Rabbit calvarial and mandibular critical-sized bone defects as an experimental model for the evaluation of craniofacial bone tissue regeneration.

Introduction: Many studies have aimed to investigate the regeneration potential of bone substitutes through animal models at different defect sites, where the bone healing mechanism varies due to developmental, structural and functional differences. This study aims to develop a rabbit model with two functionally different (non-load-bearing calvarias and load-bearing mandibular) critical-sized defects (CSD) in one rabbit.

Material & Method: The comparison of the "gold standard" autograft to a sham (no graft) control was undertaken in order to validate this model; at the same time, a 3D-printed biphasic calcium phosphate scaffold was implanted to test its utility in the evaluation of new bone substitute materials.

Chitosan/Polycyclodextrin (CHT/PCD)-Based Sponges Delivering VEGF to Enhance Angiogenesis for Bone Regeneration.

Vascularization is one of the main challenges in bone tissue engineering (BTE). In this study, vascular endothelial growth factor (VEGF), known for its angiogenic effect, was delivered by our developed sponge, derived from a polyelectrolyte complexes hydrogel between chitosan (CHT) and cyclodextrin polymer (PCD). This sponge, as a scaffold for growth factor delivery, was formed by freeze-drying a homogeneous CHT/PCD hydrogel, and thereafter stabilized by a thermal treatment.

Are the evaluation criteria used in preclinical endodontic training courses relevant? A preliminary study.

This study aimed to evaluate the relevance of a conventional evaluation protocol (CEP) for preclinical endodontic training. Seven dental students performed root canal treatments on an extracted human molar which was then evaluated by CEP (clinical and radiographic observations, including preparing the access cavities, preparing and filling the root canal, and detecting iatrogenic errors). A reference evaluation protocol (REP) based on micro-computed tomographic images analysis was used as a control.

Sirtuin 1 deficiency decreases bone mass and increases bone marrow adiposity in a mouse model of chronic energy deficiency.

Sirtuin of type 1 (Sirt1), a class III HDAC, is known to be involved in the regulation of differentiation of skeletal stem cells (SSCs) into osteoblasts and adipocytes. In caloric restriction, it has been shown that the expression and activity of Sirt1 is a tissue-dependent regulation. However, at present, no study has focused on the link between Sirt1, bone marrow adiposity (BMA) and osteoporosis related to anorexia nervosa (AN).

T1-weighted MRI images accurately represent the volume and surface of architectural mineral damage of osteonecrosis of the femoral head: Comparison with high-resolution computed tomography.

The potency of magnetic resonance imaging (MRI) to measure the exact extent of osteonecrosis of the femoral head (ONFH) remains uncertain. The objective of this study was to determine if the volume of necrosis assessed with MRI accurately reflects the volume of architectural mineral alterations in osteonecrosis of the femoral head by comparison with high-resolution microfocus X-ray computed tomography (HR-μCT). Fourteen male patients aged 53 years [46.

Mandibular bone is protected against microarchitectural alterations and bone marrow adipose conversion in ovariectomized rats.

Osteoporosis is a disease that leads to a loss of bone mass and to alterations in the bone microarchitecture that occur in a site-specific manner; however it remains controversial in the jaw. The involvement of bone marrow adipose tissue (BMAT) in the bone metabolism has been suggested in several physiopathological contexts, such as in aging and osteoporosis. To test whether the BMAT content is related to mandibular bone loss, this study aimed to investigate the potential correlations between the trabecular bone microarchitecture on one hand and BMAT content and its spatial distribution in relation to bone surface on the other hand during aging and ovariectomy (OVX) during a long-term follow-up in a mature rat model.

A Novel microCT Method for Bone and Marrow Adipose Tissue Alignment Identifies Key Differences Between Mandible and Tibia in Rats.

Bone homeostasis is influenced by the bone marrow adipose tissue (BMAT). BMAT distribution varies from one anatomical location in the skeleton to another. We developed an advanced microfocus computed tomography imaging and analysis protocol that allows accurate alignment of both the BMAT distribution and bone micro-architecture as well as calculation of the distance of the BMAT adipocytes from the bone surface.