Like human, dogs have 2 sets of teeth. There are 28 baby or primary teeth and 42 adult or permanent teeth. The baby teeth start showing up at about 3 weeks of age and the adult teeth will start to erupt at about 4 months of age. By the time the puppy is 6 to 7 months of age, all the adult teeth will have erupted.
Before the adult teeth erupt through the gums, they begin developing from tooth buds located in the upper and lower jaws. As they develop and get bigger, they begin to press against the roots of the baby teeth, stimulating the puppy’s body to begin resorbing the tooth roots. The baby tooth roots will eventually disappear, leaving only the crowns and as the adult teeth push through the gums, the crowns of the baby teeth fall out. Sometimes you can find these crowns but often they will fall out while your puppy is eating and get swallowed up with the food.
A retained tooth occurs when the tooth root is either incompletely resorbed or it did not resorb at all. When this happens the baby tooth occupies the place in the mouth that is meant for the permanent tooth, forcing the permanent tooth to erupt at an abnormal angle or in an abnormal position. This can result in crowding or malposition of the tooth, causing an abnormal bite. The most common teeth to be retained are the upper canine teeth, followed by the lower canine teeth and incisors. Other teeth can also be retained. Some breeds are more commonly seen with retained teeth, such as some small breed dogs and dogs with shorter jaws like pugs and Boston terriers.
The problems with the retained teeth is that both the baby tooth and the permanent tooth are trying to grow in the same space. This leads to crowding which can result in debris becoming trapped between the teeth. This can lead to increased tartar deposits, tooth decay, gingivitis and periodontitis. This may result in a loss of the permanent tooth.
The retained tooth can force the adult tooth to grow into an abnormal position, which can cause further problems. Malpositioned teeth can rub against other teeth, wearing away the enamel and weakening the teeth. If the retained tooth is a lower canine, the permanent lower canine is forced to grow on the inside of the lower jaw and its tip usually grows towards the roof of the mouth, causing pain and damage which makes it difficult for the dog to eat.
The rule is that if the permanent tooth crown is visible above the gum-line, then the primary tooth should be gone. If it is still in place, it should be removed as soon as possible. The procedure requires a general anesthetic. The roots of these baby teeth can be very long and very delicate and need careful extraction.
If you have any questions or concerns about your puppy’s teeth, please talk to us. We are very happy to help make sure your puppy has the healthiest mouth possible.
The photo pictured above shows a baby tooth that was retained – the root is extremely long and well attached therefore they don’t come out on their own.