The treatment depends on the tooth that is impacted, the angulation, the location, the symptomatology and more. If it is the wisdom tooth, they are usually surgically extracted. If the second molar is not in a good condition, it is suffering from large caries, then some dentists might decide to extract the second molar and make space for the wisdom tooth to erupt. But this happens very rarely.
If we are talking about a canine, dentists usually consult with an orthodontist before starting a treatment. If there is a possibility for the tooth to erupt and be a part of the dental arch, they can surgically expose the bone, help it erupt and use orthodontic forces to lead its path to the dental arch. Sometimes these teeth are impacted horizontally in the bone, and nothing else can be done, except surgical extraction.