A system of diagnostic codes for dental health care

We set out to develop and implement a system of diagnostic codes for use in the computerized management information system of the Community Dental Services of the North York Public Health Department.

We received staff input on common diagnoses, reviewed other diagnostic systems and established criteria for an ideal coding system. The codes are consistent with the format of other classification systems used in dental management information in Canada. They were implemented in 1997-98.

We developed a system of four-digit, numeric codes for dental diagnoses. The diagnostic codes are specific at the level of the patient, consistent with current evidence on the natural history and classification of diseases, consistent with conventional measures of oral conditions, and fit the paradigm of the Canadian system of treatment codes. In the first year, 91 percent of 6,740 patients had at least one diagnosis, with a mean of 2.5 per patient. The five most common diagnoses were smooth surface caries, pit and fissure caries, calculus, teeth with deep fissures, and gingivitis.

We have developed a coding system for dental diagnoses that has achieved high use and provided more accessible information on the conditions seen by staff dentists.