Originl Article Interventions for pin during fixed orthodontic pplince therpy A systemtic review Li Xioting ; Tng Yin b ; Chen Yngxi c ABSTRACT Objective: To compre the different methods of pin control intervention during fixed orthodontic pplince therpy. Mterils nd Methods: A computerized literture serch ws performed in MEDLINE (1966 2009), The Cochrne Librry (Issue 4, 2009), EMBASE (1984 2009), nd CNKI (1994 2009) to collect rndomized controlled trils (RCTs) for pin reduction during orthodontic tretment. Dt were independently extrcted by two reviewers nd qulity ssessment ws crried out. The Cochrne Collbortion s RevMn5 softwre ws used for dt nlysis. The Cochrne Orl Helth Group s sttisticl guidelines were followed. Results: Twenty-six RCTs were identified nd six trils including 388 subjects were included. Met-nlysis showed tht ibuprofen hd pin control effect t 6 hours nd t 24 hours fter rchwire plcement compred with the plcebo group. The stndrd men difference ws 20.47 nd 20.48, respectively. There ws no difference in pin control between ibuprofen, cetminophen, nd spirin. Other nlgesics such s tenoxicm nd vldecoxib hd reltively lower visul nlog scle (VAS) scores in pin perception. Low-level lser therpy (LLLT) ws lso n effective pproch for pin relief with VAS scores of 3.30 in the LLLT group nd 7.25 in the control group. Conclusions: Anlgesics re still the min tretment modlity to reduce orthodontic pin despite their side effects. Some long-cting nonsteroidl nti-inflmmtory drugs (NSAIDs) nd cyclooxygense enzyme (COX-2) inhibitors re recommended for their comprtively lesser side effects. Their preemptive use is promising. Other pproches such s LLLT hve roused reserchers ttention. (Angle Orthod. 2010;80:925 932.) KEY WORDS: Pin; Orthodontic tretment; Fixed orthodontic pplince; Met-nlysis; Rndomized clinicl trils INTRODUCTION Pin nd discomfort re common clinicl symptoms in orthodontic ptients, especilly 2 to 4 dys PhD student, Stte Key Lbortory of Orl Disese nd Deprtment of Orthodontics, West Chin School of Dentistry, Sichun University, Chengdu, Chin. b PhD student, Stte Key Lbortory of Orl Disese nd Deprtment of Endodontics, West Chin School of Dentistry, Sichun University, Chengdu, Chin. c Professor, Stte Key Lbortory of Orl Disese nd Deprtment of Orthodontics, West Chin School of Dentistry, Sichun University, Chengdu, Chin. Corresponding uthor: Chen Yngxi, DDS, PhD, Stte Key Lbortory of Orl Disese, West Chin School of Dentistry, Sichun University, No. 14, 3rd Section, Renmin South Rod, Chengdu 610041, Chin (e-mil: cyxlfx@tom.com). Accepted: Februry 2010. Submitted: Jnury 2010. G 2010 by The EH Angle Eduction nd Reserch Foundtion, Inc. fter fixed orthodontic pplinces re plced. It hs even been suggested tht orthodontic pin cn discourge some ptients from seeking tretment nd might cuse number of ptients to discontinue tretment. 1 After n orthodontic procedure, it is typicl to experience pin nd soreness 24 hours fter plcement of the pplince. The pin generlly occurs fter plcement of the first rchwire 2 4 nd subsides fter week. 5 Reserchers ttributed the initil nd delyed pin response to hyperlgesi of the periodontl ligment. This hyperlgesi mkes the periodontl ligment sensitive to relesed lgogens such s histmine, brdykinin, prostglndins, nd serotonin. 6 The increse in the levels of these meditors elicits pin response following orthodontic force ppliction. At present there is no universl recommendtion on the use of nlgesics in pin reduction. Nonsteroidl nti-inflmmtory drugs (NSAIDs) such s ibuprofen DOI: 10.2319/010410-10.1 925
926 XIAOTING, YIN, YANGXI nd cetminophen re commonly recommended. Their nlgesic ction hs been explined by their bility to inhibit the synthesis of prostglndins t the site of the tissue injury. This is thought to be through inhibition of the cyclo-oxygense enzymes COX-1 nd COX-2. 7 Becuse the use of nlgesics hs side effects, they re contrindicted in ptients who re llergic to those drugs. To find lterntives for pin relief, reserchers hve looked for other new, but sfer pproches, such s low-level lser therpy (LLLT). 8 12 LLLT is new interntionlly ccepted designtion nd is defined s lser tretment in which the energy output is low enough so s not to cuse rise in the temperture of the treted tissue bove 36.5uC or norml body temperture. 13 Becuse of its lower energy output nd intensity, its effects re minly nontherml nd biostimultory. The mechnism of lser nlgesi is its ntiinflmmtory nd regenertive effects on neurons nd its conditioning effect on tooth enmel. 14,15 Since the mesurements of pin intensity re diverse, most of the studies hve utilized visul nlog scle (VAS), which is designed to present the subject with rting scle with minimum constrints 16 to evlute pin perception. The VAS is line whose ends re nchored nd mesures the pin intensity by grdted scle from 0 to 10. The subject is expected to mrk loction on the line corresponding to the mount of pin experienced, considering 0 s no pin nd 10 s unberble pin intensity. The distnce of the mrk from the end of the scle is then tken to represent pin score. Most subjects with pin understnd the concept nd cn quickly mke the mesurement. At present, there re some niml models estblished to evlute pin relief nd tooth movement through niml behvior. 17,18 These procedures followed the Guidelines of Animl Reserch or were pproved by the institutionl review bord of the universities. However, these studies hve limited clinicl significnce, re inconsistent nd less pertinent thn clinicl studies, nd offer results tht cn only be extrpolted to the humn with gret cution. Reserchers tend to design more resonble ethicl humn intervention experiments nd to seek reltively more efficient wy to control orthodontic pin. Among these studies, rndomized clinicl trils (RCTs) nd systemtic reviews with met-nlysis re believed to be the better wy to provide more prcticl nd relible suggestions nd informtion for clinicl prctice. 19,20 The purpose of this systemtic review is to compre the clinicl outcome of different methods of pin intervention. Two questions re put forwrd: (1) Are medictions still the min tretment modlity to reduce orthodontic pin? (2) Are there ny other new Tble 1. MEDLINE (Ovid) Serch Strtegy (Use * for Trunction) Serch History Results 1. (Explode) ORTHODONTICS 37,124 2. Orthodontic*.mp. 35,946 3. Orthodontic tretment*.mp. 6046 4. Initil rchwire plcement*.mp. 4 5. 1 or 2 or 3 or 4 41,515 6. (Explode) PAIN 243,022 7. Discomfort*.mp. 21,518 8. 6 or 7 260,828 9. Ibuprofen*.mp. 7812 10. (Low-level lser therpy* or LLLT*).mp. 439 11. 9 or 10 8251 12. 5 nd 8 nd 11 22 pproches proved to be more effective in pin control? MATERIALS AND METHODS Literture Serch nd Study Selection A computerized literture serch ws performed using MEDLINE (1966 2009) (Tble 1), The Cochrne Librry (Issue 4, 2009), EMBASE (1984 2009), nd CNKI (1994 2009) with no lnguge restriction. Rndomized controlled trils nd controlled clinicl trils conducted in humns were identified. A number of useful references nd pproprite serch strtegies were received from the Cochrne Hndbook for Systemtic Reviews of Interventions. 21 Two reviewers independently conducted the study selection using pilot-tested forms 22 (Tble 1). Titles nd bstrcts of ll potentil relevnt studies were identified before retrievl of the full rticles. Full rticles were obtined if there ws insufficient dt in the title nd bstrct to mke cler decision. Selection Criteri The inclusion nd exclusion criteri re listed in Tble 2. Two reviewers independently evluted the qulity of the serched rticles to estblish whether the studies met the inclusion criteri. Disgreements were resolved by discussion, nd third reviewer consulted where necessry. The rticles in their reference lists were lso scnned to be optimlly identified. All studies meeting the inclusion criteri underwent vlidity ssessment nd dt extrction. Studies rejected t this or subsequent stges were recorded in Figure 1, which describes the review retrievl flow from selection to met-nlysis. Methodologic Qulity According to the principles nd procedures of met-nlysis, 23 two reviewers independently s-
INTERVENTION OF ORTHODONTIC PAIN 927 Tble 2. Inclusion nd Exclusion Criteri in the Anlysis Inclusion Criteri 1. All subjects begn orthodontic tretment with t lest one rchwire plcement. 2. All subjects signed n informed consent before the reserch procedures. 3. For the medicl intervention, ll subjects were helthy, with no prophylctic ntibiotic coverge required, were currently not tking ntibiotics or nlgesics, nd hd no contrindictions to the use of nonsteroidl nti-inflmmtory drugs (NSAIDs). 4. Follow-up periods were defined s short-term (eg, 2 hours, 6 hours, t night, 24 hours, 2 dys, 3 dys, 7 dys). 5. The outcomes of pin perception were mesured by either visul nlog scle (VAS) or questionnire for pin perception. Exclusion Criteri 1. The studies were not rndomized control trils (RCTs) or qusi-rcts. 2. The studies were designed for pin mngement of tooth extrction. 3. The studies were designed for pin control fter orthodontic seprtor plcement. 4. The subjects hd systemic disese or chronic pin or histories of neurologic nd psychitric disorders. 5. The rticle could not be locted. Dt Extrction nd Met-nlysis Dt were extrcted from ech study independently nd entered into computerized dtbse. The informtion extrcted included the nme of the first uthor, yer of publiction, men scores of experimentl nd control groups, nd stndrd devition of experimentl nd control groups. Differences were resolved by discussion to rech consensus between the reviewers. Met-nlysis ws conducted with the help of Rev- Mn 5 softwre provided by the Cochrne Collbortion. Stndrd men difference nd 95% confidence intervl (CI) were clculted using continuous dt of the selected studies. Sttisticl tests of heterogeneity were used to ssess whether the observed vribility in study results ws greter thn tht expected to occur by chnce. The heterogeneity between studies ws ssessed using Q sttisticl test by exmining the type of prticipnts, interventions, nd outcomes in ech study. Met-nlyses were done only if there were studies of similr comprisons reporting the sme outcome mesures. 25,26 RESULTS sessed ech selected study for methodologic qulity, bsed on the criteri defined by Jdd et l. 24, mximum score 5 nd high/cceptble score $3 (Tble 3). All of the included studies should hve cceptble methodologic qulity. Study Selection nd Dt Summry Chrcteristics of the trils Of the eight qulified trils (Ngn et l. 27, Polt nd Krmn 28, Polt et l. 29, Young et l. 30, Turhni et Figure 1. Flow digrm of study selection nd met-nlysis.
928 XIAOTING, YIN, YANGXI Tble 3. Methodologicl Qulity Criteri of Jdd et l. 24 1 Ws the study described s rndomized? Score 1 if yes 1b nd 1c Ws the method of rndomiztion described nd pproprite to concel Score 1 if pproprite nd 0 if not pproprite lloction? 2 Ws the study described s double-blinded? Score 1 if yes 2b nd 2c Ws the method of double blinding described nd pproprite to mintin doubleblinding? Score 1 if pproprite nd 0 if not pproprite 3 Ws there description of how withdrwls nd dropouts were hndled? Score 1 if yes Totl score 5; high qulity $3. l. 10, Slmssin et l. 31, Arntes et l. 32, Tortmno et l. 11 ), one tril (Polt et l. 29 ) ws excluded due to dt dupliction with uthors other tril (Polt nd Krmn 28 ) nd nother (Turhni et l. 10 ) ws judged not to be double-blinded RCT with its Jdd Scle t 2. Six eligible trils (Ngn et l. 27, Polt nd Krmn 28, Young et l. 30, Slmssin et l. 31, Arntes et l. 32, Tortmno et l. 11 ), comprising 388 subjects, met the inclusion criteri. All trils were conducted t university dentl clinics nd ll trils declred tht ptients hd signed the necessry consent informs. The dt summry of these eight trils nd their Jdd Scle re presented in Tble 4. Dt nlysis Medicine Ibuprofen vs control groups: met-nlysis Ibuprofen ws used s representtive NSAIDs on the bsis of its efficcy for postopertive relief of dentl pin. Acetminophen ws believed not to ffect tooth movement, nd spirin ws the trditionl NSAID. The question of whether ibuprofen hd n dvntge in pin relief compred to cetminophen nd spirin needs to be further studied. Totlly, three trils were included in this group. According to different control groups nd inctive group, the met-nlysis ws divided into three subgroups: (1) ibuprofen vs cetminophen (Polt nd Krmn 28 nd Slmssin et l. 31 ); (2) ibuprofen vs spirin (Ngn et l. 27 nd Polt nd Krmn 28 ; (3) ibuprofen vs plcebo (Ngn et l. 27, Polt nd Krmn 28 nd Slmssin et l. 31 ). Metnlyses of these three subgroups re summrized in Tbles 5 7. In subgroup 1, t different time points within 7 dys, the stndrd men difference rnged between 0.20 nd 0.41, indicting the results slightly fvored the control group (cetminophen). Though cetminophen ppered to hve better effect on pin relief thn ibuprofen, this difference did not rech sttisticl significnce with n overll P..05. In subgroup 2, similr results ppered between ibuprofen nd spirin. In subgroup 3, compred with the plcebo, ibuprofen ws indicted to be more effective for pin relief t 6 hours nd t 24 hours when the initil rchwire ws plced. The stndrd men differences were 20.47 nd 20.48 t 6 hours nd 24 hours, respectively, nd the overll P vlues were ll.01 (P,.05), showing tht the results fvored the experimentl group (ibuprofen) more thn the control group (plcebo). However, fter 24 hours, the stndrd men difference Tble 4. Dt Summry of Eight Qulified Trils nd Their Jdd Scle Jdd Criteri List 60 12 18 Stright-wire Study N Age, y Applince Interventions Pin Mesure NNT 1 1b 1c 2 2b 2c 3 Totl Ngn et l. 27 56 16.6 6 6.8 Begg/Edgewise Ibuprofen, spirin VAS None 1 0 0 1 1 0 1 4 Polt nd 120 Men 15.3 NA Ibuprofen, cetminophen, VAS None 1 0 0 1 1 0 1 4 Krmn 28 nproxen sodium, spirin Polt et l. 29 60 Men 16 NA Ibuprofen, nproxen sodium VAS None 1 0 0 1 0 0 1 3 Slmssin 60 12 18 NA Ibuprofen, cetminophen VAS None 1 1 0 1 1 0 1 5 et l. 31 Arntes 36 16 25 Stright-wire Tenoxicm VAS NA 1 1 0 1 0 0 1 4 et l. 32 technique Young 56 18 54 NA Vldecoxib VAS NA 1 0 0 1 0 0 1 3 et l. 30 Turhni 76 Men 23.1 Edgewise LLLT A modified NA 1 1 0 0 0 0 0 2 et l. 10 questionnire Tortmno LLLT A survey NA 1 1 0 1 1 0 0 4 et l. 11 technique VAS indictes visul nlog scle; LLLT, low-level lser therpy; NNT (number needed to tret).
INTERVENTION OF ORTHODONTIC PAIN 929 Met-nlysis Dt Summry: Ibuprofen vs Acetmi- Tble 5. nophen Time Point Stndrd Men Difference 95% CI Test for Heterogeneity Overll Effect Lower Upper x 2 P Vlue P Vlue 2 Hours 0.33 20.11 0.78 0.62.43.14 6 Hours 0.21 20.23 0.65 0.01.93.34 24Hours 0.20 20.24 0.64 0.69.41.38 2 Dys 0.21 20.23 0.65 0.05.82.36 3 Dys 0.23 20.21 0.67 0.10.75.31 7 Dys 0.41 20.04 0.85 0.13.71.07 CI indictes confidence intervl. Tble 7. Time Point Met-nlysis Dt Summry: Ibuprofen vs Plcebo Stndrd Men Difference 95% CI Test for Heterogeneity Overll Effect Lower Upper x 2 P Vlue P Vlue 2 Hours 20.02 20.39 0.35 2.42.30.92 6 Hours 20.47 20.84 20.09 2.70.26.01 24Hours 20.48 20.86 20.11 4.46.11.01 2 Dys 20.34 20.72 0.03 1.63.44.07 3 Dys 20.34 20.71 0.03 0.96.62.07 7 Dys 20.02 20.39 0.35 1.32.52.91 CI indictes confidence intervl. still fvored the ibuprofen group, but its effects hd no sttisticlly significnt difference with the plcebo (P..05) (Figure 2). Vldecoxib. One RCT ws obtined. Young et l. 30 reported tht the scores of VAS were 4.6, 6.6, 8.8, respectively, when mesuring experienced discomfort in preemptive, postopertive, nd plcebo use. This suggests tht preemptive nlgesics might be n pproch to prevent discomfort ssocited with initil rchwire plcement in helthy dults. Tenoxicm. One RCT ws obtined. Arntes et l. 32 reported tht pin intensity in the tenoxicm group ws lower thn in the plcebo groups. The difference in pin intensity between the experimentl nd control groups ws gretest t 12 hours when ssessed fter ctivtion of orthodontic tretment. Low-level Lser Therpy One tril ws included for this group, nd there ws some evidence to support the use of LLLT for pin reduction during fixed orthodontic pplince therpy. However, mny diverse opinions existed concerning this kind of clinicl tril, such s durtion of tretment, dosge (rdint power, frequency, energy density), nd pin mesure, which cused us to preclude met-nlysis. In study by Tortmno et l., 11 the ptients in the LLLT group hd less orl pin nd lower intensity of pin. The VAS score for the most pinful dy ws 3.30 Tble 6. Time Point Met-nlysis Dt Summry: Ibuprofen vs Aspirin Stndrd Men Difference 95% CI Test for Heterogeneity Overll Effect Lower Upper x 2 P Vlue P Vlue 2 Hours 0.31 21.07 1.68 8.44.004.66 6 Hours 0.10 20.76 0.97 3.50.06.82 24Hours 0.10 20.35 0.56 0.17.68.66 2 Dys 0.16 20.29 0.62 0.90.34.48 3 Dys 20.12 20.58 0.34 1.94.16.60 7 Dys 0.29 20.17 0.75 1.83.18.21 CI indictes confidence intervl. in the LLLT group compred with 7.25 in the control group with no lser tretment, nd 8.55 in the plcebo group with simulted lser tretment. Menwhile, pin cesed on the third dy in the LLLT group, but on the fifth dy in the control nd plcebo groups. This indicted the efficcy of LLLT for pin control fter plcement of the first orthodontic rchwire. DISCUSSION For tretment of pin induced by fixed orthodontic pplince, this systemtic review found evidence fvoring medicine nd low-level lser therpy for pin relief in the short term. Few in vivo studies were found in the literture serch since pin is subjective phenomenon tht is difficult to ssess. Mny vribles come into ply when one ttempts to mesure nd quntify it. 33 35 It is dependent upon fctors such s ge, gender, individul pin threshold, the mgnitude of the force pplied, present emotionl stte nd stress, culturl differences, nd previous pin experiences. 34 However, s clinicl trils, especilly well-designed rndomized clinicl trils, provide more useful informtion nd prcticl suggestions, it is impertive to offer n updte on the interventions of pin during fixed orthodontic pplince therpy, especilly fter initil rchwire plcement. Of six included trils, three reported using n orthodontic pplince, including edgewise, Begg, nd stright-wire technique. All of these pplinces re considered conventionl pplinces compred with the self-ligting brcket systems. It is believed these pplinces result in similr pin experience, nd therefore their dt re synthesized in this metnlysis. Since gstric ulcertion, bleeding disorders, llergy, etc re mong the common dverse effects in NSAIDs, orthodontic reserchers nd clinicins hve devoted themselves to finding much sfer nlgesics from the mny kinds of NSAIDs. At first, ibuprofen ws chosen to be sfe nd effective. But clinicl trils
930 XIAOTING, YIN, YANGXI Figure 2. Ibuprofen (experimentl) nd plcebo (control) groups for met-nlysis results, reported in stndrd men difference (95% confidence intervl), show evidence fvoring ibuprofen for pin reduction t 6 hours nd t 24 hours fter ctivtion of fixed orthodontic tretment. reveled tht the effect of ibuprofen on pin relief ws limited. Also, there re still mny controversies on the use of NSAIDs becuse of their potentil influence on tooth movement. 36,37 Acetminophen is preferred becuse it does not inhibit prostglndin synthesis nd hs no deleterious effects on tooth movement. 38 40 Metnlysis hs reveled tht there is no difference in pin relief between ibuprofen, cetminophen, nd spirin. Although compred with plcebo, ibuprofen hs better effect on pin control nd there lwys exists the plcebo effect. This clls for properly performed doubleblind trils to void this psychologicl effect. Recently, some long-cting NSAIDs such s tenoxicm nd COX- 2 inhibitors such s vldecoxib were studied, nd they hve proved to be more effective nd convenient thn other nlgesics. Recent reserch towrds their preemptive use s well s concentrtion on the idel dosge of those gents is promising. Considering the side effects of nlgesics, other pproches hve been tested to reduce pin from orthodontic procedures. Dt hve shown the efficcy of LLLT for pin control fter plcement of the first rchwire. 10,11 LLLT for pin relief is believed to be noninvsive nd esy to dminister, with no known dverse tissue rections. The reson for reducing its clinicl use would be the totl time (32 37.5 minutes) for ppliction to both dentl rches. Also, LLLT should be pplied immeditely fter orthodontic pplince bonding in clinics. 11 A well-designed double-blind tril is nother limittion. How could the lser therpy be hndled between the experimentl nd control groups so tht the opertors nd ptients re both blinded to the difference? Fce msk or glsses re suggested by
INTERVENTION OF ORTHODONTIC PAIN 931 reserchers in the included studies, but whether these pproches cn be properly performed to eliminte experimentl bis needs further investigtion. Aprt from mediction nd LLLT, mny reserchers hve been exploring other effective wys for pin mngement during fixed orthodontic tretment. The use of vibrtory stimultion to reduce orthodontic pin ws first reported by Mrie et l., 41 but on detiled nlysis it ws found tht once the discomfort sets in, most of the ptients were not ble to tolerte the vibrtions. Brtlett et l. 42 compred pretretment nd follow-up clls nd the effects of ech on pin perception fter initil rchwire plcement nd found tht telephone cll cn reduce ptients self-reported pin. Chewing gum or plstic wfer ws lso suggested. Hwng et l. 43 observed pin relief in the mjority of ptients fter chewing wfers (56%), but the rest of the subjects reported incresed discomfort. However, ll of these suggested pin mngement methods were devoid of well-designed RCTs, nd therefore were excluded from this systemtic review. Becuse of the limited mount of comprtive evidence, there is n pprent need for high-qulity RCTs to further investigte the effectiveness of these methods for interventions during fixed orthodontic pplince therpy. Orthodontic reserchers nd clinicins need to explore more effective tretment techniques, combintions, or pproches to evlute nd mnge orthodontic pin experienced by ptients. CONCLUSIONS N Anlgesics re still the min tretment modlity to reduce orthodontic pin. However, the phrmcologic ctions s well s their side effects should be identified before prescribing these medictions in routine clinicl prctice. N Some long-cting NSAIDs nd COX-2 inhibitors re interestingly recommended for their comprtively fewer side effects, nd their preemptive use is promising. N Other reltively sfer pproches such s LLLT hve roused reserchers ttention. Up to now, there is still limited evidence to suggest their benefit in the use of LLLT, vibrtory stimultion, nd other nonphrmcologic modlities. ACKNOWLEDGMENT We cknowledge Professor SHI Zong-do for his guidnce in conducting this systemtic review nd met-nlysis. REFERENCES 1. Oliver RG, Knpmn YM. Attitudes to orthodontic tretment. Br J Orthod. 1985;12:179 188. 2. Scheurer PA, Firestone AR, Burgin WB. Perception of pin s result of orthodontic tretment with fixed pplinces. Eur J Orthod. 1996;18:349 357. 3. Soltis JE, Nkfoor PR, Bowmn DC. Chnges in bility of ptients to differentite intensity of forces of pplied to mxillry centrl incisors during orthodontic tretment. J Dent Res. 1971;50:590 596. 4. Jones ML. An investigtion into the initil discomfort cused by plcement of n rchwire. Eur J Orthod. 1984; 6:48 54. 5. Ngn P, Kess B, Wilson S. Perception of discomfort by ptients undergoing orthodontic tretment. Am J Orthod Dentofcil Orthop. 1989;96:47 53. 6. Krishnn V. Orthodontic pin: from cuses to mngement review. Eur J Orthod. 2007;29:170 179. 7. Vne JR. Inhibition of prostglndin synthesis s mechnism of ction for spirin-like drugs. Nt New Biol. 1971;231:237 239. 8. Lim HM, Lew KK, Ty DK. A clinicl investigtion of the efficcy of low level lser therpy in reducing orthodontic postdjustment pin. Am J Orthod Dentofcil Orthop. 1995;108:614 622. 9. Limpnichkul W, Godfrey K, Srisuk N, Rttnytikul C. Effects of low-level lser therpy on the rte of orthodontic tooth movement. Orthod Crniofc Res. 2006;9:38 43. 10. Turhni D, Scheriu M, Kprl D, Benesch T, Jonke E, Bntleon HP. Pin relief by single low-level lser irrdition in orthodontic ptients undergoing fixed pplince therpy. Am J Orthod Dentofcil Orthop. 2006;130: 371 377. 11. Tortmno A, Lenzi DC, Hddd AC, Bottino MC, Dominguez GC, Vigorito JW. Low-level lser therpy for pin cused by plcement of the first orthodontic rchwire: rndomized clinicl tril. Am J Orthod Dentofcil Orthop. 2009;136:662 667. 12. Youssef M, Ashkr S, Hmde E, Gutknecht N, Lmpert F, Mir M. The effect of low-level lser therpy during orthodontic movement: preliminry study. Lsers Med Sci. 2008;23:27 33. 13. Hrris DM. Biomoleculr mechnisms of lser biostimultion. J Clin Lser Med Surg. 1991;8:277 280. 14. Okmoto H, Iwse T, Sito T, Moriok T. The possible ppliction of He-Ne lser for dentl plque control. J Jpn Soc Lser Med. 1993;14:3 7. 15. Roberts-Hrry DP. Lser etching of teeth for orthodontic brcket plcement: preliminry clinicl study. Lsers Surg Med. 1992;12:467 470. 16. Lincre JM. Visul nlogue scles. Rsch Mesurements Trnsctions. 1998;12:639. 17. de Crlos F, Cobo J, Perilln C, Grci MA, Arguelles J, Vijnde M, Costles M. Orthodontic tooth movement fter different coxib therpies. Eur J Orthod. 2007;29:596 599. 18. Shibzki T, Yozgtin JH, Zeredo JL, Gonzles C, Hotokezk H, Kog Y, Yoshid N. Effect of celecoxib on emotionl stress nd pin-relted behviors evoked by experimentl tooth movement in the rt. Angle Orthod. 2009;79:1169 1174. 19. Cowrd DD. Prtil rndomiztion design in support group intervention study. West J Nurs Res. 2002;24:406 421. 20. Torbinejd M, Bhjri K. Essentil elements of evidencedbsed endodontics: steps involved in conducting clinicl reserch. J Endod. 2005;31:563 569. 21. Higgins JPT, Green S. Cochrne hndbook for systemtic reviews of interventions 4.2.5. In: The Cochrne Librry. Chichester, UK: John Wiley & Sons Ltd; 2005.
932 XIAOTING, YIN, YANGXI 22. Cicchetti DV. Assessing inter-rter relibility for rting scles: resolving some bsic issue. Br J Psychitry. 1976; 129:452 456. 23. Torbinejd M, Bhjri K. Essentil elements of evidencedbsed endodontics: steps involved in conducting clinicl reserch. J Endod. 2005;31:563 569. 24. Jdd AR, Moore RA, Crroll D, Jenkinson C, Reynolds DJ, Gvghn DJ, McQuy HJ. Assessing the qulity of reports of rndomized clinicl trils: is blinding necessry? Control Clin Trils. 1996;17:1 12. 25. Egger M, Smith GD. Met-nlysis: potentils nd promise. BMJ. 1997;315:1371 1374. 26. Egger M, Smith GD, Phillips AN. Met-nlysis: principles nd procedures. BMJ. 1997;315:1533 1537. 27. Ngn P, Wilson S, Shnfeld J, Amini H. The effect of ibuprofen on the level of discomfort in ptients undergoing orthodontic tretment. Am J Orthod Dentofcil Orthop. 1994;106:88 95. 28. Polt O, Krmn AL. Pin control during fixed orthodontic pplince therpy. Angle Orthod. 2005;75:214 219. 29. Polt O, Krmn AL, Durmus E. Effects of preopertive ibuprofen nd nproxen sodium on orthodontic pin. Angle Orthod. 2005;75:791 796. 30. Young AN, Tylor RW, Tylor SE, Linnebur SA, Buschng PH. Evlution of preemptive vldecoxib therpy on initil rchwire plcement discomfort in dults. Angle Orthod. 2006;76:251 259. 31. Slmssin R, Oesterle LJ, Shellhrt WC, Newmn SM. Comprison of the efficcy of ibuprofen nd cetminophen in controlling pin fter orthodontic tooth movement. Am J Orthod Dentofcil Orthop. 2009;135:516 521. 32. Arntes GM, Arntes VM, Ashmwi HA, Posso IP. Tenoxicm controls pin without ltering orthodontic movement of mxillry cnines. Orthod Crniofc Res. 2009;12: 14 19. 33. Sergl HG, Klges U, Zentner A. Pin nd discomfort during orthodontic tretment: custive fctors nd effects on complince. Am J Orthod Dentofcil Orthop. 1998;114: 684 691. 34. Bergius M, Kiliridis S, Berggren U. Pin in orthodontics. A review nd discussion of the literture. J Orofc Orthop. 2000;61:125 137. 35. Erdinc AM, Dincer B. Perception of pin during orthodontic tretment with fixed pplinces. Eur J Orthod. 2004;26:79 85. 36. Sndy JR, Hrris M. Prostglndin nd tooth movement. Eur J Orthod. 1984;6:175 182. 37. Kyrknides S, O Bnion MK, Subtelny JD. Non-steroidl nti-inflmmtory drugs in orthodontic tooth movement: metlloproteinse ctivity nd collgen synthesis by endothelil cells. Am J Orthod Dentofcil Orthop. 2000;118: 203 209. 38. Kehoe MJ, Cohen SM, Zrrini K, Cown A. The effect of cetminophen, ibuprofen, nd misoprostol on prostglndin E2 synthesis nd the degree nd rte of orthodontic tooth movement. Angle Orthod. 1996;66:339 350. 39. Roche JJ, Cisneros GJ, Acs G. The effect of cetminophen on tooth movement in rbbits. Angle Orthod. 1997;67: 231 236. 40. Aris O, Mrquez-Orozco MC. Aspirin, cetminophen, nd ibuprofen: their effects on orthodontic tooth movement. Am J Orthod Dentofcil Orthop. 2006;130:364 370. 41. Mrie SS, Powers M, Sheridn JJ. Vibrtory stimultion s method of reducing pin fter orthodontic pplince djustment. J Clin Orthod. 2003;37:205 208. 42. Brtlett BW, Firestone AR, Vig KWL, Beck FM, Mruch PT. The influence of structured telephone cll on orthodontic pin nd nxiety. Am J Orthod Dentofcil Orthop. 2005; 128:435 441. 43. Hwng JY, Tee CH, Hung AT, Tft L. Effectiveness of ther-bite wfers in reducing pin. J Clin Orthod. 1994;28: 291 292.