Comparison Between 3d and 2d Images in Diagnosis and Treatment of Facial Asymmetries: a Systematic Review

PA cephalogram has been used in orthodontic for the treatment of asymmetry. The PA cephalogram provides information useful for facial asymmetric evaluation and for evaluation of the craniofacial skeleton and dentoalveolar structures in frontal plane. We know how PA cephalogram is a projection of a three-dimensional skeletal structures, into a two-dimensional surface of the film. Therefore, this transposition of images can lead to enlargement, distortion and projection error. Sometimes, PA doesn't give accurate information, particularly regarding deviation of the chin. Some studies have proposed the combined use of more radiographic exams Postero-Anterior (PA), Laterlo-lateral (LL), and submento-vertex views for 3D evaluation of the maxillofacial complex. However, 2D radiographs have the limitations of enlarging and distorting the image, and this can lead to misdiagnosis. Cephalometric measurements on PA are subject to distortion, so it should be use just to compare right and left sides in a qualitative way more than quantitatively way. Because quantitative measurement is a key element in the diagnosis of asymmetry, a 3D analysis with 2D radiographs obviously cannot be always used. Aim of this works is to evaluate the statement of art about the use of CBCT, in orthodontics, and in the diagnosis, treatment planning of the asymmetries.