3. The average inter-canine width was 27.16mm(s.d. 1.78) in both sex, 27.41mm in male, and 26.77mm in female. And the sexual difference was significant(04. The average inter-first molar width was 46.93mm(s.d. 2.67) in both sex, 47.72mm in male, and 45.7mm in female And the sexual difference was significant(0
5. ¢¥the inter-second molar width was average 56.09mm(s.d. 3.01) in both sex, 57.24mm in male, and 54.32mm in woma. And the sexual difference was significant(0
6. The arch form was classified into three shapes based on the incisal and canine angle. V-shape showed 124.88 of incisal angle and 141.64 of canine angle, U-shape showed 152.76¡Æ and 125.35¡Æ , and 0-shape showed 138:03¡Æ and 133.66¡Æ respectively. Each arch shape distribution was that the V-shape was 142%, the Ushape was 14.7%, and the 0-shape was 71.1% of the 225 study models.
7. It was thought that the use of second molar width is more reasonable than height for classifying the dental arch size. The arch size was classified into four sizes based on the 2nd molar width. Size 1 showed range of 42.24-48.¢¥23 mm, size 2 showed 48.24-54.23mm, and size 3 showed 54.24-60.23mm size 4 showed 60.24-66.23mm respectively Each arch size distribution was that the size I was 1.3%, the size 2 was 27.1%, the size 3 was 63.6%, and the size 4 was 8:0% of the 225 study models.