Skull anatomy by Leonardo da Vinci. Historicalartwork and notes on the anatomy of the humanskull and teeth, by the Italian artist andscientist Leonardo da Vinci (1452-1519). Thisbisected skull shows the external structure(right), and dissected facial sinuses (left), theair-filled spaces inside the bones of the face.The diagram at lower left shows the teeth presentin one half of the mouth: 4 incisors, 2 canines, 4pre-molars, and 6 molars. Da Vinci was the firstanatomist known to have correctly noted the numberand root structure of human teeth. The notes arean example of his mirror writing, which waswritten backwards from right to left, and could beread in a mirror.. Stunning Photo Gifts From Science Photo Library