The subjective grading of cases at the Dental Practice Board of England and Wales was compared to the Peer Assessment Rating Index (PAR) and Index of Orthodontic Treatment Need (IOTN) in assessing 1505 cases sampled at the Board between Late 1990 and mid-1991. Whilst some criteria are common to both systems, case by case there is only limited agreement; sources of disagreement are evaluated. The indices are essentially epidemiological tools; whilst they have shortcomings in assessing individual cases, they are related to peer opinion, and show good reliability when used on samples of cases. They can be readily updated, as findings of research or future peer opinion may dictate. Use of PAR and IOTN at the Board, instead of subjective gradings, would require a departure from decisions on withholding payment on a case by case basis. If, however, they were used onsamples of practitioners' caseloads to assess reduction of malocclusion, and residual malocclusion and need for treatment, practitioners fees could be up- or down-graded periodically according to their overall performance, to encourage more to adopt higher standards. Allowances could be made, however, for ‘limited objective treatments’ and cases where poor co-operation had impaired the result.