In a developing human jaw, different homeobox genes are activated in different areas, guiding each tooth bud down a pathway to become a molar, premolar, canine or incisor.

• 在发育中的人类颌部，不同的同源匣基因会在不同的位置活化，引导各个牙胚变成臼齿、前臼齿、犬齿或门齿。