A study on the 3-D standard value of mandible for the diagnosis of facial asymmetry / 대한치과교정학회지

For an accurate diagnosis and treatment planning of facial asymmetry, the use of 3-dimensional (3-D) image is indispensable. The purpose of this study was to get standard data for the 3-D analysis of facial asymmetry. Computerized tomography (CT) was taken in the 60 normal occlusion individuals (30 male, 30 female) who did not have any apparent facial asymmetry. The acquired 2D CT DICOM data were input on a computer, and the reformatted 3-D images were created using a 3-D image software. Twenty three measurements were established in order to evaluate asymmetry; 15 linear measurements (6 for ramus length, 1 for condylar neck length, and 8 for mandibular body length) and 8 angular measurements (4 for gonial angle, 2 for frontal ramal inclination, and 2 for lateral ramal inclination). The right and left difference of each measurement was calculated and analyzed. It is suggested that the right and left differences of the measurements obtained from the study could be used as references for the diagnosis of facial asymmetric patients.

Relationship between perception of facial asymmetry and posteroanterior cephalometric measurements / 대한치과교정학회지

This study was aimed at how posteroanterior cephalometric measurements affect the perception of the patient about his/her facial asymmetry. One hundred orthodontic patients, over the age of 12, who required a posteroanterior cephalogram in the Department of Orthodontics of Chonnam National University Hospital were used as the subjects. They were asked if they thought their faces were asymmetrical. Their responses were classified into 5 groups based on the level of asymmetry as follows : Definitely No, Probably No, Don't Know, Probably Yes, and Definitely Yes. Nine linear and four angular measurements from each posteroanterior cephalometric radiographs were analysed on the standard of the line between crista galli and anterior nasal spine to show the extent of asymmetry. Through this comparative study, the following results were obtained. 1. As the deviation of menton and the midline discrepancy of the upper and lower jaws were greater, the perception of patients about their facial asymmetry was higher. 2. All the measurements from the group "Don't Know" showed no statistical difference from those of the groups "Definitely No" or "Probably No." 3. All the measurements from the group "Probably Yes" showed no statistical difference from those of the group "Definitely Yes."