Diagnosis
Diagnosis
Periapical radiographs reveal the characteristic periapical radiolucency — ranging from subtle widening of the PDL space to a well-defined, corticated radiolucent lesion (suggesting cyst) or a diffuse, poorly-defined radiolucency (suggesting granuloma). The radiographic appearance does NOT reliably distinguish granuloma from cyst histologically.
CBCT provides 3D dimensions, cortical expansion or perforation, relationship to adjacent structures (inferior alveolar canal, maxillary sinus), and identifies accessory lesions from lateral canals not visible on 2D films. It is indicated for large lesions, surgical planning, and when standard radiographs are inconclusive.
Sinus tract tracing: when a sinus tract is present, inserting a gutta-percha point into the tract and taking a radiograph (sinus tract tracing) reveals the origin of the tract — typically the apex of the offending tooth. This is a simple, reliable diagnostic technique.
Definitive diagnosis is histological: periapical surgery provides tissue for biopsy. All surgical periapical specimens should be submitted for histopathological examination to exclude rare but important pathologies (cystic ameloblastoma, KCOT, central giant cell granuloma) that may mimic chronic apical periodontitis radiographically.