Microglia, the resident macrophages and phagocytic immune cells of the brain, play an important role in neurodevelopment—yet a fundamental question is whether these same roles have evolved in other regions of the fetus. My research is targeted at addressing this question by studying the contribution of macrophages to processes that shape the development of the skull and face (i.e., craniofacial morphogenesis), and whether distinct populations of these immune cells signal locally to contribute to normal development. During pregnancy, disrupting macrophage functions results in craniofacial and dental abnormalities. To explore the developmental contribution of these immune cells to the craniofacial region, we will use our established pharmacological mouse model alongside state-of-the-art expression profiling and imaging technologies. By studying how macrophages contribute to normal development of craniofacial tissues, this research will lead to advancements in our understanding of how maternal insults like maternal periodontal infection—a prevalent condition associated with adverse pregnancy outcomes—disrupts developmental programs. Overall, this research will broaden our knowledge of maternal-fetal interactions to benefit Canadians.