Periapical lesions: Assessment of clinical diagnostic accuracy and prevalence of nonendodontic lesions mimicking endodontic pathoses

Aim

Endodontic periapical lesions are prevalent in routine dental practice, yet a substantial proportion of these lesions may not be directly attributable to pulpal infection. This study aimed to assess the diagnostic accuracy of periapical lesions and the prevalence and demographic profiles of nonendodontic lesions misdiagnosed as endodontic in origin.

Methodology

The clinical and pathologic diagnoses of periapical lesions associated with the apex of nonvital or endodontically treated teeth over a 20-year period were systematically collected. These diagnoses were categorized into endodontic and nonendodontic lesions. Endodontic diagnoses included radicular cyst, periapical granuloma, periapical abscess and periapical scar. The diagnostic accuracy, receiver operating characteristics curves and the differences in clinical characteristics of these lesions were subsequently analysed. Additionally, the frequency and clinical data of nonendodontic periapical lesions were tabulated.

Results

Of the 1611 periapical lesions included, 1521 cases (94.4%) were endodontic lesions, whilst 90 cases (5.6%) were nonendodontic in origin. The overall diagnostic accuracy was 91.4%, with areas under curve (AUCs) for diagnosing endodontic and nonendodontic periapical lesions being 0.955 and 0.767, respectively. Clinicians correctly diagnosed endodontic lesions with 95.5% sensitivity, whilst the specificity of diagnosing nonendodontic lesions was 23.3%. Endodontic lesions exhibited a significantly higher prevalence of cases presenting with a size less than 2 cm, exhibiting no swelling and presenting with a rounded radiographic appearance. The frequency of nonendodontic periapical lesions clinically misdiagnosed as endodontic in origin was 69 out of a total sample of 1521 (4.5%). Most lesions (47.8%) affected the anterior maxilla. Odontogenic keratocyst (27.5%) and ameloblastoma (24.6%) were the most common pathoses mimicking endodontic lesions clinically. Malignant neoplasms constitute 5.8% of all nonendodontic periapical lesions, the most common of which were intraosseous squamous cell carcinoma.

Conclusions

Despite the high overall diagnostic accuracy, the specificity of recognizing nonendodontic periapical lesions is relatively low. Clinicians often overdiagnose endodontic lesions clinically. In the presence of periapical lesions with a diameter of 2 cm or more, clinical swelling or a nonrounded radiographic appearance, clinicians should consider the possibility of nonendodontic lesions. Diverse benign and malignant conditions can mimic endodontic pathoses. Tissue biopsy is indispensable for accurate and timely management.