22 Malocclusion – an introduction
By definition, malocclusion is an abnormality in the position of the teeth. Malocclusion is common in the dog, but also occurs in cats. The clinical significance of malocclusion is that it may cause discomfort and sometimes pain to the affected animal. In some cases, it may be the direct cause of severe oral pathology. It is consequently important to diagnose malocclusion early in the life of the animal so that preventative measures can be taken.
An outline of the more common types of malocclusion is given below.
SKELETAL MALOCCLUSION
Narrow mandible:
In some animals, the mandible is too narrow with respect to the upper jaw. The result is that the lower canines impinge on the maxillary gingivae or the hard palate instead of fitting into the diastema between the upper third incisor and upper canine on either side. The animal may not be able to close its mouth and injury to the gingivae or palatal mucosa commonly occurs. In untreated severe cases, an oronasal communication may develop over time. This condition is seen in both the primary (deciduous) and permanent dentition. Persistent primary canines will further exacerbate the condition, as the permanent canines erupt medially to their primary counterparts in the mandible. The incorrect dental interlock will interfere with the normal growth in width and length of the developing mandible. The condition can also be caused by persistent primary mandibular canines in a mandible of normal width.