At age seven Massai kids are taken by their parents and a knife is placed between their lower teeth and twisted (much like a screwdriver) until the teeth are removed. If you refuse you are called a coward.
This tradition I am told was originated by the Massai because of the prevalence of Tetanus.. As you know one of the cardinal symptoms of tetanus is the locking of the jaws together and inability to open the mouth. If a Massai developed Tetanus he or she could still feed by the gap left on the lower jaw from the extracted teeth.
This boy had accepted this tribal tradition. Many we have met refused. They are called Cowards..and some are excluded from the tribe (although this tradition is dying).
At 16 years old a Massai is expected to walk into the Bush and not return for 6 months. He shall come back in 6 months and after he has killed a lion. Although this tradition is fading away too (thanks to Game Park regulations) it is still occasionally accomplished.