bluuebunny/crossref_metadata_2025_split huggingface dataset:
Orthodontic Treatment in the General Dental Service Assessed by the Occlusal Index
Authors: Elderton R. J. , Clark J. D. 
Published: December 2014

As with all other aspects of health care, orthodontic treatment should be evaluated in as objective a manner as possible. In this study, the models of a sample of 256 patients treated by appliance therapy in the General Dental Service were examined. The Occlusal Index was first refined and variability in its use due to articulation and measurement errors was assessed. It was then used to quantify occlusal status both before and after treatment, and thereby monitor changes brought about by treatment. The mean Occlusal Index score at the beginning of treatment was 9·9. At the end of treatment, the mean score had dropped to 5·5. There was wide variation among individual cases, but some reduction was found in 88 per cent of instances. In 56 per cent of cases the reduction ranged up to 6 units, while in 29 per cent of cases the reduction was 6–12 units. However, in cases which started with a marked malocclusion, only about one-third showed a sizeable improvement. In about one-third of all cases there was little improvement in the malocclusion. While there is room for further refinement of the Occlusal Index to increase its usefulness in quantifying occlusal status brought about during orthodontic treatment, the present findings provide a basis for future comparisons.
A Comparison of Two- and Three-dimensional Incisor Angles
Authors: Richmond S. , Jones M. L. 
Published: December 2014

Two- and three-dimensional incisor angulations are compared in 40 patients using lateral radiographs and direct dental cast measurement using the Reflex Metrograph coupled to a computer. The two-dimensional upper and lower incisor angulations to the occlusal plane were also compared by the two methods. It was found that: 1. The two-dimensional radiographic and three-dimensional dental cast inter-incisor angulation showed a significant difference at a probability level 0·01> p>0·001. 2. The two-dimensional radiographic and two-dimensional dental cast upper left and right incisor angulations to the functional occlusal plane showed a significant difference at a probability level of 0·01> p>0·001. The significant differences can be attributed to the measurement of the incisor crown angulation in the dental cast measurement and the incisor tip and apex assessment in the radiographic technique. The system of dental cast measurement arguably provides a more realistic and reliable assessment of incisal angles than conventional radiographic measurement techniques.
A Functional Appliance System for the Correction of Class II Relationships
Authors: Trenouth M. J. 
Published: December 2014

A technique is described for the correction of Class II malocclusion involving a functional appliance and consisting of three phases. 1. Adjustment of posterior arch width and dental alignment, using semi-rapid maxillary expansion by means of an upper removable appliance, to co-ordinate the anticipated positions for the arches. 2. Correction of the Class II dental relationships using a modification of the twin-block functional appliance. 3. Retention, using an upper removable appliance with a very steep anterior bite plane. The technique is illustrated by a case report.
Post-orthodontic Splinting of Periodontally-involved Teeth
Authors: Saravanamuttu R. 
Published: December 2014

Shortcomings of techniques presently available for the stabilization of periodontally-involved teeth following orthodontic therapy are discussed. The rationale for rigid fixation of such teeth is questioned in the light of modern concepts of tooth mobility. An inexpensive technique of tooth stabilization based on wire and composite resin is described. The technique permits fixation allowing for individual periodontal adjustment, yet with minimal interference with tooth structure and the occlusion.
A Cephalometric Study to Compare the Effects of Cervical Traction and Andresen Therapy in the Treatment of Class II Division 1 Malocclusion: Part 1—Skeletal Changes
Authors: Derringer Kathryn 
Published: December 2014

Lateral cephalometric radiographs at the beginning of treatment, end of active treatment, and post-treatment of 30 Andresen and 40 cervical traction patients were analysed, and compared with those of a control group of 22 untreated cases. The cervical traction group was divided into a non-extraction group and an extraction of maxillary second molars group. A clinically significant reduction of ANB was achieved, mainly by mandibular changes in the Andresen group and by maxillary changes in the cervical traction groups. Cervical traction was associated with a small distal positioning and anterior downward tipping of the maxilla during treatment. A more favourable sagittal position of the mandible was achieved in the Andresen group compared to the cervical traction groups, particularly the non-extraction group, where a greater transient backward rotation of the mandible occurred during treatment. A significant, but clinically small increase in mandibular body length occurred in Andresen patients compared to the control. However, in both treatment groups this was due to an increase in growth of the vertical ramus. The lower face heights, both anterior and posterior, increased in all groups, with the anterior upper face height also increasing in the cervical traction group.
A Comparison of Orthodontic Treatment Changes as Measured from Study Casts and Cephalometric Radiographs
Authors: Jones M. L. 
Published: December 2014

Orthodontic treatment change was examined for 106 consecutively referred patients using serial lateral cephalometric radiographs and study cast records. The 2-D and 3-D measurement systems used to assess the changes were compared for five variables common to both sets of records. No statistical differences were found between the study cast and radiographic records for these variables. The 3-D measurement with the Reflex Metrograph showed marginally better precision in the measurement of the treatment changes examined. However, the main advantage was that it allowed a more thorough and accurate assessment of both individual incisor position and measurement error.
An Investigation into the Effect of a Fluoride Releasing Adhesive on the Prevalence of Enamel Surface Changes Associated with Directly Bonded Orthodontic Attachments
Authors: Mitchell L. 
Published: December 2014

Despite careful patient selection, decalcification still remains a problem during fixed orthodontic treatment. The advantages of a method of delivering fluoride to the area of the tooth most at risk, which does not rely on patient compliance, makes a fluoride releasing bonding adhesive desirable. The aims of this study were to investigate the potential of a fluoride releasing bonding material for preventing decalcification and to monitor its efficacy at retaining orthodontic brackets. In order to carry out the first part of the study it was necessary to devise a reproducible and sensitive method of recording the extent and severity of any decalcification. A photographic technique which fulfils these criteria is described.
Storage of Orthodontic Study Models in Hospital Units in the U.K.
Authors: McGuinness Niall J. , Stephens Christopher D. 
Published: December 2014

Orthodontic study models form an essential part of the dental records of patients undergoing diagnosis and treatment. In order to ascertain the problems encountered by hospital orthodontic units in the utilization and storage of study models, a questionnaire was circulated in February 1991 to members of the Consultant Orthodontists Group. All respondents took pretreatment study models, while 9 per cent took their final study models at some time other than the end of active treatment; 85·5 per cent of respondents stored their study models in their units, but most were beginning to experience difficulties in this regard. There was a wide range for storage times, and only 10 per cent of employing authorities had a stated policy on the storage of study models. There was a highly significant difference (P&z.Ltc;0·001) between the time that models are stored at present, and the desired storage times. Most respondents appeared to be rather uncertain about the precise medico-legal requirements concerning model storage. The implications for audit and medico-legal matters are discussed in the light of these findings.
An Easy Approach to Edgewise—The Progressive Light Wire Edgewise Technique of Ricketts
Authors: Senior Winston B. 
Published: December 2014

In this, the first of a three part article for the British Journal of Orthodontics, the author gives an illustrated history of the edgewise mechanism. He describes it, as it was used by the inventor 40 years ago, and explains why and how the edgewise appliance has been modified. He explains why, to the European seeing for the first time American edgewise orthodontic practices in the 1970s, there seem to be so many variations of the appliance in use. He brings the story of the edgewise mechanism up to date with a description of the Progressive Light Wire Edgewise (Bioprogressive) technique of Ricketts. This is the form of edgewise which the author has adopted in his own practice. He attempts, in Part I, to show why he believes that with a British training and experience in Watkin, twin wire arch, and some knowledge of Begg, it is easy, enjoyable and beneficial to convert to the Progressive Light Edgewise technique.
Personal Audit in Orthodontics
Authors: Richmond Stephen 
Published: December 2014

The use of different criteria to assess outcome of orthodontic treatment makes it difficult to compare treatment from one individual practitioner to the next. This article describes a method for all dentists to use to record outcome for self-audit purposes. A sample of 51 consecutively treated patients was assessed. On average, the mean percentage reduction in PAR score was 74 per cent. Eight per cent of patients were categorized as ‘Worse or no different’, 39 per cent ‘Improved’, and 53 per cent ‘Greatly improved’. To achieve a good standard of orthodontic treatment it is proposed that the mean percentage reduction in PAR score should be greater than 70 per cent. The proportion of patients falling in to the ‘Worse or no different’ category should ideally be less than 5 per cent.
An Investigation into the Response of Palatally Displaced Canines to the Removal of Deciduous Canines and an Assessment of Factors Contributing to Favourable Eruption
Authors: Power Susan M. , Short Mary B. E. 
Published: December 2014

The effect of the removal of deciduous canines on palatally displaced maxillary canines was assessed and factors contributing to a successful outcome were analysed. Thirty-nine consecutive patients of mean age 11·2 years (standard deviation 1·43), with 47 palatalfy displaced canines were included in the study. The cases were examined clinically and radiographically for a maximum period of 2 years following deciduous canine removal. Twenty-nine (62 per cent) of the 47 ectopic canines achieved a normal eruptive position and nine (19 per cent) showed some improvement in eruptive position. The outcome of the removal of the deciduous canine depended on the position of the permanent canine. Horizontal overlap of the nearest incisor was found to be the most significant factor. If this exceeded half the tooth width, success was unlikely. The presence of crowding was found to affect adversely the favourable eruption of the canine. Discriminant analysis was carried out to try to identify clinical features which could act as prognostic indicators for the outcome of deciduous canine removal.
The Clinical Evaluation of a Fluoride-containing Orthodontic Bonding Material
Authors: Turner P. J. 
Published: December 2014

A clinical trial comparing a conventional adhesive, Concise®, with a new fluoride-containing composite cement is described. The bond failure rate, plaque score, gingival health, and enamel decalcification were assessed for each material after a minimum period of 1 year. The preliminary results show no significant difference between the two materials for each of the variables examined, although there was a reduction in the number of white spot lesions using the fluoride-containing composite. The level of fluoride ion concentration required to inhibit the growth of oral micro-organisms is discussed.
A Comparative Study of the Shear Bond Strengths of Four Different Crystal Growth Solutions
Authors: Jones M. L. , Pizarro K. A. 
Published: December 2014

Previously, solutions based on polyacrylic acid have been found to initiate crystal growth on the enamel surface. Such crystals have been proposed as being suitable for the attachment of orthodontic brackets via a conventional composite interface, the advantages being improved clean-up characteristics and reduced damage to the enamel. In order to try and improve the reliability of the technique this base solution has been modified by the authors, by the addition of various ionic salts. The strength of the resultant bond was assessed for the base solution of 50 per cent polyacrylic acid and concentrated sulphuric acid, and for three more solutions modified by the addition of the sulphates of lithium, magnesium, and potassium, respectively. A standard acid/etch method of bracket attachment was also included for the purposes of comparison. The bond strength of each material was assessed by shear testing, performed on human extracted premolar teeth to a standard method. As might have been expected the acid/etch system proved to be the strongest method of bonding brackets. Amongst the crystal solutions, the addition of lithium sulphate provided the highest mean shear strength at 80 per cent of that for acid etch. Therefore, this latter solution provides the most potential for development in the future.
Orthodontic Rare Earth Magnets—In Vitro Assessment of Cytotoxicity
Authors: Bondemark Lars , Kurol Jüri , Wennberg Alf 
Published: December 2014

The aim of this study was to assess and compare in vitro the cytotoxic effects of uncoated and parylene-coated rare earth magnets, used in orthodontics. Cytotoxicity of samarium-cobalt magnets (SmCo5 and Sm2Co17) and neodymium-iron-boron magnets (Nd2Fe14B) was assessed by two in vitro methods, the millipore filter method and an extraction method. Orthodontic stainless steel brackets served as controls. Uncoated SmCo5-magnets showed high cytotoxicity while uncoated Sm2Co17-magnets demonstrated moderate cytotoxicity. Uncoated neodymium-iron-boron magnets, as well as parylene coated Sm2Co17-magnets and parylene-coated neodymium-iron-boron magnets, showed negligible cytotoxicity. Short-term exposure to a static magnetic field did not cause any cytotoxic effect on the cells.
A Study to Compare the Effects of Simulated Torquing Forces on Pre-adjusted Orthodontic Brackets
Authors: McKnight M. M. , Jones S. P. , Davies E. H. 
Published: December 2014

The transmission of torquing forces between three types of pre-adjusted bracket was investigated. 0·022-inch Roth prescription ‘A’-Company® (stain less steel), Silkon® (reinforced polycarbonate), and Allure III® (polycrystalline ceramic) brackets were used. A selection of stainless steel archwires were chosen, 0·018 × 0·025, 0·019 × 0·025, and 0·021 × 0·025 inch. The brackets were torqued with respect to the archwire and force v. angular deflection was recorded on an Instron machine. The dimension of angular change was in part dependent on the ability of the bracket to elastically or plastically deform. There were no significant differences between bracket types with the 0·018 × 0·025-inch archwire. ‘A’-Company® brackets demonstrated a significantly lower resistance to loading compared to Silkon® brackets in the 0·019 × 0·025-inch group. The greatest amount of distortion was seen in Silkon® brackets with an 0·021 × 0·025-inch archwire. Allure III® brackets demonstrated the greatest resistance to loading in all groups. As no apparent distortion under loading is seen in Allure III® brackets, it is assumed that the load is largely transmitted to the tooth. Full thickness stainless steel rectangular wires should be avoided with these brackets, in order to prevent overloading.
Stability of the Lower Labial Segment following Orthodontic Treatment—A Comparison of Treatment with Andresen and Begg Appliances
Authors: Sims A. P. T. , Springate S. D. 
Published: December 2014

This retrospective cephalometric study of Class II division 1 malocclusions investigates the effects on the lower labial segment of two form of orthodontic treatment. Non-extraction Andresen myofunctional therapy and first premolar extraction Begg treatment are compared to the lower incisor changes found in appropriate non-extraction and first premolar extraction control groups, which also presented with Class II division 1 malocclusions. Using four angular and two linear measurements, the lower labial segment was found to procline during Andresen therapy (1–2 degrees, 1–2 mm), and on withdrawal of the appliance it retroclined by about one-half of the in-treatment proclination (0.4–0.8 degrees, 0.1–0.5 mm). During extraction Begg mechanics, the lower incisors were found to retrocline (1.3–1.5 degrees, 0.4–0.9 mm), and they continued to retrocline following removal of the appliance (0.2–3.0 degrees, 0.8–1.1 mm). In general, the variables used to measure lower incisor position demonstrated only very small changes, and were near method error. The reliability of these changes are discussed. It is considered that the axial inclination of the lower incisor in relation to the mandibular plane is the most consistent and therefore still the most useful clinical measurement of lower incisor change available from cephalometric radiographs.
An Investigation to Estimate the Flouride Uptake Adjacent to a Fluoride-releasing Bonging Agent
Authors: Chadwick S. M. , Gordon P. H. 
Published: December 2014

Decalcification of the teeth remains a problem during orthodontic treatment with fixed appliances. It has been suggested that bonding agents which release fluoride could supply it to the area of the tooth most at risk from decalcification. The aim of this study was to estimate uptake by enamel adjacent to a fluoride releasing bonding agent. Acid etch biopsies were used to estimate the concentration of fluoride in enamel adjacent to brackets bonded with Vitrabond® and Geristore®. Results indicate that there was a significant increase in the concentration of fluoride in enamel adjacent to Vitrabond®. The clinical significance of the increase in the concentration of fluoride adjacent to Vitrabond® and the mechanism by which fluoride moves from the material into the enamel remain unclear.
Long-term Effects of the Herbst Appliance on the Dental Arches and Arch Relationships: A Biometric Study
Authors: Hansen Ken , Iemamnueisuk Pannamas , Pancherz Hans 
Published: December 2014

The purpose of this study was to evaluate biometrically the treatment and post-treatment effects of the Herbst appliance on the dental arches and arch relationships. The sample consisted of 53 Class II, division 1 malocclusion patients (33 boys and 20 girls) treated with the Herbst appliance. The mean age of the patients before treatment was 12·5 years (SD = 1·2 years). Dental casts were analysed before treatment, after treatment, 6 months post-treatment and at the end of the growth period (5–10 years post-treatment). The following variables were assessed: sagittal molar and canine relationships, overjet, overbite, maxillary and mandibular arch perimeters, and inter-molar and inter-canine dental arch widths. During treatment, the overjet, overbite, and sagittal molar relationship were overcorrected in most of the cases, while the sagittal canine relationship was normalized. The maxillary and mandibular arch perimeters increased during treatment, as did dental arch widths (moral and canine). In the long-term (mean = 6·7 years after treatment), Herbst appliance treatment resulted in a normal or over-corrected sagittal molar relationship in 79 per cent and a normal canine relationship in 68 per cent of the cases. Eighty-three per cent of the subjects has an overjet of 4·5 mm or less. In the long-term, the arch perimeters seemed to follow a normal dental development pattern. The increase of the upper molar and canine dental arch widths during treatment remained virtually stable whilst the lower intermolar arch widths seemed unaffected by treatment.
A Technique for the Computerized Identification of Orthodontic Instruments
Authors: Jones Malcolm L. , Shepherd Jonathan P. , Brickley Mark R. 
Published: December 2014

Increasingly, orthodontic instruments must leave the chair side or even the clinic in order to facilitate adequate sterilization. The tray system employed in an orthodontic clinic is outlined. Inevitably, there are problems with instruments being lost from these trays and finding some method for individual ‘tagging’, which is also resistant to autoclaving, would be a useful facility. To address this problem a robust procedure of automatic instrument identification, similar to bar coding, has been deployed. This system, termed matrix coding, not only facilitates easy instrument identification, but also allows every episode of clinical use and sterilization to be recorded. By such a method it could become possible to quickly establish when instruments are likely to require servicing, sharpening or replacement.
The Assessment of Crowding without the Need to Record Arch Perimeter. Part II: Crowded and Irregular Arches
Authors: Battagel Joanna M. , Johal A. S. , Crow V. P. 
Published: December 2014

A mathematically determined technique which seemed to be valid for the calculation of crowding and spacing in arches with acceptable alignment, was tested on a series of arches with varying degrees of crowding and irregularity. Upper and lower study casts of 30 individuals with sufficient malalignment and crowding to warrant orthodontic treatment with fixed appliances were examined. Models were measured by three operators, using a reflex microscope interfaced to an IBM compatible PC and a customized calculation program. The degree ofcrowdmg was compared with a ‘clinical’ assessment of each arch, in which the irregularity was measured directly using a steel ruler. Both the computer calculated and clinical values varied between observers, but the agreement between observers was better using the reflex microscope. Correlation coefficients ranged from 0·92 to 0·96 for the reflex microscope, and between 0·86 and 0·91 for the clinical assessment. Inter-observer agreement for the three operators was high: 0·93 for the reflex microscope and 0·87 where a ruler was used. This suggests that the computer program used to calculate the crowding was valid for the crowded arches under consideration.
Direct Bonding of Orthodontic Brackets—a Comparative Study of Adhesives
Authors: Reynolds I. R. , von Fraunhofer J. A. 
Published: December 2014

Various materials are currently available to orthodontists for use as adhesives in the direct bonding of orthodontic brackets to teeth. In this comparative study three factors have been examined, namely the tensile bond strength of suitable adhesives in orthodontic bracket—adhesive—human enamel combinations, the effect of water immersion on the bond strength and the effect of the acid etchant on the bond strength. This work should give the practitioner an indication of the clinical merits of some of these materials.