Conventional frontal radiographs compared with frontal radiographs obtained from cone beam computed tomography

Abstract Aim: To test the hypothesis that there is no difference between measurements performed on conventional frontal radiographs (FRs) and those performed on FRs obtained from cone beam computed tomography (CBCT) scans. Materials and Methods: This study consisted of conventional FRs and CBCT-constructed FRs obtained from 30 young adult patients. Twenty-three landmarks were identified on both types of cephalometric radiographs. Twenty-one widely used cephalometric variables (14 linear distances, 4 angles, and 3 ratios) were calculated. Paired t-tests were performed to compare the means of corresponding measurements on two cephalometric radiographs of the same patient. Results: Reproducibility of measurements ranged from 0.85 to 0.99 for CBCT-constructed FRs, and from 0.78 to 0.96 for conventional FRs. A statistically significant difference was observed between conventional FRs and CBCT-constructed FRs for all linear measurements (eurR-eurL, loR-loL, moR-moL, zygR-zygL, lapR-lapL, mxR-mxL, maR-maL, umR-umL, lmR-lmL, agR-agL, me-ans) (P < .05), except for the ans-cr measurement (P > .05). However, no statistically significant differences were noted between conventional FRs and CBCT-constructed FRs for ratios and angular measurements (P > .05). Conclusions: The hypothesis was rejected. A difference has been noted between measurements performed on conventional FRs and those performed on CBCT-constructed FRs, particularly in terms of linear measurements.