This condition, seen in Pekingese, Chihuahuas, and some other toy breeds, occurs when the cartilage that joins the two sides of the lower jaw at the chin fails to calcify. The lower incisors that are set in this soft cartilage become loose and unstable. Infection descends to the roots of these teeth and destroys the cartilage. This allows the two sides of the jaw to detach and move independently. This condition can be caused by an incorrect calcium to phosphorous ratio in the dog’s diet.
Treatment: The unstable jaw can be treated by removing the diseased teeth, administering antibiotics, and stabilizing the joint with wires or screws. If diet is a contributing factor, the diet must be corrected as well.