Assessment of the relationship between perceptions of dental aesthetics and demand for orthodontic treatment in 10-11 year old school children in Birmingham, UK.

OBJECTIVE: To examine the relationship between perceptions of dental aesthetics and demand for orthodontic treatment, and to determine whether the former can be used to predict the latter. METHOD: A prospective cross sectional epidemiological survey of a random and representative sample of comprehensive primary schools in South Birmingham, UK. Participants were 389 randomly selected school children aged 10-11 years from 7 primary schools in South Birmingham. Their perceptions of dental aesthetics were determined using the Aesthetic Component (AC) of the Index of Orthodontic Treatment Need (IOTN). Demand for treatment was assessed by asking subjects if they wanted treatment with braces to correct their teeth. RESULTS: Only 2% of subjects assessed their dentition in the "definite need" for orthodontic treatment category. Demand for treatment was significantly greater in girls than boys (49% and 37% respectively, p < 0.05). Total demand (41%) was considerably greater than self assessed aesthetics in the "definite need" and "borderline need" categories combined (14%). Demand was accurately reflected in patients who perceived their dentition as having moderate to severe (AC 6-9) and very mild aesthetic impairment (AC 1). CONCLUSIONS: Perceptions of dental aesthetics using the AC of IOTN were able to predict demand for orthodontic treatment in patients with malocclusions of moderate to severe (AC 6-9) aesthetic impairment.

Effect of sandblasting on the retention of orthodontic brackets: a controlled clinical trial.

OBJECTIVE: To study the effect of chairside sandblasting of the bases upon the retention of mesh backed orthodontic brackets. DESIGN: Prospective controlled clinical trial. METHODS: Brackets were bonded to 60 successive patients who were treated at an orthodontic practice in Amman, Jordan. Using a crossover system of allocation, quadrants were bonded using either sandblasted or non-sandblasted brackets respectively. Rely-A-Bond adhesive was used throughout. Bond failures were monitored over one year. RESULTS: 1112 brackets were assessed. The overall failure rate was 4.0% and the failure rates for non-sandblasted and sandblasted brackets were 4.7 and 3.4% respectively. The odds ratio for at least one bracket failure within the control quadrant compared with the experimental quadrant was 0.50 (95% CI 0.185 to 1.238), which was not statistically significant. CONCLUSION: Sandblasting did not significantly improve the retention of mesh based orthodontic brackets in this study.

Selective laser trabeculoplasty versus argon laser trabeculoplasty: results from a 1-year randomised clinical trial.

AIMS: To compare selective laser trabeculoplasty (SLT) and argon laser trabeculoplasty (ALT), in terms of intraocular pressure (IOP) lowering, in patients with open-angle glaucoma. METHODS: 176 eyes of 152 patients were enrolled in this study, 89 in the SLT and 87 in the ALT groups. Patients were randomised to receive either SLT or ALT treatment to 180 degrees of the trabecular meshwork. Patients were followed up to 12 months after treatment. The main outcome measured was IOP lowering at 12 months after treatment, compared between the SLT and ALT groups. RESULTS: No significant difference (p = 0.846) was found in mean decrease in IOP between the SLT (5.86 mm Hg) and ALT (6.04 mm Hg) groups at 1 year or at any other time points, nor were there any significant differences in the rate of early or late complications between the two groups. CONCLUSIONS: SLT is equivalent to ALT in terms of IOP lowering at 1 year, and is a safe and effective procedure for patients with open-angle glaucoma.

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.

Does mentoring have a role in orthodontic training programmes?

Changes within the dental profession have led to a possible need for mentoring and consideration is given in this paper to different structures for possible implementation of mentoring schemes. Further information is needed to determine whether or not mentoring may play a useful role in dentistry in general and in orthodontic specialist training in particular.

A cephalometric comparison of skulls from the fourteenth, sixteenth and twentieth centuries.

OBJECTIVES: To evaluate changes in the size and shape of the skull and jaws in British populations between the thirteenth and twentieth centuries. METHOD: Lateral cephalometric radiograms were obtained from skulls of three groups of subjects: 30 skulls were from the remains of those who died in the London Black Death epidemic of 1348, 54 skulls were recovered from the wreck of the Mary Rose which sank in 1545 and 31 skulls were representative of modern cephalometric values. RESULTS: Horizontal measurements in the base of the anterior cranial fossa and in the maxillary complex were greater in the modern group than in the medieval skulls. Cranial vault measurements were significantly higher (P=0.000) in the twentieth century skulls, especially in the anterior cranial fossa. CONCLUSION: Results suggest that our medieval ancestors had more prominent faces and smaller cranial vaults than modern man.

The effect of socio-economic status and ethnicity on the comparative oral health of Asian and White Caucasian 12-year-old children.

OBJECTIVE: To investigate the oral health of 12-year-old children of different deprivation but similar fluoridation status from South Asian and White Caucasian ethnic groups. DESIGN: An epidemiological survey of 12-year-old children using BASCD criteria, with additional tooth erosion, ethnic classification and postcode data. CLINICAL SETTING: Examinations were completed in schools in Leicestershire and Rutland, England, UK. Participants A random sample of 1,753 12-year-old children from all schools in the study area. MAIN OUTCOME MEASURES: Caries experience was measured using the DMFT index diagnosed at the caries into dentine (D3) threshold, and tooth erosion using the index employed in the Children's Dental Health UK study reported in 1993. RESULTS: The overall prevalence of caries was greater in White than Asian children, but varied at different levels of deprivation and amongst different Asian religious groups. There was a significant positive association between caries and deprivation for White children, but the reverse was true for non-Muslim Asians. White Low Deprivation children had significantly less tooth erosion, but erosion experience increased with decreasing deprivation in non-Muslim Asians. CONCLUSIONS: Oral health is associated with ethnicity and linked to deprivation on an ethnic basis. The intra-Asian dental health disadvantage found in the primary dentition of Muslim children is perpetuated into the permanent dentition.

Baseline IOP predicts selective laser trabeculoplasty success at 1 year post-treatment: results from a randomised clinical trial.

BACKGROUND/AIMS: The efficacy and safety of selective laser trabeculoplasty (SLT) has been found to be equivalent to argon laser trabeculoplasty (ALT). Since SLT produces significantly less disturbance to the trabecular meshwork and is theoretically more repeatable than ALT, it has potential to replace ALT as the standard procedure to treat medically uncontrolled open angle glaucoma. This study's objective is to determine factors that predict successful SLT at 1 year post-treatment. METHODS: As part of a randomised clinical trial comparing the efficacy and safety of SLT to ALT, data on 72 SLT patients were collected, and successful SLT defined as having an SLT induced intraocular pressure (IOP) reduction of >or=20% at 1 year post-treatment follow up. RESULTS: 43 out of the 72 patients who had completed their 1 year follow up visit had an IOP reduction of >or=20% from baseline. No glaucoma risk factors studied predicted successful SLT. The amount of trabecular meshwork pigmentation was not a significant predictor. However, it was discovered that baseline IOP strongly predicted SLT success (odds ratio=1.16; p=0.0001). CONCLUSION: SLT success was significantly predicted by baseline IOP but not by age, sex, other glaucoma risk factors, type of open angle glaucoma, or by degree of trabecular meshwork pigmentation.

British Orthodontic Society, Chapman Prize Winner 2003. A novel in vitro culture model to investigate the reaction of the dentine-pulp complex to orthodontic force.

OBJECTIVE: To develop a novel mandible slice organ culture model to investigate the effects of externally applied force on the dentine-pulp complex. DESIGN: In vitro organ culture. SETTING: School of Dentistry, Birmingham, UK. MATERIALS AND METHODS: Transverse 2 mm thick sections were cut from the mandibles of five 28-day-old male Wistar rats. Serial sections were used for control and test pairs. Springs made from 0.016-inch and 0.019 x 0.025-inch stainless steel wires were used to apply a 50 g tensile or compressive force, respectively, to test specimens. Control and test specimens were cultured for 5 days in a humidified incubator with 5% CO(2) at 37 degrees C and processed for routine histological investigation. Nine more rats were used to provide control and compression test pairs where the pulps were extirpated after 3 days culture and total RNA isolated for gene expression analysis by reverse transcriptase polymerase chain reaction (RT-PCR). RESULTS: Histology showed the dental and supporting tissues maintained a healthy appearance in the control cultures after culture. Histomorphometric analysis revealed a 20-27% increase in pulp fibroblast density in test specimens compared with controls. Gene expression analyses revealed up-regulation in the test groups of PCNA, c-Myc, Collagen 1alpha, TGF-beta1 and alkaline phosphatase, whilst expression of osteocalcin was reduced. CONCLUSIONS: The results demonstrated that the present organ culture technique provides a valuable in vitro experimental model for studying the effects of externally applied forces. These forces stimulated a cellular response in the pulp chamber characterized by altered gene expression and proliferation of fibroblasts; the latter being unaffected by the nature of the force in terms of compression or tension.

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 comparison of three light curing units for bonding adhesive pre-coated brackets.

OBJECTIVE: To compare the effectiveness of three curing lights of different types. DESIGN: Prospective randomized laboratory investigations. MATERIALS AND METHOD: Adhesive pre-coated orthodontic brackets were bonded to 9 groups of extracted premolars and the adhesive was cured using three different curing lights, each at three different times. Bond strength was tested using a shear/peel method. RESULTS: The plasma light had 3 times the light intensity of the standard quartz halogen light. The curing times recommended by the manufacturers were 2 seconds for the plasma light, 10 seconds for the high intensity quartz halogen light and 20 seconds for the standard one. Mean debond stresses with these cure times were 9.36, 11.77 and 12.00 MPa, respectively, p<0.04. Increasing the plasma light cure to 4 seconds increased the mean debond stress to 11.19 MPa, similar to that for the other lights, p=0.62. CONCLUSIONS: Use of a plasma light confers worthwhile time savings when bonding orthodontic brackets, whilst producing bonds of equivalent strength to those found with quartz halogen lights.

Deep vein thrombosis: prevalence and risk factors in rehabilitation admissions with brain injury.

OBJECTIVE: To determine the prevalence and risk factors of deep vein thrombosis (DVT) among neurorehabilitation admissions with acquired brain injury (BI). METHODS: In this prospective, sequential case series, 709 consecutive initial neurorehabilitation patients with BI < 120 days-including traumatic brain injury (TBI; n = 360), intracranial hemorrhage (ICH; n = 213), primary brain tumor (n = 66), and hypoxia/other BI (n = 70)--were screened for evidence of DVT with lower extremity venous duplex ultrasonography (VDU). The admission screening protocol combined VDU and a commercial d-dimer (Dimertest [DDLx]) latex agglutination assay. DVT was considered present based upon VDU results only. RESULTS: DVT prevalence was 11.1%, and was higher with brain tumor (21.2%) and ICH (16%) than with TBI (6.7%) (chi2 test; p = 0.001). DVT risk factors identified by multivariable logistic regression analysis in the overall sample included older age (p = 0.002), type of BI (p = 0.04), DDLx (p = 0.0001), and greater postinjury duration (p = 0.0001), with a trend observed regarding lower Functional Independence Measure (FIM) locomotion (FIM-Loco) subscale score (p = 0.07). However, risk factors also varied with type of BI. Among patients with TBI, only DDLx (p = 0.001) and greater postinjury duration (p = 0.001) were associated with DVT. CONCLUSIONS: Admission venous duplex ultrasonography revealed occult proximal lower extremity deep vein thrombosis in 11% of neurorehabilitation patients with acquired brain injury. Deep vein thrombosis risk is multifactorial in this heterogenous patient population, with relative factor risk influenced by type of acquired brain injury. Semiquantitative d-dimer latex agglutination assay correlated significantly with presence of deep vein thrombosis.

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 prevalence of tooth erosion in 12-year-old children.

OBJECTIVES: To establish the prevalence of tooth erosion in a representative sample of 12-year-old children in Leicestershire and Rutland. To determine if gender, ethnic group, deprivation or caries experience influences the prevalence of erosion. METHODS: A random sample of 1,753 12-year-olds resident in Leicestershire and Rutland were examined in 62 schools; 906 were boys and 847 girls; 1,379 were Caucasian and 316 Asian. Tooth erosion was assessed using the index employed in the survey of Children's Dental Health in England and Wales (1993). The Townsend index was used to record deprivation. RESULTS: Tooth erosion was found in 59.7% of the children, with 2.7% exhibiting exposed dentine. Significantly more boys than girls; Caucasian than Asian children; and those with caries experience, had erosion present (chi-square for all P<0.01). Overall no significant difference was found between deprivation categories, however socio-economically advantaged Caucasian children had significantly less tooth erosion than other groups. CONCLUSIONS: There was a high prevalence of tooth erosion in 12-year-old children. Significantly more erosion occurred in boys than girls, and culture appeared to influence prevalence. Children with caries experience had a higher prevalence of erosion than those without caries, which may reflect a lower level of dietary care. Deprivation seemed to affect the prevalence of tooth erosion in Caucasian children.

A multifactorial analysis of factors associated with dental erosion.

OBJECTIVES: This study prospectively examines the relationship of possible aetiological factors to the presence of tooth erosion in a cohort of children. PATIENTS AND METHODS: A random sample of 1,753 children was examined at age 12 and 1,308 of the same children were re-examined at age 14 years. The children were asked to complete questionnaires on both occasions, 1,149 subjects gave usable replies. The erosion index used was based upon the 1993 Survey of Children's Dental Health. Results were analysed using logistic regression. RESULTS: At age 12 significant positive associations were found between erosion and decay experience (odds ratio [OR] = 1.48), drinking fruit juice (OR = 1.42) or fizzy pop (OR = 1.59-2.52, depending on amount and frequency). The presence of calculus (OR 0.48) or eating fruit other than apples or citrus fruit (OR 0.48) reduced the chances of erosion. High consumption of carbonated drinks increased the odds of erosion being present at 12 years by 252% and was a strong predictor of the amount of erosion found at age 14. CONCLUSIONS: Of the factors investigated, a history of dental caries and a high consumption of carbonated drinks were most closely related to the presence of dental erosion. The risk of erosion bore a strong relationship to the amount and frequency of carbonated drink consumption.

Risk factors for the development of extended-spectrum beta-lactamase-producing bacteria in nonhospitalized patients.

Although the risk factors for acquiring infection by extended-spectrum beta-lactamase (ESBL)-producing bacteria have been investigated in hospitalized patients, such risk factors have not been defined in the community setting. In this study, clinical data from a total of 311 nonhospitalized patients with community-acquired urinary tract infection (128 with ESBL-positive strains and 183 with ESBL-negative strains) were obtained. According to a multivariate analysis, the following were identified as independent risk factors: previous hospitalization in the past 3 months (OR=8.95, 95%CI, 3.77-21.25), antibiotic treatment in the past 3 months (OR=3.23, 95%CI, 1.76-5.91), age over 60 years (OR=2.65, 95%CI, 1.45-4.83), diabetes (OR=2.57, 95%CI, 1.20-5.51), male gender (OR=2.47, 95%CI, 1.22-5.01), Klebsiella pneumoniae infection (OR=2.31, 95%CI, 1.17-4.54), previous use of third-generation cephalosporins (P=0.014, OR=15.8, 95%CI, 1.7-143), previous use of second-generation cephalosporins (P<0.0001, OR=10.1, 95%CI, 4.2-24), previous use of quinolones (P=0.001, OR=4.1, 95%CI, 1.8-9.0), and previous use of penicillin (P=0.003, OR=4.0, 95%CI, 1.6-9.0).

Factors affecting friction in the pre-adjusted appliance.

A jig was constructed to measure the frictional forces created by various tip and torque values in association with two types of straightwire bracket moving along tainless steel (SS) archwires. Forces were measured during translation of the bracket using an Instron machine. Steel and cobalt chromium brackets were tested in association with 0.019 x 0.025 and 0.021 x 0.025 inch steel archwires at tips from 0 to 3 degrees and torque values in 2 degree increments from 0 to 6 degrees. The mean values for static (2.2 N) and kinetic (2.1 N) friction were very similar (P = 0.71), as were the overall friction values for stainless steel (2.1 N) and chromium cobalt (2.2 N) brackets of similar dimensions (P = 0.44). Use of 0.021 x 0.025 inch wire produced three times as much friction as 0.019 x 0.025 inch wire, 3.0 N against 1.2 N (P < 0.01). Increased tip and torque were associated with highly significant increases in friction (P < 0.01). Every degree of tip produced approximately twice as much friction as comparable torque. The main conclusion of the study was that space closure should be completed on a 0.019 x 0.025 inch archwire before a 0.021 x 0.025 inch wire is used to complete tooth alignment.

Awareness of tooth erosion in 12 year old children and primary care dental practitioners.

OBJECTIVES: To compare the knowledge of tooth erosion in a sample of 12 year old children with that of the dentists responsible for their care and also to compare the giving and receiving of advice concerning erosion. METHOD: A random sample of 1753 children from all 62 state maintained schools in Leicestershire completed questionnaires. Questionnaires were also sent to the 257 General Dental Practitioners in Leicestershire. RESULTS: 1686 (96.2%) of children and 227 (82.5%) of dentists returned forms that could be analysed. 36% of dentists reported that they frequently noticed erosion on the teeth of their patients but 67.7% of dentists believed that less than 25% of 12 year olds had any erosion. 67.5% of dentists advised their patients about erosion only occasionally or rarely. Only 34.2% of the children had heard of tooth erosion and only 8.4% could recall their dentist mentioning the condition. 40% of children believed that the best way to avoid erosion was regular tooth brushing. CONCLUSION: The levels of awareness were low for both dentists and patients and the messages that were given by dentists were either forgotten or misunderstood by the children, or they were incorrect. Better communication and understanding is needed in this important area.

Orthodontic retention: why when and how?

Retention is normally required after active orthodontic tooth movement to hold the teeth in their new positions. This article reviews the principles of orthodontic retention and describes common retention regimes and appliances.