Bracket Slot Level에서의 Ideal Arch Form에 關한 硏究 = A stuty on the ideal arch form at bracket slot level

다국어 초록 (Multilingual Abstract)

The porpose of this study is to analyze the dental arch shapes and coordinated arch form at bracket slot level.
88 individuals who had normal occlusion with all the 2nd molars fully erupted, were selected.
The subjects were divided into 3 groups according to percentage of M.H. to M.W. of the lower arch.
The impression sectioned at bracket slot level was copied and traced. The X, Y coordinates and the angles between the buccal(labial) tangent line and A-axis were measured for drawing the ideal arch form, thereafter coordinated diagram of upper and lower ideal arch form was drawn with the aid of average amounts of bracket slot level-overjects.
The fellowing results were obtained,
1. The arrangement of posterior teeth was not lineal but curvilinear.
2. The degree of toe-in at the upper 1st molar was the largest(10.3°), on the contrast, at the lower 1st molar was minimal, at the upper 2nd molar(5.2°) and at the lower 2nd molar(4.2°).
3. The amount of upper lateral incisor inset was 0.5㎜, upper canine offset ; 1㎜, and lower canine offset ; 0.5㎜.
4. The amount of overiets which could be used as basis of arch coordination were ; 2.6㎜(central incisor area), 2.1㎜(lateral incisor area), 1.6㎜(between upper lateral incisor and lower canine), 2.6㎜(upper canine area), 2.5㎜(the 1st premolar area), 2.4㎜(the 2nd premolar area), 2.2㎜(the 1st molar area), and 1.8㎜(the 2nd molar area).