Biophysical regulation of osteotomy healing: An animal study

Abstract

Background Osteotomies have been performed for centuries yet there remains a remarkable lack of consensus on optimal methods for cutting bone. There is universal agreement, however, that preserving cell viability is critical. Purpose To identify mechanobiological parameters influencing bone formation after osteotomy site preparation. Materials and Methods A murine maxillary osteotomy model was used to evaluate healing. Computational modeling characterized stress and strain distributions in the osteotomy, as well as the magnitude and distribution of heat generated by drilling. The impact of osteocyte death and bone composition were assessed using molecular and cellular assays. Results The phases of osteotomy healing in mice align closely with results in large animals; in addition, molecular analyses extended our understanding of osteoprogenitor cell proliferation, differentiation and mineralization. Computational analyses provided insights into temperature changes caused by drilling and the mechanobiological state in the healing osteotomies, while concomitant cellular assays correlate drill speed with osteocyte apoptosis and bone resorption. Even when drilling was controlled, trabeculated, spongy (Type III) bone healed faster than densely lamellar (Type I) bone because of the abundance of Wnt responsive osteoprogenitor cells in the former. Conclusions These data provide a mechanobiological framework for evaluating tools and technologies designed to improve osteotomy site preparation.

Effects of a Pasty Bone Cement Containing Brain-Derived Neurotrophic Factor-Functionalized Mesoporous Bioactive Glass Particles on Metaphyseal Healing in a New Murine Osteoporotic Fracture Model

“…Our animal model does not allow a surgical approach of the proximal femur because of unpractical accessibility of this region and possible damage of tendons which would essentially restrict mice’s motion. Even though, metaphyseal osteotomy using the piezosurgery technique creates defects similar to fractures seen in the clinic, it can cause high temperatures in the defect area which might lead to cell death at the cut edge [ 19 ]. Still, piezosurgery is the preferential technique since osteocyte viability was significantly higher when compared to bur defects [ 20 ].…”

A Review of the Impact of Implant Biomaterials on Osteocytes

“…Preparation of the implant site with drilling tools creates a zone of apoptotic osteocytes around the osteotomy ( Chen et al 2017 ), the extent of which correlates directly with the drilling speed and the resulting thermal injury ( Wang et al 2017 ). Evidence suggests that, being mechanosensors, osteocyte-like MLO-Y4 cells induce osteoclastic differentiation under supraphysiologic loading ( Fahlgren et al 2018 ).…”

Radiological implications of crestal and subcrestal implant placement in posterior areas. A cone-beam computed tomography study

“…Experimental studies in animals ( 17 , 18 ) have reported a greater percentage bone-to-implant contact (BIC) in trabecular bone compared with cortical bone. Wang et al ( 29 ) likewise in an experimental study in animals, observed a greater presence of osteoprogenitor cells in type II and III bone, resulting in faster production of new bone than in type I bone. In this respect, Sotto-Maior et al ( 30 ) in a finite element analysis, recorded a decrease in compressive peri-implant tension when the implants were placed subcrestal (34.1 MPa), becoming completely surrounded by trabecular bone.…”