Most comminly used axis for central incisors in lateral cephalometric radiographs is the line connecting root apex and incisor edge. However, crown axis and root axis do not always coincide in cases of malocclusion parients. The angle created by these axis are called the collum angle, which should be considered in orthodontic diagnosis and treatment. In this study, 31 Class Ⅰ malocclusion, 30 Class Ⅱ division 1 malocclusion, 31 Class Ⅱ division 2 malocclusion, and 31 Class Ⅲ malocclusion patients were selected and their collum angles were measured. Correlation between these angles and malocclusions was investigated, and the correlation analysis with other parameters in cephalometrics was done. The results were as follows ; 1.The mean collum angles according to the types of malocclusions are ; 3.11^○ ±3.54^○ for Class Ⅰ, 1.23^○ ± 2.41^○ for Class Ⅱ division1. 3.77^○ ±4.39^○ for Class Ⅱ division 2, and 3.90^○ ±4.08^○ for Class Ⅲ malocclusion. 2. Statistically significant differences in collum angles were noted between Class Ⅱ division 1 group and Class Ⅱ division 2 and Class Ⅲ group. 3. Significant correlations were found between collum angles and other parameters used in cephalometrics, namely IMPA for Class Ⅰ, Wits for Class Ⅱ division 1, Overbite for Class Ⅱ division 2 and for Class Ⅲ.