Frequency and Characteristics of Incidental Findings Using Cone-Beam Computed Tomography in an Orthodontic Population

Abstract

Objectives: To explore the nature and frequency of incidental findings in large field of view cone-beam computed tomography (CBCT). Additionally, to assess the agreement among orthodontic clinicians in the assessment of the impact of maxillofacial findings identified in CBCT imaging. Methods: A total of 427 consecutive CBCT radiologic reports obtained for orthodontic purposes were retrospectively reviewed. All findings were categorized into six anatomic categories for descriptive purposes. Additionally, using a sub-sample of these findings, the agreement between 3 orthodontists was assessed with respect to need for further follow-up and potential impact of the findings on orthodontic treatment. Results: A total of 842 incidental findings were reported in the 427 CBCT scans (1.97 findings/scan). The most prevalent findings were those located in the airway (42.3%), followed by the paranasal sinuses (30.9%), dentoalveolar (14.7%), TMJ (6.4%), surrounding hard/soft tissues (4.0%), and cervical vertebrae (1.3%) regions. Non-odontogenic findings represented 718 of the 842 (85.3%) findings. In terms of agreement when assessing clinical significance of the findings, subjects demonstrated “fair-to-good” inter-rater agreement regarding CBCT findings in terms of the need for further follow-up and the potential impact on future orthodontic treatment. Subjects demonstrated “excellent” intra-rater agreement in the assessment of CBCT findings regarding both need for follow-up and potential impact on future orthodontic treatment. Conclusions: This study demonstrates the high occurrence of incidental findings in large field of view CBCT scans in a sample of orthodontically referred cases. The majority are extragnathic findings, which can be normally considered outside the regions of interest of many dental clinicians, but which may still require follow-up and/or management. Specifically, incidental findings in the nasal-oral-pharyngeal and paranasal air sinuses are the most frequent. Subjects demonstrated higher levels of agreement for dentoalveolar findings compared with all other extragnathic regions when assessing clinical significance.