Comparison of the 3D-Microstructure Between Alveolar and Iliac Bone for Enhanced Bioinspired Bone Graft Substitutes

Abstract

In oral- and maxillofacial bone augmentation surgery, non-vascularized grafts from the iliac crest demonstrate better clinical performance than alveolar bone grafts. The underlying mechanisms are not fully understood but are essential for the enhancement of bone regeneration scaffolds. Synchrotron Radiation µ-CT at a pixel size of 2.3 μm was used to characterize the gross morphology and the vascular and osteocyte lacuna porosity of patient-matched iliac crest/alveolar bone samples. The results suggest a difference in the spatial distribution of the vascular pore system. Fluid simulations reveal the permeability tensor to be more homogeneous in the iliac crest, indicating a more unidirectional fluid flow in alveolar bone. The average distance between bone mineral and the closest vessel pore boundary was found to be higher in alveolar bone. At the same time, osteocyte lacunae density is higher in alveolar bone, potentially compensating for the longer average distance between the bone mineral and vessel pores. The present study comprehensively quantified and compared the 3D microarchitecture of intraindividual human alveolar and iliac bone. The identified difference in pore network architecture may allow a bone graft from the iliac crest to exhibit higher regeneration potential due to an increased capacity to connect with the surrounding pore network of the residual bone. The results may contribute to understanding the difference in clinical performance when used as bone grafts and are essential for optimization of future scaffold materials.

Impact of the adjacent bone on pseudarthrosis in mandibular reconstruction with fibula free flaps

“…However, there are also studies showing the opposite: Rothweiler et al compared the three-dimensional microstructure of alveolar and iliac bone and found a greater distance from mineralized tissue to the closest pore-vessel boundary in alveolar bone, which was associated with a worse regenerative potential of the alveolar bone [ 29 ]. Also, the more rapid proliferation of orofacial human bone marrow stromal cells in vitro could not be proven in vivo, where iliac crest cells formed more compacted bone and were more responsive to osteogenic induction [ 26 ].…”

Mass spectrometry‐based proteomic applications in dental implants research

“…Small osseous defects are frequently augmented with xenogenic, allogenic or synthetic materials, yet autologous bone grafts remain mandatory for the reconstruction of large defects (>5 mm) [29,30]. These autologous bone grafts can be harvested from different anatomical sites, for example, mandibula, iliac crest or fibula, underlying biological differences have been discussed on the macro-and microstructural level [31][32][33]. Research on the molecular characteristics of alveolar bone is still in its infancy.…”

Uncovering the unique characteristics of the mandible to improve clinical approaches to mandibular regeneration

“…The microstructure of the mandible also differs from that of other bones. Compared with the iliac, the cortical bone of the mandible has a smaller vessel surface to bone volume ratio, and therefore a lower vessel porosity (Rothweiler et al, 2022) Frontiers in Physiology frontiersin.org and lacuna distribution have a more heterogeneous spatial distribution in the mandible than in the tibia or femur (Hesse et al, 2014). There is a higher bone density surrounding the mandibular LCN (Hesse et al, 2015).…”

“…When mandibular grafts are used, there is a slower vertical loss of the graft; furthermore, they have a lower incidence of peri-implantitis (Kang et al, 2015) and a higher implant survival rate (Sbordone et al, 2009). However, when grafts larger than 5 mm are needed, iliac bone grafts can lead to better results, as they have a structure that allows greater blood perfusion, a necessary trait for larger grafts (Troeltzsch et al, 2016;Rothweiler et al, 2022).…”