Microstructure characterization of the human frontal bone

•Microstructure characterization of human frontal bone from micrometer to atomic scale.•An obvious layered structure with alternately arranged compacted and loose layers.•A bunch of single-crystalline hydroxylapatite nanowhiskers forming a texture structure.•A high density of hydroxylapatite nanoparticles without a preferential orientation.

The frontal bone plays a vital role in supporting and protecting the delicate nervous tissue of the brain. Knowledge of microstructure of the frontal bone is of significant importance for craniocerebral and orthopedic operations. Here, through a combined study of X-ray diffraction (XRD) analysis, optical microscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM), we systematically investigate the microstructure of human frontal bone from micrometer to atomic scale. It is found that the frontal bone is mainly composed of hydroxylapatite. At the micrometer scale, the frontal bone appears an obvious layered structure with alternately arranged compacted and loose layers. Down to nanometer scale, the frontal bone in principle consists of a bunch of single-crystalline hydroxylapatite whiskers with an average diameter of ~10 nm.