Tooth shade analyzer system and methods

#In dentistry, there has been a shift in recent years from a philosophy of drilling and filling to one of prevention and cosmetics. By way of example, many people today are choosing to have clinical procedures done to enhance their smile and appearance. Most of these procedures involve the modification of tooth shape, alignment, and/or color.

#The use of intraoral video and/or imaging systems (hereinafter “intraoral camera system”) has grown rapidly in dentistry over the past few years. Such systems are widely utilized in “show and tell” settings, i.e., where the dentist can show and illustrate particular features of a patient's mouth. These intraoral camera systems are rapidly becoming key complex diagnostic and treatment planning. Presently, approximately 30% of the practicing dentists in the age group between about 35-54 own and utilize intraoral camera systems. It is expected that that percentage will only increase with increased familiarity. See Dental Procedures Report, pgs. 22-24, February 1995.

#A necessary step in altering a patient's tooth color is to determine the “shade” of the existing tooth. For example, those persons seeking a whiter, brighter smile are still assessed to establish their existing tooth color so that an appropriate before and after comparison can be made. Shade determination is even more important for those persons seeking reconstructive work, since one goal of the reconstructive process is to achieve a natural appearance. Therefore, it is important to know the existing tooth shade so that it can be accurately matched with the new restoration.

#A more complete understanding of the invention may be obtained by reference to the drawings, which illustrate preferred embodiments in which:

#FIG. 1 shows a prior art intraoral camera system;

#FIG. 2 illustrates a tooth shade analyzer system constructed according to the invention;

#A number of different aspects of the invention are disclosed. In one aspect, the invention provides a system for determining the tooth shade of a patient's tooth. A camera, preferably an intraoral camera, captures the image of the patient's tooth, including color information representative of the tooth's color. A shade analyzer sub-system is in electrical communication with the intraoral camera, and preferably has (i) a color processing section for determining the color of the patient's tooth from the color information of the image; (ii) storage memory for storing shade information representative of a plurality of tooth shades (i.e., each of the tooth shades corresponds to a different tooth color), (iii) a color correlation section for comparing the color of the patient's tooth to the plurality of tooth shades and for identifying a tooth shade with a color corresponding to the color of the patient's tooth, and (iv) means such as a display terminal for communicating the identified tooth shade to a user of the system.

#In another aspect, the system includes a monitor used to display the color image to a user of the system. The shade analyzer sub-system thus communicates a tooth color representative of the identified tooth shade to the monitor, thereby providing a user of the system with a visual comparison of the patient's tooth color with the color of the identified tooth shade.

#In a further aspect, the color processing section determines RGB chromaticities of the color image, and each of the plurality of tooth shades has a corresponding RGB representation of the tooth color stored in memory. In such an aspect, the color correlation section quantitatively compares the RGB chromaticities with the RGB representation of each of the tooth shades, and compares and identifies a tooth shade based upon an comparison of the chromaticities and the RGB representations.