自鎖式矯正牙套比較不痛、又比較快?－矯正醫生的狂想曲--- Straight teeth and life

A good orthodontist with knowledge of proper biomechanics (Moment ratios, load-deflection rates, materials, and so on)

and diagnostic skills can obtain great results with most brackets.

--- Part I. 自鎖式矯正牙套比較不痛、又比較快?

這星期又有媽媽問Dr. Lee說：XX矯正牙套是否比較不痛、又比較快? 如果對孩子比較好，貴一點也沒關係！

我們臨床上也有使用自鎖式(self-ligating) 矯正牙套，目前主要用於安格氏第三類不正咬合(Angle Class III, 俗稱戽斗)，正顎手術患者。臺灣市售自鎖式矯正牙套主要有(3M) Smart Clip, (Ormco) Demon, (GAC) In-ovation “R”, Speed 等等。自鎖式矯正牙套 1980年代開始上市，正如 Dr. Pandis 而言，令人極震驚意外的是，並未有獨立的臨床試驗或研究報告卻上市多年。It is strikingly surprising that self-ligating brackets have been advocated and marketed long before the publication of any clinical trials investigating their efficiency by independent sources.

最近的研究報告其實都顯示：自鎖式矯正牙套不會比較不痛、治療時間也沒有比較快。唯一可以確定的是：自鎖式矯正牙套價錢比較貴，患者必需額外多付15000~~20000 元。以及Ormco行銷非常成功！

平心而論，如Dr. Burrow 所言，訓練良好的矯正醫師，具備豐富生物力學、材料學知識，以及臨床病例診斷分析能力，使用大多數市售牙套，應該都能達成極佳的治療結果。A good orthodontist with knowledge of proper biomechanics (Moment ratios, load-deflection rates, materials, and so on) and diagnostic skills can obtain great results with most brackets. 而讓患者(要求)左右矯正醫師用何種牙套，或是矯正診所醫師、助理小姐大力鼓吹患者使用某種牙套，大家冷靜思考一下，應該明白這是多麼荒謬的醫療行為！你曾聽說患者要求外科醫師，開刀指定使用某種廠牌的器械或材料嗎？正如開車技術好不好跟開的是歐洲車、日本車無關；牙套/ 矯正線都只是工具，矯正醫師臨床治療能力才是最重要的吧？

最後，臨床上偶爾可見某些牙套 (患者)治療時間比較快，但治療時間主要的決定因素，應該是患者生物性的差異 (例如細胞反應、病例難易度等), 而非牙套廠牌。There might be some brackets would move faster, but it appears that the limiting factor is biology (independent of bracket type)!

我並不反對用自鎖式矯正牙套, 但不希望患者由於網路資訊, 誤認為治療比較不痛、又比較快而使用.

可能經濟不景氣，那位媽媽最後決定把錢省下來~~

Part II.

引用Samuel Jack Burrow 的文章敘述：(Am J Orthod Dentofacial Orthop 2009;136:5-6)

It is strikingly surprising that self-ligating brackets have been advocated and marketed long before the publication of any clinical trials investigating their efficiency by independent sources.

Pandis et al reported that “our findings agree with previous trials that found no difference in the crowding alleviation stage at predetermined times with conventional and self-ligating Smart Clip brackets (3M, Unitek, Monrovia, Calif) or conventional and self-ligating Damon 2 brackets.”

The overall conclusion of Pandis et al was that “no difference in the time required to correct mandibular crowding with Damon 2 and conventional brackets was observed.”

Torres et al reported “no difference in treatment duration between Damon 2 and Synergy brackets (Rocky Mountain Orthodontics, Denver, Colo) with a maxillary, split-mouth setup.”

The evidence continues to mount. In recent issue of the AJO-DO (May 2009), Fleming et al compared the efficiency of mandibular arch alignment in 3 dimensions with a self-ligating bracket, Smart Clip, and a conventional bracket, Victory series. The conclusion of this prospective, randomized clinical trial was that “alignment in the mandibular arch in nonextraction patients is independent of bracket type.”

A good orthodontist with knowledge of proper biomechanics (Moment ratios, load-deflection rates, materials, and so on) and diagnostic skills can obtain great results with most brackets. There might be some brackets would move faster, but it appears that the limiting factor is biology.

The evidence still stands that, “The limited clinical trial data now available do not support the contention that treatment time is reduced (presumably because of lower friction) with self-ligating brackets.”

REFERENCES

1. Burrow SJ. Friction and resistance to sliding in orthodontics: a critical review. Am J Orthod Dentofacial Orthop 2009;135:442-7.

2. Pandis N, Polychronopoulou A, Eliades T. Self-ligating vs conventional brackets in the treatment of mandibular crowding: a prospective clinical trial of treatment duration and dental effects. Am JOrthod Dentofacial Orthop 2007;132:208-15.

3. Miles PG. Smartclip versus conventional twin brackets for initial alignment: is there a difference. Aust Orthod J 2005;21:123-7.

4. Miles PG, Weyant RJ, Rustveld L. A clinical trial of Damon 2 vs. conventional twin brackets during initial alignment. Angle Orthod 2006;76:480-5.

5. Torres CB, Cabrilla MCP, Quintanilla DS. In: Comparative assessment of the effectiveness of dental alignment between low friction conventional ligated and self-closing brackets on the maxillary arch in 18 patients. London: European Orthodontic Society; 2005; p. 294; Proceedings of the European Orthodontic Society; 2005; Amsterdam.

6. Fleming PS, DiBiase AT, Sarri G, Lee RT. Efficiency of mandibular arch alignment with 2 preadjusted edgewise appliances. Am J Orthod Dentofacial Orthop 2009;135:597-602.

--- Part III 2011年二月的研究報告

本篇研究為隨機臨床試驗(randomized clinical trial), 比較兩組拔牙矯正病例 (一組使用Damon3 bracket 另一組用傳統牙套), 治療結果顯示使用Damon3 bracket 並未縮短治療時間,或減少看診次數; 矯正治療後的咬合狀態也沒有優於使用傳統牙套者!!

**Duration of treatment and occlusal outcome using Damon3 self-ligated and conventional orthodontic bracket systems in extraction patients: A prospective randomized clinical trial

Andrew T. DiBiase, Inas H. Nasr, Paul Scott, Martyn T. Cobourne. American Journal of Orthodontics & Dentofacial Orthopedics Volume 139, Issue 2 , Pages e111-e116, February 2011

Introduction This was a prospective randomized clinical trial comparing the effect of bracket type on the duration of orthodontic treatment and the occlusal outcome as measured by the peer assessment rating (PAR).

Methods A multi-center randomized clinical trial was carried out in 2 orthodontic clinics. Sixty-two subjects (32 male, 30 female; mean age, 16.27 years) with a mean pretreatment PAR score of 39.40, mandibular irregularity from 5 to 12 mm, and prescribed extractions including mandibular first premolars were randomly allocated to treatment with either the Damon3 self-ligated or the Synthesis conventional ligated preadjusted bracket systems (both, Ormco, Glendora, Calif). An identical archwire sequence was used in both groups excluding the finishing archwires: 0.014-in, 0.014 × 0.025-in, and 0.018 × 0.025-in copper-nickel-titanium aligning archwires, followed by 0.019 × 0.025-in stainless steel working archwires. Data collected at the start of treatment and after appliance removal included dental study casts, total duration of treatment, number of visits, number of emergency visits and breakages during treatment, and number of failed appointments.

Results Sixty-two patients were recruited at the start of treatment, and the records of 48 patients were analyzed after appliance removal. Accounting for pretreatment and in-treatment covariates, bracket type had no effect on overall treatment duration, number of visits, or overall percentage of reduction in PAR scores. Time spent in space closure had an effect on treatment duration, and the pretreatment PAR score influenced only the reduction in PAR as a result of treatment.

Conclusions Use of the Damon3 bracket does not reduce overall treatment time or total number of visits, or result in a better occlusal outcome when compared with conventional ligated brackets in the treatment of extraction patients with crowding.