The Second National Oral Health Survey of Vietnam, 1999: background and methodology.

UNLABELLED: Few high-quality epidemiological surveys of oral health have been conducted in developing countries. A National Oral Health Survey of Vietnam was previously conducted in 1989. OBJECTIVE: To conduct a Second National Oral Health Survey to facilitate planning of preventive and treatment programmes and the dental workforce in Vietnam. DESIGN: The 1999 survey utilised a multistage stratified random sampling strategy to obtain a random sample of the Vietnamese population. The population was stratified by province, urban/rural location and age in order to ensure adequate representation. Participants were clustered into schools (children) or communes (adults). Data were collected through a social survey, and dental examinations were conducted by calibrated examiners. RESULTS: High percentages of the target samples in each stratum were obtained. Inter-examiner and intra-examiner reliability were good to high (kappa: 0.48-0.98). All data were weighted to adjust for the probabilities of selection and known biases to provide unbiased estimates at provincial and national level. CONCLUSION: The National Oral Health Survey of Vietnam was a high-quality epidemiological survey with high participation rates. This was made possible through strong support from the Vietnamese Ministry of Health and regional and local officials.

Provision of extractions by main diagnoses.

AIMS/OBJECTIVES: The aim of this study was to investigate the association of extractions by the diagnoses of caries, pulpal/periapical infection and periodontal disease, controlling for visit type, insurance and age. DESIGN: Cross-sectional analysis of the 1993-94 wave of a longitudinal study. SETTING: Private general dental practice. PARTICIPANTS: A random sample of Australian registered dentists, (response rate = 74%). METHODS: Practitioners completed service logs over one to two typical clinical days. MAIN OUTCOME MEASURE: Percentage of patients receiving extractions. RESULTS: Overall, 7.05% of patients received extractions, with the highest percentages occurring for persons with caries (7.90%), periodontal disease (17.45%) and pulpal/periapical infection (17.54%). Odds of extraction were higher at emergency visits for insured and uninsured patients compared to non-emergency visits by insured patients, while odds of extraction (Logistic regression: OR = Odds ratio; 95% CI) were higher for 18-44 year-olds with caries (OR = 1.44; 1.09-1.89), for 18-44 (OR = 1.84; 1.34-2.54) and 45+ year-olds (OR = 1.83; 1.27-2.63) with pulpal/periapical infection, and for 45+ year-olds (OR = 6.82; 4.68-9.95) with periodontal disease. CONCLUSIONS: There were different age-specific causes of extraction, controlling for visit type and insurance. Effect sizes were highest for pulpal/periapical infection and periodontal disease, but caries remained a major cause of tooth loss due to the higher prevalence of this condition.

Survey of Australian and New Zealand Oral and Maxillofacial Surgery trainees and recent specialists--education and experience.

This study examined the demographic characteristics, educational background and attitudes toward training of all recent OMS specialists and all current trainees in Australia and New Zealand in 1996. The early nineties is a key period as it marks the transition from an essentially dentally based speciality (85% dental degree in 1990); to recent specialists with an increasing number with both medical and dental degrees (33% dual degree 1990-1996); to predominantly dual degree training (84.4% dual in 1996). Current trainees had more extensive experience in pathology, preprosthetic and reconstructive surgery. They were also strongly critical of the length and cost of training.

Survey of Australian and New Zealand Oral and Maxillofacial Surgery trainees and recent specialists--workforce issues.

This study examined Oral and Maxillofacial Surgeon (OMS) workforce issues in relation to current training in Australia and New Zealand. Earlier findings identified that there was a requirement of approximately 6 additional OMS specialists per year in Australia and one per year in New Zealand to maintain an adequate level of supply in the profession. It was found in this study that through to the early part of the next decade the number of OMS entering the Australian workforce is appropriate (5.9 per annum), but there would appear to be concerns about the sufficiency of the number entering the New Zealand workforce (0.7 per annum). In addition, the study also found possible maldistribution in the location of intended future practices, with possible shortages outside of the metropolitan areas.

Service provision patterns by main diagnoses and characteristics of patients.

Service provision patterns may be influenced not only by clinical oral health status leading to a diagnosis and treatment plan, but also by other variables such as patient characteristics. The main aim of this study was to investigate whether associations between services provided and patient factors would persist after controlling for the main presenting diagnosis or condition. A random sample of dentists surveyed in 1993-94 provided a response rate of 74%. Private general practitioners recorded service provision data from logs of 1-2 typical days of practice. Caries (26.5%) was the most prevalent diagnosis, followed by recall/maintenance care (19.0%), pulpal/periapical infection (10.9%), and failed restorations (10.4%). Diagnoses were associated with variation in the percentage of patients receiving services in main areas of service, and also with insurance status, sex and age distributions of patients, and type of visit (chi-square; P< 0.05). Logistic regressions of receipt of services indicated statistically significant associations with patient characteristics and diagnosis categories. Controlling for diagnosis, uninsured patients and those visiting for emergencies had less favourable service patterns (e.g., higher odds of extractions, but lower odds of preventive and crown and bridge services) compared to patients who had dental insurance or visited for check-ups or other non-emergency dental problems. The influence of these factors on services provided has implications of public health importance in terms of appropriateness of care and social inequality.

Dental service rates: age, period, and cohort effects.

OBJECTIVE: Variation in dental service provision over time has been related to changes in factors such as oral health and demographics. Dentist factors such as age and cohort effects are also potential sources of influence. The aim of the study was to examine the operation of age, period, and cohort factors on variation in service rates. BASIC RESEARCH DESIGN: data were collected by a mailed survey of a random sample of 10% of male and 40% of female dentists from each state/territory of Australia in 1983-84, 1988-89. and 1993-94 with response rates of 73, 75 and 74% respectively. MAIN OUTCOME MEASURES: Data on main areas of service were obtained from a log of service items provided on a typical day. RESULTS: Poisson regressions of rates for the 10 main areas of service over time showed increased rates over the study period for diagnostic, preventive, endodontic, crown and bridge, general/miscellaneous and orthodontic services, and decreased rates of prosthodontic services. Goodness-of-fit tests indicated that models for periodontal and endodontic services had a good fit. However, only endodontic services were readily interpretable in terms of descriptive trends. While the age-period-cohort model was preferred, age-period and age-cohort models were also examined because of problems of identification with age-period-cohort models. Endodontic rates were higher among younger dentist birth cohorts, and increased over the 10-year study period for most cohorts of dentists. CONCLUSIONS: If these effects for dentist cohorts were extrapolated over the next 10-year interval, the distribution of services would alter, with endodontic services emerging as a dominant area behind restorative, diagnostic, and preventive services.

An assessment of attitudes to, and extent of, the practice of denture marking in South Australia.

Denture marking or labelling is not a new concept in either prosthetic or forensic dentistry and its routine practice has been urged by forensic odontologists internationally for many years. In the general community it is often recommended for institutionalized persons to prevent confusion of ownership of dentures. In Australia, the Nursing Home Standards require that dentures of residents be 'discreetly labelled' and marking of all dentures is recommended by the Australian Dental Association. In some countries the marking of dentures is regulated by legislation, but elsewhere there seems to be a reluctance to effect this practice. Various methods which have been proposed include the insertion of an identifying label during the fabrication of the dentures with the utilization of a number of materials and coding systems. This study reports the results of a survey undertaken to determine the extent of the practice of denture marking in South Australia, the methods in use, and the attitudes of dentists, dental technicians and institutions to it. The results indicated that 24.5 per cent of all practitioners providing removable prostheses to their patients include an identifying label as part of the service on some occasions. This included 19.9 per cent of general dental practitioners, 25 per cent of specialist prosthodontists, 57.1 per cent of practitioners with training in forensic odontology, and 43.5 per cent of clinical dental technicians. No practitioner labelled dentures routinely. Reasons cited for not labelling dentures included cost, lack of awareness of standards and recommendations and a belief that it was of little importance.

Infant and child feeding practices: a preliminary investigation.

The objective of this preliminary investigation was to examine the feeding practices of infants and pre-school children in Adelaide, and thereby contribute to the development of appropriate preventive dental strategies. A stratified random sample of 160 two year old and three year old pre-school children in the Adelaide Statistical District was obtained. Information about feeding practices and use of comforters or 'dummies' was obtained through a self-administered questionnaire completed by parents of the selected children. Information was collected for the age periods of 0-3 months, 4-6 months, 7-12 months, 13-24 months and 25-36 months. Most of the children (81.8 per cent) were breast-fed at some stage. However the percentage of children being breast-fed decreased markedly across age periods, particularly to 13-24 months, when only 15.9 per cent of children were being breast-fed. Over half of the children, had been bottle-fed with infant formula at some stage. The highest percentage of children being bottle-fed with infant formula occurred in the 4-6 months (42.6 per cent) closely followed by the 7-12 months age period (37.4 per cent). Nearly two-thirds of children were bottle-fed with cow's milk at some stage. The highest percentage of children being bottle-fed with cow's milk occurred in the 13-24 months age period (49.6 per cent). A quarter (24.5 per cent) of the children were put to bed at some stage with a bottle containing cariogenic fluids. The majority of children used a 'dummy' at some stage during both day-time and night-time. Parents are in need of advice on appropriate feeding patterns for infants and young children.

Insurance status and provision of dental services in Australian private general practice.

Annual expenditure on dental care in Australia amounts to AUD 1.9 billion. Approximately one-third of this expenditure involves private dental insurance, yet little is known about the impact of insurance on the provision of services. The aim of this analysis was to examine differences in dental service provision between insured and non-insured patients. Data collected from a random sample of dentists from a survey conducted in 1993-94 were used, providing 817 responses (response rate 74%). Logistic regression analysis controlling for patient age and sex and reason for visit indicated that in private general practice insured patients were more likely to receive preventive (OR = 1.37), crown and bridge (OR = 2.25), and endodontic services (OR = 1.27), but less likely to receive extraction services (OR = 0.52). However, no significant differences by insurance status were found for diagnostic, restorative, or prosthodontic services in the multivariate models. These differences in service provision by insurance status indicate a more favorable pattern of services for insured patients, and point to equity issues in the provision of services.

Productivity among Australian private general dental practitioners across a ten year period.

Historical trends in Australia have shown declining levels of dentists' annual productivity from the 1960s to the 1980s. In a period of changing population demographics and oral health status appropriate levels of supply of dental services remains a key issue. Changes in practice patterns of dentists, through variables such as productivity, may influence the capacity to supply services. The aim of this study was to investigate time trends in productivity for private general practitioners at three points in time across a ten year period. A weighted, stratified random sample of Australian dentists was surveyed in 1983-84 (response rate 73 per cent), 1988 (response rate 75 per cent) and 1993-94 (response rate 74 per cent). The data were re-weighted to provide representative estimates for the age by sex distribution of private general practitioners in 1983, 1988 and 1993. Analysis of variance showed that the number of patient visits per year declined across the ten year period, related to parallel decreases in the number of patients treated per hour, while there was no significant difference during the period in the number of hours per year devoted to work.

Dentist service rates and distribution of practice styles over time.

Studies of dentist service rates have identified clusters of dentists with particular styles of practice, but these practice styles need to be investigated to determine whether patterns of care become established and remain characteristic among dentists. The aims of this study were to establish dentist practice styles and to assess the distribution of these styles of practice between 1983 and 1988. A total of 202 private general practitioners who provided service rate data in both 1983 and 1988 were used in a cluster analysis to group dentists into practice styles. For both 1983 and 1988 three clusters of dentists were obtained, characterized by service rates as "High Restorative", "Low Total Rates", and "High Diagnostic and Preventive". However, the distribution of cluster membership changed over time. The percentage of dentists in the "High Restorative" cluster decreased from 27.9% in 1983 to 16.6% in 1988, the "Low Total Rates" cluster decreased for 60.7% in 1983 to 49.2% in 1988, while the "High Diagnostic and Preventive" cluster increased from 11.4% in 1983 to 34.2% in 1988. The distribution of dentists between these practice styles may be related to aging of dentists, practice maturation, population demographics, need or demand changes, or involve subtle differences in cluster classification over time.

The training and surgical scope of oral and maxillofacial surgeons: the International Survey 1994.

In 1992, the International Association of Oral and Maxillofacial Surgeons (IAOMS) published its training guidelines document. The following survey was conducted to determine the current status of the training and scope of practice of oral and maxillofacial surgeons (OMS) worldwide. Currently, 55% of OMS practice with a single degree, predominantly a dental degree (DDS), while only 16% of the responding countries require dual qualification (MD, DDS). There is a trend toward the dual degree (MD, DDS) in the remaining 29%. In general, in those countries where dual qualification is mandatory, the scope is broadest; however, the scope in a number of countries in which surgeons practice with only the DDS degree - for example, Japan - is equally broad. This baseline information will be used to monitor the growth and development of the speciality in the future.

Service-mix provided to patients in Australian private practice.

Service-mix can reflect changes in demographic factors, oral health, patient demand and treatment philosophies. The aim of this study was to compare service-mix by patient age in 1988 with baseline data from 1983. A weighted, stratified random sample of dentists in Australia was surveyed by mailed questionnaire in 1983 and again in 1988. Service-mix was dominated by restorative, diagnostic and preventive areas. Comparing 1988 with 1983, there were significant increases for diagnostic, preventive, advanced restorative, orthodontic and general areas. Patterns across patient age groups and between years indicated younger patients were being provided with increased preventive services (patients aged 5-11, 25-44 years) and decreased restorative services (patients aged 5-11, 12-17 years), while older patients were being provided with reduced prosthodontic services (patients aged 25-44, 45-64 years), but increased restorative services (patients aged 45-64, 65+ years) and advanced restorative services (patients aged 25-44, 45-64 years). These patterns of service-mix have implications for dental education, research and service delivery.

Changing provision of restorative services in Australia.

As restorative services are major components of service distributions, changes in their level of provision could have considerable impact on dental practice. The aims of this study were to compare the number and types of restorative and related services provided in 1983 and 1988. A weighted, stratified random sample of dentists in Australia was surveyed in 1983 (n = 730, response rate 73%) and 1988 (n = 855, response rate 75%). In both 1983 and 1988 the majority of restorative services provided consisted of amalgams and resin composites. The number of fissure sealants, crowns and one-surface glass ionomers increased significantly between 1983 and 1988 while there were decreased numbers of one- and two-surface amalgams, and one-surface resin composites. Trends by patient age between 1983 and 1988 showed that for younger patients there were decreased numbers of amalgams, three-surface glass ionomers, and one- and two-surface resin composites, while there were increased numbers of one-surface glass ionomers and fissure sealants. Older patients had increased numbers of crowns, one- and three-surface amalgams, glass ionomers, and three-surface resin composites. These results demonstrate a shift in the types of restorative services and materials provided over time and between different age groups of patients.

Trends in work effort among private general dental practitioners.

Trends in the distribution and volume of dental services provide an empirical base upon which hypotheses on future service provision can be tested. The aim of this study was to examine changes in the distribution and volume of service provided in private general dental practice, and compare these with an existing conceptual model. A weighted, stratified random sample of Australian dentists was surveyed in 1983 (730 respondents, response rate 73 per cent) and 1988 (855 respondents, response rate 75 per cent). The data were weighted to provide population estimates for private general dental practitioners in 1983 and 1988. Service-mix data were converted to relative value units, a common scale based on work effort, and annual estimates of this work effort were calculated. Work effort was divided into low, medium and high level interventions. Medium level interventions comprised the greatest volume of work effort, followed closely by low level interventions, with high level interventions having the smallest volume. The pattern of work effort was in contrast to the conceptual model of service distribution, with low level interventions higher and high level interventions lower than expected. While there was a significant increase in work effort among high level interventions, there was no increase in work effort among low level interventions and no decrease in work effort among medium level interventions over the five year period 1983-88 as expected in the conceptual model for changing service provision.

Service-mix of oral and maxillofacial surgeons in Australia and New Zealand.

This study aimed to investigate the service-mix of oral and maxillofacial surgeons and its association with patient age, sex, and referral sources. Oral and maxillofacial surgeons in Australia and New Zealand were surveyed (n = 97; 71.9% response rate), and they supplied service-mix data from a week-long log of services provided to 5770 patients. Dentoalveolar services comprised 67.0% of services. Subcategories of service-mix showed high levels of removal of unerupted teeth (44.8%) and multiple extractions (10.0%), with soft-tissue lesions (5.0%), TMJ surgery (4.7%), mandible trauma (4.6%), and simple extraction (4.4%) the next categories in order of percentage. Variations in service-mix were observed for patient age and sex, among referral sources, and between private and public practice.

A consensus approach to projections of the supply of oral and maxillofacial surgeons in Australia.

The analysis presented involves projections of the future requirements for the oral and maxillofacial surgeon labour force in Australia under a range of different recruitment scenarios, followed by a consensus-seeking exercise with the Australian and New Zealand Association of Oral and Maxillofacial Surgeons (ANZAOMS) Council in an attempt to produce estimates of the most probable future requirement for oral and maxillofacial surgeons. The resulting consensus estimates would result in the maintenance of the present population-to-surgeon ratio. Different premises or beliefs underlying the projections were viewed as counterbalancing each other.

Present and future patterns of practice and workforce needs in oral and maxillofacial surgery.

Oral and maxillofacial surgeons have shown curiosity and concern for their present and future patterns of practice and workforce needs. Few oral and maxillofacial surgeons would not have an understanding of how they came to be, or opinions on where the specialty is and appears to be going. Such opinions, however, need to be rigorously tested against the best available information. Quantitative information is the substantive input to decisions on whether oral and maxillofacial surgeons wish to go where they appear to be going, and if so why, and if not, why not? The Oral and Maxillofacial Surgeons 1990 Workforce Study* aimed to provide information relevant to these questions. Oral and maxillofacial surgeons are surprising in both their heterogeneity in patterns of practice and homogeneity in most of the content of services provided. Projections of the workforce indicate that a status quo in recruitment is actually a steady decline in capacity to serve the community, a picture in contrast to the international comparative data and opinion that supports a broadening in the service role of oral and maxillofacial surgeons. The Oral and Maxillofacial Surgeons 1990 Workforce Study offers insights into present and future patterns of practice and workforce needs. Ultimately, however, decision-making in the specialty will reflect additional social, economic and dento-political factors to which the Australian and New Zealand Association of Oral and Maxillo-Facial Surgeons must be the major contributor.

Differences in time devoted to practice by male and female dentists.

Previous studies have found that female dentists work fewer hours per year than male dentists. This study examined factors which may explain the differences in hours worked per year that exist between male and female dentists in private practice. In 1988, a weighted, stratified random sample of dentists in Australia was surveyed by mailed questionnaire. There were 855 respondents (response rate = 75.5%) with 566 dentists from private practice (361 males and 205 females). Annual time devoted to dental practice was significantly lower for females, for dentists who were not the sole earner of the family income, and for dentists with young children. A significant interaction between sex of dentist and child age showed that hours per year in practice decreased only for females with young children. Hours worked per year were significantly higher among female dentists with no children, or older children. For males, hours worked remained at a higher level. The amount of time devoted to dentistry requires monitoring in the estimation and projection of capacity to supply dental services.