number or proportion of specialist residency positions have provoked considerable controversy.
In dentistry, aggregate work force planning focuses more on predoctoral enrollments than on residency positions. Moreover, most of the concern about residencies focuses on increasing the number of general dentistry positions rather than cutting the absolute number of specialist positions or specifying a percentage split between generalist and specialist positions. One concern in assessing the adequacy of supply to meet requirements for oral health services is the work load of practitioners. ADA survey data (1992f) indicate that the average general dentist works 48 weeks a year and spends an average of 37 hours per week in practice (33.6 hours treating patients). The average appointment wait time was about seven days. One ADA analysis suggests that less than two-thirds of available "capacity in dentistry" has been used in recent years. That number was derived by assuming that all dentists could provide the volume of service provided by the top quartile of dentists (ADA, 1993a).
Similarly, a study comparing educational costs and incomes for professionals reported fewer hours worked annually for dentists than for primary care and procedure-based specialty physicians, lawyers, and business people with M.B.A. degrees (Weeks et al., 1994). For example, for professionals aged 36-45, annual hours worked were 1,613 for dentists (patient care hours only, generalists and specialists); 1,893 for lawyers; 2,520 for business people; 2,674 for primary care physicians (patient care only); and 2,730 for specialists (patient care only). Differences in data definitions and sources undoubtedly account for some of this variation, and professional interpretations of terms such as "patient care hours" may vary. Nonetheless, the numbers raise the possibility of some reserve capacity in the dental work force, although differences in work load may reflect different choices about lifestyle, income, and other factors that might limit the extent to which dentists would increase their work load in response in an increase in the demand for their services.
Whatever the national supply picture, state or regional circumstances may differ. As described in the background paper by Capilouto et al., some research has attempted to assess work force requirements within states based on information and judgments about supply, demand, and need. Several regional organizations exist to assist states with higher education planning and policy. These organizations, which include the Western Interstate Commission for Higher Education, the New England Board of Higher Educa-