Proximal alveolar bone loss in a longitudinal radiographic investigation. I. Methods of measurement and partial recording.

A longitudinal radiographic investigation was made of the progression of the proximal alveolar bone loss over a 10-year period (1970-1980). The material was unselected and consisted of 669 individuals in the county of Stockholm. Sixty-one individuals were randomly selected for evaluation of a recording system using alternative methods of measurement, and 90% of the measurement sites could then be assessed. The correlations between some of the methods were high, such as between measurement of alveolar bone height and root length and between alveolar bone height and tooth length. To reduce the number of measurements, a partial recording was made, giving a high correlation coefficient between the partial recording and total recording. When five measurement sites (12 m, 11 m, 33 d, 31 d, 41 m) were were used, the correlation coefficient was 0.96, and a slight increase of the coefficient was obtained when using additional sites.