Impacted mandibular second premolars account for 12%?24% of all types of impacted teeth. For impacted mandibular second premolars, the mainstay of treatment is conservative management or orthodontic traction after surgical exposure. The choice of treatment mainly depends on root development, location, and direction of the impacted tooth. This report describes the case of a 14-year-old female patient with an impacted mandibular second premolar near the root of the first molar. The premolar was horizontally impacted in the distolingual direction. By referring to a virtual three-dimensional tooth model, the treatment plan was to extract the retained primary molar and perform orthodontic traction after surgical exposure. No complications such as root resorption of the mandibular first molar occurred during orthodontic traction of the impacted mandibular second premolar.