In certain cases, the orthodontic treatment with braces cannot solve the problem by itself. Especially when the source of the problem is the skeletal bone containing the teeth and when the patient is past the growth peak where the orthopidec devices are not efficient anymore.
A surgical procedure is required in such cases in addition to the braces to correct the relationship between both jaws and achieve optimal teeth position.
The surgical procedure can be done before, during or after the orthodontic treatment. The orthodontist and the oral surgeon are the ones to decide when is the best time to perform each procedure.
The most common malocclusion that requires orthognathic surgery to correct is the mandibular prognathism (advanced lower jaw). The oral surgeon would reduce the length of the mandible and move it backwards, this will help the orthodontist to achieve better occlusion and facial esthetic.