Structure and remodelling of the human parietal bone: an age and gender histomorphometric study

Abstract

Objective: Despite its clinical usefulness, the internal structure and remodelling of parietal bone remained poorly documented. The aim of this study was to gain reliable information on parietal bone remodelling in living humans.

Materials and methods: This study provided a site-specific analysis of static indices of turnover in relation to gender and age by using leftovers of parietal bone sampled in 100 patients (78 females; 22 males, aged 16-79 years).

Results: The bone architecture, cortical thickness, trabecular volume and cortical volume (C.Th, BV/TV, BV/CV) did not vary with gender. The number of osteoclasts (N.Oc/BPm) and the resorption surface (Oc.S/BS) were higher in females (p<0.05) when osteoclast resorbing activity did not vary with gender. Bone formation, osteoid surface (OS/BS) and surface covered by alkaline phosphatase-positive osteogenic cells (ALPS/BS) were higher in females (p<0.05 and p<0.01 respectively). All these parameters remained stable with aging. The osteocytic parameters, number of osteocytes (Ot.N/B.Ar) and number of osteocyte lacunae (T.L.N/B.Ar) were higher in females (p<0.05) and decreased with age in both genders (p<0.01).

Conclusion: This study highlights the low and stable remodelling in the parietal bone. It appears to be higher in women. This stability probably reflects the low mechanical strains applied to the skull, particularly to the parietal bone.