Purpose: The aim of this study was to evaluate the difference between Ricketts analysis measurements made on Sirona Orthophos XG Plus (Sirona Dental Systems, Charlotte,NC) lateral cephalograms, and DolphinTM generated perspective and orthogonal lateral cephalograms from CBCT (NewTom 5G; QR srl, Verona, Italy). Materials and Methods: A Sirona digital lateral cephalogram and DophinTM synthesized CBCT lateral cephalograms of a radiographic phantom in orthogonal and perspective projections were created. Horizontal and vertical measurements were made in multiple planes on the radiographic phantom to compare each imaging modality. Twenty-five lateral cephalometric radiographs were selected retrospectively from the records of patients of the LLUSD Graduate Orthodontic Clinic who had both CBCT and Sirona digital lateral cephalograms. Radiographs were excluded from the study if they displayed significant occlusal plane discrepancy (>2 mm), or missing first molars. All lateral cephalograms were digitized into DolphinTM (version 11.8; Dolphin Imaging & Management Solutions, Chatsworth, Calif) and traced using Ricketts cephalometric analysis in addition to measurements from Nasion to Menton and Nasion to Basion. Eight linear and nine angular measurements from each imaging modality were compared and analyzed using one sample Wilcoxon signed rank test and pairwise comparison. Results: Statistically significant differences were found in percent magnification of horizontal and vertical measurements between the scanned grid and the various imaging modalities. No significant single plane perspective distortion (SPPD) was detected in the vertical and horizontal directions. Multiplane perspective distortion (MPPD) was only noted in Sirona images. Ricketts Analysis linear measurements were all statistically different except for lower lip to E-plane (P =0.544). The Ricketts Analysis angular measurements were not statistically different (P <0.05) with the exception of facial axis (P =0.004) and maxillary depth (P =0.025). DolphinTM generated CBCT lateral cephalograms with orthogonal projection, adjusted to 101% magnification had the closest agreement to Sirona images. Conclusions: No clinically significant perspective distortion was found in the vertical and horizontal direction in the three modalities that were studied. DophinTM synthesized CBCT lateral cephalogram in perspective projection does not produce perspective images. CBCT Lateral cephalograms generated by DophinTM in orthogonal projection at 101% magnification is compatible with images from Sirona for clinical evaluation.

LLU Discipline

Orthodontics and Dentofacial Orthopedics


Orthodontics and Dentofacial Orthopedics


School of Dentistry

First Advisor

Leggitt, V. Leroy

Second Advisor

Caruso, Joseph M.

Third Advisor

Rungcharassaeng, Kitichai

Degree Name

Master of Science (MS)

Degree Level


Year Degree Awarded


Date (Title Page)




Library of Congress/MESH Subject Headings

Radiography - Dental; Teeth - Radiography; Cephalometry; Radiographic Image Enhancement - Methods; Cone-beam Computed Tomography;

Subject - Local

Ricketts Analysis Measurements; Sirona Orthophos XG Plus; Dolphin (TM); Lateral cephalograms;



Page Count


Digital Format


Digital Publisher

Loma Linda University Libraries

Usage Rights

This title appears here courtesy of the author, who has granted Loma Linda University a limited, non-exclusive right to make this publication available to the public. The author retains all other copyrights.


Loma Linda University Electronic Theses and Dissertations

Collection Website



Loma Linda University. Del E. Webb Memorial Library. University Archives