The topographical mapping of input is a fundamental organizing principle of sensory pathways. In the somatosensory system, a precise topographical representation of the face is first generated in the brainstem and then faithfully replicated in the thalamus and cortex. Although our knowledge of the distinct polysynaptic pathways that link cutaneous mechanoreceptors of the face with neocortical neurons has recently expanded, the molecular mechanisms controlling their neuron-type-specific assembly during development remain poorly understood. The increasing availability of genetic tools that enable manipulation of these developing circuits with cellular resolution now opens new perspectives in our understanding of the molecular mechanisms through which input from the periphery is converted into patterned central pathways.