Orthodontics is the branch of dentistry that is concerned with the diagnosis and treatment of malocclusion and related skeletal disorders. The different breeds of dogs show marked variations in occlusion based on the keletal morphology of the breed. Any malocclusion that is considered genetic, or is suspected of being genetic, should be treated orthodontically, unless the malocclusion is causing, or may cause, an oral problem. If breeding pets have a genetic malocclusion, orthodontic corrective procedures are considered unethical and should only be performed if the pet is neutered, or if you are convinced that the owner does not plan on breeding or showing. Any malocclusion that is considered acquired can be corrected orthodontically. The author described three clinical cases of acquired malocclusion. These cases treat of caudally inclined teeth (retrusion), rostrally inclined teeth (protrusion) and lingually displaced teeth (oral). The treatments were done with expansion screws, elastic power chains, buttons, hooks and brackets.