J C Davenport

Communication between the dentist and the dental technician.

In this part, we will discuss Factors contributing to good RPD design are described, including the respective inputs of the dentist and dental technician. Poor communication in current practice is reported and an appropriate format for a work authorisation presented.

Paper: Logic-based integrity constraints and the design of dental prostheses

This paper describes the ongoing development of a design assistant, RaPiD, for use in prosthetic dentistry. RaPiD integrates computed-aided design, knowledge-based systems and databases, employing a logic-based representation as the unifying medium. The users manipulation of icons representing the developing design is interpreted as a set of transactions on a logic database of design components. The rules of design expertise are represented as constraints in first order predicate logic and design alterations are subject to the checking of the constraints. When design rules are contravened as the result of some proposed alteration, a suitable critique is presented to the user. RaPiD is being developed for use in both dental education and practice.

Prosthetics: Need and demand for treatment

This article considers first, factors influencing the need and demand for removable partial dentures (RPDs) and second, the particular requirements and problems of elderly patients related to such treatment.

Combining biometric and symbolic models for customised, automated prosthesis design

In a previous paper [Artif. Intell. Med. 5 (1993) 431] we described RaPiD, a knowledge-based system for designing dental prostheses. The present paper discusses how RaPiD has been extended using techniques from computer vision and logic grammars. The first employs point distribution and active shape models (ASMs) to determine dentition from images of casts of patients jaws. This enables a design to be customized to, and visualised against, an image of a patients dentition. The second is based on the notion of a path grammar, a form of logic grammar, to generate a path linking an ordered sequence of subcomponents. The shape of an important and complex prosthesis component can be automatically seeded in this fashion. Combining these models now substantially automates the design process, beginning with a photograph of a dental cast and ending with an annotated and validated design diagram ready to guide manufacture.

A system of design.

This article describes a method of building RPD components into an effective design and indicates how the details of the design can be communicated clearly to the dental technician.

Active Shape Models for Customised Prosthesis Design

Images and computer graphics play an increasingly important role in the design and manufacture of medical prostheses and implants. Images provide guidance on optimal design in terms of location, preparation and the overall shape and configuration of subcomponents. Direct manipulation of a graphical representation provides a natural design environment. RaPiD is a CAD-like knowledge-based assistant for designing a dental prosthesis known as a removable partial denture (RPD). The expertise embedded in RaPiD encourages optimal subcomponent configuration, but currently supports only minor customisation. This paper describes how oral images and Active Shape Models (ASMs) are being used to address this limitation.

The RaPiD Project: Knowledge-based design of dental prostheses

Abstract RaPiD is a knowledge-based assistant for designing removable partial dentures. 1t employs techniques from logic data bases, declarative graphics, and critiquing, along with expert design knowledge, to provide a CAD-style graphical interface for both instructional and professional use, the latter offering some design automation. RaPiD is being evaluated in terms of usability, clinical correctness, and pedagogical value. The potential for applying the same approach to other small to medium design activities is also being investigated.

Bracing and reciprocation.

In this part, we will discuss Distribution of forces Bracing components Distal extension saddle problems Types of reciprocation Guide surfaces Distribution of forces Bracing components Distal extension saddle problems Types of reciprocation Guide surfaces

Expert design knowledge: a case study in dental education

The expertise of teachers of prosthetic dentistry in partial denture design (the design of removable partial denture, a type of dental prosthesis) has been elicited by identifying a collection of design rules and sampling expert reaction to them by first surveying 10 experts individually and then the prosthetic departments in all 17 dental schools in the British Isles. The surveys revealed an unsuspected consensus concerning the rules. This design expertise will be disseminated through RaPiD, a knowledge based assistant for the design of partial dentures. It is expected that by incorporating assistant rules into this design, which have been shown to be widely supported, the acceptability and usefulness of RaPiD for clinical education will be increased. In order to facilitate the incorporation of these rules into RaPiD semi-automated translation, rather than hand coding as PROLOG programs, is being investigated.