Originl Article Mxillry incisor inclintion of skeletl Clss III ptients treted with extrction of the upper first premolrs nd two-jw surgery Conventionl orthognthic surgery vs surgery-first pproch Heon-Mook Prk ; Yng-Ku Lee b ; Jin-Young Choi c ; Seung-Hk Bek d ABSTRACT Objective: To investigte the differences in the mount nd pttern of the mxillry incisor (MXI) inclintion chnge in skeletl Clss III ptients treted with extrction of the mxillry first premolrs (MXP1) nd two-jw surgery (TJS) between conventionl orthognthic surgery (COS) nd surgery-first pproch (SFA). Mterils nd Methods: The study included 60 skeletl Clss III ptients who hd norml mxillry position, prognthic mndible, nd mild crowding in the mxillry rch (#4 mm). The ptients were divided into group 1 (COS, n 5 36) nd group 2 (SFA, n 5 24). Lterl cephlogrms were tken before tretment (T0), 1 month before surgery (T1), within 1 month fter surgery (T2), nd fter debonding (T3) for COS ptients nd t T0, T2, nd T3 for SFA ptients. After mesurement of the skeletodentl vribles, sttisticl nlyses were performed. Results: During T0 T2, the mount of MXI inclintion chnge (DU1-SN) in group 1 ws significntly lrger thn tht in group 2 (212.8u vs 24.4u; P,.001). During T2 T3, DU1-SN in groups 1 nd 2 occurred in opposite directions (3.8u vs 25.9u; P,.001). However, the totl mount of DU1-SN during T0 T3 ws not different between groups 1 nd 2 (29.0u vs 210.3u). At T3 the U1-SN vlues for groups 1 nd 2, respectively, moved closer to norml ccording to the vlues of the norml rnge rte (ll 83%), reltive percentge rtio (102.4% nd 100.1%), nd chievement rtio (77.7% nd 97.8%). Conclusions: The results of this study might provide bsic dt for predicting the mount nd pttern of MXI inclintion chnge in SFA for skeletl Clss III TJS ptients. (Angle Orthod. 2014;84:720 729.) KEY WORDS: Mxillry incisor inclintion; Skeletl Clss III ptients; Extrction of mxillry premolr; Surgery-first pproch Grdute Student (PhD), Deprtment of Orthodontics, School of Dentistry, Seoul Ntionl University, Seoul, South Kore. b Privte Prctice, ID Dentl Clinic, Seoul, South Kore. c Professor, Deprtment of Orl nd Mxillofcil Surgery, School of Dentistry, Dentl Reserch Institute, Seoul Ntionl University, Seoul, South Kore. d Professor, Deprtment of Orthodontics, School of Dentistry, Dentl Reserch Institute, Seoul Ntionl University, Seoul, South Kore. Corresponding uthor: Dr Seung-Hk Bek, Deprtment of Orthodontics, School of Dentistry, Dentl Reserch Institute, Seoul Ntionl University, Yeonkun-dong #28, Jongro-ku, Seoul, South Kore 110-768 (e-mil: drwhite@unitel.co.kr) Accepted: October 2013. Submitted: July 2013. Published Online: November 25, 2013 G 2014 by The EH Angle Eduction nd Reserch Foundtion, Inc. INTRODUCTION The conventionl surgicl-orthodontic tretment for skeletl Clss III ptients consists of preopertive orthodontic tretment (Pre-OP-OT), orthognthic surgery, nd postopertive orthodontic tretment (Post- OP-OT). 1 Although these tretment procedures generlly produce stisfctory results, including pproprite dentl decompenstion, proper rch coordintion, nd ccurte prediction of surgicl result before orthognthic surgery, severl disdvntges hve been reported, 2 4 including worsening of nterior crossbite nd fcil profile during Pre-OP-OT nd long totl tretment time. Recently, the surgery-first pproch (SFA) hs been proposed to overcome the disdvntges of conventionl surgicl-orthodontic tretment procedures. 5,6 This pproch hs some dvntges, such 720 DOI: 10.2319/072113-529.1
721 CHANGE IN UPPER INCISORS OF CLASS III AND SFA Tble 1. Demogrphic Dt of the Smples Group 1 (n 5 36, COS), 16 Mles nd 20 Femles Group 2 (n 5 24, SFA), 8 Mles nd 16 Femles Men SD Men SD P-Vlue Age, y 22.43 4.37 22.35 4.55.9535 Durtion, mo Preopertive orthodontic tretment Postopertive orthodontic tretment Totl tretment 17.14 8.17 25.31 3.77 3.07 5.43 NA 20.88 20.88 NA 3.85 3.85 NA.0000***.0005*** 21.71 22.72 1.59 2.92 21.92 22.09 1.28 1.89.5809.3387 Vribles Amount of crowding, mm Mxillry rch Mndibulr rch Independent t-test ws performed to compre the vribles between the two groups. Group 1 indictes conventionl orthognthic surgery (COS); Group 2, surgery-first pproch (SFA); SD, stndrd devition; nd NA, not pplicble. *** P,.001. s short totl tretment durtion, erly improvement of the fcil profile, nd estblishment of proper mxillomndibulr reltionship before orthodontic tretment.2 4,7 The SFA cn be performed successfully in cses with well-ligned or mildly crowded nterior teeth, mild to moderte curve of Spee/verticl problem, little or no trnsverse discrepncy, nd norml to mildly proclined/retroclined incisor inclintion.2,4 Skeletl improvement through orthognthic surgery cn be compromised by indequte preopertive decompenstion of the incisors.3,8,9 Decompenstion of the mxillry incisors in skeletl Clss III ptients cn occur either by extrction of the mxillry premolrs nd spce closure during Pre-OP-OT or by nonextrction nd superior impction of the posterior mxill during orthognthic surgery.9 However, the SFA for Clss III ptients hs been performed minly in cses involving nonextrction nd superior impction of the posterior mxill.2 This pproch might increse the mount of surgery s well Figure 1. (A) Lterl cephlogrms tken before tretment (T0), 1 month before surgery (T1), within 1 month fter surgery (T2), nd fter debonding (T3) for group 1 (conventionl orthognthic surgery, COS). (B) Lterl cephlogrm t the T0, T2, nd T3 stges for group 2 (surgeryfirst pproch, SFA).
722 PARK, LEE, CHOI, BAEK Figure 2. Lndmrks nd reference plnes: S indictes sell; N, nsion; Or, orbitle; Po, porion; A, point A; B, point B; Pog, pogonion; Me, menton; Go, gonion; U1E, the incisl edge of the mxillry centrl incisor; UIA, the root pex of the mxillry centrl incisor; LIE, the incisl edge of the mndibulr centrl incisor (LI); LIA, the root pex of the mndibulr centrl incisor; U6MBC, the mesiobuccl cusp tip (MBC) of the mxillry first molr; L6MBC, the MBC of the mndibulr first molr; HRP, horizontl reference plne, horizontl plne ngulted 7u clockwise to the SN-line pssing through sell; nd VRP, verticl reference plne, perpendiculr line to the HRP pssing through sell. s morbidity. Therefore, s n lterntive, it is necessry to extrct the mxillry premolrs during orthognthic surgery nd spce closure during Post- OP-OT under the SFA concept. The purpose of this study ws to investigte the differences in the mount nd pttern of mxillry incisor (MXI) inclintion chnge in skeletl Clss III ptients treted with extrction of the mxillry first premolrs (MXP1) nd two-jw surgery (TJS) between conventionl orthognthic surgery (COS) nd SFA. The null hypothesis ws tht there ws no difference in the mount nd pttern of MXI inclintion chnge between COS nd SFA. MATERIALS AND METHODS The smple consisted of 60 Koren skeletl Clss III ptients (24 mles nd 36 femles; men ge 5 22.4 6 4.4 yers) who underwent TJS (one-piece LeFort I osteotomy nd bilterl sgittl split rmus osteotomy) nd orthodontic tretment with MXP1 extrction. This retrospective study ws pproved by the Institutionl Review Bord of Seoul Ntionl University Dentl Hospitl (CRI 13007). The ptients were divided into two groups ccording to surgicl-orthodontic tretment concept: group 1 (COS; N 5 36; men ge 5 22.4 6 4.4 yers) or group 2 (SFA; N 5 24; men ge 5 22.4 6 4.6 yers) (Tble 1). Ptients in group 1 were selected from Deprtment of Orthodontics, Seoul Ntionl University Dentl Hospitl; ptients in group 2 were selected from privte orthodontic clinic. The mndibulr rch ws treted with nonextrction in both groups. According to the SFA concept, none of the ptients in group 2 received Pre-OP-OT, nd the MXP1s were extrcted during surgery for ll ptients in group 2. The totl tretment durtion for group 2 ws significntly shorter thn tht of group 1 (P,.001; Tble 1). There ws no difference in the mount of crowding in the mxillry nd mndibulr rches before tretment (Tble 1). Inclusion criteri for both groups were s follows 9,10 :(1) bilterl Clss III cnine nd molr reltionships, (2) ANB of 0u or less (reltively norml nteroposterior position of the mxill combined with prognthic mndible), (3) lck of severe fcil symmetry (#3 mm of menton devition from the fcil midline), (4) mild crowding in the mxillry rch (#4 mm), nd (5) growth completion confirmed by cervicl vertebrl mturtion sttus. 11 Ptients with cleft lip/plte or other crniofcil nomlies, missing teeth (except for third molrs), nd tooth size discrepncy (eg, peg lterlis) were excluded. 9,10,12 Seril lterl cephlogrms were tken during initil exmintion (T0), 1 month before surgery (T1), within 1 month fter surgery (T2), nd t debonding (T3) in COS cses (group 1) nd t T0, T2, nd T3 in SFA cses (group 2) (Figure 1). Definitions of the lndmrks, reference plnes, nd skeletodentl vribles Figure 3. Cephlometric vribles. 1. SNA (u); 2. SNB (u); 3. ANB (u); 4. Wits pprisl (mm); 5. SN-GoMe (u); 6. A-N perpendiculr (mm); 7. Pog-N perpendiculr (mm); 8. U1-SN (u); 9. U1-UOP (u); 10. U1-NA (u); 11. U1-NA (mm); 12. L1-NB (u); 13. L1-NB (mm); 14. IMPA (u); 15. Interincisl ngle (u); 16. Overjet (mm); 17. Overbite (mm); U1, long xis of the mxillry centrl incisor; UOP, the mxillry occlusl plne; nd L1, long xis of the mndibulr centrl incisor.
CHANGE IN UPPER INCISORS OF CLASS III AND SFA 723 compenstion during the Post-OP-OT in group 2 (SFA). Independent t-test, one-wy nlysis of vrince with Duncn s multiple comprison test, chi-squre test, nd binomil test were performed for sttisticl nlysis. Figure 4. Surgicl movement of the mxill nd mndible. 1. A-V (mm), verticl distnce from A to HRP; 2. PNS-V (mm), verticl distnce from PNS to HRP; 3. U6-V (mm), verticl distnce from U6MBC to HRP; 4. UI-V (mm), verticl distnce from UIE to HRP; 5. A-H (mm), horizontl distnce from A to VRP; 6. PNS-H (mm), horizontl distnce from PNS to VRP; 7. U6-H (mm), horizontl distnce from U6MBC to VRP; 8. UI-H (mm), horizontl distnce from UIE to VRP; 9. B-V (mm), verticl distnce from B to HRP; 10. Pog-V (mm), verticl distnce from Pog to HRP; 11. L6-V (mm), verticl distnce from L6MBC to HRP; 12. LI-V (mm), verticl distnce from LIE to HRP; 13. B-H (mm), horizontl distnce from B to VRP; 14. Pog-H (mm), horizontl distnce from Pog to VRP; 15. L6-H (mm), horizontl distnce from L6MBC to VRP; nd 16. LI-H (mm), horizontl distnce from LIE to VRP. re illustrted in Figures 2 nd 3. Trcing nd digitiztion of the lterl cephlogrms were performed by single opertor (HMP) using the V-Ceph progrm (Version 5.5, CyberMed, Seoul, Kore). To ssess the mount of surgicl movement of the mxill nd mndible, the horizontl nd verticl distnces from eight reference points to the verticl nd horizontl reference plnes were mesured (Figure 4). The mount nd pttern of MXI inclintion chnge were lso mesured nd nlyzed to evlute the differences between the two groups. All vribles from 20 rndomly selected subjects were mesured fter 2 weeks by the sme opertor (HMP). Differences clculted using Dhlberg s formul 13 rnged from 0.39 mm to 0.82 mm for the liner mesurements nd from 0.40u to 0.81u for the ngulr mesurements. Since there were no significnt differences between the first nd second mesurements, the first set of mesurements ws used. The power nlysis for smple size determintion ws performed using the Smple Size Determintion Progrm, Version 2.0.1 (Seoul Ntionl University Dentl Hospitl, Registrtion number 2007-01-122-004453) using the men nd stndrd devition vlues of U1-SN from previous studies. 8 10 The vribles t ech stge nd the mount of chnge between stges were compred between COS nd SFA cses, respectively. In ddition, the mount nd pttern of decompenstion during the Pre-OP-OT nd compenstion during the Post-OP-OT in group 1 (COS) were compred with simultneous decompenstion nd RESULTS Comprison of the Vribles t Ech Stge nd Within Ech Group According to Stges nd of the Amount of Chnge in the Vribles Among T0 T2, T2 T3, nd T0 T3 Stges At T0, the two groups did not show significnt differences in the vlues of vribles, except in the cse of Wits pprisl (Tble 2). At T1, group 1 showed significnt decompenstion of the mxillry nd mndibulr incisors by Pre-OP-OT (Tble 2). After surgery (T2), group 2 hd still more lbioversed mxillry incisors nd more linguoversed mndibulr incisors thn did group 1 (DU1-SN, DU1- UOP, DU1-NA ngulr, DU1-NA liner, P,.001; DL1- NB ngulr, DL1-NB liner, P,.05; Tble 2). In ddition, group 2 hd lrger overjet (P,.001; Tble 2) due to more posteriorly positioned mndible by overcorrection (SNB, P,.05; Tble 2). When compring the preopertive nd surgicl chnges from T0 to T2, improvements in the intermxillry reltionship (DANB, DWits pprisl) nd the nteroposterior position of the mndible (DSNB, DPog- N perp) were not significntly different between the two groups (Tble 3). At T3, lthough there were no significnt differences in the dentl vribles between the two groups, group 2 showed deeper overbite thn group 1 (P,.05; Tble 2). The mxill nd mndible were more bckwrd positioned in group 2 (SNA, SNB, Pog-N perp, ll P,.05; Tble 2). When compring the postopertive chnges from T2 to T3, group 1 showed less relpse of the intermxillry reltionship thn did group 2 (DANB, P,.05; DWits pprisl, P,.001; Tble 3). Becuse group 2 showed extrction spce closure of the MXP1 nd lbioversion of the mndibulr incisors during Post- OP-OT, groups 1 nd 2 showed opposite directions of the inclintion chnge (postopertive compenstion) of the mxillry nd mndibulr incisors (DU1-SN, DU1- UOP, DU1-NA ngulr, DU1-NA liner, DL1-NB ngulr, nd DIMPA, ll P,.001; Tble 3), resulting in different mounts of chnge in the overjet (Doverjet, P,.001; Tble 3). Compring the totl mounts of chnge from T0 to T3, there were no significnt differences in dentl vribles, except for DL1-NB liner (Tble 3). However, the mxill of group 2 ws more bckwrd positioned thn tht of group 1 (DSNA, DA-N perp;
724 PARK, LEE, CHOI, BAEK Tble 2. Comprison of the Cephlometric Vribles t Ech Stge nd Within Ech Group According to Stges T0 Stge T1 Stge T2 Stge COS P- COS P- COS Vribles Norm " Men SD Men SD Vlue b Men SD Men SD Vlue b Men SD SNA, u 81.31 82.15 3.33 81.56 3.28.4960 82.07 3.13 NA NA NA 83.05 3.21 SNB, u 78.92 85.71 3.73 83.96 3.57.0690 85.70 3.88 NA NA NA 79.67 3.41 ANB, u 2.62 23.57 2.30 22.40 3.12.1182 23.63 2.64 NA NA NA 3.37 1.77 Wits pprisl, mm 21.72 210.85 3.99 27.64 4.38.0053** 211.76 3.68 NA NA NA 22.03 2.84 SN-GoMe, u 33.77 35.31 4.83 36.71 7.48.4163 35.09 5.09 NA NA NA 37.19 4.92 A-N perpendiculr, mm 20.79 1.17 2.91 0.56 3.50.4742 1.05 2.76 NA NA NA 2.21 3.06 Pog-N perpendiculr, mm 22.26 10.22 7.19 7.57 6.91.1542 10.39 7.44 NA NA NA 20.12 6.61 U1-SN, u 106.55 118.24 5.59 117.25 6.88.5572 108.29 7.29 NA NA NA 105.40 7.00 U1-UOP, u 55.16 48.27 4.96 48.38 6.81.9425 54.27 6.70 NA NA NA 55.60 5.44 U1-NA ngulr, u 29.07 36.09 4.99 35.70 6.85.8081 26.22 7.23 NA NA NA 22.35 7.04 U1-NA liner, mm 6.32 9.15 2.07 9.06 2.27.8783 5.27 2.03 NA NA NA 4.04 1.82 L1-NB ngulr, u 25.27 21.96 5.50 23.45 7.29.3916 26.50 6.37 NA NA NA 22.54 5.42 L1-NB liner, mm 6.01 5.94 2.13 6.47 3.45.5028 7.09 2.28 NA NA NA 5.50 2.02 IMPA, u 95.39 80.93 6.38 82.78 8.87.3762 85.70 6.79 NA NA NA 85.68 6.96 Interincisl ngle, u 127.09 125.24 7.65 123.70 12.10.5760 130.92 7.66 NA NA NA 131.74 8.50 Overjet, mm 3.55 21.94 2.65 20.68 2.60.0693 27.03 3.23 NA NA NA 3.27 0.88 Overbite, mm 1.52 20.52 1.75 20.06 2.51.4314 0.22 1.93 NA NA NA 1.29 0.84 SD indictes stndrd devition; NA, not pplicble; COS, conventionl orthognthic surgery; nd SFA, surgery-first pproch. The ethnic norms ( " ) re cited from Kim nd Bek, 9 Bek nd Yng, 15 nd Choi et l. 16 b Independent t-test ws performed to compre the vribles between the two groups t ech stge. c One-wy nlysis of vrince (ANOVA) test ws performed to compre the vribles mong stges in ech group nd the results were verified with Duncn s multiple comprison test. For multiple comprisons t ech stge, indictes T0 stge; b, T1 stge; c, T2 stge; nd d, T3 stge. * P,.05; ** P,.01; *** P,.001. ll P,.01; DWits pprisl, P,.001; Tble 3). Chnges in the MXI inclintion hd different pttern between the two groups, s follows: group 1 showed tht U1-SN nd U1-NA ngulr decresed by both Pre-OP-OT nd surgery nd incresed by Post-OP- OT (T3, [T2,T4], T0, ll P,.001; Tble 2; Figure 5A). However, group 2 showed grdul decreses in U1-SN nd U1-NA ngulr by both surgery nd extrction spce closure during Post-OP-OT (T3, T2, T0, ll P,.001; Tble 2; Figure 5A). The mndibulr incisor inclintion of group 1 t T3 ws not improved compred to T0 (IMPA, [T0,T3], [T1,T2], P,.01; Tble 2). Similrly, group 2 did not show significnt chnge in IMPA from T0 to T3 stges (Tble 2). Comprison of the Amounts of Surgicl Movement of the Mxill nd Mndible (Tble 4) Group 2 showed less dvncement (DPNS-H, P,.001; DU6-H nd DU1-H, P,.01; DA-H, P,.05) nd more superior impction of the mxill (DA-V, P,.01; DU6-V, P,.05) thn group 1. Although the mounts of the mndibulr setbck were not different between the two groups, group 2 showed more superior movement of the mndible (DB-V, P,.001; DL6-V, P,.01; DPog-V nd DL1-V, P,.05). Distribution of Smples According to MXI Inclintion in Ech Group nd Between Groups t the T0, T1, T2, nd T3 Stges (Tble 5) At T0, groups 1 nd 2 hd lower vlues of the norml rnge rte (NRR) for U1-SN. In group 1, NRR for U1- SN sequentilly incresed by Pre-OP-OT nd superior impction of the posterior mxill during surgery; then it decresed slightly by Post-OP-OT. On the other hnd, group 2 showed sequentil increse in NRR for U1-SN by superior impction of the posterior mxill during surgery nd extrction spce closure of MXP1 during Post-OP-OT. Although the level of contribution to U1-SN normliztion by orthodontic tretment nd surgery ws slightly different between the two groups, NRRs for U1-SN t T3 were not significntly different between the two groups (ll 83%; Figure 5). Reltive Percentge Rtio (Tble 6) In group 1, U1-SN minly cme close to the ethnic norm by Pre-OP-OT, ws slightly overcorrected by surgery, nd ws then lbilly compensted by Post- OP-OT. In group 2, U1-SN ws sequentilly normlized into the ethnic norm by both surgery nd Post-OP- OT. However, there ws no significnt difference in the reltive percentge rtio (RPR) for U1-SN t T3
CHANGE IN UPPER INCISORS OF CLASS III AND SFA 725 Tble 2. Extended. T2 Stge T3 Stge Comprison According to Stges Within Ech Group P- COS COS Men SD Vlue b Men SD Men SD P-Vlue b P-Vlue c Multiple Comprison P-Vlue c Multiple Comprison 81.71 2.90.0962 83.06 3.15 80.85 3.61.0169* 0.3753.6125 77.62 3.00.0162* 80.83 3.40 78.55 3.37.0126* 0.0000*** (c,d), (,b).0000*** (d,c), 4.09 2.02.1600 2.23 2.19 2.30 2.18.9113 0.0000*** (,b), d,c.0000***, d, c 0.70 4.24.0077** 22.72 2.91 23.29 3.82.5322 0.0000*** (,b), (c,d).0000***, d, c 38.60 5.93.3340 38.23 5.21 39.12 6.85.5871 0.0232* (,b), (c,d).3778 0.59 3.78.0822 2.02 2.73 20.31 3.26.0053 0.2130.5922 23.29 6.08.0590 1.66 6.68 21.62 5.09.0347* 0.0339 (c,d), (,b).0000*** (c,d), 112.91 6.90.0001*** 109.20 6.65 106.72 7.40.1873 0.0000*** c, (b,d),.0000*** d, c, 48.65 3.97.0000*** 52.60 5.43 50.97 4.33.2003 0.0000***, d, (b,c).1751 31.20 6.91.0000*** 26.11 6.89 25.87 7.59.9023 0.0000*** c, (d,b),.0001*** d, c, 6.91 2.94.0001*** 5.20 2.20 4.83 2.27.5287 0.0000*** c, (d,b),.0000*** d, c, 18.39 6.38.0108* 20.92 5.30 22.47 5.49.2755 0.0003*** (,d,c), b.0295* c, (d,) 4.19 2.46.0327* 5.47 1.87 4.82 2.33.2486 0.0034** (d,c,), b.0258* c, (d,) 82.16 8.60.0972 81.86 7.19 84.81 7.19.1220 0.0031** (,d), (c,b).5772 126.46 10.58.0441* 130.82 7.93 129.52 5.72.4592 0.0023**, (d,b,c).1598 9.25 2.30.0000*** 2.91 0.73 3.14 0.95.3163 0.0000*** b,, (d,c).0000***, d, c 2.09 1.79.0456* 1.60 0.82 2.15 0.84.0128* 0.0000***, b, (c,d).0001***, (c,d) between groups 1 nd 2 (102.4% nd 100.1%, respectively). Achievement Rtio (Tble 6) The chievement rtio (AR) showed similr ptterns of chnges in RPR. Group 1 hd the sme direction of chnge in U1-SN during Pre-OP-OT nd surgery nd the opposite directionl chnge in U1-SN during Post- OP-OT, resulting in 77.7% of totl AR. However, group 2 exhibited the sme direction of chnge in U1-SN during surgery nd Post-OP-OT, resulting in 97.8% of the totl AR. Tble 3. Comprison of the Amounts of Chnge in the Vribles Between the T0 T2, T2 T3, nd T0 T3 Stges COS To-T2 Stge T2 T3 Stge T0 T3 Stge COS COS Group 2, SFA Vribles Men SD Men SD P-Vlue Men SD Men SD P-Vlue Men SD Men SD P-Vlue DSNA, u 0.90 2.04 0.22 2.32.2515 0.01 1.38 20.90 1.83.0428 0.91 1.94 20.68 2.06.0043** DSNB, u 26.04 1.97 26.37 2.02.5325 1.15 1.07 0.92 1.66.5532 24.89 1.71 25.45 2.12.2843 DANB, u 6.94 2.05 6.60 2.42.5701 21.14 1.08 21.83 1.24.0320* 5.80 2.04 4.77 2.48.0979 DWits pprisl, mm 8.82 4.05 8.44 2.62.1486 20.69 2.42 23.77 3.52.0003*** 8.13 3.40 4.66 4.09.0007*** DSN-GoMe, u 1.88 3.30 2.12 4.98.8339 1.04 1.83 0.47 2.71.3756 2.92 4.07 2.60 4.81.7892 DA-N perpendiculr, mm 1.04 2.55 0.09 2.84.1537 20.19 1.19 20.95 2.31.1608 0.85 1.99 20.85 2.72.0091** DPog-N perpendiculr, mm 210.34 4.24 210.98 6.40.7844 1.78 2.21 1.65 4.41.9042 28.56 3.27 29.32 5.17.5871 DU1-SN, u 212.84 5.73 24.43 3.53.0000*** 3.80 3.22 25.89 8.30.0000*** 29.04 5.86 210.32 7.58.4880 DU1-UOP, u 7.34 5.77 0.35 5.87.0000*** 23.01 3.55 2.31 4.69.0000*** 4.33 4.80 2.66 7.01.3137 DU1-NA ngulr, u 213.74 6.58 24.66 3.83.0000*** 3.76 3.64 24.98 8.11.0000*** 29.98 6.54 29.64 7.74.8611 DU1-NA liner, mm 25.11 2.77 22.25 2.51.0000*** 1.16 1.51 21.93 2.94.0000*** 23.95 2.80 24.18 4.21.6740 DL1-NB ngulr, u 0.58 5.47 24.88 4.21.0001*** 21.62 2.58 3.84 5.39.0001*** 21.04 5.15 21.05 5.67.9948 DL1-NB liner, mm 20.44 1.51 22.16 1.84.0006*** 20.03 0.58 0.53 1.60.0644 20.47 1.46 21.63 1.98.0135* DIMPA, u 4.75 6.76 20.64 4.44.0004*** 23.81 2.92 2.44 5.02.0000*** 0.93 6.58 1.81 7.26.6378 DInterincisl ngle, u 6.49 9.01 2.62 3.82.0265* 20.91 3.51 3.00 8.58.0429* 5.58 9.14 5.63 10.17.9848 DOverjet, mm 5.21 2.89 9.91 2.85.0000*** 20.36 0.82 25.96 2.42.0000*** 4.85 2.75 3.95 2.61.1454 DOverbite, mm 1.81 1.83 2.14 2.77.8219 0.30 0.99 0.08 1.82.5391 2.11 1.75 2.22 2.59.8694 Independent t-test ws performed to compre the vribles between the two groups during T0 T2, T2 T3, nd T0 T3 stge, respectively. SD indictes stndrd devition; COS, conventionl orthognthic surgery; nd SFA, surgery-first pproch. * P,.05; ** P,.01; *** P,.001.
726 PARK, LEE, CHOI, BAEK Figure 6. The mounts of inclintion chnge in the U1-SN between the two groups. Figure 5. Comprison of the chnging pttern between the two groups. (A) The mxillry incisor inclintion (U1-SN). (B) Norml rnge rte (NRR). DISCUSSION Although severl previous studies 3,8,9 hve reported on the inclintion chnge of MXI during surgiclorthodontic tretment of skeletl Clss III ptients, these studies hve compred the inclintion chnge of MXI between COS nd orthodontic cmouflge, between COS nd SFA with nonextrction cses, or between extrction nd nonextrction of MXP1 cses only in COS. On the contrry, this study ws designed to compre the inclintion chnge of MXI between COS nd SFA with MXP1 extrction cses. After Pre-OP-OT in group 1, the U1-SN vlues decresed by bout 10u nd cme close to norml rnge (Tbles 3, 5, nd 6). This finding ws similr to the result of Kim nd Bek. 9 Similr ptterns of chnge in both groups were observed in NRR, RPR, nd AR (Tbles 5 nd 6). Our findings for group 1 lso gree with those of Kim nd Bek, 9 who reported tht Pre-OP-OT plyed n importnt role in the normliztion of MXI inclintion compred to surgicl impction of the posterior mxill nd tht 48% of chievement rtio ws decresed during Post-OP- OT. In group 2, sequentilly normlizing pttern of chnge by surgery nd Post-OP-OT llowed for the voidnce of opposite directionl chnges in U1-SN tht occurred during Post-OP-OT in group 1. These findings re in ccordnce with those of Ko et l., 3 who reported tht ptients treted with COS exhibited round-tripping movement in the mxillry nd mndibulr incisors. When we compred totl chnges during T0 T3, there ws no significnt difference in terms of the MXI inclintion between the two groups (Tble 3). This finding disgrees with tht of Ko et l., 3 who reported tht MXI inclintion fter tretment ws different between COS nd SFA (5.4u in SFA, 21.8u in COS, P,.01). Since they did not define the mount of crowding before tretment nd lso did not distinguish MXP1 extrction cses from nonextrction cses in the COS group, 3 the mounts of MXI inclintion chnge could be different from those of this study. Although there ws no significnt difference in the nteroposterior nd verticl skeletl vribles between the two groups t T0 (Tble 2), surgicl movements of the mxill in group 2 exhibited less dvncement nd more superior impction of the posterior mxill compred to group 1 (Tble 4). Therefore, chnges in the sgittl position of the mxill during T0 T3 were different between the two groups (DSNA, DA-N perp, ll P,.01; Tble 3). Also, since group 2 requires the improvement of MXI inclintion by surgery, significnt superior impction of the posterior mxill ws performed in group 2. This finding lso grees with tht of Bek et l., 2 who reported tht the MXI were significntly lingully inclined s result of superior impction of the posterior mxill fter surgery.
CHANGE IN UPPER INCISORS OF CLASS III AND SFA 727 Tble 4. Comprison of the Amounts of Surgicl Movement of the Mxill nd Mndible COS Men SD Men SD P-Vlue Anteroposterior movement, mm Mxill DA-H 1.43 1.99 0.07 2.39.0238* DPNS-H 2.28 2.70 20.58 2.30.0000*** DU6-H 0.75 2.18 21.08 2.40.0038** DUI-H 0.42 2.07 21.67 2.68.0021** Mndible DB-H 210.57 3.41 211.38 3.60.3783 DPog-H 210.38 3.69 210.73 4.98.7642 DL6-H 29.22 3.18 211.03 3.68.0524 DLI-H 29.79 3.22 211.20 3.67.1258 Verticl movement, mm Mxill DA-V 20.41 1.54 21.63 1.79.0079** DPNS-V 23.02 1.90 24.13 2.47.0665 DU6-V 21.35 1.49 22.63 2.31.0187* DUI-V 0.28 1.79 20.78 2.24.0557 Mndible DB-V 0.22 3.18 23.87 4.38.0003*** DPog-V 21.76 3.57 24.26 4.07.0167* DL6-V 21.94 2.02 23.48 2.20.0077** DLI-V 21.21 2.86 23.20 3.39.0205* Independent t-test ws performed to compre the vribles between the two groups. For the nteroposterior movement: (2) indictes setbck; (+), dvncement. For the verticl movement: (2) indictes superior impction; (+), elongtion. SD indictes stndrd devition; COS, conventionl orthognthic surgery; nd SFA, surgery-first pproch. * P,.05; ** P,.01; *** P,.001. The totl mount of DU1-SN in group 1 (29.0u; Pre- OP-OT, 210.0u; surgery, 22.9u; nd Post-OP-OT, 3.8u) nerly coincided with tht of DU1-SN in group 2 (210.3u; surgery, 24.4u; nd Post-OP-OT, 25.9u) (Tble 3; Figure 6). These findings suggest tht inclintion chnge of MXI during Post-OP-OT in SFA is due to the combintion of extrction spce closure of the MXP1 nd compenstion of the MXI inclintion to mintin norml overjet nd overbite while skeletl relpse occurred during Post-OP-OT. Therefore, surgicl tretment objective (STO) nd model surgery in SFA cses hve to reflect the mounts of expected inclintion chnge in MXI fter surgery. 14 In ddition, the mounts of superior impction of the posterior Tble 5. Distribution of Smples According to Upper Incisor Inclintion in Ech Group nd Between the Two Groups t the T0, T1, T2, nd T3 Stges U1-SN, u Distribution t T0 Stge Distribution t T1 Stge Distribution t T2 Stge Distribution t T3 Stge COS Group 2, SFA COS Group 2, SFA COS Group 2, SFA COS Group 2, SFA Norml rnge (less thn 610u compred to norm) 13 10 28 NA 31 16 30 20 Beyond norml rnge (more thn 610u compred to norm) 23 14 8 NA 5 8 6 4 P-vlue b.1325.5413.0012** NA.0000***.1516.0001***.0003*** Norml rnge rte, % 36 42 78 NA 86 67 83 83 P-vlue c.6672 NA.076 1.000 NA indictes not pplicble; COS, conventionl orthognthic surgery; nd SFA, surgery-first pproch. b Binomil test ws performed to nlyze the distribution of groups 1 nd 2. Norml rnge indictes the U1-SN vlue less thn 610u compred to the ethnic norm. 9,15,16 Norml rnge rte, [(the number of subjects who were within norml rnge/totl number of smple in ech group) 3 100]. c Chi-squre test ws performed to nlyze the difference in distribution between two groups. ** P,.01; *** P,.001.
728 PARK, LEE, CHOI, BAEK Tble 6. Efficcy in Terms of Reltive Percentge Rtio nd Achievement Rtio of the Mxillry Incisor (MXI) Inclintion COS Men SD Men SD P-Vlue Reltive percentge rtio, % T0 110.92 5.25 109.99 6.46.5228 T1 101.59 6.84 NA NA NA T2 98.87 6.56 105.92 6.47.0002*** T3 102.44 6.24 100.11 6.95.2122 Achievement rtio, % Preopertive decompenstion 85.79 85.88 NA NA NA Surgicl 28.02 52.58 41.93 35.12.2783 Postopertive compenstion 236.16 42.63 55.88 72.89.0001*** Totl 77.65 57.35 97.81 79.61.3561 Independent t-test ws performed to compre the vribles between the two groups. SD indictes stndrd devition; NA, not pplicble; COS, conventionl orthognthic surgery; nd SFA, surgery-first pproch. Reltive percentge rtio to the ethnic norm of U1-SN (106.6u) 9,15,16 mens (ctul vlue of U1-SN/106.6u) 3 100. For the chievement rtio, preopertive decompenstion chievement rtio indictes (ctul mount of preopertive orthodontic movement/expected mount of chnges in U1-SN for surgicl tretment objective [STO]) 3 100; Surgicl chievement rtio, (the mount of chnges in U1-SN by surgicl movement of the mxill/expected mount of chnges in U1-SN for STO) 3 100; Postopertive compenstion chievement rtio, (ctul mount of postopertive orthodontic movement/expected mount of chnges in U1- SN for STO) 3 100; Totl chievement rtio, (ctul mount of chnges in U1-SN with orthodontic tretment/expected mount of chnges in U1- SN for STO) 3 100. *** P,.001. mxill should be determined ccording to the MXI inclintion nd the mount of crowding in the mxillry rch before tretment. 15 Postopertive visul tretment objective (VTO) representing the expected outcome fter tretment lso needs to contin these findings. 16 Therefore, ccurte STO nd postopertive VTO for chnges in the MXI inclintion re crucil in SFA. This study focused on the inclintion chnge of the mxillry incisors during surgicl-orthodontic tretment. However, further studies with follow-up dt nd ctegorized surgicl movement of the mxill (mounts nd direction) re needed to investigte the long-term stbility of SFA. CONCLUSIONS N The null hypothesis ws rejected. N The results of this study might provide bsic dt for predicting the mount nd pttern of MXI inclintion chnge in SFA for skeletl Clss III TJS ptients. REFERENCES 1. Bell WH, Creekmore TD. Surgicl-orthodontic correction of mndibulr prognthism. Am J Orthod. 1973;63:256 270. 2. Bek SH, Ahn HW, Kwon YH, Choi JY. Surgery-first pproch in skeletl Clss III mlocclusion treted with 2- jw surgery: evlution of surgicl movement nd postopertive orthodontic tretment. J Crniofc Surg. 2010;21: 332 338. 3. Ko EW, Hsu SS, Hsieh HY, Wng YC, Hung CS, Chen YR. Comprison of progressive cephlometric chnges nd postsurgicl stbility of skeletl Clss III correction with nd without presurgicl orthodontic tretment. J Orl Mxillofc Surg. 2011;69:1469 1477. 4. Liou EJ, Chen PH, Wng YC, Yu CC, Hung CS, Chen YR. Surgery-first ccelerted orthognthic surgery: orthodontic guidelines nd setup for model surgery. J Orl Mxillofc Surg. 2011;69:771 780. 5. Hong KG, Lee JG. 2-phse tretment without preopertive orthodontics in skeletl Clss III mlocclusion. J Koren Assoc Orl Mxillofc Surg. 1999;25:48 53. 6. Ngsk H, Sugwr J, Kwmur H, Nnd R. Surgery first skeletl Clss III correction using the Skeletl Anchorge System. J Clin Orthod. 2009;43:97 105. 7. Lio YF, Chiu YT, Hung CS, Ko EW, Chen YR. Presurgicl orthodontics versus no presurgicl orthodontics: tretment outcome of surgicl-orthodontic correction for skeletl Clss III open bite. Plst Reconstr Surg. 2010;126:2074 2083. 8. Troy BA, Shnker S, Fields HW, Vig K, Johnston W. Comprison of incisor inclintion in ptients with Clss III mlocclusion treted with orthognthic surgery or orthodontic cmouflge. Am J Orthod Dentofcil Orthop. 2009;135: 146.e1 146.e9. 9. Kim DK, Bek SH. Chnge in mxillry incisor inclintion during surgicl-orthodontic tretment of skeletl Clss III mlocclusion: comprison of extrction nd nonextrction of the mxillry first premolrs. Am J Orthod Dentofcil Orthop. 2013;143:324 335. 10. Ahn HW, Bek SH. Skeletl nteroposterior discrepncy nd verticl type effects on lower incisor preopertive decompenstion nd postopertive compenstion in skeletl Clss III ptients. Angle Orthod. 2011;81:64 74. 11. Hssel B, Frmn AG. Skeletl mturtion evlution using cervicl vertebre. Am J Orthod Dentofcil Orthop. 1995; 107:58 66. 12. Johnston C, Burden D, Kennedy D, Hrrdine N, Stevenson M. Clss III surgicl-orthodontic tretment: cephlometric study. Am J Orthod Dentofcil Orthop. 2006;130:300 309. 13. Dhlburg G. Sttisticl Methods for Medicl nd Biologicl Students. New York, NY: Interscience Publiction; 1940.
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