口腔正畸科

臨床上經(jīng)常會有成人正畸患者問：“我都這么大歲數(shù)了，正牙時牙移動得肯定比小孩慢吧？”我記得以前似乎在Contemporary Orthodontics上讀到過，成人患者正畸牙移動啟動慢于青少年，而一旦啟動，則速度不亞于青少年。也正是帶著這個印象，我對這個問題的回答是“一樣快”。然而，下面這個研究卻顯示，成人患者正畸牙移動速度確實(shí)慢于青少年，慢了近1/3，已經(jīng)屬于有臨床意義的差距了。看來，今后我需要更改我的回答了。我推測造成這個差異的原因可能有兩方面：1）青少年牙周膜更厚，且反應(yīng)性更好，因而產(chǎn)生的破骨反應(yīng)更強(qiáng)更快。2）成人牙槽骨骨密度更高，對骨吸收的抵抗更強(qiáng)。但另一方面，成人比青少年牙移動速度慢，卻并不意味著成人患者的正畸療程一定比青少年長。事實(shí)上，因為成人患者依從性更好，不掉托槽，一定程度上彌補(bǔ)了他們牙移動稍慢的劣勢。這就是為什么青少年和年輕成人都是正畸最佳年齡群的原因。另，該研究還顯示性別、牙位（包括上、下頜）對牙移動速度沒有影響，盡管我們有時可能感覺女孩比男孩牙移動快、上牙比下牙移動快。———————————————————————————————————————Am J Orthod Dentofacial Orthop.2013 May;143(5):616-21. doi: 10.1016/j.ajodo.2012.12.009.Factorsrelatedto therateoforthodonticallyinducedtoothmovement.Dudic A, Giannopoulou C, Kiliaridis S.SourceAssistant professor, Department of Orthodontics, University of Geneva, Geneva, Switzerland.AbstractINTRODUCTION:The purpose of this study was to investigate the variations oforthodonticallyinducedtoothmovementin the maxillary and mandibular arches between patients and thefactorssuch as age, sex, and presence of an interference that might influence the amount oftoothdisplacement.METHODS:By using a standardized experimental orthodontictoothmovementin 30 subjects, 57 premolars were moved buccally during 8 weeks with the application of a 1-N force. Forty-four contralateral premolars not subjected to orthodontictoothmovementserved as the controls. Plaster models from before and after the experimentaltoothmovementwere digitized and superimposed to evaluate the amounts oftoothmovement. Differences intoothmovementbetween the experimental and control groups were tested by an unpaired t test. For the experimental teeth, subject-relatedfactors(age and sex) andtooth-relatedfactors(location in the maxillary or mandibular dental arch, and the presence or absence of an intra-arch or interarch obstacle such as neighboring touching teeth or teeth interfering with the occlusion) were examined with analysis of variance. Multiple linear regression analysis was performed to determine correlations betweentoothdisplacement, age, sex,toothlocation, and presence of an interference.RESULTS:Each subject contributed at least 2 experimental premolars and 1 control premolar. The displacement of theorthodonticallymoved teeth was 2.42 mm (range, 0.3-5.8 mm). Younger subjects (<16 years; n = 19; number of teeth, 36) had significantly greater amounts oftoothdisplacement compared with older subjects (≥16 years; n = 11; number of teeth, 21): 2.6 ± 1.3 mm vs 1.8 ± 0.8 mm; P <0.01. When an interarch or intra-arch obstacle was present, the amount oftoothmovementwas significantly less (2.6 ± 1.3 mm vs 1.8 ± 0.8 mm) (P <0.05). Neither sex nor the location of the experimental teeth in the mandible or the maxilla had any effect.CONCLUSIONS:Younger patients showed greatertoothmovementvelocity than did older ones. An interarch or intra-arch obstacle decreased the amount oftoothdisplacement.

正畸期間，由于佩戴固定矯治器，對刷牙影響較大，矯治器周邊不易清潔，增加了菌斑附著面積，同時也增加了清除菌斑的難度。菌斑、軟垢和牙石很容易在牙面堆積，刷牙變得相對困難，容易形成牙齦炎癥，表現(xiàn)為牙齦紅腫、出血、增生，反過來又妨礙正畸的順利進(jìn)行。因此，正畸期間定期洗牙更為重要。