Cone beam computed tomography (CBCT) is an indispensable diagnostic imaging tool for dento-alveolar examination. CBCT scanning has become a valuable imaging modality in the field of Periodontology for the detection of very small osseous defects. A patient reported to the department of Periodontology with a complaint of loose teeth. Clinical and direct digital radiographic (DDR) examination revealed advanced periodontal destruction, but failed to diagnose the morphology of generalized osseous defects, around all the surfaces of each tooth. CBCT images were obtained for detailed examination of each and every osseous defect around all the teeth. Patient was then diagnosed with generalized aggressive periodontitis. Flap surgery was performed in order to eliminate the periodontal pockets, exposing and degranulating the osseous defects. Actual measurements of surgically exposed osseous defects were compared with that seen in CBCT images and found to be exactly identical. CBCT has proved to be as accurate in measuring osseous defects as direct measurements with a periodontal probe. Buccal and lingual periodontal defects that could not be diagnosed by conventional radiography can be identified with CBCT.