Curved Planar Reformation: A Useful Method for Screening Dental Pathologies in Chronic Rhinosinusitis via Paranasal Sinus Computed Tomography

Abstract

(1) Background: Curved planar reformation (CPR) is a multiplanar reformatting technique of computed tomography (CT) commonly used during dental cone-beam CT (CBCT) to generate panorex-like images for dental evaluation. Here, we evaluated the utility of an additional CPR sequence in detecting dental pathologies in patients with chronic rhinosinusitis (CRS). (2) Methods: CRS patients who underwent paranasal sinus CT were enrolled retrospectively. The CT images featured three orthogonal sequences and a reconstructed CPR sequence. Additional dental CBCT was performed in patients with pathologies with a strongly suspected odontogenic origin. Dental pathologies detected by CT, CPR, and CBCT were analyzed. (3) Results: A total of 82 CRS patients (37 females and 45 males; mean age 47.3 ± 13.7 years) were included, of whom 23 underwent dental CBCT. In total, 1058 maxillary teeth were evaluated. Compared with paranasal sinus CT, CPR identified greater frequencies of dental pathologies, particularly caries (p < 0.001), periapical lesions (p < 0.001), and fistulae (p = 0.014). CBCT identified greater frequencies of periodontal dental pathologies (p = 0.046) and premolar caries (p = 0.002) compared with CPR. CBCT and CPR detected molar dental pathologies at similar frequencies. (4) Conclusions: CPR could increase the diagnostic rate of odontogenic pathologies compared with standard CT orthogonal views, especially when the sinusitis is caused by caries, periapical lesions, or fistulae. The addition of a CPR sequence allows for simple screening of dental pathologies in CRS patients without a need for additional radiation.

Keywords: cone-beam computed tomography; curved planar reformations; dental pathology; fistula; odontogenic sinusitis; periapical lesion.

Figure 1

Continuous panoramic images of the maxillary teeth for detecting dental pathologies were yielded after CPR. (A) A series of CPRs were generated by drawing a reference line (red line) along the centerline corresponding to the maxillary teeth. Continuous CPR images were reconstructed according to lines parallel to the reference line. (B) A simulated dental panoramic image was created after reconstruction. (C) CPR detected a periapical abscess with a fistula in a left maxillary molar (no. 26, *).

Figure 2

CPR and dental CBCT could identify more dental pathologies than conventional CT images. (A) The parasagittal CT view identified a periapical lesion of a left maxillary molar (no. 27, asterisk); however, both (B) CPR and (C) CBCT revealed a co-existing fistula (*).