The feminisation of the orthodontic workforce.

OBJECTIVE: To describe the status and activity of women in the UK orthodontic workforce. DESIGN AND SETTING: Postal questionnaire based on the UK orthodontic workforce. SUBJECTS: All orthodontic providers in the UK. MATERIALS AND METHODS: A questionnaire was circulated to the total study population. The variables studied relating to sex were numbers, age, number of sessions worked, productivity, professional status and retirement intentions. RESULTS: The response rate was 72.7%. 31.4% of the participants were female. The average age of female providers was 42.7 (SE 0.48) years, who were on average 4 years younger than males. Sixty-six percent of specialist trainees are women and 34% men. 41.5% of male providers and 31.6% of female providers plan to retire in the next 15 years. The mean number of sessions worked by women was 7.2 (SE 0.1) and men 8.2 (SE 0.1). Women completed 24.2 (SE 1.9) cases per session and men 25.6 (SE 1.3). CONCLUSIONS: The orthodontic workforce is becoming increasingly feminised. The cumulative effect of more women completing fewer cases will mean that workforce planners will need to consider increasing numbers to allow for this feminisation.

An introduction to dento-legal issues and risks in orthodontics.

Orthodontic treatment is not without risk. This article aims to look at some of the dento-legal issues surrounding orthodontic treatment, the risks to both the clinician and the patient, and how some of these risks can be mitigated.

The orthodontic condition and treatment status of a sample of 14-year-old children in North Derbyshire.

In conjunction with a survey of the general dental health of 14-year-old children in North Derbyshire, an investigation was undertaken into their orthodontic condition and treatment status. It was found that approximately 60 per cent of children had not already received and were not scheduled for orthodontic treatment, but that many of these had abnormalities warranting orthodontic intervention. Girls were more likely than boys to receive orthodontic treatment, but children of socio-economic classes 1, 2 and 3N were not significantly more likely to receive treatment than were children of socio-economic classes 3M, 4 and 5.

Variations in the perceived need for orthodontic treatment in a sample of 14-year-old children in North Derbyshire.

The investigation explored the possibility that failure to present for orthodontic treatment might result from failure by the child or parent to recognise the existence of an irregular dentition, or to perceive an irregular dentition as a cause for concern. Although a previous investigation by the present authors revealed that a substantial number of the 14-year-old children who had not received and were not scheduled for treatment were in need of orthodontic intervention, use of the SCAN index showed that the great majority did not perceive themselves as having a markedly unattractive dental appearance. Furthermore, almost 86 per cent of the children who had not received and were not scheduled for orthodontic treatment declared themselves happy with their dental aesthetics, as did a similar proportion of their parents. On the other hand, a large majority of children scheduled for orthodontic treatment, together with their parents, reported themselves unhappy with the dental aesthetics.

The use of light-cured resin and orthodontic archwire to immobilise a transplanted maxillary canine.

A technique is presented which uses light-activated bonding materials and orthodontic archwire to immobilise a surgically transplanted impacted maxillary canine. The technique is quick and effective. It uses materials commonly available in the dental surgery and does not require technical laboratory support. The treatment result of the presented case is encouraging.

Differentiation of developmental and post-orthodontic white lesions using image analysis.

The aim of this study was to investigate differences in shape and size characteristics between developmental opacities and post-orthodontic white enamel lesions using computerized image analysis. Material, in the form of 35 mm slides, was obtained from the archive of photographic patient records in the orthodontic clinic at the Charles Clifford Dental Hospital. Images of 30 teeth with developmental white lesions and 30 teeth with post-orthodontic white lesions were selected using strict inclusion and exclusion criteria. The slides were converted to a digital format, coded, placed in a random order and analysed blindly using a computerized image analysis system by one clinician. After a 2 week interval, the images were recorded, placed in a new random order and the measurements repeated. The outcome measures were: area and luminance proportionality, and the shape of the perimeter line (expressed as the mathematical factor, roundness). Reproducibility was assessed by a paired samples t-test for systematic error and the intra-class correlation coefficient (ICC) for random error. Differences between groups were tested using the Mann-Whitney U-test for non-parametric data. Reproducibility was substantial for all measurements except for developmental white lesion roundness, which was moderate. There was a statistically significant difference between developmental white opacities and post-orthodontic white lesions for measurements of luminance intensity, proportionality (P = 0.002) and roundness (P = 0.001). Developmental white opacities had a higher luminance (i.e. were whiter) and the boundaries were more circular in shape than the post-orthodontic lesions. Roundness is a useful measure when distinguishing developmental and post-orthodontic demineralization.

The measurement of tooth whiteness by image analysis and spectrophotometry: a comparison.

Digital image capturing and analysis techniques have been used to measure the colour of teeth and to compare with spectrophotometric results and visual observations. A non-linear image analysis approach was developed and, for the colour range of human teeth, allows device-dependant digital camera colour data to be quantitatively transformed to Commission Internationale de l'Eclairage (CIE) colorimetric values. With reference to a CIE standard illuminant, two different lighting arrays have been used. For flat and non-translucent white and yellow surfaces, spectrophotometric results showed that this transformation achieves required accuracy. It was found, in all of the present studies, which included measurements on the VITA Lumin Vacuum shade guide and extracted teeth, that spectrophotometry invariably underestimated values of the CIE whiteness index. However, the results from these two types of measurement correlated well. There was also a reasonably good correlation between earlier data obtained by visual assessment and the present data by the two instrumental methods. For extracted teeth, both instrumental methods used in this work did not confirm a whitening effect for 2-min brushing with toothpaste, but did show significant whitening results for bleaching with 15% hydrogen peroxide.

Soft tissue profile changes following correction of class III malocclusions by mandibular surgery.

The relative movement of the soft and hard tissues were studied in 41 Class III cases treated by mandibular surgery. Lateral head films were traced and the hard and soft tissue changes were measured against vertical and horizontal reference lines. In 26 cases changes occurring more than 1 year after surgery were studied. It is concluded that the soft tissues move consistently slightly less than the underlying hard tissues and also that a change in form of the lips occurred. Prediction of profile changes by the cutting up of profile photographs is unlikely to given an accurate picture of the soft tissue profile response.

White lesions after orthodontic treatment: does low fluoride make a difference?

OBJECTIVE: To compare and measure the changes in size of post-orthodontic demineralized white lesion enamel lesions treated with a low fluoride (50 ppm) versus a non-fluoride mouthrinse/toothpaste regime. STUDY DESIGN: An experimental double-blind prospective randomized clinical controlled trial. SETTING: A university dental school orthodontic clinic (Sheffield, UK). PARTICIPANTS: Twenty-six patients identified as having post-orthodontic demineralized white lesions on removal of their fixed appliance. METHOD AND INTERVENTIONS: The participants were randomly and blindly assigned to either a low fluoride mouthrinse/toothpaste treatment regime or an inactive control. Computerized image analysis of calibrated photographic images taken under polarized light were used to measure the lesions. OUTCOME MEASURES: Lesion size and proportion (DWL%t) and percentage reduction (ADPR) at debond, and at 12 and 26 weeks later. RESULTS: Five participants dropped out of the study, 12 had the low fluoride regime and 9 did not. As a percentage of the total labial tooth area (DWL%t) the mean size of the lesions at debond was 8.1% (SD 3.7). After 12 weeks the mean size of lesion had reduced to 4.6% (SD 2.6), which was a significant reduction (p=0.03). After 26 weeks the mean size was 3.5% (SD 2.1), which was a very significant reduction (p<0.003). This confirmed statistically that post-orthodontic demineralized white lesions do reduce in size with time reflecting remineralization or other enamel surface changes. Intervention using a test low fluoride mouthrinse/toothpaste combination at 26 weeks showed an average difference percentage reduction (ADPR) of 54.3% (Upper 95% CI=62.08, Lower 95% CI=46.44%) compared with a non-active control combination, which showed an ADPR of 66.1% (Upper 95% CI=77.74, Lower 95% CI=54.51%). This failed to show any differences or therapeutic affect. CONCLUSIONS: Post-orthodontic demineralized white lesions reduced in size during the 6 months following treatment by approximately half the original size. There was no clinical advantage in using the low fluoride formulation of mouthrinse/toothpaste in this study.

The anchorage bend in the Begg technique.

The anchorage bend is an essential feature of the Begg technique. The factors which affect the degree of the anchorage bend include operator preferences as well as certain mechanical features of the case being treated. A test jig was constructed so as to be able to measure on the bench the intrusive forces developed by an anchorage bend over the six anterior teeth for a selection of different archwires. The amount of force developed was proportional to the degree of anchorage bend and also to the diameter of the archwire. The jig was modified in order to measure the frictional resistance to distal movement generated by the anchorage bend. The resistance was found to be greater than the usually quoted forces designed to slide the upper archwire distally. An oval tube was placed on to the test jig and doubled back archwires used. A reduction in intrusive force for a particular degree of anchorage bend was seen although frictional resistance was not affected when using doubled back archwires.

Thumb sucking habit and associated dental differences in one of monozygous twins.

A case report is presented of a set of monozygotic twins aged 14 years, one of whom sucked her thumb and one who did not indulge in the habit. The thumb sucker had a wider lower arch and a narrower upper arch than the non-thumb sucker. The thumb sucker also appeared to have a more forward position of her premaxilla on cephalometric analysis together with an increased overjet. Superimposed outlines of the tongue showed that the thumb sucker was adopting a lower position of the dorsum of the tongue at the time of initial examination.

The Consultant Orthodontists Group 1994 survey of the use of the Index of Orthodontic Treatment Need (IOTN).

A questionnaire, relating to the use and acceptance of occlusal indices and in particular the Index of Orthodontic Treatment Need (IOTN), was sent to all UK hospital consultants in the orthodontics. Of the respondents 74.6 per cent routinely recorded the Dental Health Component of IOTN for their new patient referrals. The reasons for the increased acceptance of the IOTN amongst hospital orthodontic consultants are evaluated and some of the difficulties in usage, reported by respondents, are discussed.

Combined surgical and orthodontic treatment of bilaterial double teeth: a case report.

A case of bilateral 'double teeth' is described. The patient, aged 8 at initial presentation, was unhappy with the appearance of his two abnormally large upper central incisor teeth. Endodontic treatment was carried out on both teeth followed by surgical splitting and the removal of half of each so as to leave two reasonably-shaped central incisors. Comprehensive orthodontic treatment was then carried out to align the teeth and reduce the overjet, following which the central incisors exhibited no increased mobility or any periodontal problems.

Changes in the axial inclinations of upper and lower incisors after mandibular surgery in class III cases.

Cephalometric radiographs of the position of upper and lower incisors following mandibular surgery only were undertaken in 31 cases. All cases were seen before and after treatment, and after all retention had ceased. Pre-treatment records revealed some compensation of the incisor angulation for the skeletal discrepancy, and post-operatively the upper incisors proclined further and the lower incisors remained unchanged.

Maxillary incisor root resorption in relation to the ectopic canine: a review of 26 patients.

A retrospective study of 26 patients with maxillary incisor root resorption relating to the presence of an ectopic canine was undertaken from case records. The group consisted of nine male and 17 female patients with a mean age of 12.5 years. There was a total of 35 resorbed teeth, 26 lateral and nine central incisors, and these were related to 32 ectopic canines. The resorption tended to be extensive, 30 teeth had pulpal involvement. In two-thirds of cases the pattern of resorption involved both apical and middle thirds of the root. Despite the extensive nature of the involvement there were few clinical signs and symptoms reported by patients. 43.8 per cent of canines were lying palatal to the arch, 18.7 per cent were in the line of the arch and 37.5 per cent were buccal. Significantly 15.6 per cent were buccal and erupted. The path of canine eruption was mesio-horizontal in 21 cases. No relationship could be found between resorption and the retention or loss of the deciduous canine. The canine root formation was virtually complete in 31 of the involved canines. The study indicated that the problem is often diagnosed late both in relation to the patient's age and the extent of resorption present. It is suggested that the problem may be underestimated by dental practitioners.

Maxillo-nasal dysplasia, Binder's syndrome: review of the literature and case report.

A 12-year-old girl with maxillo-nasal dysplasia (Binder's syndrome), featuring maxillary hypoplasia and relative mandibular prognathism, presented with a Class III incisal relationship. Her treatment was managed orthodontically. The principal features of the syndrome and management of these cases is discussed.

Reproducibility of quantitative measurement of white enamel demineralisation by image analysis.

The reproducibility of measuring artificial enamel white spot lesions from captured photographic images using computerised image analysis was assessed. Enamel lesions were induced on the buccal surface of 22 human teeth over periods of 3, 7 and 14 days. Standardised photographs were taken from above and below the occlusal plane. These were repeated after 2 weeks. The photographs were converted into TIFF images and mean grey scale levels of the areas of etched enamel were measured using computerised image analysis. Assessment of repeat readings of the same slide showed good reproducibility for photographs taken below the occlusal plane. The limits of agreement showed reasonable agreement between readings carried out on two slides of the same tooth. Capturing TIFF images via 35-mm film and measuring grey scale levels by computerised image analysis is a useful method of quantitative study of early enamel demineralisation. This may be developed for application in the clinical setting.

Non-completion of active orthodontic treatment.

Over a 1-year period, all patients attending a consultant orthodontist's new patient clinics in North Derbyshire and whose treatment plans involved active appliance treatment, were accepted into a prospective longitudinal study. In all 294 patients were included in the study. Subsequent to the consultant's new patient clinic the patients' active treatments were undertaken in the Hospital, General, or Community Dental Services. Four years after the commencement of the study, 207 patients had completed active treatment and 50 had non-completed during active treatment. This gave an overall non-completion rate (NCR) of 19.5 per cent for the study. Of the 50 patients who did not complete treatment during active treatment 23 (46 per cent) non-completed during the first 6 months of active treatment. A predictive model of non-completion of active orthodontic treatment (NCT) over time is suggested.

The Consultant Orthodontists Group survey of hospital waiting lists and treated cases.

A questionnaire sent to all U.K. hospital orthodontic consultants resulted in an 88 per cent response rate. The average waiting time for initial consultation was 31.6 weeks for routine cases and 3.6 weeks for urgent cases. The average waiting time for out patient treatment was 68.7 weeks for routine cases and 7.5 weeks for urgent cases. Nearly 33 per cent of hospitals used the Dental Health Component of the Index of Orthodontic Treatment need (IOTN) as a guide to placing patients on waiting lists. 'Urgency' and 'Complexity' were used more frequently than indices. Sixty-nine per cent of hospitals exclude some categories of malocclusion from treatment in their departments. A prospective survey reported on 2480 completed treatments over a six week period and there was an average discontinuation rate of 9.2 per cent of all cases finished during the period. Comparison of the completed and discontinued groups revealed few significant treatment-related factors. There was some evidence that the more senior and experienced the operator, the less the rate of discontinuation. A greater rate of discontinuation was seen in removable appliance cases when compared with fixed appliance cases.

Evaluation of soybean resistance to Phialophora gregata culture filtrate in tissue culture.

Resistance to the fungal pathogen, Phialophora gregata (Allington and Chamberlain) W. Gams, the cause of brown stem rot (BSR) in soybean [Glycine max (L.) Merr.], is an important trait for cultivars grown in the northern USA. A novel tissue culture method was developed where ten soybean cultivars were differentiated on the ability of their excised cotyledons to remain green and initiate callus in a tissue culture medium containing P. gregata culture filtrate. Cultivar BSR classifications by the cotyledon method corresponded to greenhouse root-dip assay classifications in 80%, 100%, and 90% of the three P. gregata isolate treatments. Another method, employing pieces of somatic callus exposed to the culture filtrate, had a 70% average correspondence to the greenhouse results. Physiologic specialization was demonstrated in parallel in vivo/in vitro assays for the first time. These data suggest that the cotyledon method would accurately identify soybean lines resistant to certain aberrant or wild-type P. gregata isolates.