Borrador

ORIGINAL ARTICLE

Effectiveness of early orthodontic treatment with the Twin-block appliance: A multicenter, randomized, controlled trial. Part 1: Dental and skeletal effects
Kevin O’Brien, PhD, MSc, BDS, FDS, DOrthRCSEng,a Jean Wright, MSc, BSc,b Frances Conboy, MA, BA,b YeWeng Sanjie, BDS, MSc,c Nicky Mandall, PhD, BDS, FDSRCSEng, MOrthRCSEng,d Stephen Chadwick, BDS, FDSRCSEdin,MOrthRCSEng,e Ivan Connolly, BDS, FDSRCPSGlasg, FFDRCSIrel, MOrthRCSEng,f Paul Cook, MDSc, BChD, FDSRCPSGlasg, LDS, FDS, DOrth, MOrthRCSEng,g David Birnie, BDS, FDSRCSEdin, FDS, MOrthRCSEng,h Mark Hammond, MSc, BDS, FDS, RCPSGlasg, MOrthRCSEng,i Nigel Harradine, MB, BS, BDS, FDSRCSEdin, MOrthRCSEng,j David Lewis, BDS, FDS, DOrthRCSEng, FRSH,k Cathy McDade, BDS, FDSRCSEdin, DOrthRCSEng,l Laura Mitchell, MDS,BDS, FDSRCPSGlasg, MOrthRCSEng, DOrthRCSEng,m Alison Murray, BDS, MSc, FDSRCPSGlasg, MOrthRCSEng,n Julian O’Neill, BDS, MSc, FFDRCSIrel, MOrthRCSEng,o Mike Read, BDS, FDSRCSEdin, DOrthRCSEng,l Stephen Robinson, MSc, BDS, FDSRCPSGlasg, MOrthRCSEng,h Dai Roberts-Harry, MSc, BDS, FDSRCPSGlasg, MOrthRCSEng,g Jonathan Sandler, MSc, BDS, FDSRCPSGlasg, MOrthRCSEng,p and Ian Shaw, PhD, MScD, BDS, FDS,DOrthRCSEngq Manchester, Chester, Portadown, Leeds, Portsmouth, Stourbridge, Bristol, Bolton, Bradford, Derbyshire, Kettering, Chesterfield, and Sunderland, United Kingdom This study evaluated the effectiveness of early orthodontic treatment with the Twin-block appliance for the developing Class II Division 1 malocclusion. This multicenter trial was carried out in the United Kingdom. A total of 174children, aged 8 to 10 years old, with Class II Division 1 malocclusion were randomly allocated to receive treatment with a Twin-block appliance or to an untreated, control group. Data were collected at the start of the study and 15 months later. Results showed that early treatment with Twin-block appliances resulted in reduction of overjet, correction of molar relationships, and reduction inseverity of malocclusion. Most of this correction was due to dentoalveolar change, but some was due to favorable skeletal change. Early treatment with the Twin-block appliance is effective in reducing overjet and severity of malocclusion. The small change in the skeletal relationship might not be considered clinically significant. (Am J Orthod Dentofacial Orthop 2003;124:234-43)

his article describes arandomized, controlled trial that studied the effectiveness of early orthodontic treatment with the Twin-block appliance. One area that causes much controversy in orthodontic treatment is the role of dentofacial orthopedics or orthodontic growth modification in the treatment of Class II malocclusion. The controversy is
Professor and chair, Unit of Orthodontics, University Dental Hospital ofManchester. b Research associate, University Dental Hospital of Manchester. c Visiting student (from Wuhan University, People’s Republic of China), University Dental Hospital of Manchester. d Lecturer in orthodontics, University Dental Hospital of Manchester. e Consultant orthodontist, Chester Royal Infirmary, previously Blackburn Royal Infirmary. f Consultant orthodontist, Craigavon Area Hospital,Portadown, Northern Ireland. g Consultant orthodontist, Leeds Dental Institute. h Consultant orthodontist, Queen Alexandra Hospital. i Consultant orthodontist, The Corbett Hospital, Stourbridge. j Consultant orthodontist, Bristol Dental Hospital.
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further compounded by the issue of timing, specifically whether it is more effective to provide treatment in 2 separate phases. Phase I is treatmentwith a functional appliance, to correct the Class II skeletal discrepancy, when the child is 7 to 10 years old. This is followed by phase II treatment with fixed appliances when the
Consultant orthodontist, Bolton General Hospital. Consultant orthodontist, University Dental Hospital of Manchester. m Consultant orthodontist, St Luke’s Hospital, Bradford. n Consultant orthodontist, Derbyshire...