 Expert systems are increasingly being used for diagnosis and treatment planning, but can be constrained by complex rule-based strategies and the need for knowledge engineers during maintenance. A new approach called Ripple Down Rules was used to develop EIC01, an expert-maintained system for automating orthodontic reports with a knowledge base of 680 rules applicable in clinical situations and has potential as an interactive advisory tool. This article was authored by Pong Kachai and Freer Terrence J.