Class III Facial Asymmetry, Mandibular Deviation and Its Related Surgical Orthodontic Treatment
Pp. 228-258 (31)
Isao Saito and Naoko Watanabe
The Class III facial asymmetry, mandibular deviation and its related surgical
orthodontic treatment will be discussed in this chapter. The number of orthodontic
patients with a diverted bite and/or facial asymmetry has been increasing recently.
Diagnosis and treatment for Class III patients with facial asymmetry and/or mandibular
deviation tend to be more complex than those without asymmetric mandible are.
Orthodontists have to discriminate between asymmetric problems of dental nature as
opposed to skeletal origin. For instance, the amount of dentoalveolar compensation in
the molar region should be part of the diagnosis. Management of the developing Class
III malocclusion with mandibular deviation is important since malocclusion tends to
deteriorate with growth. On the other hand, skeletal Class III patients are frequently
accompanied by facial asymmetry or midline deviations and some eventually need
surgical orthodontic treatment. In this chapter, the authors will review the literatures on
prevalence of orthodontic asymmetries, possible changes in Class III mandibular
deviation with age, morphological features of Class III mandibular deviation, including
three-dimensional evaluation and perception of facial asymmetry. In addition, Class III
facial asymmetry cases treated with orthognathic surgery will be introduced. Since twojaw
surgery has been recently indicated, more often than before for better outcomes,
surgical orthodontic cases corrected with one-jaw or two-jaw surgery will be discussed.
Postoperative changes of the frontal facial appearances in skeletal Class III patients with
deviation will be compared between one-jaw and two-jaw surgeries as well as
postoperative stability of Class III cases with facial asymmetry that surgically treated.
Facial asymmetry, Mandibular deviation, Prevalence of facial
asymmetry and morphological deviation, Etiology of facial asymmetry and
morphological deviation, Analysis and evaluation of facial asymmetry, Frontal
cephalogram, Superimposition of frontal cephalograms, Perception of facial
asymmetry, Questionnaire investigation of facial asymmetry, CT mages, Threedimensional
(3D) analysis of morphological asymmetry, 3D deviation ratio, 3D
morphological symmetry ratio, Deterioration of mandibular deviation with growth
beyond prediction, Surgical Orthodontic treatment of Class III facial asymmetry,
3D analysis of dental casts using laser scanner, SSRO, IVRO, two-jaw surgery,
3D analysis of postoperative soft tissue changes.
2-5274 Gakkocho-dori, Chuo-ku, Niigata 951-8514, Japan.