The Practice of Dentistry by Australian- and Overseas-Trained Dentists in Australia: Discriminant Analysis of key Predictors.

INTRODUCTION: Overseas-trained dentists comprise at least one-fourth of the overall Australian dental workforce. This study examined characteristics and practice differences between Australian- and overseas-trained dentists to identify key predictors that best differentiate their dentistry practices. METHODS: Data for the study were from the Longitudinal Study of Dentist Practice Activity (LSDPA), a survey of a nationally representative random sample of dentists in Australia commencing in 1983-1984 and repeated every 5 years. Dentists were surveyed on a wide range of items including participant characteristics, practice patterns, practice inputs, direct demand, and productivity measures. Data were weighted to provide national estimates by age, sex, and practice type. Discriminant function analysis was used to examine the predictor variables that best distinguished between the two groups. Analysis was limited to the most recent wave of the study. RESULTS: A total of 1148 dentists (response rate = 67%) responded to the survey in 2009-2010; 648 cases were available for the discriminant analysis. The discriminant functions for the full sample and each of the 3 age groups (<35 years; 35-50 years; and 50+ years) were found effective to separate dentists into 2 groups (Australian and overseas), with the proportion of cases correctly classified being highest for the oldest age group (89.7% for 50+ years). Female gender, type of practice (working in public sector), and working in disadvantaged areas were significant predictors, with more prominence in the 35- to 50-year age group. Practice inputs, demand, and productivity measures offered less discriminative capacity between the dentists. CONCLUSION: Overseas-trained dentists contribute towards providing dental care to underserved populations, the public sector, and in rural and remote locations. This study provided basis to argue that policies to encourage overseas-trained dentists to contribute towards areas of need locations have been successful, and key productivity measures were also similar to Australian-trained dentists.

Periodontal diseases in the Australian adult population.

Periodontal diseases are some of the major oral diseases and conditions in adults. OBJECTIVE: The study aimed to present the population patterns of periodontal diseases and trends of periodontitis in the Australian adult population. METHODS: Data collected in the recent National Study of Adult Oral Health (NSAOH) 2017-18 were used to present the current population patterns of periodontal diseases. Periodontal assessment was carried out at three sites per tooth for all present teeth, excluding third molars. Prevalence of gingivitis, periodontal pocket depth of 4+ mm, gingival recession of 2+ mm, and clinical attachment loss of 4+ mm were calculated and reported. The US CDC/AAP case definition was used to define cases of moderate to severe periodontitis. NSAOH 2017-18 data were combined with data collected in NSAOH 2004-06 using similar methods to describe age- and cohort-related trends of periodontitis. RESULTS: The prevalence of periodontal diseases and conditions were relatively high in the Australian adult population. Some three in every ten Australian adults had moderate to severe periodontitis. There was a tendency of higher prevalence of periodontitis in NSAOH 2017-18 than in NSAOH 2004-06 among people of the same age. CONCLUSION: Periodontal diseases and conditions remain a significant problem in the Australian adult population.

A longitudinal study of medication exposure and xerostomia among older people.

OBJECTIVE: To describe the incidence of xerostomia among a population of older people over a 6-year period, with particular attention to medications as risk factors. BACKGROUND: Understanding the natural history of xerostomia requires longitudinal epidemiological research, but only one study has examined changes in xerostomia over time. While medication is a recognised risk factor for dry mouth, the role of particular medication categories continues to be controversial. MATERIALS AND METHODS: Older South Australians (aged 60+) underwent an interview and dental examination at baseline, and these assessments were repeated 2, 5 and 11 years afterward. Medication data were collected at baseline, 5 and 11 years. Xerostomia data were collected at 5 and 11 years using the Xerostomia Inventory (XI) and a standard question. RESULTS: Of the 1205 dentate participants assessed at baseline, 669 remained after 5 years, and 246 were assessed at 11 years. Medication prevalence increased over the observation period, such that 94.8% of the cohort were taking at least one medication by 11 years. The prevalence of xerostomia increased from 21.4% to 24.8% between 5 and 11 years (p > 0.05), and the mean XI score increased from 20.0 (SD, 6.7) to 21.5 (SD, 7.9; p < 0.001). Some 14.7% of participants were incident cases of xerostomia, while 11.4% were remitted cases; 10.1% were cases at both 5 and 11 years. After controlling for gender and 'baseline' xerostomia severity (represented by the XI score at 5 years), participants who commenced taking daily aspirin after 5 years had over four times the odds of becoming incident cases, while those who commenced taking a diuretic after 5 years had nearly six times the odds of doing so. CONCLUSIONS: While the overall prevalence of xerostomia increased during the observation period, there was considerable instability, with one-quarter of the cohort changing their status. Medication exposure was strongly associated with the incidence of the condition, with recent exposure to diuretics or daily aspirin strongly predicting it.

The shape of the socioeconomic-oral health gradient: implications for theoretical explanations.

OBJECTIVES: The nature of the relationship between status and health has theoretical and applied significance. To compare the shape of the socioeconomic -oral health relationship using a measure of relative social status (MacArthur Scale of Subjective Social Status) and a measure of absolute material resource (equivalised household income); to investigate the contribution of behaviour in attenuating the socioeconomic gradient in oral health status; and to comment on three hypothesised explanatory mechanisms for this relationship (material, psychosocial, behavioural). METHODS: In 2003, cross-sectional self-report data were collected from 2,915 adults aged 43-57 years in Adelaide, Australia using a stratified cluster design. Oral conditions were (1) < 24 teeth, (2) 1+ impact/s reported fairly often or very often on the 14-item Oral Health Impact Profile; (3) fair or poor self-rated oral health, and (4) low satisfaction with chewing ability. Prevalence ratios and 95% confidence intervals (PR, 95%CI) were calculated from a logistic regression model. Covariates were age, sex, country of birth, smoking, alcohol use, body mass index, frequencies of toothbrushing and interdental cleaning. RESULTS: There was an approximately linear relationship of decreasing prevalence for each oral condition across quintiles of increasing relative social status. In the fully adjusted model the gradient was steepest for low satisfaction with chewing (PR = 4.1, 95%CI = 3.0-5.4). Using equivalised household income, the shape more closely resembled a threshold effect, with an approximate halving of the prevalence ratio between the first and second social status quintiles for the adverse impact of oral conditions and fair or poor self-rated oral health. Adjustment for covariates did not attenuate the magnitude of PRs. CONCLUSIONS: The nature of the relationship between social status and oral conditions differed according to the measure used to index social status. Perception of relative social standing followed an approximately straight-line relationship. In contrast, there was a discrete threshold of income below which oral health deteriorated, suggesting that the benefit to oral health of material resources occurs mostly at the lower end of the across the full socioeconomic distribution.