Do you have a clipper blade that is not combing through the hair? One thing that may be happening is a bent tooth on the comb blade. The picture to the left is a #40 comb blade. If you look close you will see a bent tooth in the middle. I would not recommend trying to straighten these teeth. As soon as you try to straighten a bent tooth on a clipper blade comb, you will break it off. If you break off a tooth, the clipper will grab or drag through the hair in this area. As a groomer this is your call if you want to keep the blade once a tooth is missing. You can still groom your pet. It will just leave a streak in the hair. Once you have several teeth missing, then it is time to replace the blade.
Clipper blade teeth get bent or broken from being dropped or knocked around. Try to avoid tossing blades on a table. Also when shipping a blade to be sharpened, always wrap each blade. I get blades in that are loose in a box and I will usually find a broken tooth.