EN
Lingualy displaced mandibular canines, resulting in the change of vestibular axial inclination into one parallel to the sagittal plane, occur relatively seldom among malocclusions. This sort of displacement is qualified - beside isolated rotations as well as frontal or lateral cross-bites - as a class I malocclusion and is susceptible to treatment provided the etiology is not a hereditary one. There are off-genetic factors leading to malocclusion, such as persistent deciduous canine, trauma coinciding with tooth-eruption, narrowing of the mandible or its underdevelopment in a transversal dimension and vestibular displacement of the erupting upper canine. The described ectopy leads to a mechanic leisure of gingival and palatal tissues. Protection of the dog against those side effects calls for either interceptive or regular treatment based on gingivoplasty, orthodontic therapy, shortening of the canine crown and - in extreme cases - extraction of causal teeth.