacientuê, u kteryâ ch k fixaci uâ lomkuê bylapouzï ita1 minidlahana obou stranaâ ch dolnõâ cï elisti, askupinou pacientuê, u kteryâch byly k fixaci uâ lomkuê pouzïity 2 minidlahy na obou stranaâ ch dolnõâ cï elisti. Vy sledky sledovaâ nõâ vedou k zaâveï ru, zï e stabilita CCW rotace dolnõâ cï elisti nenõâ zaâ vislaâ napocï tu pouzï ityâ ch minidlah. AutorÏi nemajõâ komercï nõâ, vlastnickeâ nebo financï nõâ zaâ jmy na produktech nebo spolecï nostech popsanyâ ch v tomto cïlaâ nku. Literatura/ References 1. Swinnen, K.; Politis, K.; Willems. G.; De Bruyne, I.; Fieuws, S.; Heidbuchel, K.; Van Erum, R.; Verdonck, A.; Carels, C.: Skeletal and dentoalveolar stability after surgical orthodontic treatment of anterior open bite: a retrospective study. Eur. J. Orthodont. 2001, 23, cï. 5, s Proffit, W. R.; White, R. P.Jr.; Sarver, D.M.: Contemporary Treatment of Dentofacial Deformity. St. Louis: Mosby, Wolford, L. M.; Chemello, P. D.; Hilliard, F.W.: Occlusal plane alteration in orthognatic surgery. J. oral maxillofacial Surg. Surg. 1993, cï. 51, s Schendel, S. A.; Eisenfeld, J.; Bell, W. H.; Epker, B. N.; Mishelevich, D. J.: The long face syndrome: Vertical maxillary excess. Amer. J. Orthodont. dentofacial Orthop. 1976, 70, cï. 4, s RybõÂnovaÂ, K.: Ortodonticko-chirurgicke rïesï enõâ zaâ va zïnyâ ch skeletaâ lnõâch anomaâ liõâ druheâ trïõâdy. AtestacÏ nõâ praâ ce v oboru ortodoncie. Praha, Folta n, R.: Chirurgicka leâ cï baotevrïeneâ ho skusu. II. cï eskoslovenskyâ ortodontickyâ kongres ax. kongres CÏ eskeâ ortodontickeâ spolecï nosti. PrÏednaÂsÏ ka, Mikulov, Joondeph, R. D.; Bloomquist, D.: Open bite closure with mandibular osteotomy. Amer. J. Orthodont. dentofacial Orthop. 2004, 126, cï. 3, s Lim, B. R.: Stability of treatment of anterior open bite with mandibullar surgery and rigid fixation. Thesis abstracts in: Amer. J. Orthodont. dentofacial Orthop. 1992, 101, cï. 4, s Mobarak, K. A.; Espeland, L.; Krogstad, O.; Lyberg, T.: Mandibular advancement surgery in high-angle, and low-angle, Class II patients: different long-term skeletal responses. Amer. J. Orthodont. dentofacial Orthop. 2001, 119, cï. 4, s Epker, B. N.; Stella, J. P.; Fish, L. C.: Dentofacial Deformities. Integrated Orthodontic and Surgical Correction. Volume II, 2nd edition, St. Louis : Mosby, Wolford, L. M.; Chemello, P. D.; Hilliard, F. W.: Occlusal plane alteration in orthognatic surgery- Part I: effects on function and esthetics. Amer. J. Orthodont. dentofacial Orthop. 1994, 106, cï. 3, s Arnett, G. W.: A redefinition of bilateral sagital osteotomy (BSO) advancement relapse. Amer. J. Orthodont. dentofacial Orthop. 1993, 104, cï. 5, s Conclusions The changes after surgical treatment of the mandible with CCW rotation 1 year after the intervention were studied. Two groups of patients were compared - Group 1 with 1 miniplate on each side, Group 2 with 2 miniplates applied on each side. Results of our analysis lead us to a conclusion that the stability of CCW rotation of the mandible does not depend on the number of miniplates used. The authors have no commercial, proprietary, or financial interests in the products or companies described in this article. 13. Arnett, G. W.; Mc Laughlin, R. P.: Diagnostika, plaâ novaâ nõâ oblicï ejoveâ estetiky aleâcï by u ortodonticko-chirurgickyâch pacientuê. Kurz, Praha, Proffit, W. R.; Turvey, T. A.; Phillips, C.: The hierarchy of stability and predictability in orthognathic surgery with rigid fixation: an update and extention Mehra, P.; Downie, M.; Pita, M.; Wolford, L.M.: Pharyngeal airway space changes after counterclockwise rotation of the maxillomandibular complex. Amer. J. Orhodont. dentofacial Orthop. 2001, 120, cï. 2, s Folta n, R.; HoffmannovaÂ, J.; Donev, F.; Vlk, M.; SÏ edyâ, J.; Kufa, R.; Bulik, O.: The impact of Le Fort I advancement and bilateral sagittal split osteotomy setback on ventilation during sleep. Int. J. oral maxillofacial Surg. 2009, 38, cï. 10, s Cangialosi, T. J.: Skeletal morfologic features of anterior open bite. Amer. J. Orthodont. 1984, 85, cï. 1, s Burstone, C. J.; James, R. B.; Legan, H.; Murphy, G.A.; Norton, L.A.: Cephalometrics for orthognathic surgery. J. oral. Surg. 1978, 36, cï. 4, s Abbaszadeh, S.: Long-term stability of surgical counterclockwise rotation of the maxillomandibular complex. Amer. J. Orthodont. dentofacial Orthop. 2007, 132, cï. 4, s Chemello, P. D.; Wolford, L.M.; Buschang, P. H.: Occlusal plane alteration in orthognatic surgery - Part II: Long term stability of results. Amer. J. Orthodont. dentofacial Orthop. 1994, 106, cï. 4, s Arnett, W. G.; Tamborello, A. J.: Progressive Class II Development. Female Idiopatic Condylar Resorption. Oral maxillofacial Surg. Clin. 1990, 2, cï. 4, s Reitzik, M.; Barer, P. G.; Wainwright, M.W.; Lim, B.: The surgical treatment of skeletal anterior open-bite deformities with rigid internal fixation in the mandible. Amer. J. Orthodont. dentofacial Orthop. 1990, 97, cï. 1, s MUDr. Lusine Samsonyan Stomatologicka klinika 1.LF UK a VFN KaterÏinska 32, Praha redakce@orthodont-cz.cz