A patient with a bilateral Class III molar relationship came to the Department of Orthodontics clinic at Case Western Reserve University. Our first choice for treatment was a combination of orthodontic therapy and orthognathic surgery. The patient, however, opted for a nonsurgical approach that took 34 months and involved the extraction of 4 first premolars and a remaining deciduous tooth, and Class III vertical elastics. Although orthodontic treatment was considered to be a second-line alternative, the results suggest that, for some surgical patients, orthodontic treatment alone might be a better choice because of the favorable cost/benefit ratio.
Three dimensional (3D) plain film radiographic cephalometric analysis of boney skull landmarks may be used for patient diagnosis, treatment planning, prosthetic design, intra- operatively, and outcome assessment. To test the accuracy and reliability of 50 cephalometric landmarks, three dry human skulls, with and without metallic markers affixed to the landmarks, were digitized in our 3dCEPH software by 4 operators. The average inter-operator variability about mean landmark position, across all operators, for all 3 skull image pairs, was 3.33 mm. Ten landmarks exhibiting least variability were 1.15 mm average distance from the mean, including: B point 0.69 mm, Lower Incisal Edge 0.85 mm, and Anterior Nasal Spine 0.90 mm. The average rms error from the metallic fiducials for these 4 operators across all 50 landmarks, and 3 skulls was 5.03 mm. The 10 landmarks with the least variability exhibited 2.01 mm average distance from the fiducial, including: B point 1.69 mm, upper incisal edge 1.71 mm, lower incisal edge 1.78 mm. Additional studies are needed to test the robusticity of the hypothesis of homologous anatomy. Homology of landmarks is important to cephalometric comparisons between image pairs representing patient and 'normative,' pre- and post-surgical alteration, and different ages of the same patient.