In recent years, facemask/ palatal expansion therapy has become a predictable approach to the correction of Class III malocclusion. Studies have shown the correction occurs primarily by forward and downward movement of the maxilla in conjunction with a downward and backward rotation of the mandible. This approach is ideally suited for patients with vertical and a-p maxillary deficiency and excessive over bite due to over-closure of the mandible. Although protraction of the maxilla may be necessary, the vertical movement that occurs along with the clockwise rotation of the mandible exacerbates the open bite. Factors contributing to the structural etiology of the Class 3 will be discussed in relation to biomechanical principles of treatment. The principles of active therapy, as well as retention, will be demonstrated including preferred appliances.
Understand the importance of the vertical dimension in early Class 3 treatment.
Identify ways to measure the etiology of facial height.
Identify treatment approaches to control the vertical dimension in Class 3 treatment.