Marzia Ferretti

The aim of this study was to morphologically evaluate the differences in the cutting surfaces of bone segments obtained by reciprocating saw (RS) and two piezosurgical devices (Piezosurgery Medical—PM—and Piezosurgery Plus—PP) in ex vivo human fibulae. The ultimate goal was to identify the presence of debris, scratches, and microcracks on the cutting surface that might affect bone healing, a key aspect in oral and maxillofacial surgery. Ten patients who underwent a microsurgical reconstruction of the mandible with a free fibula flap were enrolled. The fibula segments usually discarded after surgery were cut using RS, PM, and PP, obtaining transverse sections to analyze under an environmental scanning electron microscope to perform a histomorphological qualitative evaluation. Bone surfaces cut with the RS presented several scratches, and haversian canals were frequently filled with bone debris/chips. On the contrary, PM and PP devices produced smoother and sharper cutting surfaces, with lower production of bone debris/chips, preventing vascular spaces’ closure. Microcracks were found in both PM and PP cut specimens, and they could be associated with the triggering of bone remodeling, thus improving the formation of new bone, while their presence was rarely observable in RS cut samples. The use of piezosurgical devices showed superior performance, providing cleaner and smoother cutting surfaces that favor vascularization and bone remodeling; altogether, these processes could lead to accelerated bone healing, a fundamental goal in all surgical procedures that involve bone cutting.

It’s known that a magnesium (Mg)-deficient diet is associated with an increased risk of osteoporosis. The aim of this work is to investigate, by a histological approach, the effects of a Mg-deprived diet on the bone of 8-weeks-old C57BL/6J male mice. Treated and control mice were supplied with a Mg-deprived or normal diet for 8 weeks, respectively. Body weight, serum Mg concentration, expression of kidney magnesiotropic genes, and histomorphometry on L5 vertebrae, femurs, and tibiae were evaluated. Body weight gain and serum Mg concentration were significantly reduced, while a trend toward increase was found in gene expression in mice receiving the Mg-deficient diet, suggesting the onset of an adaptive response to Mg depletion. Histomorphometric parameters on the amount of trabecular and cortical bone, number of osteoclasts, and thickness of the growth plate in femoral distal and tibial proximal metaphyses did not differ between groups; these findings partially differ from most data present in the literature showing that animals fed a Mg-deprived diet develop bone loss and may be only in part explained by differences among the experimental protocols. However, the unexpected findings we recorded on bones could be attributed to genetic differences that may have developed after multiple generations of inbreeding.