Diagnosis and evaluation of skeletal Class III patients with facial asymmetry for orthognathic surgery using three-dimensional computed tomography

Patients with facial asymmetry, especially skeletal Class III, have skeletal asymmetry in the cranial base, maxilla, mandible as well as asymmetry of soft tissues including the masticatory muscles. Three-dimensional (3D) computed tomography is considered as an effective tool to analyze these patients, since it enables accurate measurement without distortion regardless of head orientation using real anatomic surface landmarks and 3D representation of complex morphology including volumetric measurements. In this article, morphologic characteristics of the cranial base, mandible, and masticatory muscle in skeletal Class III patients with facial asymmetry are addressed, and 3D analysis for these patients is suggested. Furthermore, 3D evaluation of hard- and soft-tissue changes after orthognathic surgery is discussed, which can contribute to treatment planning for predictable treatment results.