Extracting deciduous teeth is also warranted in cases of dental interlock. During growth and development in puppies, the mandible
and maxilla grow independently. Sometimes during growth spurts, one jaw grows faster than the other, and the deciduous teeth
can become interlocked, interfering with the normal growth of the shorter jaw. Extracting the deciduous teeth will not promote
jaw growth in a dog that is genetically destined to have malocclusion. But in cases in which the interlock has resulted from
a temporary discrepancy in jaw growth, relieving dental interlock by extracting the interfering deciduous teeth may allow
the shorter jaw to lengthen to its genetic potential. Careful case selection, client education, and meticulous extraction
technique to avoid iatrogenic damage to the developing permanent tooth are the keys to successfully removing persistent deciduous
In many breeds, especially in dogs < 22 lb (10 kg), the teeth are large in relation to the jawbones they occupy. In these
instances, crowding can occur. Crowded teeth predispose dogs to periodontal disease and may even interfere with jaw closure
(Figure 3). In cases of crowding, treatment may include orthodontic movement of crowded teeth into healthier positions. But if there
is not enough space in the mouth to accomplish such orthodontic correction, selected teeth should be extracted.
Figure 3. A chihuahua with crowded teeth. A mandibular canine tooth is directly impacting the maxillary third incisor (arrow)
and preventing the dog from closing its mouth. Extracting the maxillary third incisor will allow this dog to close its mouth
and will give it a healthy, nontraumatic occlusion.
Linguoversion of the mandibular canine teeth
Linguoversion of the mandibular canine teeth can be observed in deciduous teeth as well as in permanent teeth. The trauma
to the palate caused by the abnormally positioned lower canine teeth not only is painful (these dogs are often head shy) but
also can lead to oronasal fistula formation.
Deciduous mandibular canine teeth that exhibit linguoversion should be extracted. In cases of permanent mandibular canine
tooth linguoversion, orthodontic tipping of the canine teeth into a healthy position is usually successful. In certain cases,
especially if this condition is combined with a class II malocclusion, there may be nowhere to move these teeth to because
the maxillary canine teeth are positioned just lateral to the malpositioned mandibular canine teeth. In these cases, crown
reduction with vital pulp therapy is indicated. If movement into a healthier position is possible, several options are available.
Rubber ball therapy
One study showed that having young dogs with lingually displaced mandibular canine teeth hold an appropriately sized rubber
device (e.g. a lacrosse ball or a spherical hard rubber chew toy) in their mouths for a minimum of 15 minutes three times a day can correct
many of these malocclusions.3 The ball acts like an inclined plane, causing tipping forces to be placed on the affected teeth every time the dog bites
down on the ball. The elegance of this physical therapy option is its simplicity and lack of need for anesthesia. However,
it is imperative for the clinician to choose a rubber device that is the correct size and shape for each individual patient
and to carefully instruct the pet owner in its use.3
In mild cases of linguoversion of the mandibular canine teeth, a wedge of gingival tissue can be removed from the maxilla
between the third incisor and the canine tooth.4 This procedure is relatively simple and requires only a single anesthetic episode.