Somatosensory information from peripheral sensory neurons innervating the oral region is projected into the thalamus via the trigeminothalamic tract and from there to the primary somatosensory cortex. Representation of oral sensation in the human primary somatosensory cortex has been demonstrated by invasive technique (direct cortical stimulation and intracranial recording of somatosensory-evoked potentials) and non-invasive neuroimaging. The present review describes the projection pathway of the human trigeminothalamic tract and the cortical somatotopic organization of the dent-oral structure-representing area in the primary somatosensory cortex, and gives a brief introduction to non-invasive neuroimaging.