利用皮質骨的微小骨穿孔及骨切穿處理以加速老鼠矯正時的牙齒移動之研究

Using micro-osteoperforation and corticision for accelerating orthodontic tooth movement in rats

謝學吟(Hsueh-Yin Hsieh)

指導教授 ： 蔡吉陽

臺北醫學大學/口腔醫學院/牙醫學系碩博士班/碩士(2016年)

摘要

<研究目的>：

根據美國矯正學會(AAO)的統計，全口齒顎矯正治療的平均耗時依不同的病例複雜度及治療計劃而異，約為18至30個月。治療時間延長可能帶來較多副作用，增加其他風險。因此，在臨床上，學者及臨床醫師們一直希望能夠找到有效的方式來加速齒顎矯正速度。

近年來，以骨創傷促使牙齒加速移動，成為一個熱門的議題。而微小骨穿孔及骨切穿皆被證實能夠加速局部的牙齒移動。本篇實驗的目的，希望在實驗老鼠身上，比較齒槽骨的微小骨穿孔及骨切穿對牙齒矯正移動速率的影響。此外，再合併兩種術式，進一步觀察，當骨創傷量增加時，是否也會促使牙齒矯正移動速率增加。同時，微觀來說，以micro-CT分析骨頭密度的變化，並以組織切片分析蝕骨細胞數量變化。

<材料與方法>：

本實驗選用60隻8周大的Sprague-Dawley成年雄性大鼠，隨機分為四組。每隻老鼠於第一天給予矯正拉力，拉動左上第一大臼齒。實驗三組加上手術創傷如下。

●實驗組I: 微小骨穿孔 + 矯正力量
實驗組II: 骨切穿 + 矯正力量
實驗組III: 微小骨穿孔 + 骨切穿 + 矯正力量
實驗組IV: 單純矯正力量 (控制組)

實驗時間共為期六週，每週紀錄牙齒移動的情形。在第三及第六週時，各組犧牲一半數量，觀察其骨密度及蝕骨細胞的數量變化。

<結果>：

就牙齒總移動距離而言，在實驗六週期間，三組實驗組的總移動距離皆比控制組多。在第二週時，微小骨穿孔組及骨切穿組之牙齒總移動距離皆顯著的比控制組多。除第二週外，其餘週數實驗組及控制組間則無統計上顯著差異。

另外就每週牙齒移動速率而言，在第二週時，骨切穿組的週移動速率顯著的大於微小骨穿孔＋骨切穿組及控制組。除第二週外，其餘幾週四組間之每週牙齒移動速率無統計上顯著差異。

從T3 (第三週) 到T6 (第六週)，四組骨密度(BV/TV)皆下降。在T3時，三組實驗組之骨密度(BV/TV)皆較控制組低，但沒有統計上顯著差異。到T6時，四組間骨密度(BV/TV)亦無統計上顯著差異。經過T3到T6，四組的骨礦化密度(BMD)皆降低。實驗三組的骨礦化密度(BMD)在T3及T6時都比控制組來得低，但皆無統計上顯著差異。

從組織切片計算單位面積的蝕骨細胞數量。在T3時，實驗三組的蝕骨細胞數量顯著的比控制組多。而T6時，實驗三組蝕骨細胞數量稍微下降但仍比控制組多，控制組數量則略為上升。此時四組間皆無統計上顯著差異。另外可以觀察到不論在T3或T6時，實驗三組牙根吸收現象皆比控制組少。

<結論>：

經過微小骨穿孔、骨切穿手術、及微小骨穿孔合併骨切穿手術，可以增加骨質代謝、重塑能力，增加蝕骨細胞數量，而使牙齒移動有局部加速現象發生。另外也可以降低牙根吸收的嚴重程度。在實驗前兩週時可以顯著地加速老鼠牙齒矯正移動。以實驗結果來看，此三種術式並沒有絕對的優劣關係。在本實驗中，增加手術造成的骨創傷量無法等比例的加速牙齒移動，但可觀察到牙齒移動速率可維持較長時間的上升。

關鍵字

微小骨穿孔 ； 骨切穿 ； 加速矯正

並列摘要

:

In vivo studies have revealed significant and nonsignificant differences in the rate of orthodontic tooth movement after micro-osteoperforation and corti-cision. Because most studies have been performed under different condition, their results are incomparable.

We compared the 2 surgical approaches—micro-osteoperforation and corti-cision—without flap elevation under identical conditions. Furthermore, we combined the 2 approaches to determine whether increasing surgical trauma increases the rate of tooth movement.

:

60 male adult Sprague-Dawley rats were enrolled at 8 weeks of age, and upper left first molars were pulled forward by orthodontic appliance from upper incisors with a force of 50-g. Three kinds of surgical interventions were conducted in Group 1 to 4: micro-osteoperforation (MOP + F), corti-cision (C + F), micro-osteoperforation + corticision (MOP + C + F), and or-thodontic force only (control; F). The experimental duration was 6 weeks, and distance and velocity of tooth movement, bone density, and osteoclasts were analyzed.

:

Application of the three flapless minor surgeries reduced bone density and significantly increased osteoclastic activity at week 3 and increased tooth movement and velocity at week 2. The three flapless minor surgeries showed no significant difference in tooth movements, bone density and osteoclastic activity in rats.

:

With the three flapless minor surgeries, it had increased amount and rate of tooth movement during the early stage. Tooth movement rate and the un-derlying bone density and osteoclasts number did not increase proportion-ally with surgical trauma; however, the increase in tooth movement velocity lasted longer.

並列關鍵字

micro-osteoperforation ； corticision ； accelerating orthodontic tooth movement

參考文獻

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