Orthopedic approach to severe skeletal Class III malocclusion

Abstract

B ecause of significant improvements in materials and techniques in orthodontics, full-banded appliances have become prevalent in the treatment of malocclusion. Such techniques are effective and produce satisfactory results in correcting dentofacial malocclusions in the permanent dentition. As a result, many orthodontists have given little consideration to treatment during the mixed dentition. In severe skeletal Class III cases, however, the effect of treatment by full-band techniques only is limited because of abnormal relationships between the jaws. In severe skeletal Class III cases, despite an anterior cross-bite, the maxillary incisors are usually inclined labially and the mandibular incisors are retrusive and tipped lingually. An orthopedic approach in the early developmental stages often is necessary. The object of treatment is, first, to improve the skeletal imbalance by orthopedic forces and, second, to improve tooth alignment and establish intercuspal relations by orthodontic means. From time to time, controversies have arisen over the effect of orthopedic force upon the maxillofacial complex. Graberls 2 and Sassouni3 cite the Milwaukee brace as an example of the effect of orthopedic forces. Both conclude that it is possible to alter the vertical and anteroposterior proportions of the face by orthopedic means, that is, by influencing the position and size of the maxilla and the mandible. Haas reported cephalometric changes in patients treated by palatal expansion and maxillary traction in an anterior direction. He defined the intensity of orthopedic force as follows: “Orthodontic forces are ideally measured in grams and ounces, while orthopedic forces must be calculated in pounds.” Most recently, Lee Graber5 studied thirty-five Class III malocclusions in children under chin cap therapy for at least 3 years between the ages of 5 and 8 years.