比較傳統口外錨定與迷你植體錨定 於成年患者上顎齒槽前突之矯正治療結果

Abstract

影響齒顎矯正治療成果的因素很多，“錨定控制“是其中非常重要的一環；迷你植體的應用可為許多矯正患者提供優質穩定的矯正錨定。本研究的目的即在評估及比較口外裝置錨定與迷你植體骨性錨定在治療上顎齒槽前突的效益。本回溯性臨床研究共包括58位患者，其所有病患的診斷皆為安格氏一級異常咬合合併上下雙顎前突或是安格氏二級異常咬合合併上顎前突，病患在拔除左右兩側第一小臼齒後立刻裝上全口0.018”x0.025”方線固定式矯正裝置，並輔以最大錨定需求做上顎前牙與齒槽骨的後退。依據矯正錨定裝備分成實驗組與對照組。實驗組有30位病人接受固定式矯正裝置輔以迷你植體為錨定，對照組有28位病人接受固定式矯正裝置輔以頭套和transpalatal arch為錨定。治療結果的評估方法方面包括測顱分析以及三度空間立體模型分析。研究結果顯示：迷你植體錨定組的前牙後退量比口外頭套錨定組多1.55 mm，治療時間迷你植體錨定組有比口外頭套錨定組少3.4個月的傾向。由測顱描繪重疊評估門齒向後移動的形式(controlled tipping，translation或 uncontrolled tipping) ，迷你植體錨定組可以有較好的整體牙齒向後移動。在兩側犬齒寬度的變化方面，兩組在矯正治療後之兩側犬齒寬度都有變寬。比較兩組的高位下顎平面開展角之治療結果發現，在上顎第一大臼齒區迷你植體錨定組比口外頭套錨定組平均多向內壓入(intrusion) 0.59 mm，雖然不大，但具有統計學上的顯著差異，下顎平面開展角則減少1.44o，意即下顎作逆時針旋轉，此變化有助於改善安格氏二級異常咬合的外觀。比較迷你植體錨定組的迷你骨釘病例和迷你骨板病例顯示，迷你骨板組比迷你骨釘組的上顎第一大臼齒多向內壓入 0.77 mm，下顎平面開展角減少1.25o，作逆時針旋轉。在測顱分析中也觀察到A point的改變，說明齒槽骨的重塑現象，但是個體變異性大。綜合而言，本研究顯示使用迷你植體錨定的治療時間有縮短，在垂直與前後方向可以有較好的錨定控制，特別是下顎平面開展角是高位的患者，可以做到後牙向內壓入，改善安格氏二級異常咬合的外觀。

INTRODUCTION: Among the factors affecting the treatment outcome of orthodontics, “anchorage control” is the one that plays a very important role. Recent application of the mini-implants provides good and stable orthodontic anchorage for patients requiring maximum anchorage without patient’s compliance. This is a retrospective clinical study to compare the orthodontic treatment outcome between the patients with traditional extra-oral appliance and the ones receiving the mini-implant for maximum anchorage. MATERIAL & METHOD: We compare the treatment outcome of two groups of patients, receiving different anchorage systems during their orthodontic treatment for maximum retraction of the maxillary dentoalveolar process. They were diagnosed either as Angles Class l bimaxillary dentoalveolar protrusion or Angle Class II malocclusion with maxillary dentoalveolar protrusion, with the treatment plan including extraction of bilateral maxillary first premolars. Group 1 (n=28) received traditional anchorage with the transpalatal arch and headgear; group 2 (n=30) received mini-implants (miniscrews or miniplates) for anchorage control. Superimpositions of pre- and post-treatment lateral cephalograms ,and 3-D images obtained via using 3-D digitizer recording on pre- and post-treatment dental models were used to compare (1) the amount of retraction (2) torque of maxillary central incisor (3) change of transverse width of maxillary dentition (4) change of mandibular plane angle between 2 groups. RESULTS: The results showed that the mini-implant anchorage group had more anterior teeth retraction than the headgear group (1.19 mm) with a shorter treatment duration (3.4 months ). Analysis the types of incisor movement (controlled tipping, translation, or uncontrolled tipping) showed mini-implant anchorage group had more translation movement than the headgear group. The intercanine width was wider after orthodontic treatment in both groups. When the cases receiving either miniscrews or miniplates were compared, the cases receiving miniplate had more intrusion of maxillary first molar (0.77 mm ) than that receiving miniscrews, with a counterclockwise rotation of the mandibular plane (1.25 o ). When cases with high mandibular plane angle were analyzed, the subjects receiving mini-implant anchorage had more intrusion on the maxillary first molar (0.59 mm) than that receiving headgear, with a counterclockwise rotation of the mandibular plane (1.44o) to improve the profile of Class II malocclusion. We also observed some remodeling in A point in cephalometric analysis. A point was retracted in the headgear group and protracted in the mini-implant group, though the latter with a larger individual variation. CONCLUSION: The treatment time of the mini-implant anchorage was reduced. The mini-implant anchorage performed better both in sagittal and vertical directions for retraction and eliminating the opening of the mandibular plane angle without patient compliance. Especially in the cases with high mandibular plane angle, the maxillary posterior teeth were successfully intruded to obtain for more satisfactory profile in addition to improving the Class II relationship.