Magister Chirurgiae Dentium - MChD (Orthodontics)

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A critical investigation of paedodontic education with special reference to graduates of the University of Stellenbosch
(University of Stellenbosch, 1983) Peters, R; Prins, F.X
In South Africa the general dental practitioner has sole re$ponsibility for the provision of child dental care. Accordingly, at Stellenbosch University the objective of the undergraduate paedodontic curriculum is to train a general dental practitioner who is able to provide comprehensive dental care for all categories of children.As this approach is not in accordance with that prevailing in most countries, particularly countries acknowledged to be leaders in the field of 'paedodontics, the objective of this investigation is to examine and test the validity of the philosophy of paedodontic education as it exists in South Africa in general and at the University of Stellenbosch in particular.
Trends in skeletal maturation patterns in a Western Cape sample
(University of the Western Cape, 1987) Hansa, Ahmed Ismail; Singh, S.
Skeletal age assessment is not only an important aspect in orthodontic treatment planning, but is also widely used in forensic medicine and physi cal anthropology. Vari aus studi es have shown that chronological age may be at variance with an individual's biologic age. Current research would seem to indicate that the hand-wrist radiograph provides the most accurate method of assessing skeletal age for diagnostic purposes. In recent years the number of patients presenting with malocclusions of a skeletal nature at the University of the Western Cape has increased si gnifi cantly. If it i s accepted that treatment of jaw discrepancies associated with malocclusion is dependent on a large component of dentofacial orthopedics, then by implication it is necessary that a substanti al amount of faci al growth remai ns. The need has therefore arisen for the establishment of skeletal maturation trends in the Western Cape. Skeletal maturity was assessed from hand-wrist radiographs in a sample of 318 Western Cape chi 1dren aged 6 to 16 years for both sexes, utilising the bone specific Tanner-Whitehouse TW-2 scoring system. Data obtai ned from the present study showed a marked di fference in skel etal maturati on trends between femal es of the Western Cape to that of the British norm, while the males showed less divergence. Further, these findings show that in both sexes the epiphyseal bones matured in advance of the TW-standard. Carpal maturation, however, was delayed in the male when compared to the British standard, while that of the female conformed to that of the British standard.
Trends in skeletal maturation patterns in a Western Cape sample
(University of the Western Cape, 1987) Hansa, Ahmed Ismail; Singh, S.
Skeletal age assessment is not only an important aspect in orthodontic treatment planning, but is also widely used in forensic medicine and physi cal anthropology. Vari aus studi es have shown that chronological age may be at variance with an individual's biologic age. Current research would seem to indicate that the hand-wrist radiograph provides the most accurate method of assessing skeletal age for diagnostic purposes. In recent years the number of patients presenting with malocclusions of a skeletal nature at the University of the Western Cape has increased si gnifi cantly. If it i s accepted that treatment of jaw di screpancies associated with malocclusion is dependent on a large component of dentofacial orthopedics, then by implication it is necessary that a substanti al amount of faci al growth remai ns. The need has therefore arisen for the establishment of skeletal maturation trends in the Western Cape. Skeletal maturity was assessed from hand-wrist radiographs in a sample of 318 Western Cape children aged 6 to 16 years for both sexes, utilising the bone specific Tanner-Whitehouse TW-2 scoring system. Data obtai ned from the present study showed a marked difference in skel etal maturati on trends between femal es of the Western Cape to that of the British norm, while the males showed less divergence. Further, these findings show that in both sexes the epiphyseal bones matured in advance of the TW-standard. Carpal maturation, however, was delayed in the male when compared to the British standard, while that of the female conformed to that of the British standard.
The prevalence of occlusal traits in a Western Cape population
(University of Stellenbosch, 1988) Ferguson, Maurice; Moola, M. H.
At the University of the Western Cape there has been a rapid increase in the number of patients requesting orthodontic therapy. The Extent of the problem in this area is not known as no studies have been undertaken in this regard. The purpose of this study was to determine occlusal trends in a Western Cape population, to establish norms with a view to ascertaining treatment needs.
A clinical, study of the protective effects of the application of fissure sealant prior to the direct bonding of orthodontic brackets
(University of the Western Cape, 1990) Sundrum, Dayalan; Samsodien, M G
Orthodontic treatment sometimes has the unfortunate sequela of white spots forming around the margins of the brackets. These white spots or demineralized areas are of concern to the orthodontist ds they may present an aesthetic problem which might require costly restorative work later. AIso at debonding the orthodontist is often faced with the time consuming and arduous task of removing residual composite from the tooth surface. The purpose of this study was to establish whether a fissure sealant used with or without a fluoride containing mouth rinse would prevent white spot formation around orthodontic brackets and whether, coincidently, the use of the fissure sealant moved the fracture site closer to the enamel/resin interface, thereby leaving a clean enamel surface at debonding, saving the orthodontist chairside time. One hundred patients undergoing orthodontic treatment at the Dental Faculty of University of the Western Cape were chosen for this study. The patients were given basic oral hygiene instruction, scaling and polishing and instructed to brush with a fluoride containing dentifrice. The mouth of each patient was divided into four quadrants, with fissure sealant (pelton clear unfilled resin) being applied to two alternate quadrants. The sample was divided into two groups, one of which rinsed with a fluoride containing mouthrinse. There was a significant difference in white spot formation when comparing fissure sealed and non-fissure sealed surfaces. Of the group which rinsed with fluoride mouthrinse, 86t had no white spots or demineralization. Also, the results of this study have shown unequivocally that the prior use of fissure sealant moved the fracture site closer to the enamel/resin interface, thereby leaving Iittle or no residual composite on the enamel surface at debanding.
The prevalence of occlusal traits in a selected Western Cape population
(University of the Western Cape, 1993) Kaka, Joolam; Moola, M. H.
state funded programmes are essential to provide a treatment for the dentally handicapped. To address this need a study was undertaken under the auspices of the Orthodontic Department of the University of the Western Cape to assess the orthodontic needs of children in the Western Cape. The purpose of this study was to determine the occlusal traits of Indian children in the Western Cape and to compare them with samples internationally. The sample consisted of 355 children, 12-14 years old, from schools administered by the House of Delegates. They were examined and recorded according to the methods set out by Baume et al. (1973), and Angle's Classification (1899) with the Dewey- Anderson (1919 and 1960) and EI-Mangoury and Mustafa (1991) modifications The results of this study showed that bilateral molar relationships were: normal in 72.9%; mesial in 5.8% and distal in 15.5% of the children examined. The remaining had an asymmetrical molar relationship (5.8%). The upper incisal area was found to be the most crowded area in the mouth followed by the lower incisal area. Anterior crowding was present in 58.2% and spacing in 12.7% of the sample. The mean overjet was 2.7mm and the mean overbite 2 .1mm. In the posterior segments, open bites accounted for approximately 6.5% and crossbites for 8.3% On the basis of Angle's Classification it was found that 17.1% had a normal occlusion and 54.9% an Angles Class I malocclusion, 16.9% an Angle's Class II malocclusion and 5.5% an Angle's Class III malocclusion. 5.6% of the candidates had an asymmetrical molar relationship. In comparison to other population groups the results suggest that the incidence of some occlusal traits of this Western Cape sample was similar to that of other population groups while some traits were more prevalent. The pattern of the distribution of Angles Classification was also similar to that reported in studies done elsewhere.
Research related to Pathoses of the oral mucosa in South Africa (1964 - 1995)
(University of the Western Cape, 1995) van Wyk, CW; Dreyer, WP
Investigations of pathoses of the oral cavity encompass a relatively wide spectrum of diseases, abnormalities, tumours and tumour-like conditions affecting and occurring in the dental hard tissues and supportive structures, the bony skeleton of the face and the soft tissues of the. mouth. It involves a study of the normal - oral biology - and the abnormal - oral pathology. Oral pathology is a relatively new specialized field of dental science and practice. In South Africa, prior to the nineteen-fifties, research in oral pathology was primarily directed towards dental disease. Two people - Julius Staz of the University of the Witwatersrand and Tony Ockerse of the University of Pretoria - were the doyens in this field and made major contributions to dental science. Staz reported on the status of dental caries and tumorous malformations of teeth and Ockerse on the prevalence and severity of fluorosis in South Africa. During the fifties a second generation of dental surgeons, who were interested in soft tissue, bone and tumour pathology, emerged. They ,were Bertie Cohen, George Baikie, Mervyn Shear and John Lemmer who, at that time, were all from the University of the Witwatersrand. Bertie Cohen later joined the Royal College of Surgeons of England. Mervyn Shear led the field with his research on cysts of the oral cavity. The practice of oral pathology, moulded on anatomical pathology, was established in the early sixties and Mervyn Shear and the author, from the University of Pretoria, became known as oral pathologists. Research at that early stage comprised clinical and histological observations of oral lesions, diseases, tumours and tumour-like conditions. Observation techniques became more sophisticated during the sixties and seventies with the advent of histochemistry and electronmicroscopy. The next major development which blossomed in the seventies and early eighties was the application of epidemiological methods in the study of disease. Epidemiological principles enabled the correct recording of profiles of oral pathoses in the community. Much was learnt about the prevalence and distribution of oral conditions. The application and use of experimental models, especially laboratory animals, became popular in the eighties. Amongst others, a germfree animal unit was established in the Faculty of Dentistry of the University of Stellenbosch enabling workers to study the microbiological aetiology of dental and oral disease. Morphological observations of tumours and mucosal lesions were further enhanced during this period with the development of immunocytochemistry Experimental cell studies by means of cell culture techniques, commenced late in the eighties and was established in the early nineties. These models fostered molecular biology techniques which have become useful tools for the investigation of the aetiology of disease at a cellular and molecular level. At present molecular techniques are also popular in other spheres of oral pathology such as microbiological, immunological and oncological research. The author's first contact with oral pathology as a subject, forming an important and interesting part of dentistry, was the prescribed textbook "Oral and Dental Diseases", 2nd ed., 1951., by HH Stone of the University of Liverpool in the United Kingdom. Subsequently an enduring interest in the subject and research was cultivated by three teachers and colleagues, Ivor Kramer, Robert Bradlow and Mervyn Shear. Ivor Kramer, Professor of Oral Pathology in the Eastman Dental Institute of the University of London was a superb postgraduate teacher of oral pathology, and revelled in research. The Dean of the Institute, Professor Sir Robert Bradlow was a clinician and splendid diagnostician. He correlated the clinical and histopathological features of oral diseases. These two teachers set the course in oral pathology for the author during his postgraduate studies. In the sixties, after a spell at the University of Pretoria, the author joined Professor Mervyn Shear at the University of Witwatersrand. It was here that the author could further his skills of presenting lectures and research papers in an orderely manner and strengthen his love of research. The research carried out by the author reflects to a large extent the development of research in oral pathology in South Africa since 1960.. It includes studies of diseases and lesions of the oral mucosa, the dental hard tissues, tumours of the oral cavity and jaws and forensic odonto-stomatology. To date 139 articles have been published and accepted in scientific journals of which I was the first or co-author. The research presented here, however, comprises only those studies related to pathoses of the oral mucosa as it occurs in South Africa. Fifty-four papers and two abstracts are submitted. The papers are grouped into two divisions which include studies on (I) normal human oral and ectocervical mucosa and (II), those related to pathoses of the oral mucosa. The latter is subdivided into sections on: the profile of lesions of the oral mucosa in the community; cytological, clinical and morphological features of lesions of the oral mucosa; and studies on the aetiology of lesions of the oral mucosa. Each division and section is preceded by a declaration as to the contribution of the author or co-authors and a précis of the aims, objects and research findings. In the introduction of the précis statements are made explaining the aims of the study. These statements are not referenced because they appear in the respective articles.
A cephalometric and dental analysis of treatment outcomes of unilateral cleft lip and palate children treated at the Red Cross children's hospital
(University of the Western Cape, 2000) Kaskar, Salim; Bellardie, Haydn
This study was a cephalometric and dental investigation of the treatment outcomes of UCLP children treated at the Red Cross Children's Hospital (RCCH) with respect to craniofacial morphology and dental arch relationship. The quality of the outcome for the RCCH group was compared with the outcomes reported for the Six-Centre International Study (Melsted et al., 1992; Mars et al., 1992). The sample consisted of 20 (11 females, 9 males) consecutively treated UCLP children who had cephalometric and dental records taken between the ages of8 to 11years (mean 10.13 ± 1.2 years). The cephalometric analysis described by Melsted et al. (1992) was used to evaluate the skeletal and soft tissue morphology. The quality of the dental arch relationship was measured according to the Gosion Yardstick (Mars et al., 1987). The treatment outcome of children treated at the RCCH was evaluated with respect to craniofacial form and dental arch relationship. When comparing the mean cephalometric skeletal parameters of the RCCH to the six centres in the Eurocleft study, a significant difference was found between the RCCH group and centre D for most of the variables. A significant increase in the upper incisor inclination and maxillary inclination was found in the RCCH patients compared to the European centres. The difference in the soft tissue parameters was limited to the relative protrusion of the nose and the sagittal soft tissue variable sss-ns-pgs. The analysis of the Goslon scores showed a significant difference between the RCCH group and centres C, D, and F. According to the Goslon score, 85% of the RCCH patients had good to satisfactory dental arch relationship, which was comparable to that recorded for centres A(92%), B(89%) and C(94). In conclusion, the results of the cephalometric analysis and the Goslon Yardstick showed a significant difference between the RCCH group and centre D. The GosIon score indicated good quality of the dental arch relationship, which faired favourably with the better centres in the Six Centre Study.
Digitized and computerized recordkeeping in dentistry (Orthodontics) : A Technologically Advanced Alternative to the Analysis and Storage of Study Models
(University of the Western Cape, 2002) Kleinloog, A.D.; Joseph, VP
The research is aimed at investigating and finding alternatives to the physical necessity of producing and storing plaster casts or stone models of the tissues of the mouth. The quest for time and space is universal and the successful management of both results in stress free, financially stable and uncluttered work circumstances. Study models do playa very important role in diagnostics and treatment planning as well as communicating final results in Dentistry, especially in Orthodontic practice. Conventional study models are bulky, fragile, and expensive diagnostic tools produced from impressions taken of the patient's mouth and cast in plaster or stone. The storage of these records creates major space problems, and recalling or retrieving models at some later stage also causes logistical problems. Ideally, the tissues of the mouth could be scanned and from this a 3-D image produced on screen, which could later be milled (machining process of reproducing, explained in Appendix B) if necessary. Three dimensionally accurate, visually pleasing, reproducible, measurable and retrievable records, would be the solution. Computerizing dental records has already revolutionized the industry in the fields of Radiology and written patient data. This information is available at the click of a mouse, and integrated diagnostic tools can be displayed on screen. A thorough investigation of all methods of capturing dental data and 3D images from previously researched and publicized studies was conducted before attempting the latest technology. The final project involved: 1. requesting an introductory and explanatory demonstration on the scanning possibilities in South Africa 2. organizing and attending a demonstration of the laser and contact scanner on study models and impressions. 3. undergoing training in the use of a contact scanner. Computerizing of these results and comparing data derived from analyzing both study models and impressions, manually and digitally. 4. researching and collecting of data with engineering professionals, to establish the validity and viability of this method ( aiming to use uncomplicated, widely accepted and thoroughly applicable basic criteria in all experiments.) 5. evaluation of data statistically by a statistician. Discussion: Digitizing and computerizing of images derived from scanning the models or impressions offers the most attractive alternative for record keeping. Laser scanning disappointed in general due to the relative unavailability in South Africa, the expensive nature of the service elsewhere and limiting factors due to the sensitivity of the laser beam. It is the most promising alternative in future research, because of improved accuracy, higher speed of scanning, uniformity and reproducibility. Contact scanning proved to be available, reliable and adjustable. In most applications, the best results in terms of accuracy and quality of surface finish are obtained using contact scanning. The disadvantage of this method is the time factor and therefore it becomes expensive and economically not viable. The direct scanning of impressions, albeit with laser or contact scanning, remains a scientific and clinical viable option. Conclusion: Digital imaging is still a young technology and many aspects are not yet completely explored. It is a promising technology and its significance is increasing because it opens the door to diagnostic information. Another important development is that the software for digital imaging will become more integrated with other computerized dental applications in the dental office, enabling patient data between different and remote practices to be exchanged more easily. Further progress is not limited by a lack of available image processing tools but rather by our restricted understanding of the various components of diagnostic imaging in dentistry. A Bioengineering exhibition mounted by the University of Munich during a December 2000 conference, displayed a specially adapted CT Scanner that could scan information directly from the mouth. This leads to more possibilities of deriving images without impressions or study casts.
Assessment of tooth movement in the maxilla during orthodontic treatment using digital recording of orthodontic study model surface contours
(University of the Western Cape, 2006) Harris, Angela Manbre Poulter; Nortje, C.J.; Wood, R.E.; Dept. of Orthodontics; Faculty of Dentistry
The aim of this project was to measure changes in dimension of the first three primary rugae and to evaluate tooth movement in the maxilla during orthodontic treatment in patients treated with and without premolar extractions.
Incidence, trends of prevalence and pathological spectrum of head and neck lymphomas at national health laboratory services- Tygerberg
(University of the Western Cape, 2007) Chetty, Manogari; Hille, JJ; Bezuidenhout, J
MChD (Oral Pathology) minithesis, Department of Oral and Maxillofacial Pathology, Faculty of Dentistry, University of Western Cape Among malignant lesions, lymphoma ranks second only to squamous cell carcinoma in frequency of occurrence in the head and neck. Lymphomas in HIV patients' are second in frequency to Kaposi's sarcoma as AIDS-defining tumours. About 50% of lymphomas in HIV patients are extranodal and more than half of these occur in the head and neck area. The number, variety and diagnostic complexity of lymphoma cases that have primarily arisen in the head and neck region has steadily increased in the surgical pathology service of the National Health Laboratory Services (NHLS) - Tygerberg. This observation is particularly relevant in the context of increasing HIV infection rates in the population of South Africa as demonstrated by a study in 2006 conducted by the Medical Research Council of South Africa. This is a retrospective study using the records of cases of head and neck lymphomas diagnosed at NHLS-Tygerberg over the last five years. The aim of this study is to investigate the prevalence of head and neck lymphomas (HNL) at NHLS-Tygerberg from January 2002 to December 2006. The objective of this study is to determine the frequency and types of HNL and to determine, if possible, an association between the incidence of HNL and the HIV status of the patients. Trends of prevalence in terms of gender, referral centres, HIV status, age of patients and site of presentation are also examined. The results of this study show an increase in the number of patients with HNL from January 2002 to December 2006. A significant increase is noted in the number of HIV positive patients documented each year, from 17% in 2002 to 33% in 2006. Western Cape- urban (WC-U) remains the largest referral center. A notable increase is seen, each year, in the number of patients referred to Tygerberg-NHLS from the Eastern Cape (EC) and Western Cape- rural (WC-R) areas. A significant number of HIV positive patients are referred from the Eastern Cape and Western Cape rural areas. The average age of disease presentation in the HIV positive group of patients is 35 years with the unknown group being 46 years and the HIV negative group being 54 years. The main categories of lymphoma that presented in HIV positive patients are plasmablastic lymphoma (PBL) and diffuse large B-celllymphoma (DLBCL), which together form 56% of cases. 26% of cases are Hodgkin's lymphoma (HL); the second largest group of HNL cases. Burkitt's lymphoma (BL) consists of 8% of cases. 7% of cases are T-cell lymphomas. 3% of cases are Mantle zone lymphomas. No cases of SLL and Follicular lymphomas (FL) are described in this group of patients. DLBCL and HL form 27% each of the cases in patients with a negative HIV status. A significant number of Follicular lymphomas (15%), small lymphocytic lymphoma (SLL) (9%), MALT (7%), and T-cell lymphomas (8%) are identified. No PBL are seen in this group of patients. The incidence of HNL at NHLS-Tygerberg has increased over the last five years. This trend parallels that seen in other developing countries such as Tanzania, Nigeria, Thailand and India. This increase is possibly due to an increase in the number of referrals to our center, an increase in the overall population of the Western Cape, an increase in the number of HIV positive patients and the high incidence of EBV infection in the general population of the Western Cape. Social issues, such as poverty, lack of adequate education, female dependence on partners, rural communities and the non-availability of anti-retroviral drugs (ARV) and highly active anti-retroviral therapy (HAART) to most of the population that require these drugs, are considered major contributing factors. A trend is noted in the increased number of female patients diagnosed each year with HNL. A predominance of DLBCL was identified in our series. This is consistent with previous reports and studies on HNL. The number of biologically aggressive lymphomas, such as DLBCL, Plasmablastic and Burkitt's lymphomas diagnosed each year, has also significantly increased. These were prevalent mainly in the HIV positive group of patients who were also younger compared to the HIV negative patients. The documented findings of this study will serve as a guideline for the estimation of head & neck lymphoma burden and risk assessment at NHLS- Tygerberg.
The accuracy of visualized treatment objectives in bimaxillary protrusion patients
(University of the Western Cape, 2008) Murphy, Desmond.; Murphy, Desmond; Harris, A.M.P.; Dept. of Orthodontics; Faculty of Dentistry
The aim of this research project was to assess the accuracy of four different types of VTO [Steyn (1979), Jacobson and Sadowsky (1980), Ricketts (1982) and Holdaway (1984)], in predicting the final result of the incisor and soft tissue response to orthodontic treatment in bimaxillary protrusive patients.
The soft-tissue profile preferences of a group of lay persons and professionals
(University of the Western Cape, 2008) Suliman, Shameela Haroon; Shaikh, A.B.; Samsodien, M.G.; Dept. of Orthodontics; Faculty of Dentistry
Although facial aesthetics has always been a part of orthodontic diagnosis and treatment planning, the criteria for facial evaluation have been somewhat arbitrary. They are often based on parameters from the field of art or from evaluating faces chosen by orthodontists or other professionals. The aims and objectives of the study were to determine the soft-tissue profile preference of a group of lay persons and professionals; to compare the preferences of the male and female assessors (lay persons group) with regard to the preferred profiles for the maleand female patient respectively; to test similarities and differences in the professional's perceptions of the various profiles. This qualitative study was undertaken at the orthodontic clinic at UWC using post-treatment soft tissue profile photographs of patients who had attended the orthodontic clinic.
Efficacy of enamel sealants in preventing demineralisation
(University of the Western Cape, 2008) Nkosi, P.M.; Shaikh, A.B.; Amra, I.; Dept. of Orthodontics; Faculty of Dentistry
To compare the efficacy of two fluoride containing materials, namely, FluorSure and Duraphat, in protecting the enamel around and underneath the orthodontic brackets against decalcification.
Changes in arch dimensions after extraction and non-extraction orthodontic treatment
(University of the Western Cape, 2008) MacKriel, Earl Ari.; Harris, A.M.P.; Dept. of Orthodontics; Faculty of Dentistry
The aim of this study was to determine whether there are changes in the interdental arch widths and arch lengths of the mandibular and maxillary arches during nonextraction and extraction orthodontic treatment. The records of 78 patients treated by one orthodontist were used for this study. Three treatment groups were selected: a nonextraction group (Group NE), a group treated with extraction of maxillary and mandibular first premolars (Group 44), and a group treated with extraction of maxillary first premolars and mandibular second premolars (Group 45). The arch width measurements were measured in the inter-canine, inter-premolar and inter-molar areas. The arch length was measured as the sum of the left and right distances from mesial anatomic contact points of the first permanent molars to the contact point of the central incisors or to the midpoint between the central incisor contacts, if spaced.Statistical analysis included descriptive statistics of the data, analysis of the correlation matrices, Wilcoxon Signed Rank tests and Kruskal-Wallis tests of the changes which occurred during treatment. The intercanine widths in the mandible and maxilla increased during treatment in all three groups, with the extraction groups showing a greater increase than Group NE (p<0.05). In Group NE the mandibular arch length increased (p>0.05), while the maxillary arch length remained essentially unchanged. Both extraction groups showed decreases in arch length in the dentitions (p<0.05), with greater decreases occurring in the maxilla. The difference in arch length change between the two extraction groups was not significant (p<0.05). The inter-canine arch width increased in all three treatment groups, more so in the two extraction groups. From this it is evident that extraction treatment does not necessarily lead to narrowing of the dental arches in the canine region. The inter-second premolar arch width decreased in both extraction groups. Non-extraction treatment resulted in an increase in the inter-premolar and inter-molar arch widths.
Perception of occlusal appearance among schoolchildren in Limpopo Province
(University of Western Cape, 2011) Sehowa, Nelly Mokgadi; Myburgh, Neil
The aim of this study is to determine the perceptions of different occlusal appearance observed by schoolchildren aged 13 -16yrs in the Capricorn District of Limpopo Province in South Africa. The study determined schoolchildren’s perceptions of different occlusal appearances, by assessing the self-perception of schoolchildren toward their occlusal appearance using the Aesthetic Component (AC) of the Index of Orthodontic Need (IOTN). These were compared with the perceptions held by schoolchildren across age, gender and place of residence in Limpopo Province.
A Cephalometric Comparison of Class II Extraction Cases Treated with Tip-Edge and Edgewise Techniques
(University of the Western Cape, 2012) Ngema, Maureen Nkosazana; Harris, A. M. P.
The Tip-Edge and edgewise techniques are the main techniques that are mostly used in orthodontics, and are applicable to the treatment of any type of malocclusion from the most simple to the most complex. The edgewise bracket wire combination produces bodily tooth movement simultaneously or separately in all three planes of space and hence permits correction of the most extreme tooth malpositions. On the other hand Tip-Edge offers a differential tooth movement (just like the previously used Begg technique) within an edgewise based bracket system (Parkhouse 2003). When treating patients using the Tip-Edge technique, it is recommended that a specialized archwire i.e. Australian stainless steel wire be used. This wire can be described as a round austenitic stainless steel wire that is heat-treated and cold-drawn to its proper diameter. This was done in order to produce its special and needed properties such as toughness, resiliency and tensile strength (Kesling, 1985). It is used in conjunction with light (2oz) class II elastics. The aim of this study was to compare cephalometric changes in skeletal and dento-alveolar parameters in cases treated by these two different orthodontic techniques. This was to be established by calculating and comparing the pre- and post-treatment cephalometric variables of cases treated with these techniques by looking at the skeletal and dento-alveolar measurements. Thirty Tip-Edge and thirty edgewise treated cases that had class II malocclusion, had extraction of four premolars and were treated with Class II elastics were selected. The gender distribution between the Tip-Edge and the edgewise techniques were 47% and 60% respectively for females. For males it was 53% in Tip-Edge and 40% in the edgewise techniques.
Comparison of the accuracy of digital models obtained from scans of impressions versus direct intra-oral scans
(University of the Western Cape, 2016) Dubula, Vuyani Goodman; Harris, AMP; Johannes, K
Measurements and a variety of analyses of dental casts are essential for precise diagnosis of an orthodontic case. Study models have long been an essential part of orthodontic diagnosis and treatment planning. Currently virtual computerized models are available to clinicians, supplemented by dedicated software for performing needed measurements (Zilberman et al, 2003). Digital impression methods are now available and intraoral digital scanning techniques make it possible to generate study models directly from the scanning of the dentition. The aim of this study was to compare measurements taken after scanning the dental impressions to the measurements obtained from using direct intraoral scanning of the dentition. Alginate impressions of the maxillary and mandibular dentitions were taken on 20 patients and these impressions were scanned using a 3 Shape R 700 TM scanner. Direct intraoral scans of both dentitions were then performed for the same patient. Ortho analyzer TM software was used to measure the mesiodistal widths of individual teeth, and the intercanine and intermolar on digital models of the scanned impressions and digital models obtained from direct intraoral scans of the maxillary and the mandibular dentitions. The results indicated that there were no statistically significant differences between mesiodistal widths, and intercanine and intermolar distances between the two techniques (p > 0.05). Because of the high level of accuracy of the virtual measurements compared to those of the scanned impressions, it can be concluded that direct intraoral scanning of the dentition can be used with confidence in the clinical situation to measure tooth sizes and inter-arch distances for orthodontic purposes. Orthodontists commonly use models for various areas in the practice, clinical research and medico-legal documentation (Marcel, 2001)
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.
A retrospective study comparing the Holdaway and Ricketts Visual Treatment Objectives (VTOs) to orthodontic treatment outcomes
(The University of the Western Cape, 2017) Khatib, Yoemna; Shaikh, A.
Traditionally orthodontic treatment planning was predominantly based on the dental occlusion without too much emphasis on and consideration for facial proportions and aesthetics. Predicting treatment outcomes has always been part of science. The ability to predict is important in other areas of science and medicine, and it is important in the treatment of orthodontic patients. Holdaway coined the term "visualized treatment objective" (VTO), to describe his predicted treatment outcome. Ricketts stated that all treatment planning constituted some sort of prediction. His prediction analysis allowed for forecast of the soft tissue profile which was based on the reactions of the skeletal and dental components due to orthodontic treatment. The aim of this study was to compare the predicted outcomes of two popular VTO's, viz Ricketts and Holdaway, to the actual outcomes of adult patients. The complete Holdaway VTO and Ricketts VTO were done on each pre-treatment cephalogram using the space analysis values from the records. These VTOs predicted where the soft tissue profile (nose tip to chin) would be, in relation to the H-line and E-plane respectively. The posttreatment tracings were done. The two tracings for each patient were then superimposed.

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