MATERIALS AND METHODS
This is a retrospective investigation based on pre-treatment cephalometric radiographs of patients seeking orthodontic treatment at the UAB School of Dentistry Orthodontics Department. The sample consisted of 54 males and 42 females with an average age of 12.3 years old.
Subject Selection Criteria Subjects for the study were selected from the database of patients at the University of Alabama School of Dentistry Orthodontics Department. 96 subjects were evenly divided into 3 groups of 32 based on A-P relationships of the skeletal bases. The 3 groups were made of Class I, Class II, or Class III patients, as determined by the Wits and ANB measurements. Both measurements had to agree on the patient’s skeletal pattern …show more content…
After collecting the cephalograms, each image was digitized using the UAB Dolphin Imaging software (Dolphin Imaging & Management Solutions, Chatsworth, CA). Necessary points for the McNamara and Arnett/McLaughlin analyses were identified and plotted. All radiographs were digitally traced in Dolphin Imaging by one operator (J.S.). Images that displayed a head position that was deemed as unnatural were adjusted to NHO by the first observer. A second observer (N.S.) later reviewed the original images and made positional changes, as deemed necessary. Any disagreement between the 2 examiners for either resulted in registration of the average head position between the 2 assessments. Assessments were also made for intra- and inter- observer reliability for films that needed adjustment. TVL was then established as a vertical line parallel to the edge of the film, through subnasale. Na Perp was established as a 90º angle to FH, through Nasion. Points whose location was sensitive to the eventual placement of Na Perp, such as Porion, Orbitale, and Nasion, were also checked by the second observer (N.S.). A summary of cephalometric landmarks and planes used can be found in Table 1. After establishment of Na Perp and TVL was complete, the images were available for measurement and statistical
This is a retrospective investigation based on pre-treatment cephalometric radiographs of patients seeking orthodontic treatment at the UAB School of Dentistry Orthodontics Department. The sample consisted of 54 males and 42 females with an average age of 12.3 years old.
Subject Selection Criteria Subjects for the study were selected from the database of patients at the University of Alabama School of Dentistry Orthodontics Department. 96 subjects were evenly divided into 3 groups of 32 based on A-P relationships of the skeletal bases. The 3 groups were made of Class I, Class II, or Class III patients, as determined by the Wits and ANB measurements. Both measurements had to agree on the patient’s skeletal pattern …show more content…
After collecting the cephalograms, each image was digitized using the UAB Dolphin Imaging software (Dolphin Imaging & Management Solutions, Chatsworth, CA). Necessary points for the McNamara and Arnett/McLaughlin analyses were identified and plotted. All radiographs were digitally traced in Dolphin Imaging by one operator (J.S.). Images that displayed a head position that was deemed as unnatural were adjusted to NHO by the first observer. A second observer (N.S.) later reviewed the original images and made positional changes, as deemed necessary. Any disagreement between the 2 examiners for either resulted in registration of the average head position between the 2 assessments. Assessments were also made for intra- and inter- observer reliability for films that needed adjustment. TVL was then established as a vertical line parallel to the edge of the film, through subnasale. Na Perp was established as a 90º angle to FH, through Nasion. Points whose location was sensitive to the eventual placement of Na Perp, such as Porion, Orbitale, and Nasion, were also checked by the second observer (N.S.). A summary of cephalometric landmarks and planes used can be found in Table 1. After establishment of Na Perp and TVL was complete, the images were available for measurement and statistical