Three-dimensional localization of tooth germs without ionizing radiation : Proof-of-concept study using magnetic...

This study aimed to evaluate the feasibility and accuracy of using magnetic resonance imaging (MRI) for the three-dimensional (3D) localization of tooth germs. A MRI 3D dataset was compared to a cone-beam computed tomography (CBCT) dataset, which is the current gold standard method in the localization of tooth germs. In this proof-of-concept study, the potential of eliminating the exposure of patients to ionizing radiation for tooth germ localization was evaluated.

A halved pig head (Sus scrofa domestica) was imaged with MRI and CBCT. The MRI data were manually segmented using InVesalius 3.1.1 (Centro de Tecnologia da Informação Renato Archer, Campinas, Brazil) to generate a 3D model, later processed in OnyxCeph3™ (Image Instruments GmbH, Chemnitz, Germany). The CBCT data were directly imported into OnyxCeph3™ for processing. Both datasets were combined with intraoral scans, and 12 raters took measurements to compare the ability to localize tooth germs with the help of the two modalities.

A total of 144 measurements were obtained (2 modalities × 6 measurement sections × 12 raters). The interrater reliability was high (intraclass correlation coefficients [ICCs] ≥ 0.99 for both modalities). The average differences between CBCT and MRI measurements ranged between -0.43 mm (Bonferroni-Holm-corrected 90% confidence interval [-0.69 mm, -0.16 mm]) and 0.48 mm [0.34 mm, 0.63 mm] and were equivalent with respect to a margin of -1 mm to 1 mm in all measurement sections (Bonferroni-Holm-corrected P < 0.01 in all sections).

MRI demonstrates high potential as a nonionizing alternative to CBCT for 3D localization of impacted and displaced teeth, particularly in children and adolescents. The fluid-filled dental follicle provides excellent contrast in MRI, aiding precise localization. Future clinical studies with larger sample sizes are essential for validation.