OBJECTIVES: To compare dentoalveolar and skeletal changes in two groups of Class II division 1 patients treated with different designs of Clark's Twin Block (CTB), with (Group 1) or without (Group 2) an upper labial bow. MATERIALS AND METHODS: A randomized controlled trial was conducted in the Department of Orthodontics at the East Kent Hospitals University NHS Foundation Trust, UK. Sixty-two white subjects (aged 10-14 years at the start of treatment, minimum overjet > 6 mm, molar relationship at least ½ unit Class II) were recruited. Subjects were divided into age- and sex-matched pairs, were randomly allocated to treatment with either appliance design, and were treated for 12 months, at which time additional data were collected. RESULTS: Sixty participants were available for final data collection. The two groups were well matched with respect to age (mean 12.5 years in Group 1; 12.3 years in Group 2). No statistical difference was noted between groups for any dentoalveolar or skeletal variables measured. Both groups experienced a reduction in overjet as a result of maxillary incisor retroclination, mandibular incisor proclination, and forward positioning of the pogonion. Maxillary molar distalization, mandibular molar mesialization, and ANB reduction also occurred in both groups. CONCLUSIONS: The addition of a maxillary labial bow to the CTB has no influence on dentoalveolar or skeletal changes, or on rate of overjet reduction, in relation to appliance therapy.
OBJECTIVES: To compare dentoalveolar and skeletal changes in two groups of Class II division 1 patients treated with different designs of Clark's Twin Block (CTB), with (Group 1) or without (Group 2) an upper labial bow. MATERIALS AND METHODS: A randomized controlled trial was conducted in the Department of Orthodontics at the East Kent Hospitals University NHS Foundation Trust, UK. Sixty-two white subjects (aged 10-14 years at the start of treatment, minimum overjet > 6 mm, molar relationship at least ½ unit Class II) were recruited. Subjects were divided into age- and sex-matched pairs, were randomly allocated to treatment with either appliance design, and were treated for 12 months, at which time additional data were collected. RESULTS: Sixty participants were available for final data collection. The two groups were well matched with respect to age (mean 12.5 years in Group 1; 12.3 years in Group 2). No statistical difference was noted between groups for any dentoalveolar or skeletal variables measured. Both groups experienced a reduction in overjet as a result of maxillary incisor retroclination, mandibular incisor proclination, and forward positioning of the pogonion. Maxillary molar distalization, mandibular molar mesialization, and ANB reduction also occurred in both groups. CONCLUSIONS: The addition of a maxillary labial bow to the CTB has no influence on dentoalveolar or skeletal changes, or on rate of overjet reduction, in relation to appliance therapy.
Authors: Kevin O'Brien; Jean Wright; Frances Conboy; YeWeng Sanjie; Nicky Mandall; Stephen Chadwick; Ivan Connolly; Paul Cook; David Birnie; Mark Hammond; Nigel Harradine; David Lewis; Cathy McDade; Laura Mitchell; Alison Murray; Julian O'Neill; Mike Read; Stephen Robinson; Dai Roberts-Harry; Jonathan Sandler; Ian Shaw Journal: Am J Orthod Dentofacial Orthop Date: 2003-08 Impact factor: 2.650