Thesis (M.Sc.) - Cairo University - Faculty of Oral and Dental Medicine - Department of Orthodontics

Objective: Was to compare the reliability of six Frankfurt Horizontal planes versus the true Horizontal plane in adults having normal occlusion and balanced facial profile. Material and methods: CBCT images were collected from thirty seven Egyptian adult subjects using the I-CAT CBCT machine and anatomage 5.3 software to generate 3D volumetric reconstructions (3D CBCT). The inter and intra-observer reliability was confirmed after identification of the 3D landmarks for randomly selected 10% of the sample by two observers using the correlation coefficient. A newly constructed coordinate reference system that depends on the true vertical was used for accurate measurements. Six different Frankfurt planes were constructed and were compared to the true Horizontal plane. Results: The intra-observer, inter-observer reliability for landmarks showed high concordance with identical ICC and CCC exceeding 0.751 and 0.78 respectively. All the Frankfurt constituting points showed high reproducibility with high correlation values varied from 0.776 to 0.999 in the intra-observer readings and exceeded 0.994 in the inter-observer readings. All proposed Frankfurt planes showed insignificant difference in their mean cant that varied from 0.7 to 1.2 to the true horizontal plane. All planes showed no statistical significant difference from True Horizontal plane (p >0.05) on their comparison with the true horizontal plane using McNamaras{u2019} analysis

Issued also as CD