How can I determine the age of kittens using a teeth chart?

To determine the age of kittens using a teeth chart, you can look at the development of their teeth. Kittens' teeth start coming in at around 2 weeks old, with all baby teeth usually present by 6 weeks. As they grow, their baby teeth will be replaced by adult teeth starting around 3-4 months old. By examining the number and condition of their teeth, you can estimate their age within a certain range.