A removable orthodontic device includes an anchorage cap segment, a moving cap segment, a pair of spring elements, and a guiding wire. The anchorage cap segment is removably worn on the anterior teeth of a dental arch. The moving cap segment is removably worn on at least one posterior tooth on one side of the dental arch. The spring elements are disposed between the anchorage and moving cap segments to generate an elastic resilient force to move the moving cap segment relative to the anchorage cap segment. The guiding wire has a U-shaped portion and two rod portions. The U-shaped portion is embedded in and disposed around three sidewalls of the moving cap segment, and the rod portions are received in guiding channels formed in the buccal and lingual sidewalls of the anchorage cap segment to guide the movement of the moving cap segment.
