Modified tandem traction bow appliance compared with facemask therapy in treating Class III malocclusions

Transcription

1 Originl Article Modified tndem trction bow pplince compred with fcemsk therpy in treting Clss III mlocclusions Tub Tortop ; Emine Kygısız b ; Deniz Gencer c ; Sem Yuksel ; Zeynep Atly d ABSTRACT Objective: To compre the effects of the modified tndem trction bow pplince (MTTBA) nd the fcemsk in treting ptients with Clss III mlocclusion. Mterils nd Methods: The mteril consisted of the pre-post tretment\pre-post observtion lterl cephlogrms of 65 subjects with skeletl nd dentl Clss III mlocclusion. In the first group 21 ptients (men ge: 10 yers, 6 months) were treted with Delire-type fcemsk (FM). In the second group 22 ptients treted (men ge: 10 yers) with MTTBA. The remining 22 children (men ge: 9 yers, 7 months) were observed without tretment for 11 months. Results: Increse in SNA, N-FH A, nd ANB ngles were significntly greter in the tretment groups compred to the control group. However, ANB ngle showed significntly greter increse in the FM group ( u) thn in the MTTBA group ( u). The overjet nd molr reltion incresed significntly in both tretment groups, but in the FM group ( mm) increse in overjet ws significntly greter thn in the MTTBA group ( mm). Mesil movement of upper molr nd incisor were found to be greter in the FM group compred to the modified TTBA group. Conclusions: Both pplinces were found to be effective in the tretment of Clss III mlocclusion. Their skeletl nd dentl effects showed differences due to their design. (Angle Orthod. 2014;84: ) KEY WORDS: Clss III mlocclusion; Fcemsk; Tndem trction bow INTRODUCTION Fcemsk (FM) nd its modifictions re generlly preferred in the tretment of children who hve Clss III mlocclusion with n underdeveloped mxill. Bsed on review of the literture, the effects of FM therpy cn be summrized s protrction of mxill nd mxillry dentition, improvement of mxillo-mndibulr reltion, nd clockwise rottion of the mndible. Lingul tipping of lower incisors nd soft tissue effects resulting from skeletl chnges were lso reported. 1 4 Professor, Deprtment of Orthodontics, Fculty of Dentistry, Gzi University, Ankr, Turkey. b Lecturer, Deprtment of Orthodontics, Fculty of Dentistry, Gzi University, Ankr, Turkey. c Orthodontist, Privte Prctice, Ankr, Turkey. d Orthodontist, 75th Yer Hospitl, Ankr, Turkey. Corresponding uthor: Dr Tub Tortop, Gzi Universitesi, Dis HekimligiFkultesi, Ortodonti Anbilim Dlı, 06510, Emek- Ankr, Turkey (e-mil: tubtortop@gzi.edu.tr) Accepted: October Submitted: August Published Online: November 25, 2013 G 2014 by The EH Angle Eduction nd Reserch Foundtion, Inc. There hve been lso some introrl pplinces used in the tretment of ptients with Clss III mlocclusion Though most uthors reported tht the Fränkel III pplince ws effective with regrd to mndibulr growth, conflict existed with regrd to the effects of the pplince on the mxill Comprison of pltes nd functionl orthopedic pplinces with fcemsk showed tht sgittl skeletl effect ws more pronounced by FM therpy. 12,13 The tndem trction bow pplince (TTBA) ws introduced s n introrl pplince in the tretment of Clss III mlocclusion; it crried the expecttion tht it would result in enhnced ptient coopertion. 5 Atly nd Tortop 14 reported tht stisfctory correction of the skeletl nd dentl Clss III mlocclusion ws obtined with modified TTBA (MTTBA). A literture review showed tht there re not ny studies regrding the comprtive evlution of the effects of MTTBA nd FM. Therefore, the purpose of this study ws to ssess nd compre the dentoskeletl effects of MTTBA nd FM therpy in the tretment of Clss III mlocclusion. MATERIALS AND METHODS This retrospective study comprised 65 ptients with skeletl Clss III reltionship due to mxillry retrusion 642 DOI: /

2 643 TREATING CLASS III MALOCCLUSIONS Figure 2. Modified TTBA. Figure 1. Delire-type fcemsk ppliction. or combintion of mxillry retrusion nd mndibulr protrusion. None of the ptients hd congenitl syndrome. All of them hd n Angle Clss III mlocclusion with negtive overjet nd n optimum SN/GoGn ngle (between 26u nd 38u). The study protocol ws pproved by the Ethics Committee of Gzi University (2013/ ). Two tretment groups nd n untreted control group were evluted for this study. In the first tretment group, 21 ptients (eight girls, 13 boys; men ge: 10 yers, 6 months 6 1 yer, 4 months) were treted with Delire-type FM nd removble upper pplince (Figure 1). A totl force of 600 g ws pplied, nd the ptients were instructed to wer their pplinces pproximtely 16 hours dy. The removble upper pplince hd two Adms clsps t the molrs, two bll clsps, lbil bow, nd two hooks t the nterior region for extrorl elstics. The verge tretment time ws 10.5 months. In the second tretment group, 22 ptients (eight girls, 14 boys; men ge: 10 yers 6 1 yer, 4 months) wore MTTBA, which comprised n upper splint, lower splint, nd trction bow (Figure 2). Construction bites were tken without sgittl ctivtion nd with 5 6-mm verticl opening t the molr region. A modified hedger fcebow ws used s the trction bow nd it ws pplied to the ctivtor tubes, which were embedded in the lower splint. Two elstics tht exerted force of g on one side were worn between the lbil hooks of the upper splint nd the trction bow. The ptients were instructed to wer the pplince pproximtely hours dy. The verge tretment time ws 12 months. The tretment groups were compred with n untreted control group of 22 subjects (10 girls, 12 boys; men ge: 9 yers, 7 months 6 1 yer, 3 months). The observtion period ws 11 months. Lterl cephlometric rdiogrphs were tken before tretment nd fter Clss I molr reltionship ws obtined with n overjet of 2 3 mm. Ten liner nd 10 ngulr mesurements were evluted (Figure 3). Totl superimpositions were mde on the best fit of the nterior crnil bse (Figure 4). Locl superimpositions were mde on the best fit of the pltl structures for the mxill (Figure 4b) nd on the best fit of the posterior border of the symphysis nd inferior border of the mndible (Figure 4c). For ech superimposition, the pretretment trcing T-W line (T: the most superior point of the nterior wll of the sell turcic t the junction with tuberculumsell; W: the point t which the middle crnil foss is intersected by the sphenoid bone) ws used s the horizontl reference line. A verticl line perpendiculr to T-W t point T ws used s the verticl reference plne. The lterl cephlometric rdiogrphs of 15 subjects were retrced, nd superimpositions nd mesurements were repeted fter 15 dys. Method error coefficients were clculted nd found to be within cceptble limits (rnge: ). Sttisticl nlysis ws done with SPSS for Windows, version 16.0 pckge (SPSS Inc, Chicgo, Ill).

3 644 TORTOP, KAYGISIZ, GENCER, YUKSEL, ATALAY RESULTS Figure 3. Cephlometric mesurements: 1. SN; 2. SNA; 3. SNB; 4. ANB; 5. CoA; 6. CoGn; 7. N FH-A; 8. N FH-Pg; 9. N-Pg A; 10. SN/GoGn; 11. ANS-PNS/Go-Me; 12. SN/ANS-PNS; 13. ANS-Me; 14. overbite; 15. overjet; 16. molr reltion; 17. upper molr/ans- PNS; 18. lower molr/go-me; 19. upper incisor/na; nd 20. lower incisor/nb. To check dt normlity the Shpiro-Wilk test ws pplied. As result of the norml distribution of dt, pired t-test ws used to evlute the tretment effects nd chnges during the observtion period in ech group. Differences between the groups were determined by vrince nlysis nd the Duncn test. The sttisticl comprison of the pretretment vlues showed upper molr inclintion ws significntly greter in the MTTBA group thn in the FM group (Tble 1). In the FM group, SNA nd ANB vlues nd Co-A dimension incresed significntly (P,.001), while SNB vlue nd Co-Gn dimension showed significnt decrese (P,.01). Increse in N FH-A (P,.01) nd decrese in N FH-Pg (P,.05) were found to be sttisticlly significnt. Significnt increses were observed in SN/GoGn nd ANS-PNS/Go-Me (P,.01). SN/ANS-PNS ngle decresed significntly (P,.05), but lower fcil height (ANS-Me) showed significnt increse (P,.001). Decrese in overbite ws found to be sttisticlly significnt (P,.001). Sgittl dentl forces resulted in significnt increse in overjet nd molr reltion (P,.001). Upper molr/ ANS-PNS nd lower incisor/nb ngle decresed significntly (P,.01 nd P,.001, respectively) (Tble 2). On totl superimposition, point A-T dimension incresed significntly (P,.01), while pogonion-t dimension ws showing significnt decrese (P,.05) during FM therpy. Pogonion-TW lso chnged significntly (P,.001). On locl superimposition upper molr-t nd upper molr TW incresed significntly (P,.01). Increse in upper incisor-t ws found to be sttisticlly significnt (P,.001). Lower incisor-t nd lower incisor-tw showed significnt decreses (P,.05 nd P,.001, respectively) (Tble 3). Figure 4. () Mesurements on totl superimposition: 1. point A-T; 2. point A-TW; 3. Pogonion-T; nd 4. Pogonion-TW. (b) Mesurements on mxillry locl superimposition: 5. upper molr-t; 6. upper molr-tw; 7. upper incisor-t; nd 8. upper incisor-tw. (c) Mesurements on mndibulr locl superimposition: 9. lower molr-t; 10. lower molr-tw; 11. lower incisor-t; nd 12. lower incisor-tw.

4 TREATING CLASS III MALOCCLUSIONS 645 Tble 1. Pretretment Men Vlues nd Sttisticl Differences Between Groups FM (1) (n 5 21) MTTBA (2) (n 5 22) Control (3) (n 5 22) P X Sx X Sx X Sx SN, mm SNA, u SNB, u ANB, u CoA, mm CoGn, mm N FH-A, mm N FH-Pg, mm N-Pg A, mm SN/Go-Gn, u ANS-PNS/Go-Me, u SN/ANS-PNS, u ANS-Me, mm Overbite, mm Overjet, mm Molr reltion, mm Upper molr/ans-pns, u * Lower molr/go-me, u Upper incisor/na, u Lower incisor/nb, u X indictes men; Sx, stndrd error of men. * P,.05. In the MTTBA group SN, SNA, ANB, CoA, CoGn, nd N Pg-A mesurements incresed significntly (P,.001). SNB ngle showed significnt decrese (P,.01). Significnt increses in SN/GoGn, ANS- PNS/Go-Me, nd ANS-Me were observed, nd significnt decrese in overbite ccompnied these chnges (P,.001). Overjet nd molr reltion incresed significntly (P,.001). Upper incisor Tble 2. Tretment Chnges of Fcemsk (FM) nd modified tndem trction bow pplince (MTTBA) groups, Observtion Period Chnges of Control Group, nd Comprison Among Groups FM (1) (n 5 21) MTTBA (2) (n 5 22) Control (3) (n 5 22) P D SD P D SD P D SD P SN, mm ** *** *** SNA, u *** *** * * SNB, u ** ** * * * ANB, u *** *** * * * * CoA, mm *** *** *** * CoGn, mm ** *** *** N FH-A, mm ** ** N FH-Pg, mm * * * N-Pg A, mm *** *** * * * SN/Go-Gn, u ** *** * * ANS-PNS/Go-Me, u ** *** * * SN/ANS-PNS, u * ANS-Me, mm *** *** ** * * Overbite, mm *** *** * * Overjet, mm *** *** * * * Molr reltion, mm *** *** * * Upper molr/ans-pns, u ** * * Lower molr/go-me, u ** * * Upper incisor/na, u * *** Lower incisor/nb, u *** *** * * D indictes men differences; SD, stndrd error of men differences. * P,.05. ** P,.01. *** P,.001.

5 646 TORTOP, KAYGISIZ, GENCER, YUKSEL, ATALAY Tble 3. Tretment Chnges of Fcemsk (FM) nd Modified Tndem Trction Bow Applince (MTTBA) Groups nd Observtion Period Chnges in Control Group on Superimpositions FM (1) (n 5 21) MTTBA (2) (n 5 22) Control (3) (n 5 22) P D SD P D SD P D SD P Totl superimposition Point A-T ** *** * * Point A-TW ** *** Pogonion-T * * * * Pogonion-TW *** *** ** * Locl superimposition Upper molr-t ** *** * * Upper molr-tw ** * ** Upper incisor-t *** *** * * * Upper incisor-tw ** ** Lower molr-t * ** * Lower molr-tw Lower incisor-t * *** * * * Lower incisor-tw *** *** * * D indictes men differences; SD, stndrd error of men differences. * P,.05. ** P,.01. *** P,.001. proclintion nd lower incisor retroclintion were found to be sttisticlly significnt (P,.001) (Tble 2). Significnt forwrd (point A-T) nd downwrd (point A-TW) movement of point A ws observed in the MTTBA group (P,.001 nd P,.01, respectively). Totl superimpositions lso showed significnt downwrd movement of the pogonion (pogonion-tw) (P,.001). Increses in upper molr-t nd upper incisor-t were sttisticlly significnt (P,.001). Lower molr-t nd lower incisor-t distnces showed significnt decreses in this group (P,.05 nd P,.001, respectively) (Tble 3). In the control group, significnt increse in SNB nd decrese in ANB were present (P,.05). SN, CoA, nd CoGn dimensions incresed significntly (P,.001). Lower fcil height (ANS-Me) showed significnt increse (P,.001) (Tble 2). Point A-TW distnce incresed significntly in the control group (P,.001). Significnt forwrd (pogonion-t) nd downwrd (pogonion-tw) movement of pogonion were observed (P,.05 nd P,.01, respectively). Forwrd movement of upper (upper incisor-t) nd lower (lower incisor-t) incisors were found to be sttisticlly significnt (P,.05). Lower molr-t distnce showed significnt increse (P,.01) (Tble 3). Comprison Among Groups Increses in SNA, N Pg-A, nd ANB nd decreses in SNB nd N FH-Pg in both tretment groups showed significnt differences compred with the control group. Increse in ANB in the FM group ws significntly greter thn in the MTTBA group. Greter increses in SN/GoGn, ANS-PNS/Go-Me, nd ANS-Me were observed in both tretment groups compred to the control group. Chnge in overbite in tretment subjects ws significntly different compred to tht noted in the control group. Although the increse in overjet in both tretment groups showed significnt difference compred with the control group, it ws lso significntly greter in the FM group thn in the MTTBA group. Significnt differences in upper molr nd lower molr inclintions were observed between the tretment groups (P,.05) (Tble 2). Chnges in the sgittl position of point A (point A-T) nd pogonion (pogonion-t) in tretment subjects were significntly different compred with the control subjects. Pogonion-TW distnce showed greter increse in the MTTBA group thn in the control group. Forwrd movement of the upper molr (upper molr-t) nd upper incisor (upper incisor-t) ws significntly greter in the FM group thn in the MTTBA nd control groups. Lower molr-t showed significnt difference between the MTTBA nd control groups. Decreses in lower incisor-t nd lower incisor-tw in both tretment groups were significntly different compred with the control group (P,.05) (Tble 3). DISCUSSION It hs been shown tht the percentge of skeletl discrepncy in the etiology of Clss III mlocclusion is over 60%. 15 Protrction FM is commonly used pplince to normlize this underlying skeletl discrepncy. MTTBA is offered s n lterntive tretment pproch for Clss III mlocclusion. To our knowledge, this study is the first to compre the

6 TREATING CLASS III MALOCCLUSIONS 647 skeletl nd dentl effects of FM nd MTTBA in the tretment of Clss III mlocclusion. Ptients treted with FM nd removble pplince were preferred for the FM group, s the MTTBA is removble pplince. Skeletl Chnges In both tretment groups, the skeletl complex ws ffected sgittlly when compred with the control group. Forwrd movement of the mxill ws similr in both tretment groups nd significntly greter compred to the control group. Sttisticl evlution of tretments with FM nd some removble pplince in Clss III mlocclusion reveled n increse in mxillry protrusion. 4,6,7,9,16,17 Though significnt decrese in SN/ANS-PNS ws observed in the FM group, the verticl position of the mxill (Point A-TW; SN/ANS- PNS) did not show ny significnt difference between the groups. Westwood et l. 16 noted no rottion of the pltl plne following rpid mxillry expnsion nd FM therpy. Contrry to the findings of the present study, significnt rottion of the pltl plne ws reported in some other FM studies. 17,18 It should be kept in mind tht severl fctors, such s direction of force or point of ppliction, might cuse chnges in the verticl position of the pltl plne. Decreses in SNB, N FH-Pg, nd pogonion-t mesurements nd increses in SN/GoGn nd ANS-PNS/Go-Me indicted the bckwrd rottion of the mndible in both tretment groups. A bckwrd rottion of the mndible ws mong the results of severl Clss III tretment studies. 6,7,11,16,19 22 Atly nd Tortop 14 reported the verticl control of the MTTBA s doubtful. Chnges in the mxill nd mndible in the tretment groups resulted in increses in ANB (FM: 2.8u; MTTBA: 2.0u) nd N-Pg A (FM: 2.2 mm; MTTBA: 1.5 mm). Both tretment pproches could be ccepted s effective in treting subjects with Clss III mlocclusion, s these chnges were significntly different compred with the control group. Skeletl improvements in both groups were in ccordnce with previous FM 1,17,21,23 25 nd TTBA 14,26 findings. Cozz et l. 23 reported 2.8u improvement in ANB ngle with combined protocol of FM nd removble bite block pplince. Though the chnges in the mxill nd the mndible were similr in both tretment groups, increse in ANB is greter in the FM group thn in the MTTBA group. In reverse twin block study skeletl effects were found to be miniml, while significnt mxillry dvncement occurred with FM therpy. 27 Becuse of the significntly greter increses in the SNA nd ANB ngles, FM tretment ws reported 13 to be more effective thn double plte pplince in stimulting mxillry growth. Godt et l. 12 emphsized tht improvements in sgittl skeletl reltion were more pronounced with FM thn with functionl orthopedic pplinces, but they lso pointed out tht removble pplinces were ble to induce minor improvements nd to counterct the progression of Clss III bnormlities. Dentl Chnges Mesil movement (upper molr-t) nd mesil inclintion (upper molr/ans-pns) of the upper molr were significntly greter in the FM group compred to the MTTBA nd control groups. Ucem et l. 13 reported tht increse in U6-PTV distnce ws greter in the FM group thn in the control group; however, mesurements of locl superimpositions did not support this finding. Uprighting (lower molr/go-me) of lower molr due to the forces pplied by the removble pplince of MTTBA showed significnt differences compred to FM nd control groups. Retrusion (lower incisor-t) nd lingul tipping (lower incisor/nb) of lower incisors were observed in both tretment groups. However, protrusion of upper incisors (upper incisor-t) in the FM group ws significntly different compred to the MTTBA nd control groups. Most of the studies regrding the effects of FM greed tht protrusion of the upper incisor nd/or retrusion of the lower incisor contributed to the correction of mlocclusion. 17,18,28 Similr results were reported with introrl pplinces. 9,11,13,14,27 Lck of retroclintion of the lower incisors ws mentioned with the bone nchor mxillry protrction tretment. 29 Cozz et l. 23 suggested tht s result of the crylic blocks, FM nd bite block combintion did not cuse ny chnge in the position of the incisors. The positive overjet nd improvement in molr reltion in both tretment groups were in ccordnce with those observed in previous studies. 14,16,24,26 Assessment of FM nd rpid mxillry expnsion by pitchfork nlysis showed tht the contribution of dentl movements to the overll molr nd overjet correction ws miniml. 30 Increse in overjet in the FM group ws significntly greter thn in the MTTBA group. Seehr et l. 27 reported tht both FM nd reverse twin block therpies resulted in similr overjet chnges. Ucem et l. 13 concluded tht chnges in upper nd lower incisors in the double plte group could be responsible for the overjet difference, s compred to FM tretment. In this study, chnges in the upper incisor seemed to be responsible from the difference in overjet between the groups. It could be concluded tht the skeletl effects of toothborne pplinces were limited, but they might be useful in coopertion nd control of the progression of Clss III mlocclusion during the erly tretment period.

7 648 TORTOP, KAYGISIZ, GENCER, YUKSEL, ATALAY CONCLUSIONS N Though the chnges in ANB, overjet, nd molr reltion showed tht both tretment pproches were effective in the tretment of Clss III mlocclusion, greter increses in ANB nd overjet during FM tretment ws observed. N Skeletl improvement occurred becuse of the mxillry protrusion combined with the mndibulr rottion. N While protrusion of the upper incisor nd mesil movement of the upper molr were greter in the FM group, uprighting of the lower molr ws found to be greter in the MTTBA group. REFERENCES 1. Bcetti T, Frnchi L, McNmr JA Jr. Tretment nd posttretment chnges fter rpid mxillry expnsion nd fcemsk therpy. Am J Orthod Dentofcil Orthop. 2000; 118: De Toffol L, Pvoni C, Bcetti T, Frnchi L, Cozz P. Orthopedic tretment outcomes in Clss III mlocclusion: systemtic review. Angle Orthod. 2008;78: Ngn P, Hägg U, Yiu C, Merwin D, Wei SHY. Soft tissue nd dentoskeletl profile chnges ssocited with mxillry expnsion nd protrction hedger tretment. Am J Orthod Dentofcil Orthop. 1996;109: Vughn GA, Mson B, Moon HB, Turley PK. The effects of mxillry protrction therpy with or without rpid pltl expnsion: prospective, rndomized tril. Am J Orthod Dentofcil Orthop. 2005;128: Chun Y, Jeong SG, Row J, Yng SJ. A new pplince for orthopedic correction of Clss III mlocclusion. J Clin Orthod. 1999;33: Tollro I, Bcetti T, Frnchi L. Crniofcil chnges induced by erly functionl tretment of Clss III mlocclusion. Am J Orthod Dentofcil Orthop. 1996;109: Grttini G, Levrini L, Crozzoli P, Levrini A. Skeletl nd dentl modifictions produced by the Biontor III pplince. Am J Orthod Dentofcil Orthop. 1998;114: Bik HS, Jee SH, Lee KJ, Oh TK. Tretment effects of Fränkel functionl regultor III in children with Clss III mlocclusions. Am J Orthod Dentofcil Orthop. 2004;125: Kilic N, Celikoglu M, Okty H. Effects of functionl regultor III on profile chnges in subjects with mxillry deficiency. Eur J Orthod. 2010;32: Ulgen M, Firtli S. The effects of the Fränkel s function regultor on the Clss III mlocclusion. Am J Orthod Dentofcil Orthop. 1994;105: Kidner G, DiBise A, DiBise D. Clss III twin blocks: cse series. J Orthod. 2003;30: Godt A, Zeyher C, Schtz Mier D, Göz G. Erly tretment to correct Clss III reltions with or without fcemsks. Angle Orthod. 2008;78: Ucem TT, Ucuncu N, Yuksel S. Comprison of double plte pplince nd fcemsk therpy in treting Clss III mlocclusions. Am J Orthod Dentofcil Orthop. 2004;126: Atly Z, Tortop T. Dentofcil effects of modified tndem trction bow pplince. Eur J Orthod. 2010;32: Studt CB, Kiliridis S. Different skeletl types underlying Clss III mlocclusion in rndom popultion. Am J Orthod Dentofcil Orthop. 2009;136: Westwood PV, McNmr JA Jr, Bcetti T, Frnchi L, Srver DM. Long-term effects of Clss III tretment with rpid mxillry expnsion nd fcemsk therpy followed by fixed pplinces. Am J Orthod Dentofcil Orthop. 2003; 123: Yvuz I, Hlıcıoğlu K, Ceyln I. Fcemsk therpy effects in two skeletl mturtion groups of femle subjects with skeletl Clss III mlocclusions. Angle Orthod. 2009;79: Tkd K, Petdchi S, Skud M. Chnges in dentofcil morphology in skeletl Clss III children treted by modified mxillry protrction hedger nd chin cup: longitudinl cephlometric pprisl. Eur J Orthod. 1993;15: Kjiym K, Murkmi T, Suzuki A. Comprison of orthodontic nd orthopedic effects of modified mxillry protrctor between deciduous nd erly mixed dentitions. Am J Orthod Dentofcil Orthop. 2004;126: Ngn PW, Hägg U, Yiu C, Wei SHY. Tretment response nd long-term dentofcil dpttions to mxillry expnsion nd protrction. Semin Orthod. 1997;13: Tortop T, Keykubt A, Yuksel S. Fcemsk therpy with nd without expnsion. Am J Orthod Dentofcil Orthop. 2007; 132: Tuncer C, Uner O. Effects of mgnetic pplince in functionl Clss III ptients. Angle Orthod. 2005;75: Cozz P, Bcetti B, Mucedero M, Pvoni C, Frnchi L. Tretment nd posttretment effects of fcil msk combined with bite-block pplince in Clss III mlocclusion. Am J Orthod Dentofcil Orthop. 2010;138: Msucci C, Frnchi L, Defri E, Mucedro M, Cozz P, Bcetti T. Stbility of rpid mxillry expnsion nd fcemsk therpy: long-term controlled study. Am J Orthod Dentofcil Orthop. 2011;140: Ngn P, Hägg U, Yiu C, Merwi D, Wei SHY. Tretment response to mxillry expnsion nd protrction. Eur J Orthod. 1996;18: Kim H, Chun Y, Lim WH. Mxillry protrction effects of TTBA (Tndem Trction Bow Applince) therpy in Koren Clss III children. Koren J Orthod. 2007;37: Seehr J, Fleming PS, Mndll N, DiBise AT. A comprison of two different techniques for erly correction of Clss III mlocclusion. Angle Orthod. 2012;82: Bik HS. Clinicl results of the mxillry protrction in Koren children. Am J Orthod Dentofcil Orthop. 1995; 108: Cevidnes L, Bcetti L, McNmr JA, DeClerck H. Comprison of two protocols for mxillry protrction: bone nchor versus fce msk with rpid mxillry expnsion. Angle Orthod. 2010;80: Frnchi L, Bcetti T, McNmr JA. Postpubertl ssessment of tretment timing for mxillry expnsion nd protrction therpy followed by fixed pplinces. Am J Orthod Dentofcil Orthop. 2004;126: