A class 3 malocclusion is an abnormal bite where the lower jaw is longer than the upper jaw. Although it is “normal” for some breeds of dogs it is entirely a man-made problem created by breeders. These dogs (Pugs, Shih Tzu’s and other similar breeds) are not a natural creature. They would likely not survive long in nature because of the malocclusion. It would limit their ability to capture, kill and eat their pray.
The function of normal incisor teeth (front teeth) is to perform delicate grasping tasks. These include grooming, picking up food or toys from the ground or removing small amount of tissue from a recently killed prey. Due to this malocclusion your pet is unable to perform such tasks.
Imagine trying to pluck an eyebrow with tweezers in which one arm is long and the other arm is short so that the tweezer tips do not meet. It will be impossible to grasp the eyebrow hair. In a similar manner, your pet was born with a mismatch in jaw length such that her upper jaw is short, relative to the lower jaw. The result is that his/her occlusion is also non-functional and the front part of her mouth works about as well as the broken pair of tweezers.
Beyond being non-functional, the teeth are contributing to her/his discomfort. The upper teeth are cutting in to the floor of her mouth behind the lower incisor teeth. In some animals her/his lip will be bitten when it becomes entrapment between the opposing arches of incisor teeth.
If the trauma continues it can lead to damage that goes deep enough to also effect the lower incisor and at times even the lower canines (corner teeth).
Thus, treatment is indicated to enhance your pets comfort and improve her/his health despite her/his man-made appearance.
a- Front view B- Side View C- Damage to lower jaw