[header] How to choose a toothbrush [title] Make sure your toothbrush works for the shape of your mouth. [step] Based on past toothbrushes, you should have some idea of the general shape of your mouth. Some mouths are more narrow or wide than others, and you need a toothbrush that works for your mouth and teeth. 
[substeps] You want a brush that can comfortably reach the back of your molars. The shape of your mouth, and whether it's wider or narrower, will affect how easily a given brush can reach your molars.