UWCScholar :: Browsing by Author "Harris, Angela"

Browsing by Author "Harris, Angela"

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The accuracy of non-radiographic mixed dentition predictive methods used for the diagnosis of space discrepancies in orthodontic patients in the mixed dentition phase in Africa: A systematic review of diagnostic test accuracy
(University of Western Cape, 2021) Brijlall, Sarika; Harris, Angela
Orthodontic space analysis is a critical component into informing diagnosis and leading to targeted interceptive treatment planning in the mixed dentition stage of tooth development. Accurate and reliable space analysis methods - radiographic and non-radiographic - are beneficial for the early detection of imbalances between the mesiodistal diameter of unerupted permanent teeth and its alveolar bone support, which can contribute significantly in preventing severe malocclusions. Due to the ease and simplicity in its application, the non-radiographic mixed dentition space analysis methods; Moyers, and Tanaka and Johnston; were widely recommended. However, due to these space analysis methods derived from data of a Caucasian European population in the early 1970s, the external validation question, with dubious applicability of these methods in other populations, has been questioned. This has prompted researchers to seek newer, more context-specified prediction tables and equations for specific sample population groups.
Comparative bond strengths of stainless steel orthodontic brackets bonded with different bonding agents
(University of the Western Cape, 2007) Hudson, Athol Peter Gilfillan.; Grobler, Sias; Harris, Angela; Faculty of Dentistry
The aim of this project was to compare the shear bond strengths of three light cure orthodontic adhesive resins with three different stainless steel molar brackets.
Comparison between the alpha angle of the maxillary impacted canines on panoramic radiographs and cone beam computed tomography
(University of the Western Cape, 2019) Alenazi, Khaled; Harris, Angela
There is a paucity of studies that make use of the alpha angle as a diagnostic tool to assist with the interceptive treatment, prognosis, treatment duration and surgical outcome of possible maxillary canine impaction in orthodontics. While the literature is replete with studies that utilise the sector method, the alpha angle is an alternative approach to assess the possible eruptive outcome of the unerupted canine. It has been reported that if the alpha angle is greater than 25°, there is the possibility of external root resorption. However, if the alpha angle is more than 31°, the prospect of canine eruption decreases even if the deciduous canine is extracted as an interceptive measure. The dental pantomograph has historically been used to predict canine eruption or possible impaction. The use of this method, however, is wrought with limitations. These limitations include magnification, distortion and blurred images. The use of cone-beam computed tomography has been advocated as a means to overcome these limitations.
Comparison of the accuracy of direct versus indirect bracket placement in orthodontics: An in vitro study
(University of the Western Cape, 2020) Streit, Günther Arthur; Harris, Angela
The purpose of this study was to compare the accuracy of direct versus indirect bracket placement in orthodontics in a controlled setting. The more accurate the initial bracket placement is the less time will be required in terms of treatment. Accurate bracket placement can reduce the envelope of error in the three dimensions of vertical (incisal height, height of tooth), horizontal (mesial-distal) and angular (degrees incisal to root apex causing rotational irregularities) based on Andrews’ six keys to normal occlusion (Andrews, 1979). In this comparative experimental study, 10 Class I molar relation study models were selected from the researcher’s practice archives. Only the MBT pre-adjusted or angulated orthodontic brackets were used on manikins, followed by the use of 3D CAD CAM technology to evaluate the results against a pre-determined golden standard.
Early identification and management of mandibular canine ectopia
(South African Dental Association, 2011) Hudson, Athol; Harris, Angela; Mohamed, Nadia
Mandibular canine impaction and transmigration have serious consequences for the patient, as removal of the tooth or teeth in question is often the only solution. The loss of one or both mandibular canines complicates orthodontic treatment. Early warning signs of mandibular canine ectopia are explored in this paper as well as how to assess the potential for displacement, impaction and/or transmigration. This paper highlights the value of interceptive treatment once the early signs of an aberrant mandibular canine have been detected.
Evaluation of sterilising methods for re-implantation of orthodontic mini-implants
(The University of the Western Cape, 2017) di Pasquale, Taryn; Harris, Angela; Basson, Nicolaas
Re-implantation of mini-implants would be financially advantageous in orthodontics and could encourage an increase in use of these devices. An analysis of the bacterial contamination after different sterilising methods has currently not been performed. The aim of this study was to determine the most effective method in sterilising of orthodontic mini-implants for re-implantation in the same patient. The sample included 40 retrieved mini-implants which were collected from private orthodontists, orthodontic registrars, and a maxillo-facial and oral surgeon in South Africa after completed use in patients. They were allocated into groups that underwent different sterilising processes. Gr1 was autoclaved; Gr2 was immersed in 37% phosphoric acid for 10 minutes, followed by being soaked in Milton for 30 minutes; Gr3 was dipped in 70% ethanol and then flamed in a butane gas burner; and GrC did not undergo any processing and served as the control. Bacteria remaining after processing were cultured in Brain Heart Infusion Medium and incubated at 37 degrees Celsius to determine whether any bacterial contamination remained on the mini-implant. To investigate the effects of the sterilising methods on the surface of the mini-implants, they then underwent scanning electron microscopy analysis to assess amount of visible tissue remnants which remained on the surface. These miniimplants were further subjected to energy dispersive spectroscopy (EDS) to investigate their elemental composition. All processing methods were able to sterilise the mini-implants tested and no bacterial growth was present after culturing in Brain Heart Infusion Medium. There were, however, differences in their surface appearances. Gr2 displayed the least amount remaining surface remnants (mean 5.21%), whereas Gr1 (autoclave) and Gr3 (burnt) showed mean of 30.08 and 47.04% tissue remnants on their surfaces respectively. Titanium, aluminium, vanadium, carbon and oxygen were found on all surfaces of the groups. Additional elements, namely, calcium, potassium, sodium, phosphorous, sulphur, silicon, bromine, chlorine, nitrogen, and magnesium were found in the tissue remnants of all the processing groups. Sterilising methods autoclave and burning (Gr1 and Gr3), which made use of heat, had almost double the atomic percentage of carbon. Gr2, etch and Milton, had the lowest atomic percentage of calcium and none of the mini-implants in this group showed traces of iron, which was present in the other groups. Based on the methods tested in this study, Gr2 which involves immersing the mini-implant in 37% phosphoric acid for 10 minutes, followed by soaking mini-implant in Milton for 30 minutes is the suggested method of sterilising mini-implants before re-implantation. Further studies looking into additional sterilisation methods, possibly with the use of sonication or scrubbing, are required to draw up protocols on reimplantation of mini-implants. Additional histological and ion release tests will also be required to confirm which method of sterilisation will result in no additional complications in the patient to that of insertion of a new, unused mini-implant.
Evaluation of the friction generated by self-ligating and conventional bracket-systems in various bracket-archwire combinations: An in vitro study
(University of the Western Cape, 2017) Cupido, Jacqueline Renee; Harris, Angela
The aim of the study is to compare the frictional resistance generated between two types of self-ligating brackets; Smart-Clip Metal SL (3M Unitek) and Damon Clear SL (Ormco), with conventional stainless steel brackets, Victory Series (3M Unitek) when coupled with various stainless steel and nickel-titanium archwires. Materials and Methods: All brackets had a 0.022" slot and tested using three archwires: 0.016" nickel-titanium, 0.019 x 0.025" nickel-titanium and 0.019 x 0.025" stainless steel archwires. Friction was evaluated for the upper right quadrant of the typodont. For each testing procedure, new brackets and archwire was employed to eliminate the influence of wear. Results: The mean results showed that the Smart-Clip self-ligating brackets generated significantly lower friction than both the Damon Clear self-ligating brackets and Victory Series brackets. However, the analysis of the various bracket-archwire combinations displayed that Damon Clear SL brackets generated the lowest friction when tested with 0.016" round nickeltitanium archwire and significantly higher friction than Smart-Clip and Victory Series brackets when tested with 0.019 x 0.025" stainless steel rectangular archwires. All brackets showed higher frictional forces as the wire size increased. Clinical relevance: The production of high levels of friction during orthodontic sliding mechanics presents a clinical challenge to the orthodontists. The generation of high levels of friction may reduce the effectiveness of the mechanics, decrease tooth movement efficiency and further complicate anchorage control. The amount of friction is variable in the orthodontic system and can be altered somewhat by the orthodontist's choices.
Foetal alcohol syndrome: A cephalometric analysis of patients and controls
(Oxford University Press, 2006) Naidoo, Sudeshni; Harris, Angela; Swanevelder, Sonja
Foetal alcohol syndrome (FAS) consists of multi-system abnormalities and is caused by the excessive intake of alcohol during pregnancy. The teratogenic effect of alcohol on the human foetus has now been established beyond reasonable doubt and FAS is the most important human teratogenic condition known today. The purpose of this study was to analyse the craniofacial parameters of children with FAS and compare them with matched controls. Ninety children diagnosed with FAS (45 males, 45 females) and 90 controls were matched for age, gender, and social class. The mean age of the FAS children was 8.9 years with the controls slightly older at 9.1 years. This age difference was not signifi cant ( P = 0.34). A standard lateral cephalometric radiograph of each subject was taken. The radiographs were digitized for 20 linear and 17 angular measurements. These 37 variables were formulated to assess the size, shape, and relative position of three craniofacial complexes: (1) the cranial base, (2) midface, and (3) mandible. In addition, nine variables were computed to compare the soft tissue profi les. The study showed that measurements related to face height and mandibular size appear to be the most important features when distinguishing FAS children. Overall, the FAS children in the present study presented with vertically and horizontally underdeveloped maxillae, together with features of long face syndrome with large gonial angles and a short ramus in relation to total face height. There was also a tendency for the development of an anterior open bite, which appears to be compensated for by an increase in the vertical dimension of the anterior alveolar process to bring the incisor teeth into occlusion. The latter adaptation occurred mainly in the mandible.
Is conventional sugar-free chewing gum effective in the management of orthodontic pain associated with fixed appliances? A randomised clinical trial comparing the pain-reducing effects of sugar-free chewing gum versus a placebo medicament
(University of the Western Cape, 2020) Govender, Yolin; Harris, Angela
Background and aim: Managing orthodontic pain traditionally involves the prescription of non-steroidal anti-inflammatory drugs combined with other analgesic medication. Sugar-free chewing gum has been advocated in the control of orthodontic pain due to its mechanical and physiological effects on periodontal tissue; however, the literature is scant. The ‘placebo effect’ that conventional sugar-free chewing gum may have in the relief of orthodontic pain has not been documented. The aim of this study was to compare the effectiveness of conventional sugar-free chewing gum in reducing orthodontic pain associated with fixed appliances with a placebo (sugar-free sweets) medicament. Objectives: The objectives of the study were to determine if there were differences in pain reporting between the sugar-free chewing gum and the placebo, to ascertain whether gender influenced pain scores and to observe any differences in pain reporting between different orthodontic techniques.
Maxillary canine management in the pre-adolescent: A guideline for general practitioners.
(South African Dental Association, 2010) Hudson, Athol; Harris, Angela; Mohamed, Nadia
This paper focuses on the identification of ectopic eruption patterns of the maxillary canines from the dental ages of approximately 8 to 12 years. The timing and suitability of interceptive treatment in pre-adolescents are discussed.
The mixed dentition pantomogram: A valuable dental development assessment tool for the dentist
(South African Dental Association, 2009) Hudson, Athol; Harris, Angela; Mohamed, Nadia
The mixed dentition pantomogram is routinely used in paediatric patients. This paper discusses the value of the pantomogram for early identification of problems in dental development during the mixed dentition stage. Aspects regarding dental maturity, leeway space, the sequence of eruption of the permanent teeth, anomalies and the development of the canines will be reviewed.
Orthodontic molar brackets: the effect of three different base designs on shear bond strength
(Master Publishing Group, 2011) Hudson, Athol; Grobler, Sias Renier; Harris, Angela
The purpose of the study was to assess the relative base designs of three different maxillary molar stainless steel brackets with reference to the shear bond strength of three different adhesive resins. The molar brackets used were Victory series (3M Unitek), Upper Molar (GAC) and Optimesh XRT (Ormco). The adhesives used were Transbond XT (3M Unitek), Enlight (Ormco) and Sure Ortho Light Bond (Sure Orthodontics). The human enamel specimens (144) were randomly divided into nine groups and each group (n=16) was allocated to a bracket/adhesive combination. The contact surface of each of the bracket bases was measured three dimensionally using a reflex microscope. The base designs were also subjected to further microscopic investigations. The brackets were bonded to the enamel, temperature cycled and the shear bond strength was measured. The size and design of each of the brackets was different. The base size, surface treatment, mesh strand diameter and aperture size of the bracket base mesh have a significant effect on the shear bond strength at the bracket/adhesive interface. The shear bond strengths of all three Ormco bracket/adhesive resin combinations (5.8-6.8 MPa) were significantly lower (p<0.05; Kruskal-Wallis) than the other six bracket/adhesive combinations (9.4-12.1 MPa). The different adhesive types (3 types) could not be mainly responsible for the low shear bond values found for the Ormco bracket. The 3M Unitek combination of the Victory series bracket and Transbond XT adhesive proved to have a high shear bond strength without enamel damage.
Orthodontic treatment need and demand in the Upington area of the Northern Cape Province
(University of the Western Cape, 2018) Booysen, Jeannette; Harris, Angela
When considering a person's self-esteem, behavioural patterns and personal interactions, the one feature having the most impact is their physical appearance. In an ideal world, every person should have a fair opportunity to reach their full potential in life. Orthodontics can improve a person's quality of life by creating confident smiles and a functional occlusion (Sheiham, 1993). Uncorrected malocclusions can adversely affect one's speech, general health and self-esteem. Improving the general physiological implications malocclusions has on person, may make them more employable and more successful in relationships, creating an overall happier, healthier and more successful community. The more people are offered affordable orthodontic treatment, the more acceptable orthodontic treatment may become. Thus, the perceived benefits of Orthodontic treatment in a population group are Improvement of Oral Health and enhancement of psychosocial welfare. Accurate data on the prevalence, distribution and severity of malocclusion is needed by provincial oral health management. They also need accurate data of the orthodontic treatment need of the children in that specific area. This data is vital for the effective planning of the education, training and deployment of dental workers, as well as the resources and distribution thereof in specific, designated areas (Holtshousen, 1997; So & Tang, 1993). This study's focus was to estimate the prevalence of malocclusion amongst adolescents in Upington area in the Northern Cape, and to determine the need for orthodontic treatment in the area using the Index for Orthodontic Treatment Need (IOTN).
The orthodontic treatment needs in children aged 12-15 years in a school in Khomas region, Namibia
(University of the Western Cape, 2018) Serebe, Catherine; Harris, Angela; Kimmie-Dhansay, Faheema
In modern day dentistry, aesthetics forms an integral part of our social perception almost as much as functionality. Malocclusion has been brought to the forefront of developmental anomalies as it can affect mastication, speech as well as the appearance of the face. Furthermore, pre-pubertal and pubertal changes have compounded existing malocclusions in this growth period thus spiraling the need for orthodontic treatment. Therefore, it is essential to determine the normative and selfperceived need for orthodontic treatment in a population. The epidemiological data collected can be used to facilitate policy changes to manage malocclusion in Khomas, Namibia. Aim: The aim of this study was to determine the orthodontic treatment needs of a population of 12-15 year-old children attending a school in Khomas and to express it as percentages of those with subjective and objective orthodontic treatment need over the whole sample population. The objectives were to find associations between treatment needs and some demographic and socioeconomic factors.
A radiographic comparison of the proclination of mandibular incisors between Class II extraction and non-extraction cases using the Damon® self-ligating system
(University of Western Cape, 2021) Walton, Leeren; Harris, Angela
The stable position of the mandibular incisors, and the extent to which their spatial position may be changed in the sagittal plane, represents a key point in determining orthodontic treatment goals and objectives. According to the equilibrium theory, the mandibular incisors lie in a narrow zone of stability that is governed by pressure from the lips, cheek, tongue and periodontium. Proclining the mandibular incisors more than 2 mm leads to instability because of an increase in lip pressure. The magnitude of incisor proclination therefore determines aesthetics, stability and function.
Retrospective evaluation of transverse arch dimensional changes in non-extraction and premolar extraction cases using a passive self-ligating bracket system
(University of the Western Cape, 2022) Coetsee, Marthinus Johannes; Harris, Angela
The effect of extraction and non-extraction treatment protocols on the dental arch width has comprehensively been researched. The effect of non-extraction protocols using passive selfligating systems has also been adequately investigated. Although the literature comes to contrasting conclusions and further research is always encouraged, the impact on the dental arch width using an extraction protocol in combination with a passive self-ligating system has not been defined thoroughly. Aim: this study investigated the effect of 2 treatment protocols on transverse arch width, before and after treatment, using a passive self-ligating system. The null hypothesis to be tested was that treatment with a second premolar extraction protocol would result in no difference in transverse arch width changes compared to treatment with a non-extraction protocol.
Soft tissue profile changes in patients treated with non-extraction versus second premolar extraction protocols - using the Damon system
(University of the Western Cape, 2018) Julyan, Johan Christian; Harris, Angela
Orthodontic treatment has the ability to improve the aesthetics and the function of patients. In order to create space, orthodontic treatment often requires removal of teeth. The most common teeth removed for orthodontic treatment are the premolars. It has become popular to remove second premolars in certain cases where the soft tissue profile should not be altered. The Damon self-ligating orthodontic system is renowned for not requiring dental extractions in the majority of cases. The effect of extractions on the soft tissue profile of patients, in conjunction with using the Damon system, has therefore not been researched. It is important to understand the effect that orthodontic treatment and extractions can have on the soft tissue profile of patients. This effect can accurately be determined by making use of the soft tissue cephalometric analysis, developed by Dr Reed A. Holdaway in 1983.
Use of the passive lower lingual arch in the management of anterior mandibular crowding in the mixed dentition
(South African Dental Association, 2013) Hudson, Athol; Harris, Angela; Mohamed, Nadia; Joubert, Jo-Anne
Leeway space preservation in the mixed dentition is a well-documented method of space management. In the mandibular arch it may be saved for utilization in the correction of minor anterior crowding by the placement of a passive lower lingual arch (LLA) during the transition from the mixed dentition to the permanent dentition

Browsing by Author "Harris, Angela"

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