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Intra- and Inter-observer Agreement In Evaluation Of Periapical Lesions Using The Periapical Index: Comparison of Periapical and Panoramic Radiographs

Esra Seden Navruz


Suleyman Demirel University, Department of Oral and Maxillofacial Radiology


Introduction: As a result of trauma or infection, inflammation can occur on periapical region. Radiological evaluation is important in the determination of periapical lesions. The periapical index (PAI) demonstrates a 5 scale scoring for periapical region.

Aim: The aim of this study was to assess observer complience in the radiographic evaluation of periapical lesions by using PAI on periapical and panoramic radiographs according to jaw regions and imaging methods.

Material and Methods: Patients aged 18–45 (mean age±sd: 30.89±6.84) years with periapical lesion detected on panoramic radiographs that had underwent at periapical imaging for endodontic treatment were involved in the study. Periapical and panoramic radiographs of 180 patients were exported in TIFF format and numbered. The observers calibrated for the PAI system by evaluating 50 images. Initially panoramic radiographs and after two weeks periapical radiographs were evaluated by the blinded observers according to PAI. 30 teeth for 6 different regions (maxillary molar, premolar, incisor, mandibular molar, premolar, incisor) were evaluated. Intra- and interobserver agreement were described by using kappa statistics.

Results: The visual analysis of panoramic radiographs revealed intra-observer agreement of 0.85 for observer 1 and 0.63 for observer 2, and an inter-observer agreement of 0.45. The intra-observer agreement for periapical radiographs was 0.87 and 0.71 for observers 1 and 2, respectively, and the inter-observer agreement was 0.62. The highest values of interobserver agreement were observed for mandibular molar teeth both on periapical (κ=0.67) and panoramic radiographs (κ=0.49). The intra-observer agreement for the evaluation of the same teeth on panoramic and periapical images was 0.65 and 0.43 for observers1 and 2, respectively.

Conclusions: PAI scoring on periapical radiographs demonstrated higher intra and inter- observer agreement than panoramic radiographs. Training on the method and becoming experienced of the examiners is recommended to obtain high agreement.