bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Prevalence and Severity of Malocclusion and the Need for Orthodontic Treatment in 9-, 12-, and 15-year-old Glasgow Schoolchildren
Authors: Hill Peter A. 
Published: December 2014

An epidemiological investigation involving 765 Glasgow schoolchildren aged nine, twelve, and fifteen years was undertaken to assess the severity of malocclusion, the need for Orthodontic treatment, and the proportion of children in each age group who had previously received treatment. An index termed the Malocclusion Severity Index (MSI) was developed to establish objectively the severity of malocclusion in each individual. Fifty sets of orthodontic study models and six Orthodontics assessed the reproducibility and validity of the index. Although there was a significant reduction in the proportion of children in need of Orthodontic treatment between 9 and 15 years of age, a considerable number were still in need of treatment; crowding of their dentitions being responsible for the majority of the treatment requirement. The MSI was found to be as precise and valid as previously developed occlusal indices, for estimating the treatment needs of sample populations.
An Easy Approach to Edgewise—The Progressive Light Wire Edgewise Technique of Ricketts—Part II
Authors: Senior Winston B. 
Published: December 2014

In the first part of this short series of articles the author viewed the history of the edgewise mechanism through the eyes of a European trained orthodontist. He brought the story of the edgewise mechanism up-to-date with a description of the progressive light wire edgewise (bio-progressive) technique of Ricketts, which he has adopted and adapted to his own practice. In Part II he continues to compare and contrast the modern edgewise technique he is using with the advanages and disadvantages of other techniques more commonly used in Britain today. The treatment of three cases is described with photographic and line illustrations. These show the basic principles upon which the Progressive light edgewise technique of Ricketts is based.
Changes in Tooth Position and Vertical Dimension in Severe Class II Division 1 Cases during Begg Treatment
Authors: Menezes D. M. 
Published: December 2014

This study was based on a cephalometric analysis of 45 children composed of two groups: a treated group with an Angle Class II division 1 occlusion and an untreated control group. The object of this study was to investigate changes in the dentofacial complex as a result of Begg therapy in the group of children having an Angle Class II division 1 occlusion compared with the untreated control group. Each child of the treated group had lateral skull radiographs taken during the experimental period: one before commencement of treatment, the second at the end of the first stage of treatment; that is as soon as the incisors reached an edge-to-edge relationship; and the third at the end of treatment 12 months after appliances were removed. Two lateral skull radiographs were taken of the children who formed the control group, one at the beginning, and the other at the end, of the experimental period. It was found that short term changes in the dento-facial complex during Begg treatment were associated with a significant increase in the height of the lower molars, a significant reduction in the height of the lower incisors and a significant reduction in apical base difference. The long term changes in the dentofacial complex as a result of Begg treatment were associated with a significant increase in the height of the lower molars, a significant reduction in apical base difference and some increase in lower facial height.
The Lower Lip Position and Incisor Overjet
Authors: Haynes Sydney 
Published: December 2014

1147 children aged 11–12 years were examined to determine the mean overjet values relative to five defined postural lower lip/maxillary central incisor relationships. A mean overjet of 3·025 mm was found in those children having a postural lower lip position related to the middle third of the maxillary central incisor; and those having no lower lip cover had a mean overjet of 4·26 mm. In contrast, the mean overjet value was 9·18 mm for those children having a “negative” lip position. The observed differences between the mean overjet values relative to each lower lip position are statistically significant, but the only lower lip/maxillary central incisor relationship which appears to have any marked clinical significance is the one defined as—1 (i.e. the trapped lower lip).
The Retroclined Upper Incisor
Authors: Fletcher G. G. T. 
Published: December 2014

In the interest of further clarification of the interaction of the multiple causative factors of upper incisor retroclination, the development of Class II Division 2 occlusion is contrasted to that of Class I. The patients whose records were used had not received orthodontic treatment. It was found that upper incisor retroclination in Class II Division 2 occurred after their emergence into the oral cavity. The effect is attributed to the upper incisors being able to erupt well within the cover of the lower lip through a combination of circumstances related to the proportional balance of the patient's facial structures in the vertical dimension. The lower lip would guide the upper incisors into retroclined positions, only if the latter were unobstructed by digit, tongue or other teeth of either arch. This implied not only a critical balance in size and relationship of the facial structures in the vertical dimension but also equally critical balances in the antero-posterior and lateral dimensions, without which the lower lip factor alone would be ineffective.
The Influence of Bracket Material, Ligation Force and Wear on Frictional Resistance of Orthodontic Brackets
Authors: Keith O. , Jones S. P. , Davies E. H. 
Published: December 2014

Planar static frictional phenomena were investigated for two types of ceramic and one type of stainless steel orthodontic bracket against rectangular stainless steel archwire. The brackets studied were ‘Starfire’ (single crystal aluminium oxide), ‘Allure III’ (polycrystalline aluminium oxide), and ‘Dentaurum’ (stainless steel). The investigative parameters were: bracket material, force of ligation and whether the brackets were new or ‘worn’. Without exception, both types of ceramic bracket produced greater frictional resistance than the stainless steel brackets throughout testing. At a ligation force of 500 g, the Starfire bracket gave the greatest frictional resistance. At ligation forces of 200 and 50 g, the greatest frictional resistance was seen with Allure III. After a period of simulated wear, frictional resistance of Starfire tended to increase at the greatest ligation load while that of both ceramics decreased slightly at the two lower ligation loads. The ceramic brackets caused abrasive wear of the archwire surfaces and the consequent wear debris may have contributed to the changes in frictional resistance seen with Starfire and Allure III. Dentaurm brackets produced minimal frictional resistance in any test and negligible change with wear.
The Role of Sandblasting on the Retention of Metallic Brackets Applied with Glass Ionomer Cement
Authors: Millett D. , McCabe J. F. , Gordon P. H. 
Published: December 2014

A laboratory investigation of the shear and strength of stainless steel brackets applied with glass ionomer cement (Ketac-Cem®) and a conventional adhesive (Right-on®) is described. Sandblasting of the bracket base was undertaken in half of the sample bonded with Ketac-Cem and produced a significant reduction in the probability of failure relative to the unsandblasted sample. Brackets with sandblasted and unsandblasted bases, bonded with Ketac-Cem were subjected to mechanical fatigue in a ball mill for a total of 20 hours. Mean survival time (MST) was then calculated for each group and was found to be significantly improved by sandblasting of the bracket base (P <0·01).
Identification of the Relapsing Class III Face: Chernoff Faces in Orthodontics
Authors: Battagel Joanna M. 
Published: December 2014

Thirty Class III patients, treated by a standard non-extraction technique, provided the material for this study. Records were examined at the beginning of treatment and a minimum of 2 years out of all retention. On the basis of their post-retention occlusions, children were sub-divided into three groups: stable, borderline, and relapsed. Using this classification, a four-variable discriminant model had been generated which correctly indicated the eventual Outcome from the pretreatment data. A graphical technique not previously described in orthodontics and suitable for displaying multivariate data: ‘Chernoff faces’, provided a pictorial illustration of the discriminant values for each individual. These stylized, cartoon faces were examined to determine whether any common, characteristic facial patterns existed at the beginning of treatment in children of a single outcome group. Whilst the information given by the faces was easier to assimilate than tabulated data, no typical stable or relapsing face could be identified using the features chosen. The reason for this and further possible applications of Chernoff faces to orthodontics are discussed.
The Aetiology of Class III Malocclusion Examined by Tensor Analysis
Authors: Battagel J. M. 
Published: December 2014

This study compares and contrasts the differences in facial pattern between groups of young people, employing a modified tensor analysis. One-hundred-and-thirty-eight children with Class III malocclusions were compared with 105 control individuals of similar ages: 126 subjects were prepubertal (age range 7 to 10 years), whilst the remaining 117 were between 15 and 22 years of age. Males and females were examined separately. The tensor analysis permitted the computation of differences in form (that is in size and shape) without specifically measuring either. Mean values for 18 conventional cephalometric landmarks were determined for each sub-group of control and Class III individuals. Customized programs were developed to assess the differences between 23 triads of points between the two occlusal groups.
Facial Aesthetics following Edgewise and Fränkel Appliance Therapy: The Application of Chernoff Faces
Authors: Battagel Joanna M. , Battagel N. J. 
Published: December 2014

This study investigates an application of the graphical technique of multivariate data description, ‘Chernoff faces’, to orthodontics. This method of pictorial presentation allows the simultaneous examination of several measurements in a single figure. Each variable is represented by a scaled feature of the human face: the size and position of the ears, eyes, eyebrows, nose, and mouth, as well as the face itself, are used to display data in a diagrammatic form. Using this method, the individual post-treatment results of 62 severe Class II division 1 cases treated by either Fränkel or Edgewise appliance therapy were compared. Nine cephalometric variables were chosen, describing the profile and the antero-posterior positions of the lower jaw and teeth, and stylized cartoon faces drawn for each child. These were compared with a control face prepared from untreated children of the same sex and age. Overall, children treated with Fränkel appliances showed a more normal relationship of the lips to Ricketts' aesthetic line and a greater prominence of the lower face. This difference between the two groups was most marked in the soft tissues. In a few cases, however, the appearance of the Edgewise treated children was indistinguishable from that of the controls. It is concluded that Chernoff faces, by portraying several pertinent aspects of data simultaneously, may be a useful adjunct to the presentation of orthodontic findings.
Extracranial versus Intracranial References in Individual Cephalometric Analysis
Authors: Özbek M. Murat , Köklü A Yşegül 
Published: December 2014

This study was undertaken to determine whether angles SNA and ANB genuinely represent both the degree of maxillary prognathism and the intermaxillary relationship in natural head position (NHP). Pearson's r correlation coefficients were used to assess the associations between these angles, and variables based on NHP and extracranial reference lines. A large sample (n=106) was used, comprising subjects with a variety of facial patterns. This was also divided into subgroups comprising subjects with similar facial configurations, determined by natural head position parameters. For the subgroups, SNA and ANB were not associated with the variables based on. NHP, and showed high variations in subjects with similar facial patterns. SNA also showed statistically significant and high correlation with the inclination of the NSL to the true vertical.
A Comparison of the Forces Required to Produce Tooth Movement ex vivo through Three Types of Pre-adjusted Brackets When Subjected to Determined Tip or Torque Values
Authors: Sims A. P. T. , Waters N. E. , Birnie D. J. 
Published: December 2014

Friction in fixed appliance systems has received considerable attention in recent literature, although that attributable to varying second order (tip) and third order (torque) adjustments in either the bracket or the archwire has not been fully investigated. The ex vivo study of 0·022 × 0·028-inch slot Minitwin®, Activa®, and Standard Straight Wire® brackets investigates friction when known values of tip or torque were applied to 0·018 × 0·025-inch stainless steel wires. The resistance to sliding of the wire through the ligated brackets was measured on a vertically-mounted Instron testing machine. The results showed that the self-ligating Activa® brackets consistently produced less friction than the other conventionally tied brackets. Minitwin® brackets were slightly more resistant to movement than the Standard® brackets during torquing, but the converse was found when tip was applied. Increasing tip and torque (ranges tested 0–6 degrees and 0–25 degrees, respectively) produced almost linear increases in friction for all brackets, although increasing tip had the more profound effect on friction, particularly in Activa brackets.
Late Lower Arch Crowding: The Role of Differential Horizontal Growth
Authors: Richardson Margaret E. 
Published: December 2014

Eighty-five subjects, recorded soon after eruption of second permanent molars, were followed longitudinally for 3 or 4 years. Correlation and multiple regression analyses were used to examine the relationship between the change in lower arch space condition and (1) the horizontal component of the change in position of various points on or near the anterior borders of the maxilla and mandible, (2) the differential horizontal-vertical change in these points and (3) differences in horizontal change between maxillary and mandibular, and between intramandibular points. No significant differences in amount or direction of growth were found between the maxillary and mandibular teeth or jaws. Pogonion changed more in a horizontal direction than B point. Increased lower arch crowding was weakly associated with differential horizontal growth of the teeth and jaws. Reduced horizontal growth and greater vertical as opposed to horizontal growth of the maxilla and teeth, and increased growth of the mandibular base were to some extent related to the crowding increase.
The Incidence of Cleft Lip and Palate in Northern Ireland from 1980–1990
Authors: Gregg Terry , Boyd Dorothy , Richardson Andrew 
Published: December 2014

This study reports the incidence of the various types of cleft lip and/or palate drawn from a regional database of all affected children born in Northern Ireland during the period 1980–1990. The incidence of these anomalies was 1·28 per 1000 live births (1:781). Fifty-three per cent of clefts involved the secondary palate only, 16 per cent the primary palate only, 26 per cent involved both primary and secondary palate, and 5 per cent were unconnected. Overall, more males than females were affected and there were more males than females in the group having complete clefts. Separate clefts of lip and palate occurred exclusively in males with only one exception. Unilateral clefts were more common on the left side. Within the group showing complete unilateral cleft of the primary and secondary palate, left-sided clefts were more commonly male, right-sided clefts were more commonly female. There were no statistically significant sex differences between sides in the unilateral primary palate cleft group.
An Investigation into the Fluoride Release of a Variety of Orthodontic Bonding Agents
Authors: Chadwick S. M. , Gordon P. H. H. 
Published: December 2014

The purpose of this study was to compare the fluoride release from a variety of orthodontic bonding agents, Fluoride release into de-ionized water was measured over a 20-week period. Material based on the fluoride exchange resin was also tested in a saline solution. Fluoride release from a variety of orthodontic bonding agent was compared and the amount of release found to be highly variable. Glass ionomer-based materials showed substantially greater fluoride release when compared with resin-based materials. The presence of anions (Cl−) did not improve the release from fluoride exchange resin. Glass ionomer/resin hybrid material (Vitrabond®) released the greatest amount of fluoride.
The Consultant Orthodontists Group Survey of Hospital Waiting Lists and Treated Cases
Authors: Willmot D. R. , Dibiase D. , Birnie D. J. , Heesterman R. A. 
Published: December 2014

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.
An Evaluation of the Views of General Dental Practitioners who have Participated in an Extended Orthodontic Training Scheme
Authors: Power S. M. , Hodgkins J. F. W. , Stephen C. D. 
Published: December 2014

A questionnaire was sent to 255 dental practitioners who had participated in an extended orthodontic training scheme, incorporating formal teaching and supervised clinical sessions over a period of not less than 24 months. The response of the practitioners was good; 78 per cent of the forms returned were suitable for analysis. Overall, the practitioner responded favourably to the schemes and felt that they had been of benefit to their clinical practice. The majority undertook more orthodontic treatment as a result and on average, fixed appliances were used in half of these treatments.
Dental Hygienists in Australia and their Employment in Orthodontic Practice
Authors: Wexler Geoffrey 
Published: December 2014

Dental hygienists are the designated dental auxiliary of the future in Australia. This article explains how their duties came into existence and why their duties in orthodontic practice seem limited in some instances. Dental hygienists, a class of operating dental auxiliaries, work in Australian orthodontic practices, but their employment is not widespread. The ratio of hygienists to dentists is reported to be 1:40 in Australia and 1:10 in South Australia (Pash, personal communication).
The Effects of Sandblasting on the Retention of First Molar Orthodontic Bands Cemented with Glass Ionomer Cement
Authors: Millett D. T. , McCabe J.F. , Bennett T. G. , Carter N. E. , Gordon P. H. 
Published: December 2014

This study examined the effect of sandblasting, in vitro, on the bond strength and survival time of first molar orthodontic bands. Survival time was assessed following simulated mechanical fatigue in a ball mill. The amount of cement left attached to the band after debanding was also assessed. In addition, the effect of sandblasting on the failure rate of 320 first molar bands cemented in 107 patients was examined in a half-mouth trail. Ketac-cem®, mixed according, to manufacturers' instructions was used as the luting agent for both laboratory and clinical trails. In vitro, sandblasting increased bond strength by 27 per cent (P<·01) and produced a three-fold increase in the median survival time relative to the untreated sample (P<0·001) in the ball mill experiment. Sandblasting resulted in more cement remaining on the band rather than on the tooth enamel after band removal. in vivo, sandblasting reduced the clinical failure rate of the first molar bands (P<0·001).
A Report on the Hazards Encountered When Taking Neonatal Cleft Palate Impressions (1983–1992)
Authors: Chate R. A. C. 
Published: December 2014

A questionnaire was sent to 193 United Kingdom Hospital Consultant Orthodontists, in order to survey their individual involvement and clinical protocols for neonatal cleft palate impressions. Information regarding any untoward events that might have been experienced with this procedure during the period 1983–1992 was sought. Sixteen episodes where withdrawal of an impression had been extremely difficult and five respiratory obstructions due to an impression fragment were reported. Eighty-nine cyanotic events were reported, of which four resulted in asphyxiation, although none progressed to a fatality. Factors such as the level of consultants' experience or the choice of impression material used did not appear to be contributory.
An Ex Vivo Study of Self-, Light-, and Dual-cured Composites for Orthodontic Bonding
Authors: Sargison Anne E. , McCabe John , Gordon Peter H. 
Published: December 2014

It was postulated that using a dual-cured composite to bond orthodontic brackets could result in bond strengths comparable with those of chemically-activated materials and higher than those for light-activated materials. The shear bond strength of four composite resins used to attach mesh-backed orthodontic brackets was measured at 24 hours and following mechanical insult in the ball-mill. Analysis of variance and an SNK range test showed that at 24 hours Dual-cured Porcelite® gave a significantly higher mean bond strength than the other materials (P<0·05). However, following ball-milling the mean bond strength for Right-on® was apparently significantly higher than that of the other materials. (P<0·05). In this study, the mode of bond failure is also analysed and the use of Weibull analysis in bond strength testing is described.