Incidental findings in cone beam computed tomography (CBCT) scans for implant treatment planning: a retrospective study of 404 CBCT scans

Abstract

Objectives: To investigate the prevalence of incidental findings and need for further dental treatment and analyse the influence of size of field-of-view (FOV) and age in cone beam computed tomography (CBCT) for pre-implant planning.

Methods: 404 CBCT scans were examined retrospectively for incidental findings and need for further dental treatment. Incidental finding-frequencies and need for further treatment were assessed for different age (< 40 years, 40-60 years, > 60 years) and FOV groups (small, medium, large). Intraexaminer and interexaminer agreements were evaluated.

Results: In 82% of the scans at least one incidental finding was found, with a total of 766 overall. More incidental findings were found in scans with large FOV (98% vs. 72%, OR = 22.39 large vs. small FOV, p < 0.0001) and in scans of patients > 60 years (OR = 5.37 patient's age > 60 years vs. < 40 years, p = 0.0003). Further dental treatment due to incidental findings was needed in 31%. Scans with large FOV were more likely to entail further treatment (OR = 3.55 large vs. small FOV, p < 0.0001). Partial edentulism and large FOV were identified as risk factors for further treatment (p = 0.0003 and p < 0.0001). Further referral of the patient based on incidental findings was judged as indicated in 5%. Intra- and inter-examiner agreements were excellent (kappa = 0.944/0.805).

Conclusions: A considerable number of incidental findings with need for further dental treatment was found in partially edentulous patients and in patients > 60 years. In pre-implant planning of elderly patients, the selection of large FOV CBCT scans, including dentoalveolar regions not X-rayed recently, help to detect therapeutically relevant incidental findings.

Keywords: Cone beam computed tomography; Dental implant planning; Field of view; Incidental finding; Maxillofacial radiology.

Fig. 1

Small volume (4 × 4cm) CBCT scan of a 36-year-old male patient for implant pre-treatment examination in lower first molar position. A periapical radiolucency (apical lesion) of the root-treated neighbouring second premolar was identified as incidental finding. Sagittal (A), coronal (B) and axial (C) image

Fig. 2

CBCT scan for digital implant planning with large FOV (10 × 10 cm) in a partially edentulous 79-year-old male patient. Opacification (over 50%) of the partially imaged left maxillary sinus antrum with inhomogeneous osseous appositions basally and absence of the left lateral nasal wall is conspicuous. In the right maxillary sinus, an opacification was present in the lower half of the antrum. Due to the incidental findings in the maxillary sinuses, further evaluation by an otorhinolaryngologist was indicated. Sagittal (A), coronal (B) and axial (C) images

Fig. 3

CBCT scan of a 71-year-old female patient with a small FOV (6 × 4 cm) for implant pre-treatment examination in free-end posterior right lower jaw. In the lower right wisdom tooth position a radiopaque concrement of dental filling material with circumferential radiolucency is visible. Furthermore, multiple small radiopaque concrements are recognizable in the residual socket and adjacent to the bone in the soft tissue (fragmented dental material in bone/in soft tissues). In the axial plane dish-like root remnants are identifiable in second premolar site, where implant placement was planned. Sagittal (A), coronal (B) and axial (C) images

Fig. 4

CBCT scan of a 41-year-old female patient with a large FOV (10 × 10 cm) with multi-unit gaps. A cervical root resorption was discovered as an incidental finding on the second lower left molar. Furthermore, in the coronal plane (B) a small radiopaque concrement is visible on the buccal bone as well as circumferential thickening of the maxillary sinus mucosa in the left maxillary sinus. Sagittal (A), coronal (B) and axial (C) images