Relationship between linear and area measurements of radiographic bone levels utilizing simple computerized techniques.

Abstract

Three methods were used to measure the percent alveolar bone remaining about the premolar teeth in standardized perapical radiographs from eight female beagle dogs. The first method utilized straight‐line measurements of bone remaining along the tooth root, the second method used measurements which followed the curved path of the tooth root, and the third method measured the area of tooth root supported by alveolar bone as projected on a radiograph.An inexpensive digitizer‐computer system was used to determine linear, curvilinear, and area measurements. The percent remaining alveolar bone determined by each of these three methods were compared in order to determine the simplest technique which most completely describes the bone remaining about each tooth root. There was no significant difference between the percent bone remaining determined by straight line and curvilinear measurements. Similarly, there was no significant difference between straight line and area measurements of percent remaining alveolar bone when there was little loss of alveolar bone (<15%). However, when there was moderate to severe bone loss on the radiograph (>15% loss), area measurements were significantly lower than linear measurements. The relationship between area measurement and linear measurement may be described by a quadratic equation. These data indicate that simple linear measurements of percent remaining alveolar bone on a radiograph may be transformed to the more complete area description of percent remaining alveolar bone using a quadratic equation. Thus, in beagles, simple linear measurements of percent remaining alveolar bone may be used to provide as complete a description of radiographic support as the more complex area measurements.