Digital breast tomosynthesis (DBT) has the potential to enhance breast cancer detection by reducing the confounding effect of superimposed tissue associated with conventional mammography. In addition the increased volumetric information should enable temporal datasets to be more accurately compared, a task that radiologists routinely apply to conventional mammograms to detect the changes associated with malignancy. In this paper we address the problem of comparing DBT data by combining reconstruction of a pair of temporal volumes with their registration. Using a simple test object, and DBT simulations from in vivo breast compressions imaged using MRI, we demonstrate that this combined reconstruction and registration approach produces improvements in both the reconstructed volumes and the estimated transformation parameters when compared to performing the tasks sequentially.