August 6, 2010

Orthodontics

No, we are not talking about “Hollywood Smiles” and braces for pets. Orthodontic care in pets focuses on relieving teeth that are positioned incorrectly and causing pain. Orthodontic care in pets can take many forms, including acrylic appliances, brackets, elastics, and simple extractions. The typical arch wire appliances used in humans are almost never used.

One form of orthodontic care, called “interceptive orthodontics”, is employed when deciduous (baby) teeth are positioned incorrectly, or fail to be shed as the adult teeth erupt. (See the FAQ on “Double Teeth”) The presence of more than one tooth in the same place at the same time can lead to a painful malpositioning of the adult teeth. In some cases, early extraction of the baby teeth will allow the adult teeth to come in normally. To correct the problem, the entire root structure must be extracted. Some breeders will simply “clip” the baby teeth off with nail trimmers. This cruel practice is painful, leads to infection under the gum line, and rarely helps the permanent teeth position themselves normally. Clipping off the baby teeth is not humane, and is discouraged.

Extraction of malpositioned deciduous (baby) teeth.

Eight week old puppy with the lower incisors incorrectly placed in front of the upper incisors (underbite).

Ulcerated areas where the upper incisors are hitting the lower gums.

All the deciduous (baby) incisors were extracted. The white lines separate the visible part of the tooth from the root. Note how much longer the roots are by comparison. The entire root must be extracted.


Retained baby teeth causing adult tooth to be pushed out of normal position.


Retained baby canine tooth (long arrow) is pushing the adult tooth (short arrow) to the right, which is crowding the other teeth in this area. The baby tooth was extracted.

Retained lower canine teeth (short arrows) are causing the lower adult canine teeth to be displaced toward the inside (longer arrows) of the mouth. This commonly results in the lower permanent canine teeth pushing into the roof of the mouth, termed “base narrow” canines.


Correction of base narrow permanent (adult) lower canine teeth traumatizing the roof of the mouth.

At times, the lower canine teeth are positioned so that they place painful pressure on the roof of the mouth, leading to ulcers or even the formation of a hole into the nasal passages. In some cases, this can be corrected with an acrylic appliance placed on the upper teeth, which gently re-directs the offending teeth into normal alignment.


Lower canine tooth is displaced to the inside, creating a hole in the roof of the mouth. The upper canine tooth has already been moved back by the elastic band to make space for the lower canine tooth.

Acrylic appliance fabricated on the patient, with an inclined groove fashioned to direct the lower canine tooth into a normal position. When the lower canine tooth tips out enough to reach the black mark (arrow), the appliance can be removed.

After one month, the lower canine tooth is now tipped out into a normal position.

After removal of the incline plane, the canine tooth is in a normal, non-painful position. The reddened areas heal within a few days after the splint is removed.


Correction of base narrow primary (baby) lower canine teeth traumatizing the roof of the mouth.

When base narrow lower canine teeth are seen in puppies, more than one treatment option exists. Extraction of the lower baby canine teeth will make the patient more comfortable, but this treatment rarely prevents the same condition from occurring in the permanent teeth. A newer treatment for these puppies involves placement of curved composite tip extensions (see case below) on the baby teeth to orthodontically tip them into a more normal position. When these baby teeth are then naturally lost around 5 months of age, the permanent canine teeth will usually erupt into a normal and comfortable position. For this technique to work, the tip extensions must be placed no later than 14 weeks of age. Placement around 12 weeks of age or earlier is preferred.


This 10 week puppy has painful lesions in the roof of the mouth created by the malpositioned lower canine (fang) teeth.

Composite tip extensions have been placed on the lower canine teeth to tip these baby teeth into a normal position.

Two weeks after placement, the lower canine teeth have been tipped out.

The permanent teeth in the patient have erupted into a normal and comfortable position.