http://hdl.handle.net/10386/172 2013-06-17T11:20:02Z http://hdl.handle.net/10386/654 Title: Prevalence of impacted mandibular third molar teeth at Medunsa Oral Health Centre Authors: Tsabedze, Vusumuzi Ndumiso Description: Thesis (M.Dent.(MFOS))-- University of Limpopo, 2012 2012-01-01T00:00:00Z http://hdl.handle.net/10386/464 Title: Bolton ratios on a sample of South African blacks Authors: Singh, Shivani Abstract: Good occlusion requires that teeth be proportional in size. If large upper teeth occlude with small lower teeth, it would be almost impossible to achieve ideal occlusion. The concept of ideal intercuspation assumes a strict relationship between tooth size and the size of maxillary and mandibular arches. Specific dimensional relationships must exist between the maxillary and mandibular teeth to ensure proper interdigitation, overbite, and overjet. It is important to determine the amount and location of tooth size discrepancies that may exist as a part of treatment planning. The relationship between maxillary and mandibular tooth sizes were established by Wayne A. Bolton in 1958 on a Caucasian sample. Bolton’s anterior ratio was 77.2% (SD 1.65) and the Bolton overall ratio was 91.3% (SD 1.91) (Bolton, 1958). Previous studies have shown that populations differ with respect to inter-arch tooth size relationships, and Blacks have larger teeth than Caucasians (Schirmer and Wiltshire, 1997; Khan, Seedat, and Hlongwa, 2007). A ratio that has been formulated on a Caucasian sample will over calculate or over predict tooth size discrepancies when used on a Black sample (Richardson and Malhotra, 1975; Smith, Buschang and Watanabe, 2000). The purpose of this study was to establish mesio-distal tooth width ratios for a select sample of South African Blacks. One hundred study models of untreated cases with excellent occlusion were obtained from the Department of Orthodontics archive records at the Medunsa Oral Health Centre, University of Limpopo. This sample were of South African Blacks (50 males and 50 females) selected according to a set criteria. The mesio-distal widths of permanent teeth up to and including the xvii first permanent molar in each arch were measured using a digital vernier caliper. The anterior and overall tooth width ratios were calculated on this sample. The mean, range and standard deviation were calculated for the size of the teeth, and a co-efficient of variation was obtained for the tooth size ratio. The results indicated that the male and female groups did not differ significantly and were therefore combined into one group. A 2-sample t-test was used to test for the statistical difference between means. The tooth size ratios obtained were compared to the Bolton’s ratios. Ninety five percent confidence intervals were calculated for the anterior and overall tooth width ratios for the select sample of South African Blacks. The anterior ratio was found to be 77.26% (SD 2.65), equivalent to Bolton’s anterior ratio 77.2% (SD 1.65), whereas the overall ratio was 92.31% (SD 2), significantly larger than Bolton’s overall ratio of 91.3% (SD 1.91). These results indicated that an overall tooth size ratio of this select sample differed from that of Bolton’s overall ratio and therefore, Bolton’s overall ratio may not be fully applicable to this select sample. KEY WORDS: Tooth size, tooth size discrepancy, Bolton’s ratios, South African Blacks. Description: Thesis (M. Dent.(Orthodontics))--University of Limpopo (Medunsa Campus), 2010 2010-01-01T00:00:00Z http://hdl.handle.net/10386/444 Title: Application of the dental aesthetic index in the prioritization of orthodontic service needs Authors: Maumela, Patricia Mutsinda Abstract: Introduction: Orthodontic services in South Africa are mainly offered by the private sector and to a lesser extent by the four government funded training institutions which are plagued by limited resources. The majority of patients cannot afford private fees and seek treatment at these training institutions. The growing number of patients on waiting lists is a problem. Prioritization of orthodontic services would assist to ensure that these services are preferentially provided to those patients most likely to derive the greatest benefit. The Dental Aesthetic Index (DAI) is used to estimate orthodontic treatment need and can also be used as a screening tool to determine treatment priority (Cons, Jenny & Kohout, 1986). The DAI focuses on aesthetics and therefore omits other malocclusion traits thereby limiting its comprehensiveness as an assessment tool. To date no published study has been found that identified other malocclusion traits not included in the DAI and examined the influence that these malocclusion traits have in the prioritization of orthodontic service needs whilst using the DAI. Thus the aim of this research was to assess the application of the DAI to prioritize orthodontic services needs within a government funded institution. The objectives were: 1) To identify other malocclusion traits not included in the DAI. 2) To evaluate how much influence other malocclusion traits not included in DAI have in the prioritization of orthodontic service needs. 3) To compare the mean DAI scores according to age and gender. Materials and methods: One hundred and twenty (120) pre-treatment study models of patients in the permanent dentition stage were collected from the records archive of the Department of Orthodontics, University of Limpopo (Medunsa campus) using a systematic sampling method. The study models were assessed using the DAI by two calibrated examiners. Other malocclusion traits were identified and recorded according to the basic method for recording occlusal traits (Bezroukov et al., 1979). Specific codes were assigned to each identified malocclusion trait from code 01 to 09. The traits were recorded once, by marking the respective code/malocclusion trait with an x when present on each study model. Descriptive statistics, Pearson correlation coefficient, Chi-square values and t-tests were employed to analyze the data and p values of less than or equal to 0.05 (p < 0.05) were considered statistical significant. Results: The sample consisted of 58 females and 62 males, aged 10-45 years with a mean age of 17.9 years and a SD of 6.2 years. The DAI scores showed that 19.1% had normal or minor malocclusion, 17.5% had definitive malocclusion, 21.7% had severe malocclusion and 41.7% had handicapping malocclusion. The mean DAI score was 35.2 with a SD of 10.3. A statistical significant difference was found between mean DAI score of adults and adolescence (p < 0.05), while no statistical significant difference was found between males and females (p > 0.05). The study identified the following other malocclusion traits: crowded and rotated posterior teeth (27.5%), posterior crossbite (22.8%), retained primary teeth (13.4%), missing molars (10.7%), partially erupted teeth (9.4%), deep overbite (8.1%), transposition (3.4%), peg lateral (3.4%) and supernumerary teeth (1.3%). These malocclusion traits accounted for 21.1% of the total malocclusion traits of the sample whilst the DAI accounted for 78.9%. About 47.6% of these other malocclusion traits were found in handicapping category of the DAI, 19.5% in the severe category, 18.1% in the definitive category and 14.8% in the normal or minor category. The distribution of subjects over the four DAI categories and the distribution of subjects with other malocclusion traits over the same DAI categories did not differ significantly (Chi-square test, p = 0.917). The intra and inter examiner reliability was tested using the Pearson correlation coefficient and found to be highly correlated (r = 0.9). Conclusions: The study showed that the DAI is a valid and reliable index that can be applied to prioritize orthodontic service needs in a financially constrained situations without any modification as two thirds of other malocclusion traits were found in categories which the DAI had already prioritized for treatment. Description: Thesis (M Med (Orthodontics))--University of Limpopo, 2010. 2010-01-01T00:00:00Z http://hdl.handle.net/10386/433 Title: Oral HIV-associated Kaposi sarcoma: A clinical study from theGa-Rankuwa area, South Africa Authors: Khammisa, Razia Abdool Gafaar Abstract: Background: Kaposi sarcoma (KS) is the most common neoplasm diagnosed in HIV-seropositive subjects. HIV-associated KS (HIV-KS) may affect any body system and the disease may be slowly progressing or fulminant. Oral involvement is frequent and extensive oral HIV-KS is associated with poor prognosis. Methods: All cases of oral HIV-KS treated in the Department of Periodontology and Oral Medicine over a period of seven years were included in this retrospective study. A record was made regarding the clinical and laboratory features, and differences in these features between males and females were statistically tested. The differences between the percentages of the different clinical appearances of oral HIV-KS lesions; and between the features of oral HIV-KS in patients who contracted HIV infection before the diagnosis of oral KS and those who were diagnosed with HIV infection at the time of oral KS presentation were also tested. Results: Of the 37 patients included in the study, 54% were females and 46% were males and two patients (5%) were children. In 21 patients (57%) the initial presentation of HIV-KS was in the mouth. Seventeen patients (46%) were diagnosed with HIV infection and oral KS at the same time. At the time of oral HIV-KS diagnosis, 29 patients (78%) had multiple lesions affecting one or several sites. There were no statistically significant differences between males and females regarding the clinical and laboratory features of oral HIV-KS except for the size of the lesions. The percentage of lesions <10mm was significantly lower in females than males (chi-squared test: p=0.007), whereas the percentage of lesions ≥10mm≤50mm was significantly higher in females than in males (chi-squared test: p=0.0004). There were significantly more patients with multiple oral HIV-KS lesions than patients with single oral HIV-KS lesions (binomial distribution test: p=0.0003). At the time of oral HIV-KS diagnosis, the difference between ix the average CD4+ T cell counts of the patients who were concurrently diagnosed with HIV infection and oral KS (130cells/mm3), and those who contracted HIV infection before developing oral HIV-KS (90 cells/mm3) was not statistically different. Nine patients (24%) developed facial lymphoedema in association with multifocal exophytic oral HIV-KS lesions. The average CD4+ T cell counts of these patients at the time of oral HIV-KS diagnosis was 28 cells/mm3, and was statistically significantly lower (t-test: p= 0.01) than the average CD4+ T cell count (133 cells/mm3) of those who did not develop facial lymphoedema. All the patients with facial lymphoedema died, on average within two weeks from the occurrence of facial lymphoedema. One patient (2.7%) developed immune reconstitution inflammatory syndrome (IRIS) – associated oral HIV-KS, and his oral HIV-KS resolved following administration of highly active antiretroviral therapy (HAART) and systemic cytotoxic chemotherapy, and surgical excision. Out of the 28 patients who were not lost to follow-up, 21 (75%) died, on average within 13.6 weeks from the time of oral HIV-KS diagnosis and seven (25%) survived. At the time of oral HIV-KS diagnosis the difference in the average CD4+ T cell count of the patients who died (64 cells/mm3) and those who survived (166 cells cells/mm3) was statistically significant (t-test: p=0.016). The prognosis of the patients who received cytotoxic chemotherapy was better than the prognosis of those who received only HAART, or those who were HAART-naïve. Conclusions: Oral HIV-KS affects females more frequently than males (M:F = 1:1.2), and it is not uncommon in children. A lower CD4+ T cell count at the time of oral HIV-KS diagnosis is associated with a poor prognosis. Patients who develop facial lymphoedema during the course of HIV-KS disease, die soon thereafter. Oral HIV-KS can be successfully treated with systemic cytotoxic chemotherapy. Description: Thesis (M Med (Periodontics and Oral Medicine))--University of Limpopo, 2011. 2011-01-01T00:00:00Z