Biomedical subjects
D J Spary
Publications and source records attributed to D J Spary.
A clinical comparison of bracket bond failures in association with direct and indirect bonding.
OBJECTIVE: To compare bond failure rates between direct and indirect techniques for bonding orthodontic brackets. DESIGN: A two-centre single blinded prospective randomized controlled clinical trial. MATERIALS AND METHODS: This study was undertaken at the Birmingham Dental Hospital and Good Hope Hospital, Sutton Coldfield. Thirty-three subjects meeting the inclusion criteria were selected from orthodontic waiting lists and assigned to either of two study groups according to a split-mouth study design. The number and site of bracket failures between tooth types was recorded over 1 year. Statistical analysis was carried out using chi-square tests. RESULTS: Brackets were lost from 14 of the 553 teeth bonded, giving an overall bond failure rate of 2.5%. There were no significant differences in bond failures between direct and indirect bonding or in the tooth types of the failures. CONCLUSIONS: There was no significant difference in the bond failure rates between direct and indirect bonding.
A jig for measuring incisor inclination.
The aim of this study was to design and construct a jig for measuring the inclination of the upper incisors to the maxillary plane and of the lower incisors to the mandibular plane. After several prototypes had been tested, the required properties for a successful jig were identified and a simple inexpensive device was produced. Measurements obtained when using the jig on 51 subjects were compared with cephalometric values by means of regression analysis. This revealed that measurements obtained using the jig against the upper and then the lower incisor crowns could be converted to cephalometric incisor angulations with 96 per cent accuracy to 10 degrees, by adding 23 and 3 degrees, respectively. The jig was accurate to 5 degrees on 69 per cent of occasions for the upper teeth. The 5 degrees accuracy with the lower incisors was only 27 per cent, although over a 6 degree range it improved to 78 per cent. For upper and lower tooth measurements combined, the jig was accurate to within 6 degrees on 75 per cent of occasions.
A randomized controlled trial comparing the quadhelix and the expansion arch for the correction of crossbite.
OBJECTIVE: To compare the use of the quadhelix and the expansion arch for the correction of crossbite. DESIGN: A prospective randomized clinical trial supported by preliminary laboratory measurements. The null hypothesis was that there was no difference in the clinical effectiveness of the two expansion devices in terms of crossbite correction. SETTING: Queen's Hospital, Burton on Trent and The University of Birmingham, School of Dentistry. PARTICIPANTS: The first 60 patients on the orthodontic waiting list at Queen's Hospital who required expansion of the maxillary arch as part of the treatment plan were allocated to be treated with either a quadhelix or an expansion arch by random allocation. Twenty-eight and 27 members of each respective group completed the study. MATERIALS: Commercial quadhelix arches (3M Unitek) and custom-made expansion arches METHODS: The force produced by the type of expansion arches used in the study was measured in the laboratory to be 1.8 N at 10 mm of expansion. Quadhelix arches of sizes 2 and 3 were found to produce equivalent forces at 5 and 7 mm of expansion respectively. Either expansion device was fitted to the 60 participants according to random allocation and expanded by the standard amount. Intermolar and intercanine expansion was measured after 4, 8 and 12 weeks. Patient opinion was assessed by using a questionnaire. RESULTS: The quadhelix and the expansion arch were equally effective in producing expansion (p>0.05). After 12 weeks, the two types of archwire had produced mean intermolar expansions of 4.54 and 5.09 mm and intercanine expansions of 1.41 and 2.12 mm, respectively. Both types of arch were reported as uncomfortable by a majority of patients, the quadhelix affected mainly the tongue and the expansion arch the cheeks. The appearance of the quadhelix was disliked by 25% of participants, while 70% disliked the expansion arch. CONCLUSIONS: The null hypothesis was confirmed. However, the expansion arch had several advantages that made it a cheap alternative to the quadhelix for crossbite expansion, because it can be made and fitted at the chairside.
A randomized clinical trial comparing the accuracy of direct versus indirect bracket placement.
OBJECTIVE: To determine the accuracy of direct or indirect bracket placement. DESIGN: A prospective, randomized comparison of 2 different methods of bracket placement. SETTING: Queens Hospital, Burton upon Trent, UK between February and May 2001. MATERIALS AND METHOD: Twenty-six consecutive patients requiring upper and lower MBT trade mark pre-adjusted Edgewise appliances had their labial segments bonded directly or indirectly according to a split mouth system of allocation. Before and after bond-up all brackets were photographed and measured from tracings to determine positional differences from the ideal. RESULTS: Using ANOVA (General Linear Model), vertical errors were found to be greater than those in the horizontal plane, which in turn were greater than angular errors (p<0.05). Errors were greater in the maxillary arch than in the mandibular arch. There was no significant difference between the mean errors produced by the two methods of bracket placement. CONCLUSIONS: Mean bracket placement errors were similar with both techniques.
The Burton approach to indirect bonding.
There has been a resurgence of interest in the indirect bonding technique for orthodontics. The procedure is not often used in the UK and the reasons for this, as well as the renewal of interest, are explored. A costing exercise suggests that the cost-effectiveness of the technique may be improved by the described Burton technique and, in the light of current manpower considerations, the implications for its use in the future are also discussed.
The split Tru-tain: a simple answer to a common problem.
A cheap and easy to wear alternative to the Barrer appliance is described. This appliance can be used in either jaw for the treatment of very mild malocclusions, the correction of post-treatment relapse or as a retainer where minor changes are desirable after the removal of fixed appliances.
The palatal movement of the apices of upper incisors using intra-oral elastics: a case report.
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The male is more dangerous than the female.
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