Examine and interview 780 pupils of grade 1-5 (7-11 years old) who has the first permanent molar and 4 madibular insicors errupting already. The authors found that: Changing occlusal relationship of the first molar: 76 percent ELDM in axillary have Angle II. 52,5 percent ELDM in mandibular have Angle III. Causing ncorrect position of the first molar, increasing the rate of deep bite, in correct midline position, affecting to the symmetry of the arch. Lack of space in the side which have ELDM comparing with the other side and the mesio-distance dimension of the succedaneous teeth.