Many breeds experience incorrect bites and some breeds have been bred to have them. There are three different types of incorrect bites. An overshot bite is caused when the upper jaw is extended past the lower jaw. This causes difficulties in grasping and in more severe cases; the lower teeth can bite into the roof of the mouth causing serious injuries. An undershot bite is more commonly seen, especially in other breeds. It is when the lower jaw extends out past the upper jaw. Although it is standard in some breeds, it can cause difficulties in others and may need to be corrected with surgery. The last type of incorrect bite is wry mouth, which is a twisting of the mouth caused by one side growing faster then the other. It causes difficulties with eating and grasping. In some cases, all incorrect bites can correct themselves while the puppy is still growing. If the incorrect bite has not self-corrected by the time the puppy is 10 months of age, it is likely that the bite will never be corrected naturally. If surgery is needed to correct the bite, it is suggested that it wait until the puppy has finished growing. Corrective surgeries can include tooth extraction, crown height reductions or the use of spacers. It is important to note that dogs with incorrect bites should not be used for breeding.