Comparison of conventional two-dimensional and digital three-dimensional imaging in orthodontics : A systematic...

Digital imaging techniques are important in dental diagnostics and therapy planning. Thus, the goal was to investigate the current state of the science regarding two- (2D) and three-dimensional (3D) imaging for clinical orthodontic issues via a systematic literature review and meta-analysis.

Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, the search was carried out using common electronic databases with the following terms: cbct AND opt AND dentistry, cbct AND opt AND orthodontics, cbct AND opt, three-dimensional imaging AND two-dimensional imaging AND orthodontics, cbct AND lateral cephalogram. A forest plot was utilized to depict the standardized mean differences (SMD) using a random-effects model to account for study heterogeneity. Heterogeneity assessment of the various trials was conducted using the I²-value and the Q‑test.

Of the 362 articles (1987-2023) identified, 41 articles met the inclusion criteria. The studies were categorized into four groups based on clinical background: mini-implant placement, root resorptions, impacted canines and cephalometric measurements. For mini-implant placement, 4 papers explored the benefits of 3D imaging. Root resorption detection was the focus of 4 studies, while 8 articles investigated 3D diagnostics for impacted canines. Overall, while 2D imaging suffices for evaluating mini-implant placement, CBCT images offer enhanced accuracy for investigating root resorptions and improved sensitivity in identifying impacted canines. Comparability of 2D and 3D imaging, with a focus on cephalometric measurements, was evaluated in 25 studies. Within this group, 10 papers were included in a meta-analysis, comparing SNA, SNB and ANB angle measurements. The random-effects model was used to compare the results of the SNA, SNB and ANB angles, which were presented in forest plots. No significant differences were found in the comparison of 2D and 3D imaging techniques for the SNA angle (p = 0.338; SMD = 0.39; 95% CI -0.40 to 1.18), the SNB angle (p = 0.650; SMD = 0.11; 95% CI -0.35 to 0.57), and the ANB angle (p = 0.666; SMD 0.89; 95% CI -0.32 to 0.50), whereby heterogeneity was high for all (I² = 90.27%, p < 0.001, I² = 76.81%, p = 0.004, and I² = 93.29%, p < 0.001, respectively).

Based on the findings and the additional meta-analysis, 3D imaging is either equivalent or potentially superior to conventional 2D imaging for all subgroups. Further studies are required.