Frequency and Clinical Significance of Incidental Findings on CBCT Imaging: a Retrospective Analysis of Full-Volume Scans.

Objectives: This retrospective study aims to identify incidental findings in cone-beam computed tomography scans of patients irradiated for preoperative evaluation for implant placement and obtained using the same imaging unit as well as the same field of view. The incidence of each incidental finding, as well as the overall incidence, were calculated and the findings were ranked according to their clinical significance.

Material and methods: A total of 741 cone-beam computed tomography (CBCT) examinations with extended field of view (15 x 15 cm) were retrospectively evaluated for incidental findings (IFs). These were identified, recorded, classified as to their location, and ranked according to their clinical significance.

Results: The vast majority of CBCT examinations presented at least one IF, resulting in a surprisingly high prevalence in total. If extreme anatomical variants are considered (nasal septum deviation, sinus septations etc.), the cumulative prevalence exceeds 99%. IFs of major significance, that may require immediate attention, are beyond 10% in frequency.

Conclusions: We found high prevalence of incidental findings on cone-beam computed tomography examinations performed for preoperative evaluation for implant placement (99.5% if anatomical variants included). Most incidental findings were of minor significance. Although the number of incidental findings that require immediate attention is relatively low, there is a considerable number of cases that need periodic evaluation and/or referral.