Trabecular alveolar bone microarchitecture in the human mandible using high resolution magnetic resonance imaging.

OBJECTIVES Cancellous bone microarchitecture in the mandible can influence the success of dental implant osseointegration. The aims of this study were to explore the feasibility of two-dimensional (2D) high resolution magnetic resonance imaging (MRI) for the evaluation of trabecular bone architecture and to compare architecture parameters derived from MR images between different areas in the mandible, and between sex and dental status. METHODS 45 mandibular bone specimens (8 mm thickness) were cut from 15 fresh cadavers. MR images were obtained at 2 T using a multislice 2D spin-echo sequence. After MR image binarization, histomorphometry parameters, i.e. bone area fraction (BAF), specific perimeter (La), trabecular bone width (Tb.Wi), trabecular bone separation (Tb.Sp) and trabecular network anisotropy (R), were computed from the mean intercept length. The angle between trabeculae and tooth axis and the Euler-Poincaré characteristics (EPCs) were also computed. RESULTS BAF, Tb.Wi and R were significantly higher in male specimens compared with female specimens, whereas Tb.Sp was significantly lower. The apparent Tb.Wi was found to be significantly higher in dentate specimens compared with edentulous ones. The highest anisotropy, corresponding to the smallest R value, was seen in the incisal specimens. The preferential orientation of the trabeculae was close to perpendicular to the tooth axis, especially in the molar specimens. CONCLUSION BAF, La, Tb.Wi, Tb.Sp and R, the most variable parameters, may potentially have a relationship with the biomechanical competence of trabecular bone and play a role both in primary stabilization of dental implant and the time needed before loading.