祝 靜，冉屹東

改良Nance弓配合上頜前方牽引矯治骨性Ⅲ類錯的效果

祝 靜1，冉屹東2

1 對象與方法

1.2 研究方法

1.2.2 X線片頭影測量及模型PAR指數(shù)測量 頭影測量包括20項(xiàng)軟硬組織測量指標(biāo)，PAR指數(shù)測量包括6項(xiàng)測量指標(biāo)。所有治療前后X線頭顱定位側(cè)位片和模型測量工作由同一工作人員在同一時間段內(nèi)描圖及測量。

1.2.3 數(shù)據(jù)處理 將21例樣本治療前后頭影測量指標(biāo)及模型測量的PAR指數(shù)測量值輸入EXCEL文檔進(jìn)行處理。PAR指數(shù)各指標(biāo)測量依照Richmond等[2]的研究結(jié)果。

2 結(jié) 果

X線頭影測量及模型PAR指數(shù)測量結(jié)果見表1，具體分析如下。

測量項(xiàng)目治療前治療后差值頜骨矢狀向 SNA(°)77．89±2．3581．26±3．393．37±1．22② SNB(°)80．12±2．4379．96±2．62-0．16±0．23 ANB(°)-2．22±1．491．30±1．143．52±1．57② NA?PA(°)-3．15±2．612．54±2．655．69±2．66② Ptm?A(mm)38．72±1．3140．87±2．342．15±0．67① ANS?Ptm(mm)43．22±2．9144．43±15．221．21±0．61① Wits值(mm)-5．76±2．34-2．02±1．373．74±1．65②頜骨垂直向 ANS?ME(mm)54．52±2．1856．13±2．671．61±0．75① ANS?NE/N?Me(%)51．76±1．5953．03±1．851．27±0．64① Yaxis(°)62．34±3．1264．22±3．281．88±2．05② MP?SN(°)30．81±4．3234．75±3．433．94±2．58② FH?MP(°)24．34±1．0927．78±1．413．44±1．22②牙齒 U1?NA(mm)4．13±1．606．93±1．462．80±1．02① U1?SN(°)100．67±6．73105．24±4．814．57±2．13② L1?NB(mm)6．23±1．786．01±1．46-0．22±0．78 L1?MP(°)88．53±4．2187．71±3．86-0．82±0．68①軟組織 UL?E(mm)-2．34±1．73-0．86±1．661．48±1．05② LL?E(mm)1．99±1．381．46±1．32-0．53±1．04① Z角(°)80．87±3．0975．96±3．87-4．91±2．43② H角(°)8．71±3．6211．57±2．802．86±2．07②PAR指數(shù) 牙齒排列(分值)12．79±4．2611．34±2．181．45±1．09 后牙咬合(分值)5．09±3．521．68±0．943．41±8．08① 覆蓋(分值)3．69±1．080．53±0．313．16±1．08② 覆(分值)2．45±1．900．62±0．321．83±0．79② 中線(分值)1．45±0．911．27±0．490．18±0．32 加權(quán)PAR減少百分率(%)——86．67±12．54①

注：治療后與治療前比較，①P<0.05，②P<0.01

2.1 頜骨矢狀向變化 改良Nance弓前方牽引矯治后，上頜骨向前生長， SNA、ANB、NA-PA、Ptm-A、ANS-Ptm、Wits值均增大，A點(diǎn)明顯前移。

2.2 頜骨垂直向變化 矯治后垂直高度增加，下頜骨向后下旋轉(zhuǎn)，ANS-ME、ANS-NE/N-ME、Y軸角、MP -SN、FH-MP增大。

2.3 上下切牙的變化 矯治后上切牙唇向傾斜，下切牙舌向傾斜， U1-NA、U1-SN增大，L1-MP減小。

2.4 軟組織的變化 矯治后上唇突度增大，下唇突度減小，原有軟組織側(cè)貌的凹面型得到改善，UL-E和H角增大，LL-E和Z角減小。

2.6 矯治療程 較小年齡組對矯治力更加敏感，平均療程較短，6～7歲組平均療程(5.4±2.0)個月，8～10歲組平均療程(8.9±2.0)個月。

3 討 論

3.1 矯治前后X線頭影測量結(jié)果分析

3.1.1 頜骨改變 本組矯治后SNA、ANB、NA-PA、Ptm-A、ANS-Ptm、Wits值均增加。SNA增加3.37°，說明改良Nance弓前方牽引同樣能促進(jìn)上頜骨向前發(fā)育。有學(xué)者指出，對年齡較小的兒童不宜應(yīng)用快速擴(kuò)弓，以免造成鼻子形態(tài)的改變；如果患兒不存在寬度不調(diào)，年齡又較小，可以不配合擴(kuò)弓而直接進(jìn)行前方牽引[3]。本研究結(jié)果表明，改良Nance弓前方牽引沒有配合擴(kuò)弓，同樣取得了較好的骨骼效應(yīng)。SNB減小0.16°，差異無統(tǒng)計學(xué)意義，說明下頜突度的減小主要是由于下頜骨發(fā)生順時針旋轉(zhuǎn)所致。

3.1.3 軟組織改變 在軟組織測量中，UL-E和H角增大，LL-E和Z角減小，上唇顯著前移，頦部向后向下移動，Ⅲ類凹面型得到明顯改善。

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[7] West wood P V,Mcnamara J A Jr,Baccetti T,etal.Long-term effects of class Ⅲ treatment with rapid maxillary expansion and facemask therapy followed by fixed appliances[J].Am J orthod Dentofacial Orthop,2003,123 (3) : 306-320.

(2014-02-13收稿 2014-03-20修回)

(責(zé)任編輯 梁秋野)

CombinedmodifiedNancearchandmaxillaryprotractionincorrectionofskeletalclassⅢmalocclusion

ZHU Jing1and RAN Yidong2. 1. Department of Stomatology, Ningxia Autonomous Regional Hospital, Chinese People’s Armed Police Forces, Yinchuan 750001, China; 2. Department of Stomatology，the No. 2 Hospital of Baoding, Baoding 071000, China

ObjectiveTo evaluate the dental, skeletal and profile changes in the patients with skeletal class III malocclusion after using maxillary protraction appliance combined with modified Nance arch.Methods21 patients with skeletal class Ⅲ malocclusion in mixed dentition were treated by maxillary protraction combined with modified Nance arch. Cephalometric radiographs and plaster model were analyzed to evaluate skeletodental and profile changes and Peer Assessment Rating (PAR) index before and after treatment.ResultsSNA and ANB angle, NA-PA, Ptm-A, ANS-Ptm, Wits values were increased and subspinale was protracted by 2.15 mm. All of the changes were statistically significant (P<0.05).PAR index indicated that the weighted PAR reduction percentage was 86.67%. The anterior overjet and overbite, posterior occlusion were effectively improved. All the patients’ anterior crossbites were corrected after treatment, but there was no significant change in teeth alignment and midline correction.ConclusionsThe maxillary protraction combined with modified Nance arch are obviously effective for skeletal class III malocclusion in mixed dentition, but posterior occlusion, teeth alignment and midline need to be adjusted with fixed appliance in the further treatment.

skeletal class Ⅲ malocclusion; modified Nance arch; maxillary protraction; cephalometric analysis; PAR index

祝 靜，碩士，副主任醫(yī)師，E-mail: jing88_happy@163.com

1.750001銀川，武警寧夏總隊(duì)醫(yī)院口腔科； 2.071000,河北省保定市第二醫(yī)院口腔科

冉屹東，E-mail: ranyidong@126.com

R783.5