Cephalometry
Diptesh Guha; Dolly Patel; Surina Sinha
Abstract
Aim: To validate Pi angle with other sagittal discrepancy indicators like Beta angle, Yen angle and W angle in skeletal Class I, II and III patients, to correlate the Pi angle with the size and position of the mandible, and to evaluate the reliability of Dolphin imaging software.
Methods: One hundred ...
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Aim: To validate Pi angle with other sagittal discrepancy indicators like Beta angle, Yen angle and W angle in skeletal Class I, II and III patients, to correlate the Pi angle with the size and position of the mandible, and to evaluate the reliability of Dolphin imaging software.
Methods: One hundred fifty subjects were nominated based on the inclusion criteria and their lateral cephalograms were traced based on their ANB angle, they were placed into skeletal Class I, II and III groups. A-P discrepancy indicators and parameters of the size and position of the mandible were traced manually and digitally.
Results: Pi angle had 85% and 100% accuracy in identifying skeletal Class II and III groups, respectively. Parameters of the morphology of the mandible were found to have statistically significant correlation with Pi angle e.g., mandibular base length (-0.265), SNB (-0.408), articular angle (0.277), facial angle (-0.800), and Y axis (0.728), etc. When data was compared between manual and digital tracing, there was no difference in the mean values of Pi angle (P=0.87), Beta angle (P=0.73), and Yen angle (P=0.64) between the two techniques, suggesting good accuracy of Dolphin imaging software.Conclusion: The Pi angle could accurately differentiate the sample into skeletal Class I, II and III groups. A statistically significant correlation was determined between Pi angle and most of the parameters of the size and position of the mandible. It was found that the imaging software Dolphin 3D is dependable to the analysis of cephalometric variables, which are not available in the software.
Cephalometry
Azita Tehranchi; Setrareh Sohrabi; Farnaz younessian; Fatemeh Zahedipour
Abstract
Aim: Following maxillary impaction, the mandible rotates around a center. Inaccurate determination of mandibular rotation can have profound effects on orthognathic surgical treatment planning and final surgical outcome. The present study determined the relationship between the cephalometric characteristics ...
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Aim: Following maxillary impaction, the mandible rotates around a center. Inaccurate determination of mandibular rotation can have profound effects on orthognathic surgical treatment planning and final surgical outcome. The present study determined the relationship between the cephalometric characteristics of candidates for maxillary impaction surgery using sagittal and vertical locations of the center of rotation of the mandible.Methods: In a descriptive and cross-sectional trial, 36 candidates for LeFort I maxillary impaction surgery were selected. Two lateral cephalograms were obtained in open and closed mouth positions. The center of rotation of the mandible was determined by the Reuleaux technique. Cephalometric measurements of the patients with the determined center of mandibular rotation locations (regions 1 and 4 of the coordinate axis) were done and the results were subjected to the student t-test.Results: The center of mandibular rotation was located in region 1 of the coordinate axis in 17 (50%) and in 17 (50%) in the 4th region of the coordinate axis. Statistically significant differences existed regarding the MP-SN (p<0.006), CO-GO (p<0.006), and CO-GN (p<0.04) at two regions of 1 and 4 for the center of rotation of the mandible in the coordinate axis.Conclusion: With the decreased length of the ramus and increased inclination of the plane, the center of rotation of the mandible tended to be situated at region 1 of the coordinate axis, and together with the increased length of the ramus and decreased plane inclination, the center of mandibular rotation tended to be located at region 4 of the coordinate axis.
Cephalometry
Hosur Krishnaiah Vedavathi; Priyanka Roy; Prasanna Kumar P Shashanka; Sowmya Kyathanahalli Subbaiah
Abstract
Aim: Frankfurt horizontal and Sella-Nasion lines are the most widely accepted and used landmarks in cephalometric analysis. This study investigates the use of the Orbito-Condylion line extending from the Orbitale to the Condylion as a novel horizontal line for substituting the Frankfurt horizontal line. ...
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Aim: Frankfurt horizontal and Sella-Nasion lines are the most widely accepted and used landmarks in cephalometric analysis. This study investigates the use of the Orbito-Condylion line extending from the Orbitale to the Condylion as a novel horizontal line for substituting the Frankfurt horizontal line. Similarly, the evaluation of the Orbito-Basion line as an alternative to the Sella-Nasion line in cephalometric analysis was done. We evaluated the reproducibility of the new horizontal lines and measured the angle between the Orbito-Condylion line and the Frankfurt line; and the angle between the Sella-Nasion and Orbitale-Basion line.Methods: This investigation was carried out on 30 individuals. The Porion, Orbitale, Condylion, Sella, Nasion, and Basion were identified and marked. The angles between the orbito-meatal line (inferior orbital rim to the Porion; the Frankfurt line) and the Orbito-Condylion line (inferior orbital rim to the Condylion) were measured. Likewise, the angles between the Sella-Nasion line (center of sella tursica to Nasion) and the Orbito-Basion line (inferior orbital rim to Basion) were measured.Results: Significant interobserver and intraobserver bias did not exist. The mean angle between the Frankfurt line and Orbito-Condylion line was 0.5°±2.27° and the mean angle between the Sella-Nasion line and Orbito-Basion line was 3.48°±3.11°.Conclusion: This study showed the new lines have good reproducibility, reliability, and efficacy. The Orbito-Condylion and Orbito-Basion lines are reliable, reproducible, and easily identifiable, and has the potential as novel standard horizontal lines to supersede or complement the Frankfurt line and Sella-Nasion line in anthropological studies and clinical applications.
