Studies on the occurrence, distribution and progression of periodontitis

Jenkins, William Murdoch MacRae (1995) Studies on the occurrence, distribution and progression of periodontitis. DDS thesis, University of Glasgow.

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The Periodontal Index of Russell (1956), either in its original or in modified form, was once the principal index for a series of epidemiological studies that correlated disease scores with a number of clinical and social determinants. By the late 1970s, however, there were considerable doubts about the validity and reliability of the Periodontal Index. There were substantial and unexplained differences in prevalence rates between different populations, and major inconsistencies were apparent in the reported prevalence of chronic periodontitis in the United Kingdom. It was also noteworthy that UK populations appeared to have substantially more periodontal disease than populations in the United States of America and Sweden. It appeared that the diagnostic criteria, employed to describe prevalence and severity of periodontitis, often did not reflect the true presence or absence of the disease. Very few studies had been carried out which measured attachment loss directly by probing, and, although radiographic studies of bone loss were plentiful, most provided incomplete data, e.g. partial recording or one estimator of severity. Most epidemiological data had been reported in mean severity scores, leading to the assumption that periodontitis was more or less evenly distributed among individuals of the same age and standard of oral hygiene, and, although it had been shown that the prevalence and severity of periodontitis increased with decreasing standards of oral hygiene, the data available were insufficient to indicate the extent to which unknown risk factors might influence the disease process. Accordingly, central to the investigative work described in this thesis is a descriptive cross-sectional epidemiological study, based on a detailed radiographic analysis of periodontal marginal bone levels in 800 unreferred casual attenders at Glasgow Dental Hospital and School in 1978. The specific aims were to determine the prevalence, severity, extent and within-population distribution of marginal bone loss, and to compare the findings with those obtained from a similar survey of Swedish shipyard employees (Bjorn, 1971). A rotational tomographic view was taken for each patient, and the height of alveolar bone at each proximal surface was calculated with a transparent ruler using the crown tip and root apex as reference points. The ruler was calibrated to score bone loss in 'quarters' of optimum bone height (Bjorn & Holmberg, 1966). A score value was awarded at 78.6% of proximal surfaces, the remainder being deemed unmeasurable. Marginal bone loss increased with age and was slightly more severe in males than females and in males among the lower social classes. The development of bone loss with age was attributable both to an increase in affected surfaces and to progressive destruction at some of these surfaces. A high prevalence of marginal bone loss was found. However, very few individuals had generalised bone loss exceeding 25% of optimum bone height. Furthermore, only a tiny proportion of teeth were affected by bone loss exceeding 50% of optimum height. Use of the 'Bjorn ruler' enabled the findings for males aged 20-64 years to be viewed alongside those of a comparable population of Swedish males. These different populations had similar marginal bone levels. Further analysis revealed that, with age, in parallel with other investigations, a small but increasing minority of patients accounted for most of the bone destruction. For example, in the 50-73-year age-group, 28% of patients accounted for 75% of the advanced bone loss. This cross-sectional study showed, in common with established belief, that age, sex and socio-economic status are determinants of periodontitis. However, such great variation existed within these subgroups that none of these attributes could be considered to be reliable indicators of the presence of periodontitis or predictors of its progress. The study was, therefore, extended to include a radiographic assessment of carious and restored teeth among the 800 subjects so that the susceptibility to caries and periodontitis within the same individual could be compared. The caries risk was determined radiographically from the total decayed and filled teeth (DFT), as a percentage of all the teeth measured. The Mantel-Haenszel technique was used for analysis of the relationship between periodontitis and caries, and data were stratified on four categories of age, sex and numbers of teeth present. This analysis failed to reveal any systematic patterns, indicating that the risks of caries and periodontal disease are unrelated (chi2 = 0.00; df =1; p > 0.50). (Abstract shortened by ProQuest.).

Item Type: Thesis (DDS)
Qualification Level: Doctoral
Additional Information: Jenkins, W.M.M. and Allan, C.J. (1994) Classification and Epidemiology. In Guide to Periodontics (3rd edn) , Ch 5, pp 41— 50. Oxford: Wright.
Keywords: Dentistry, pathology.
Subjects: R Medicine > RK Dentistry
Colleges/Schools: College of Medical Veterinary and Life Sciences > School of Medicine, Dentistry & Nursing > Dental School
Supervisor's Name: Supervisor, not known
Date of Award: 1995
Depositing User: Enlighten Team
Unique ID: glathesis:1995-74680
Copyright: Copyright of this thesis is held by the author.
Date Deposited: 13 Nov 2019 15:58
Last Modified: 05 Aug 2022 08:26
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