JOURNAL OF 108 - CLINICAL MEDICINE AND PHARMACY Vol.12 - N"l / 2 0 H |
Danh gia su dn dinh sau phau thuat xoay phuc hop ham tren - ham duol cung chieu kim dong ho
Evaluation of the bone stability after osteotomy with clockwise rotation of maxilla - mandible
INguySn Tai Sffn, L6 T i n Hung Benh vien Trung uang Quan doi 108
Tom tat
Muc dich: Danh gia su 6n djnh xuong sau ph^u thuat cat xuong Le Fort I vdi xoay cung chieu kim dong ho va cat doc canh dUng xuong h^m dudi t r o n g dieu tri l§ch lac xuong ham loai III. Bdi tuang va phuang phap: Gom 34 benh nhan ngudi Viet bj lech lac xuong h^m toai III duoc dieu t n bang phau thuat cat xuong Le Fort I vdi xoay cCing chieu kim dong ho va day ICii xUOng ham dudi bang phau thuat eSt doc canh dUng. Phim sp nghieng dUpc chup trude phau t h u l t (Tl), ngay sau phau thuat (T2) va trung binh 12 thang sau mo (T3). TUOng quan theo chieu ngang, chieu ddng cija nhOYig mde giai phau d xuong ham tren, xuong ham dUdI den mat phang tham chieu va nhdng thay ddi m d m e m dUOC danh gia. Ket qua:
Trong khoSng T2-T1 cd su dl chuyen len tren va ra trudc cCia phan sau (PNS, UMD); dUa ra trUdc va lun d phan phia trudc (ANS, d i l m A, DIE) xuong ham tren. Trong khoSng T3-T2, xUOng ham t r i n cd su tai phat xoay ngUOc chieu kim ddng ho. Phan phia sau kha dn djnh dac biet theo chieu d d n g , phan phia trudc c6 chieu hudng di chuyen ra sau va len tren. Nhdng mde giai phau d xuong ham dudi cho thay su tai phat ra trudc theo c h i l u ngang va t^i len tren theo chieu ddng. Theo sau nhung thay ddi cCia xUOng, md m i m cua tang mat dudi nhln n g h l i n g duoe xoay theo chieu kim ddng ho. Kit ludn: Phau thuat hai ham va xoay cung chieu kim ddng ho mat phang khdp can trong d i l u trj lech lac xuong ham loai III cd k i t qua dn dinh (dac biet d nhdng diem mdc phia sau cda xUOng ham tren), ed t h i giup lam tang tham my mat d ngUdi Viet
TCf khoa: On djnh xuong, xoay theo chieu kim ddng ho. * Summary
Objective. To assess the bone stability after Le Fort I osteotomy with clockwise rotation and longitudinal osteotomy of ramus of mandible In the treatment of Class III jaw deviation. Subjea and method. The sample included of 34 Vietnamese patients with Class III Jaw deviation were performed by Le Fort I osteotomy with clockwise rotation and longitudinal osteotomy of ramus of mandible. Lateral radiograph was taken preoperatlvely a i ) , postoperatively CT2) and average 12 months post-procedure (T3). Horizontal and vertical con-elation of anatomical landmarks in the maxilla, mandible to reference plan and the changes of soft tissue were assessed. Result During T2-T1, there was a moving anteriosuperiorly in the posterior part (PNS, UMD);
moving anteriorly and subside In anterior part (ANS, point A, UIE) of maxilla. During T3-T2, there was a recurrence reversely clockwise In maxilla. Posterior part stayed stable, especially vertically Anterior part tended to move backwards and upwards. The anatomical landmarks in mandible showed the horizontally 3
Ngay nlign Ml: 21/1212016, ngay chdp nhan ltang:09IOmOn
Nguaiphan hit: Nguyen Tai San, Email: [email protected] - Benli vien Tning mmg Qudn doi 108
TAP CHf Y DUOC L A M SANG 108 Tap 12-561/2017 anterior recunence and vertically superior recunence. Following the changes in bone, soft tissue o f lateral maxillary division that rotates clockwise. Conclusion: le Fort I osteotomy procedure with clockwise rotation in the surgical treatment of Class III jaw deviation gains stable results especially in the rear landmarks o f the maxilla), i t could help inaease the aesthetic effect for Vietnamese people.
Keywords: Bone stability, clockwise rotation.
I.Datvande
Phau t h u a t eat x u o n g Le Fort I la m o t t r o n g nhQng p h l u t h u a t p h o bien nhSt de si!ifa chOa nhCfng b i l n dang ham m a t nham muc dich khoi phuc chCfc nang binh t h u d n g cOa x u o n g ham tren va t h a m m y mat [1]. De thUe hien diTOc nhOfng muc t i e u cfo, viec chan doan chinh xac, lap ke hoach dieu trj thieh h o p , di ehuyen chinh xac nhOfng phan doan xUong vho vj t r i mong m u o n va sU o n d j n h sau m o la nhOfng yeu to khong t h e t h i l u duac [2], [3], [4]. Viec di chuyen theo chieu tru6c sau, tren dUdi co t h e duac thUe hien cho nhOfng phan doan xuong d i ctpng, va sU o n dinh nhung phan doan x u o n g sau khi di chuyen trong m o i chieu khong gian da duac danh gia bc^
rat nhieu tac gia khac nhau [5]. CiJng v6i s u phat trien ky t h u a t phau t h u a t va trang t h i e t b| ngay cang hien dai, phau t h u a t cat Le Fort I da duac mo t a la ky thuat Idia on djnh. Tuy nhien. P r o f i t va cong sU [3]
da cong bo gan 2 0 % benh nhan v6i sai kh6p can loai Hi sau phau t h u a t di chuyen xUOng ham tren se bj tai phat p h i n phia sau xUOng ham tren 2 - 4 m m sau 1 nam p h l u t h u a t va khong co lien quan vdi p h u o n g phap CO ^ n h . Theo Bell va Scheideman [1], luong xuong ham tren di chuyen khong co lien quan d e n sutai phat, nhung t r o n g khoang t h d i gian s6m sau mo (2 - 3 thang), tai phat khoSng 2 m m da xay ra.
Trong trUcfiig h o p lam lOn xuong ham tren, sU dn dinh sau m o dUOc biet !a cue k^ on d j n h . Vdi m o n g muon chtnh thUe hoa viec dieu trj lech lac xUOng ham loai III bang phau t h u a t xoay phUe h o p ham tren - ham dudi theo chieu kim d o n g h o n h u la m o t phuong phap dieu t r i chon lUa t r o n g t r u d n g h o p dieu tri truyen t h o n g se co ket qua khong n h u m o n g doi va mang lai m o t can ban khoa hoc cho thiet ke phau t h u a t nay tai dat nude ta, chung t o i thUe hi§n de tai "Dieu t r i lech lac xuong ham loai III b I n g phau thuat xoay phUc h o p ham tren - ham dudi", nham Ddnh gid su vdng on cua rang - xuang 6 rang, xUdng
nin ham trin, ham dudi va hiiu qud thdm my trong loai hinh phau thudt ndy.
2. Dot tUOng va phiTomg phdp 2.1.Dditd^g
Gom 34 b e n h nhan n g u d i Viet (9 n a m , 25 nO), do t u o i t r u n g b i n h la 25,6 t u o i , dUOc dieu t n b a n g phau t h u a t Le Fort I v d i xoay cung chieu kim d o n g ho va d a t lui x u o n g ham dUdi bang ky t h u a t BSSO td t h a n g 1 0 / 2 0 1 2 - 5 / 2 0 1 6 tai Benh vien Rang Ham M a t TP. Ho Chi M i n h va Benh vien Trung u o n g Quan d p i 108 (Hlnh 1).
Hinh 1 . Phim so nghieng duoc ehup trudc phau thuat [T1), ngay sau phau thuat (T2) va 12 thang sau phau
thuat Cr3)
2.2. Phdcfng phdp
Do m a t phang t h a m chieu t h e o chieu ngang d i qua Porion - Orbitale {mat p h ^ n g FH) va m a t p h a n g t h a m chieu t h e o chieu dOfng la m a t phang v u o n g gde vdi m a t phang t h a m chieu t h e o chieu n g a n g va di qua ^ e m Sella. NhOfng d i e m mdc xUOng va rang tren p h i m d o sp (diem A, ANS, PNS, canh can rang cuTa giOfa ham t r ^ n [UIEl,tnat xa rang cdi Idn thiJ n h a t ham tren [UMD], d i e m B, m e n t o n , canh cSn rang ciia giQa h a m dUdi [LIE], m a t xa rang cdi Idn thtjf nhat ham d u d i [LMD] va m a t phang k h d p can) dupe xac dinh t r o n g Hlnh 2. K h o i n g each t h e o chieu dUng va chieu ngang tCr m o i mdc den dUdng t h a n g dijfng va d u d n g ngang dUpc d o .
JOURNAL OF 108 - CLINICAL MEDICINE AND PHARMACY Vol.12-N''l/2017
Hinh 2. NhQng diem mdc va mat phang tham chieu M6 m e m dupe danh gia bSng mOfc d p thay doi 6 gde mui m o i va gde cCia dUdng vien khuon mat giOfa T l va T3 t r ^ n p h i m d o so {Hinh 3). Mo m e m d hlnh i n h T2 khong dupe d ^ n h gia vl sU phCi ni sau m d .
Ve net va d o t r e n p h i m sp n g h i e n g d d i vdi mu'c d d di chuyen va tai phat phau t h u a t d u p e t h i i e hien bdi c u n g 1 bac sT (Huynh Thj Ly) sCf d u n g ehuong t r i n h Ortho vision (phi§n b i n 2013). Cac d d n vj dUpc t i n h d mCCc 0,1 ° va 0,01 m m .
Phdn tich thdng ki: Phep kiem T bat cap (Pairredt-test) va p h a n m e m t h d n g ke (SPSS15.0) dupe s\l d u n g de p h a n t i c h t h d n g ke.
O l kiem d m h sai lam p h u o n g p h a p , 10 trudng h p p d u p e c h p n lUa ngSu n h i e n , t a t e3 v i l e ve netva d o duac lam lai bdi c u n g 1 ngUdi dieu tra (Trln Th^
Thp). Nhufng sai lam cua viec d o dUpc kiem dmh bang cong thiJc Dahlberg s=^'Y^{d)2/2x\
t r o n g d o d la sU khac n h a u giiJa gia t r i d u p c do lai va n la sd t r u d n g h p p d o hai l l n (n = 10). Sai so do cija m o i mdc va gia t n thUc cCia n d t h i x e m nhU khdng co y nghia ve mat lam sang.
3 . K e t q u a va b a n l u a n 3.i.Ketqu&
3.1.1. Mdc dp di chuyen phau thudt vd tdi phdt cda xuang ham tren trong khodng thdi gian T2-T1 vd T3-T2 Hinh 3. Phan tich mo mem
Bang 1 . Mu'c d o c h u y e n cda x i f o n g h a m t r e n T 2 - T 1 , m m
ANS_Y ANS_X A_Y A_X PNS_Y PNS_X UIE_Y UIE_X UMD_Y UMD_X Goc mat phang khdp c i n
T r u n g b i n h -0,9 1,68 -0,69 2,47 -3,24 3,31 -0,18 1,09 -2,16 1,83 3,45
SD 1,9 2,99 2,64 3,11 136 2,32 2,82 3,04 2,17 2,7 3,39
D o t i n cay 9 5 % N h d n h a t
-1,59 0,58 -1,66 1,33 -3,92 2,46 -1,22 -.0,3 -3,4 0,84 2,21
Ldn n h a t -0,2 2,77 0,28 3,16 -2,56 4,16 0,85 2,2 -1,81
2,82 4,7
P 0,013 0,004 0,154 0,000 0,001 0,002 0,781 0,055 0,000 0,001 0,001 (p<0,05)
Trong k h o j n g T2-T1, ed su di c h u y i n len trin va ra trudc cda p h i n phia sau (PNS, UMD) vh n h d ra trUdc cda phan phia trddc (ANS, d i l m A, UIE; BSng 1) mdc d d d i chuyen t r u n g binh la 3,24mm len tren va 3,31mm ve phia trudc tai PNS, 0,9mm len tren va 1,68mm ra trddc tai ANS, va 0,18mm len tr«n va 1,09mm ra trudc tai
TAP CH( Y DI/PC UM SANG 108 T5p12-S6 1/2017
UIE. Tam xoay cda xuong ham tren dUOC dat tai ria cSn cda rang cda ham tren suot qua trinh di chuyen xoay cda xUdng ham tren.
3.1.2. Mdc dd tai phdt cOaxifang ham tren
Bing 2. lUdc tfo phat cda xUOng ham tren
T 3 - T 2 , m m ANS_Y ANS X A Y A X PNS_Y PNS_X UIE_Y UIE_^X UMD_Y UMD X Goc mat phang khdp can
Trung binh -0,21 -0,15 -0,4 -0,1 0,38 -0,36 -0,47 0,4 0,06 0,37 -0,71
SO 1,78 1 3 2,05 1,84 0,78 1,53 2,05 2,95 1,01 2,63 2,28
D o tin cay 9 5 % N h i nhat
-0,67 -0,8 -1,66 -0,77 0,08 -0,92 -1,21 -0,7 - 0 3 -0,6 -1,54
Ldnnhat -0,63 0,52 0,35 0,58 0,66 0,21 0,3 1,47 0,44 1,32 0,13
P 0,947 0,676 0,281 0,768 0,013 0,207 0,225 0,47 0,692 0,451 0,09
(p<0,05)
Trong khoang T3-T2, phan doan xUOng ham tren tai phat theo hudng xoay ngUpc chieu kim ddng ho.
Lupng tai phat trung binh la 0,38mm xudng dudi va 0,36mm ra sau tai PNS, 0,21 mm len tren va 0,15mm ra sau tai ANS, va 0,47mm len tren va 0,4mm ra trUdc tai UIE. Phan phfa sau thi dn ^ n h dac biet theo chieu dufng hon la phan doan phia trUdc. Tuy nhien nhOfng tai phat nay khong cd y nghTa lam sang bdi vl nhflng gia tri ft hon 0,5mm. Them vao do khdng cd sy khac nhau co y nghia ve mat thdng ke ngoai tri^ PNS-Y va mat phang khdp cin.
3.1.3. Mdc do di chuyen vd tdi phdt cua ham dUdi trong khodng thdi gian T2-T1
Bdng 3. Mufc do chuyen cOa ham difdiT 2 - T 1 , m m B Y B^X POG Y POG_X ME_Y ME X LIE Y LIE X LMD_Y LMD_X
Trung binh
^ , 0
^ , 4 -2,7 -4,69 -2,82 -5,04 -3,25 -5,02 -3,07 -4,16
SD 4,17 4,74 4,55 6,83 3,66 7,29 3,68 4,19 2,59 4,47
B o tin cay 9 5 % Nhd nhat
-5,52 -6,13 -4,38 -7,18
^ , 1 7 -7,73
^ , 5 9 -6,57 -4,01 -5,79
Ldnnhat -2,46 -2,66 -1,04 -2,18 -1,48 -2,38 -1,9 -3,49 -2,11 -2,51
• p 0,001 0,002 0,005 0,004 0,006 0,002 0,003 0,007 0,004 0,008
(p<0,05)
Trong khoang T2-T1, xdong ham dddi di chuyen len trSn va ra sau (Bang 3). Luong di chuyin trung binh
la 4,0mm len tren va 4,4mm ra sau tai diem B va 2,7mm len tren va 4,69mm ra sau tai Pogoinon.
JOURNAL OF 108 - CLINICAL MEDICINE AND PHARMACY Vol.12-N°1/2017
3.1.4. Mdc dp tdi phdt cOa hdm dudi
B i i n g 4 . MuTc do t a i p h a t cQa h a m d i f d i T 3 - T 2 , m m
B„Y B X POG Y POG X ME_Y ME_X LIE_Y LIE_X LMD_Y LMD_X
Trung binh -0,51
0,8 -0,09 0,55 -0,11 0,54 -0,39 0,85 -0,43 0,95
SD
2,56 3,75 2,15 4,16 1,74 4,44 2,04 2,64 2,59 2,88
D a t i n c | y 9 5 % N h i nhat
-1,46 -0,58 0,86 -0,99 -0,75 -1,1 -1,13 -0,13 -4,01 -0,12
Ldn nhat 0,42 2,17 0,71 2,06 0,52 2,16 0,37 1,81 -2,11 1,99
P 0,271 0,248 0,845 0,479 0,716 0,509 0,308 0,087 0,001 0,079
(p<0,05) I
Trong khoang t h d i gian T2-T3 xUOng ham d u d i tai phat ra t r d d c t h e o m a t p h a n g n g a n g va len tren theomat p h i n g d d n g doc. Luong di ehuyen t r u n g b i n h la 0,51mm len tren va 0,8mm ra t r u d c tai d i e m B va p,09mm len tren, 0,55mm ra sau tai Pogoinon. Luong tai phat theo chieu ngang xUong ham d u d i Idn hdn • xuong ham tren nhUng khdng ed y nghia v l mat t h d n g ke.
3.1.5. Mute dd thay doi mo mem (T3-T1)
Bang 5. Goc m u i m d i vh goc d d d n g v i e n m a t d 1 1 , T3
Gde mui mdi
Gde dudng vl^n mat
T l T3 T l T3
Trung binh 87,32 96,42 0,2 -8,3
SD 11,01 9,74 5,65 5,14 3.1.6. Mdc dd thay doi cua goc mui mdi vd goc dddng viin mat
Bdng 6. Mijfc d 6 t h a y d o i cCia g o c m u i m d i va g o c dufdng v i e n m a t
T3-T1 Goc mui mdi Gde dudng vien mat
Trung binh 9,09 -8,49
SD 5,85 4,23
Od tin cay 95%
Nhd nhat 6,95 -6,94
Ldn nhat 11 -10
0,001 0,003 (p<0,05)
MUc do thay ddi m d m I m dUOc danh gia vdi t h i ddoc d o bdi gde d u d n g v i l n k h u d n mat, mdc goc m u i mdi va goc d u d n g vien khudn m a t Gde m u i t r u n g binh la -12°. Theo sU t h a y d d i x u o n g , m d ' m l m moil bieu thj su nhd cCia mdi t r e n ; pham vi t h a m cda t a n g mat dudi duoc xoay edng chieu k i m ddng ehieu la 85 - 105°. GUOng mat ldm cda khudn mat h d . Gde m u i m d i va goc d u d n g vien k h u d n m a t t a n g r|
nhln nghiSng t r o n g lech lac x u o n g ham loai III cd t r o n g khoSng T3-T1 va ed y nghia ve m a t t h d n g ke
FAR CHf Y DUOC L A M SANG 108 T i p 12-56 1/2017
Nam 1994, Larry Wolford da gidi thi&u t h i e t ke phau t h u a t thay doi mat phang khdp e i n bang each xoay phtfc h p p ham tren - ham d u d i t h e o chieu kim ddng h d de dieu t r i cho nhQng benh nhan bj lech lac xUOng ham loai III cd mat phang khdp can thap.
Nam 2006, Johan Reyneke da chdng m i n h day la ky thuat CO d p d n d i n h cao va ket qua t h a m m y t o t [6].
fld dn dinh cOa phau t h u a t chinh ham lien quan den nhieu yeu t d nhU kieu cd d j n h , ky t h u a t phau t h u a t dupe d u n g , chinh nha sau m d , 5nh h u d n g sinh \yf cfla CO, vj tr! Idi cau va hUdng di ehuyen phau thu§t.
Ngay nay, eac xuong ham da duac tai d j n h vj se vOfng d n hon vdi sU phat tri^n eua ky t h u a t phau thuat va ed d j n h ben t r o n g . DUdng eSt xuong Le Fort I dupe eho la m o t t h u t h u a t d n d m h ngay ca t r o n g trudng h p p benh nhan khe h d m d i - v d m mieng [7].
Trong cac loai di chuyen cCia x u o n g ham tren sau khi c^t xUOng Le Fort 1, tai d m h vj ien tren cd t h e dupe xem n h u la m o t thQ t h u a t phau t h u a t chinh ham d n djnh hon nhOfng loai di chuyen phau t h u a t kh^c.
V\ic xoay mat phang khdp can theo c h i l u kim d o n g ho da la m o t p h u o n g phap dupe ch^p nhan de dieu trj nhOfng benh nhan co mat phSng khdp can t h a p va da dupe xem n h u la dn djnh bdi vl v o n g chSn budm - CO c^n khdng bj cang hoae ngan lai. TU quan diem ky thuat, chung tdi da diJng m o t m u i khoan trdn dudng kfnh 5 m m d ^ eat xUPng mat t r o n g t h e o chieu ngang. B i n g each lam nhU vay, chung ta ed the tranh dUpc can t r d cd t h e xSy ra giCfa cac phSn doan xuong t r o n g khi xoay t h e o chi^u kim d d n g h d .
Hlnh 4. SCf dung mui khoan tron dudng kinh 5mm de cat mat trong xUOng ham dudi T r o n g n g h i e n cUu cCia chUng t d i , sau khi c^t x u o n g Le Fort I, xoay t h e o chieu kim d d n g h d , cac d i l m mdc xUOng ham tren t h e hien m d t khuynh
h u d n g tai p h a t xoay n g u p c chieu k i m d d n g h d . D o d n d m h cDa cac d i e m m d e phia sau (PNS, UMD) t h i cao h o n cd y nghta so v d i d p d n d j n h cCia p h a n phia trUde (ANS, d i l m A) dac b i ^ t la t h e o chieu diJng. VI t h d , co t h e n h a n d j n h rang eac d i l m m d c phfa sau t h i d n d m h hOn cac d i e m mdc phfa trUde t r o n g khi xoay t h e o c h i l u k i m d d n g h d p h a n d o a n xUong h a m t r ^ n . Tuy n h i e n , v l mu'c d p d i c h u y e n p h a u t h u a t d p h a n phia t r u d e rat it va sU tai p h a t t h i n h d hPn 0,5mm nen sU tai p h ^ t nay c d t h e k h d n g ed y nghTa ve m a t lam sang. Do d o , cSt x u o n g Le Fort I c u n g vdi xoay t h e o chieu k i m d d n g h d cd t h i duac x e m n h u la m d t t h u t h u a t t i e n d o a n dupe va cd t f n h d n d j n h cao.
Gan day, tren t h e gidi dat b i l t 1^ cae q u d c gia D d n g A, xoay mat phang khdp c i n t h e o chieu k i m d d n g h d t h u d n g dupe thUc hi§n vl cac ly d o t h a m my; n d lam giam d p nghieng cOa cae rang cCfa, dieu nay se cai t h i e n goc m u i m d i bi n h p n [8], [9]. 0 cac nude chau A t r o n g do cd Viet Nam c h u n g t a , n g u d i dan m u d n t r o n g t h o n g p n d v u n g x u o n g ham d u d i phia sau khi nhln tU phfa trUde. Va dieu nay cd t h i dat dupe b^ng each xoay mat phang khdp can. Khi mat p h ^ n g khdp can dUde xoay t h e o chieu k i m d d n g h d se lam cho c h i l u cao mat phia sau g i a m cUng vdi sU gia t a n g gde mat phang ham dUdi.
NhOfng benh nhan bj sai khdp can loai III d cac nude chau A, t h u d n g cd sU kem t a n g t r u d n g t a n g gida mat va sU xoay t h e o c h i l u kim d d n g h d m a t phang khdp can lam eae c^u true quanh m i j i di ra trude ma khong c^n dat i m p l a n t m u i [10].
Ve p h u o n g d i l n chdc nang, t h u t h u a t nay cd t h e lam t a n g dp dn d j n h sau m d do k h d n g lam cang v d n g chan bUdm - co can, cd kha nang d d n g lai khdp can h d phia trudc vdi su dn d j n h cao. TO" quan d i e m t h a m my, xoay phde h p p ham tren - ham d u d i t h e o chieu kim d d n g h d cd m o t sd Uu diem: (1) dupe dUa ra lam t a n g d u d n g vien vOng can m u i ; (2) d p nghieng cCia gde rang cCfa ham tren glSm, lam cai thien gde m u i m d i ; va (3) g u o n g mat b e n h n h a n t r o n g thanh t u h o n do giam chieu cao t a n g m a t d u d i phia sau khi nhin tU phfa t r u d c va phia b e n .
Sau phau thuat, cac diem mdc xUPng ham dudi cd khuynh hudng tai phat theo chieu trudc - sau. NhUng nd dn djnh hPn khi so vdi cae nghien edu khac.
JOURNAL OF 108 - CLINICAL MEDICINE AND PHARMACY Vol.12-N'1/2017
B i n g 7. T^ le t a i p h a t t h e o chieu n g a n g duoic b^o c i o t r e n y v a n
Nghien cdu Franco 1989 Sorokolitl990 Profflt1991 Ingen/all 1995 Schatz 1995
Mobarak2000 Mau
14 25 11
29 13
80
Thdi gian theo doi (thang)
6 - 3 6 7 - 4 2 12
14 12
36
Diem moc Pogonlon Diem B B l e m B Pogonion Pogonlon O i l m B Pogonlon B l e m B Pogonion Pogonion
Ldi (mm) 4,87
5,1 5,8 4,6 6,0 7,27 7,13 6,93 6,28 5,1
T^i phat (mm)
2,13 0,51 3,6 4,2 1,3 2,85 3,52 1,27 1,63 2,6
T^ le tai phat
%
43,7 9,8 62,1 91,3 21,7 39,2 49,4 18,3 25,9 51,0
Trong nghien cCia chung tdi, mdc dp ICii trung binh la 4,4mm (diem B) va 4,69mm (POG), va mdc dp tai phat trung binh theo chieu trudc - sau la 0,8mm (diem B) va 0,55mm (POG). T^ I I tai phat la 18,00%
(diem B) vai 1,53% (POG).
Dd ddc cua mat phSng khdp can cd the la mot yeu td ddng gdp cho dp dn dinh sau md eCia xUOng ham dudi. Trong khi ha mieng hoac khi nhai, cac co nhai nhu cP can, co chan budm trong, ph^n phfa trudc cua co thai duong keo xuong ham dudi theo hudng lln tren va ra trUde, va dd cd the la mdt yeu td quan trpng cho su t^i phat ra trUdc. Mat phang khdp can dupe lam ddc hon cd the lam gi^m hoat ddng CO khdng thuan Ipi trong hoat ddng chdc nang.
Cac thay ddi md mem ed the cho thay r^ng cat xuong Le Fort I va xoay phde hpp ham tren - ham dudi theo chilu kim ddng hd ed the hOu ich de dieu tri cac benh nhan cd rang cda tren bj nghieng ngoai, mdi tren nhd va xuong ham dUdi tang trudng qua mdc. Trong trudng hpp lech lac xUPng ham loai III cd khoang each gida rang cda ham trln va ham dUdi bi ngan, xoay theo chieu kim ddng hd mat phang khdp can eho phep lUi nhilu hPn diem phfa dUdi eua xuong ham dudi ch^ng han nhu Pogonion. Kiem soat mat phang khdp c^n theo hudng xoay theo ehieu kim ddng hd ed t h i lam thay ddi su di ehuyen cua phan doan gan eOa phau thuat liai xuong ham
dudi, va dieu nay cd the lam tang mdc dp cai thiln net nhln nghieng. Mac dCi t^ le tai phat la cd y nghfa thdng ke d mdt sd diem mde, tuy nhien mdc dp tai phat khdng Idn, vl the hau qua ci!ia sU tai phat dudng nhu khdng dang k l trong kit quei lam sang.
4. Ket luan
Xoay mat phang khdp can theo chilu kim ddng hd trong dieu trj nhQng trudng hpp lleh lac xUong ham loai III cd the dupe xem nhUlamdtthOthuatdh dmh, dac biet d cac v\ tri theo chieu ddng cua eac dilm mdc phfa sau, hdu fch de chTnh sCfa loai mat c6 mat phang khdp c|n thap va khdp can hd, cai thien tham my mat.
Tai lieu tham khSo
1. Bell WH Jacobs JD (1981) Tridimensional planning for - surgical orthdontic treatment of mandibular excess.
Am orthod 80:263-288.
2. Wolford L, Chemello PD, Milliard FW (1993) Occlusal plane alteration in orthognathic surgery. J Oral Maxillofae Surg 51:730-740.
3. Proffit WR, Phillips C, prewitt JW et al (1991) Stability ] Arter surgical-orthodontic correction of skeletal class III malocclusion. Int j Adult Orthognath Surg 6:71-80.
4. Satrom KD Sinclair PM, Wolford LM (1991) The
stability of double jaw surgery: a comparison of rigid i
TAP CHlY DLfOC U M SANG 108 Tap12-S6 1/2017
versus wire fixation. Am J Orthod Dentofacial Orthop 99:550-563.
Bell WH, McBride KL (2007) Correction of the long face syndrome byie fort I osteotomy. A report on some new technical rrmdifications and treatment results. Oral Surg oral Med oral Pathol 44:493-520.
Johan P Reyneke (2006) Postoperative skeletal stability folbwing clockwise and counter<lockwise rotation of the maxillomandibular complex compared to conventional orthognathic treatment. British Joumal of Oral and Maxillofacial Surgeiy45 (2007): 56-64.
Schenel SA, Eisenleld j . Bell WH et al (1976) 77ie long face syndrome: vertical maxillary excess. Am j orthod 70:398-408.
Proflit WR, Phillips C, Tun/ey TA (1987) Stability following superior repossitiong of the maxilla byLe Fort I. Amj Orthod Dentoiaeical Orthop 92:151-161.
Reyneke JP Evans WG (1990) Surgical manipulation of the occlusal plane. Int J Adult Orthodon Orthognath Surg 5:99-110.
. Sorokolit CA, Nanda RS (1990) Assessment of the stability of mandibuhr setback procedures elth rigkl fixation. J oral IVIaxilloiac Surg 48:817-82Z