Selection of the most accurate method of conventional radiography for the assessment of periodontal osseous destruction.

The purpose of the present study was to compare the radiographic measurements of periodontal osseous destruction with the surgical measurements, which represent the true value of osseous destruction, and to select the most successful method of conventional radiography in detecting and accurately assessing periodontal osseous destruction. A total of 5072 proximal surfaces in 2536 teeth of 100 patients with periodontitis were evaluated surgically during periodontal flap surgery and radiographically by using periapical and panoramic radiography. Comparative evaluation of the measurements obtained by these 3 different methods of osseous destruction assessment revealed the following. (1) The radiographic detection ability of small osseous destruction (1-4 mm) was very low for both methods of assessment and became even lower for the initial osseous destruction (1 or 2 mm). (2) Periapical radiography was more successful than panoramic in the detection of osseous destruction, especially of the small destruction (4.7x). (3) Panoramic radiography underestimated the osseous destruction, whereas periapical radiography was relatively accurate in the osseous destruction assessment. (4) Periapical radiography was more accurate in the osseous destruction assessment than panoramic, regardless of the location of the dental surfaces (jaw, tooth group, mesial or distal) and the degree of osseous destruction. (5) The deviation of the radiographic measurements of osseous destruction from the surgical measurements, as well as the difference between the two radiographic methods, depended on the jaw location, the tooth group and the degree of osseous destruction. (6) The radiographic assessment of osseous destruction underestimated the osseous destruction in initial periodontitis, it was relatively accurate in moderate periodontitis, but overestimated it in severe periodontitis. The radiographic measurements of osseous destruction deviated least from the surgical measurements in the group of moderate periodontitis and most in that of severe osseous destruction. (7) The 2 radiographic methods agreed most in the assessment of osseous destruction in the severe periodontitis group and least in the initial periodontitis group. (8) The indirect Schei method was less successful in detecting the small osseous destruction and less accurate in assessing the osseous destruction than the direct millimetric method of radiographic evaluation. (9) The osseous destruction as assessed from periapical radiographs by the Schei method was not significantly different from that assessed by the radiopaque Fixot-Everett grid. The results of the present study suggest that periapical radiography is more successful in detecting periodontal osseous destruction and more accurate in assessing it than panoramic radiography.