British Orthodontic Society, UTG Session Abstracts

s of Research Projects British Orthodontic Society, UTG Abstracts 2008: The Presentation Abstract from the University Teachers Group Seminar at the British Orthodontic Conference. September 2008 Predictors for demineralisation: A post-hoc analysis of RCT recruits E. F. Al Maaitah, A. A. Adymoi, S. M. Pender, S. M. Higham, N. Pender, J. E. Harrison; (University of Liverpool). Objective: To determine predictors for the presence and degree of demineralisation after orthodontic treatment. Design: Post-hoc analysis of RCT recruits. Setting: Liverpool University Dental Hospital Subjects: 250 patients were screened for demineralization, at debond, using quantitative lightinduced fluorescence to determine their eligibility for an RCT assessing the effectiveness of different toothpastes at reducing demineralisation during retention. Methods: Data about patients’ demographic details, treatment, oral hygiene and pre-treatment status of first permanent molars (6s) were extracted from case notes. Data on the presence and number of white spot lesions (WSLs) and degree of demineralisation were obtained from the trial’s data base. Univariate analyses and multiple regression were undertaken to assess for associations between the factors and the presence and number of WSLs and degree of demineralisation. Results: Mean number of WSLs/patient5 2.9 (95% CI 2.5, 3.3). 65 patients (28.3 %) had no WSLs and 165 (71.7%) had 1–12. Patients with WSLs were significantly younger (p50.002). Boys (p50.001) and participants with diseased 6s (p50.05) had a significantly greater degree of demineralisation. Conclusion: Gender, pre-treatment age and status of 6s may be used as predictors for the development and severity of WSLs during orthodontic treatment. A Randomised Trial Comparing Three Methods of Delivering Orthodontic Education M. Bains*, P. Reynolds, F. Mcdonald, M. Sherriff, T. Newton (Guy’s Hospital, KCLDI). Objective: To evaluate what effect the mode of education delivery has on students’ learning outcomes and experiences by conducting a quantitative and qualitative comparison of face-toface (F2FL), blended (BL) and e-learning (EL). Design: Prospective cluster randomised trial comparing four parallel groups. Setting: Guy’s campus (KCLDI). Materials and Methods: Eight firms of fourth year dental undergraduates were randomly allocated to one of four intervention groups (EL, F2FL, BL1, BL2). Two BL groups were used to evaluate the effect of the order of learning. Each group received the same cephalometrics tutorial. Baseline comparability was assessed before the tutorial. Effectiveness and acceptability were evaluated immediately afterwards using a MCQ and questionnaire respectively. This was followed by a focus group meeting. Results: Ninety students completed the study. Pearson’s x test found no significant difference between F2FL and BL but EL alone was less effective (p,0.05) for four MCQ questions. Overall students were positive towards each method but a one-way ANOVA found BL was the most and F2FL the least accepted (p50.002). EL was the least preferred (p50.028). The order of BL had no significant effects. Conclusions: BL is the ideal mode of delivering undergraduate orthodontic education with F2FL timetabled and supportive EL freely accessible. Randomised controlled trial of mandibular alignment with two pre-adjusted appliances P. S. Fleming*, A. T. Dibiase, R. T. Lee (Royal London Dental School). Objective: To compare mandibular arch alignment with SmartClip and Victory brackets in nonextraction cases. Journal of Orthodontics, Vol. 35, 2008, 223–228 # 2008 British Orthodontic Society DOI 10.1179/14653120722716 Design and Setting: A prospective randomized controlled clinical trial based in the Royal London Dental School and Kent & Canterbury Hospital. Subjects and Methods: Sixty-six participants were randomly allocated to two parallel groups. A 0.016 inch NiTi wire (3M Unitek) was placed in all subjects. Irregularity in three dimensions was measured on pre-treatment reference models and on models taken 8 weeks after placement of the appliances. Transverse dimensional changes and labial segment inclination were analysed after passive engagement of a . 019 X . 025’’ SSW after 30 weeks of treatment using reference model and cephalometric data, respectively. Results: Following adjustment for pre-treatment differences by ANCOVA, bracket type had little influence on alignment efficiency in the mandibular arch overall (P50.08), in the buccal (P50.173) or in the labial segments (P50.528). More significant intermolar expansion arose with SmartClip (P50.009). Otherwise no statistically significant differences in arch dimensional changes were observed between subjects treated with the appliance systems. Conclusions: The efficiency of alignment in the mandibular arch in non-extraction cases is independent of bracket type and determined primarily by the degree of irregularity initially. There was little difference in the pattern of arch alignment and leveling related to the 2 pre-adjusted appliances. Craniofacial features of transgenic mice overexpressing sonic hedgehog L. Hagan, J. Sealby, Z. Webster, P. T. Sharpe, M. T. Cobourne (King’s College London; Imperial College London). Objective: To analyse the craniofacial characteristics of transgenic mice over-expressing Sonic Hedgehog (Shh). Design: Histological and skeletal analysis of transgenic mouse embryos. Materials and methods: Transgenic mice were generated using pronuclear injection of a DNA construct consisting of the mouse Shh gene under control of a human Keratin-14 (K14) promoter. This construct drives high expression of Shh in early epithelium of the epidermis and craniofacial region, including the jaws. Skeletal and histological sections of transgenic mutant mice were compared with control littermates for differences in their craniofacial characteristics. Results: Mutant mice demonstrated skin anomalies, polysyndactyly and spina bifida. In addition, significant variation in the craniofacial characteristics of mutants were observed compared to controls. The main features that distinguished mutants included profound exencephaly, an absence of the cranial vault skeletal apparatus, fusion of the frontal, temporal and zygomatic bones and a bifid secondary palate. In addition, mutants had a marked skeletal open bite associated with a flattened cranial base angle and diminutive mandibular condyle. Conclusion: This investigation demonstrates the importance of Shh signalling activity in the developing craniofacial region. Whilst it is established that reduced levels of Shh activity can lead to severe anomalies of craniofacial development, here we show that increased activity can also have important consequences for normal development of this region. Orthodontic Referral Behaviour of General Dental Practitioners in West Sussex O. A. Jackson*, S. J. Cunningham; D. R. Moles, J. R. Clark (St. Richard’s Hospital; UCL Eastman Dental Institute). Objective: The aim of the study was to determine whether dentists were able to make orthodontic referrals at the appropriate time and to the most appropriate provider for particular malocclusions; and to determine the level of use of the Index of Orthodontic Treatment Need (IOTN) when making orthodontic referrals. Design: Postal questionnaire survey with picture tests of a variety of malocclusions. Setting: West Sussex Primary Care Trust (PCT) during 2006. Subjects and Methods: All dentists (349) on the PCT database who undertook orthodontic referrals. Results: A 70% response rate to the questionnaire was achieved. 52% of dentists made the correct decision in choosing the appropriate orthodontic provider in all cases, and overall 80% of the decisions made about where to refer patients for orthodontic treatment were appropriate. 20% of dentists made the correct decision on the timing of referral for orthodontic treatment in all cases. 77% of dentists do not routinely use IOTN when making orthodontic referral. 224 British Orthodontic Society, UTG session abstracts Features Section JO December 2008