When many factors involved in the eruption of the teeth act as negative effects, they can cause eruption disturbance. Periodic observation, space acquirement, surgical exposure, orthodontic traction, orthodontic traction accompanied with surgical exposure, and surgical repositioning are considered as the treatment options of an impacted tooth, which is a form of eruption disturbance. In the first case, a male patient, age 9, visited Yonsei University Dental Hospital (YUDH) with a chief complaint of ectopic impaction of the upper left lateral incisor. We extracted the upper left primary lateral incisor and primary canine, and 5 months later, a window opening procedure was executed. Eight months later, the upper left lateral incisor partially erupted, and 18 months after the extraction, the axis of the tooth improved and the tooth erupted spontaneously. In the second case, a male patient, age 10, visited YUDH with a chief complaint of ectopic impaction of the upper right first premolar. We extracted the upper right first primary molar. Ten months later, the upper right first premolar erupted partially, and 19 months after the extraction, the upper right first premolar erupted spontaneously. We reported two cases in which improvement of eruption path and spontaneous eruption of an ectopic impacted tooth was achieved by extracting the deciduous tooth which interfered with the proper eruption of it.