1989 Volume 35 Issue 7 Pages 1749-1759
Dentofacial deformities are generally classified with the lateral cephalogram. Such classification, however, is incomplete because facial asymmetry could not be diagnosed if the evaluation of the posterior-anterior cephalometric radiogram (P-A) is not considered. Sixty adults (30 male and 30 female) who had normal occlusion were randomly selected and their P-A cephalometric radiograms were traced on acetate tracing paper. We selected 18 landmarks as follows; MHW, CG, Lo, Rof, Po, Zyg, Ms, Nf, Zm, Mx, CMo, Mo, Co, ARE, Go, U1, L1, Me. According to Sassouni's report, a line connecting left and right lateroorbitale (Lo-Lo') was used as a horizontal reference line. The median sagital plane passes through the point Cista Galli (CG) and runs perpendicularly to the (Lo-Lo') line. We measured the difference between right and left points on the coordinate and calculated the standard deviation. Then we established the statistical chart of the P-A view based on the standard diviation (SD). We chose 3 points, Mx, Go and Me as the representation. If each point shifted beyond 2 SD, we difined it as deviation.
According to the chart, the dentofacial deformities were classified into following 3 groups.
Group 1; The deviation only on the mandible.
Group 2; The deviation not only on the mandible but on the maxilla.
Group 3; The deviation only on the maxilla.
Totally 239 patients were operated in our hospital for past 10 years. 67 patients among 239 (approdmately 28%) had some degree of facial asymmetry. 43 patients belonged to group 1, 24 were group 2, and there were none in the group 3.