This study aimed to compare chin deviation in angle measurement on posteroanterior(PA) cephalogram and computed tomography (CT). Chin deviation was assessed as menton(Me) deviation in angle measurement on PA cephalogram and CT images of 35 patients who had orthognathic surgery (19 male and 16 female with average age of 22.1±3.33yr). The difference between the Me deviation was calculated and statistical analysis was performed to compare the deviation direction and asymmetry severity on the two imaging modalities. There was statistically significant difference in the difference of Me deviation between PA cephalogram and CT by one-simple t-test (p<.05). The mean difference of Me deviation was 2.21°± 1.84°. The maximum difference of Me deviation was 8.64°. There were statistical agreements in the deviation direction (k =0.82, p<.05) and in the severity of facial asymmetry (k =0.37, p<.05). The difference of the deviation direction was detected in 2 patients (5.71 %). The difference of the severity of facial asymmetry was in 15 patients (42.86%). The chin deviation in angle measurement might be different between PA cephalogram and CT in some patients.

• 윤숙자(전남대학교 치의학전문대학원, 구강악안면방사선학교실) | Suk-Ja Yoon (1)School of Dentistry, Chonnam National University, Department of Oral and Maxillofacial Radiology, School of Dentistry)
• 강병철(전남대학교 치의학전문대학원, 구강악안면방사선학교실) | Byung-Cheol Kang (1)School of Dentistry, Chonnam National University, Department of Oral and Maxillofacial Radiology, School of Dentistry)
• 이재서(전남대학교 치의학전문대학원, 구강악안면방사선학교실) | Jae-Seo Lee (School of Dentistry, Chonnam National University, Department of Oral and Maxillofacial Radiology, School of Dentistry)
• 진문환(전남대학교 치의학연구소) | Jin Mun Hwan (Dental Science Research Institute, Chonnam National University)
• 이은주(구강해부학교실) | Eun Joo Lee (Dental Science Research Institute, Chonnam National University, Department of Oral Anatomy, School of Dentistry) Corresponding author