Retrospective longitudinal study of the rate of alveolar bone loss in humans using bite-wing radiographs.

This study investigates the possible use of unstandardized bite-wing radiographs to determine the rate of alveolar bone loss over long periods of time. A total of 100 pairs of bite-wing radiographs obtained from patients of two general dental practitioners were read on a 3M Reader, normally used for reading microfilm. For the purpose of measurement, two reference points were selected on the teeth; the highest point on the occlusal surface of the crown, the mesial and distal points of the cemento-enamel junction. Both vertical and horizontal bone loss was measured. Initially bone levels on 20 full mouth bite-wing radiographs on all posterior teeth were measured, then in the next 80 cases, an abbreviated index was used. The bone heights were first examined at the beginning and then at the end of a 10-year time span. The percentages of measurable distances were 28% and 57%. From the Occlusal measurement point and the C E J measurement points, reasons for unreadability were also recorded. The annual rate of horizontal bone loss was 0.06 mm and 0.04 mm from the Occlusal reference point and the CEJ reference point. The rates for the vertical bone loss was 0.05 and 0.03 mm. In order to study whether there was a constant loss over a period of time, bone levels were measured in 10 successive years. The findings suggest that the bone loss rat per year fluctuated. The study suggests that the bite-wing radiographs can be used in longitudinal studies of periodontal disease and can provide important information on the natural history of the disease.