PURPOSE: To understand the bone modeling/remodeling process of functionally loaded implants by observing the alignment of the biological apatite (BAp) c-axis. MATERIALS AND METHODS: Commercially available titanium implants with TiO2 grit-blasted surfaces were placed in the fourth premolar and the first molar of the beagle dog and were functionally loaded with casted crowns and were compared to the non-loaded controls. After being killed, the samples were subjected to histological observation and to a microbeam x-ray diffraction (μXRD) analysis with a transmission optical system to evaluate the preferential BAp c-axis alignment. RESULTS: The non-loaded group presented mostly nonoriented BAp c-axis around the implant, whereas for the loaded group, preferential alignment of BAp c-axis was observed along the loading direction of the implant suggesting that the Bap aligned itself based on the direction of the functional mechanical loading. CONCLUSION: The μXRD revealed that the c-axis orientation was perpendicular to the implant thread working against the functional loaded direction, which may contribute in designing an optimal implant macrogeometry.