A normal puppy has 28 teeth when it reaches six months. Most dog breeds will have 42 teeth when the dog reaches adulthood.
The way the upper teeth align with the lower teeth is called occlusion. Occlusion refers to the alignment of teeth and the way that the upper and lower teeth fit together (bite). Ideally, all upper teeth fit slightly over the lower teeth. The points of the molars fit the grooves of the opposite molar. Malocclusion occurs when the bite does not fit accordingly.
Most malocclusions are hereditary, resulting from genetic factors that control the rate of growth of the upper and lower jaws. Some incorrect bites re caused by retained baby teeth, which push the erupting adult teeth out of line.
Smaller front teeth between canines are called incisors and used to grasp food. Canines or fangs are found behind front teeth and they also function same as incisors. Premolars are located behind the canines and their function is to shear or cut the food. Molars are used for chewing and they are found at the back of the mouth.
Common problems that are associated with malocclusion are
Soft-tissue defects from tooth contact in the floor of the mouth and the roof of the mouth (palate)
Wear on the teeth
Dogs affected by this condition are prone to difficulty picking up food, are prone to eat only large pieces and tartar and plaque build-up.
There are several types of diagnosable malocclusion:
Wry mouth or bite
Base narrow canines
The tips of the premolars (the teeth right behind the canines) should touch the spaces between the upper premolars, which is called the scissor bite. However, it is normal for flat-faced breeds such as Boxers, Shih Tzus, and Lhasa Apsos not to have scissor bites.
With an overbite, the upper jaw is longer than the lower one. When the mouth is closed, a gap between the upper and lower incisors occurs. Puppies born with an overbite will sometimes have the problem correct itself if the gap is not too large. However, a dog's bite will usually set at ten months old. At this time improvement will not happen on its own. Your pet's overbite may worsen as the permanent teeth come in because they are larger and can damage the soft parts of the mouth. Teeth extractions are sometimes necessary.