Comparison between panoramic and periapical radiography in the diagnosis of periodontal bone loss.

Panoramic and periapical radiography was performed on 100 patients. Five observers each registered the scores for marginal bone level, presence of bone defects and furcation involvement in the radiographs of 20 patients and the results were compared. The overall concordance in scoring the marginal bone level was high when panoramic and periapical radiography was compared. In the upper arch, 66% of the sites showed concordant scores, 31% deviated by one and 3% by two score-points. In the lower arch, 74% of sites had concordant scores, 25% deviated by one and 1% by two score-points. The panoramic radiographs more often indicated a more severe bone loss than the periapical radiographs. The concordance was related to the degree of bone loss. In sites with no bone loss the concordance was high whereas it was lower in those with severe bone loss. The concordance of the two radiographic methods for the mandibular canine, premolars and first molar was equally as high as the intra-observer overall agreement, but lowest for the mandibular central incisors and the maxillary molars. Bone defects were more easily identified by periapical radiography.