Retained Deciduous Teeth

Retained deciduous or primary teeth are a common dental condition that occurs in young dogs between 4-7 months of age. Small breed dogs like the Yorkshire Terrier (top photo) are more commonly affected than larger breed dogs.

We like to refer to the “Two tooth rule”. If two teeth (primary and permanent) are present at the same time the primary tooth should be extracted. If left untreated the primary tooth may direct the permanent tooth into an abnormal position.

Retained mandibular canine teeth are more likely to cause a malocclusion. In these pets the permanent teeth (red arrow) will erupt on the inside of the deciduous teeth (blue arrow). The permanent teeth will remain “base narrow” and in time contact the palate. This is painful and requires immediate extraction or orthodontic therapy.

A retained maxillary deciduous canine may cause the permanent tooth to be directed rostrally. The space between the lateral incisor and canine tooth (green arrow) will become too narrow. This may leave no room for the mandibular canine to rest.

It is important to monitor for retained deciduous teeth between 4-7 months of age. After the teeth have erupted consider scheduling the pets neutering, to allow extractions to be performed under the same anesthetic.

Due to the retained teeth in the last photo, can you list some potential problems that have occurred or may occur in this pet?

• Collapse of the space between the upper incisor and canine tooth- Extract upper retained tooth!
• Discolored/fractured lower deciduous canine tooth. It will become infected- Extract it!
• Base narrow lower left canine tooth – will cause a contact ulcer on palate (Ouch!)- Orthodontically move it! – if it does not move laterally after extracting the retained deciduous tooth.

In many cases, the extraction of the retained tooth will prevent a malocclusion and an orthodontic procedure.