The objectives of the present investigation were to analyze intraoral radiographs and to study 1) the distribution of the distance between the cemento-enamel junction
(CEJ) and the alveolar bone level (BL) and 2) the prevalence and severity of vertical defects, and furcation lesions in 416 individuals seeking dental care. Full mouth radiographs were enlarged 7.5 times and the mesial and distal distances between CEJ and bone level were measured. The extent of interradicular molar radiolucencies was also measured. Images of 10,282 teeth were studied. Subjects were between 15 to 94 years (mean age: 47.2, S.D. ± 15.2). On average they had 24.8 teeth (S.D.±5.5). The mean distance CEJ-BL increased significantly up to age 45 (r2 = 0.07; β = 0.29; P < 0.0001) and remained stable thereafter r2 = 0.09, β = -0.02, N.S.). The mean distance CEJ-bone level was 1.4 mm (S.D.±0.7) in the 15 to 24 age group; 3.0 (S.D.±1.5) in the 45 to 54 age group; and 3.02 (S.D.±1.4) in the 75 to 94 age group. No vertical defects were found in 163 participants (39.3%); vertical defects ≥ 3.0 mm were found in 30.2% (126). Mesial defects were significantly more common that distal defects (P < 0.001). The extent of horizontal bone loss was correlated to extent of vertical defects (r2 = 0.88; P < 0.0001). The number of remaining teeth was not associated with horizontal or vertical bone loss. In conclusion, the study indicated that few of the individuals had extensive horizontal bone loss. Vertical defects suitable for guided tissue regeneration procedures however, were found in many patients. J Periodontol 1998;69:348–356.