To learn to draw cartoon teeth, study the shape of teeth, and observe their placement in the mouth, sketch practice teeth and stylize or exaggerate the teeth as necessary to match the style of the cartoon. While looking at photographs or models for reference, break the teeth down into basic shapes, and look at how they fit together inside the mouth. Understanding mouth anatomy helps you draw teeth that complement the rest of your cartoon.
Caricature drawing tutorials, such as those on artist Tom Richmond's website, often illustrate different ways to draw cartoon teeth. You can draw very simple teeth by adding a few lines to your cartoon's mouth, or you can add more complex details, such as gum lines, gaps and buck teeth. If drawing a cartoon of a specific person, study what makes your subject's teeth distinctive and include that in your cartoon.
If you wish to draw a cartoon of a tooth, you can find references by studying photographs of teeth or searching clip-art websites such as ClassroomClipart.com for similar cartoons. Different kinds of teeth have different shapes, so decide what kind of tooth you wish to draw before starting. You may want to add details or props, such as a toothbrush or an award for a successful dentist visit, to your cartoon tooth.