Intrusive luxation is an injury involving the axial displacement of a tooth into the alveolar socket. This paper describes apexification using calcium hydroxide medicaments of an immature permanent central incisor in which spontaneous re-eruption as well as severe inflammatory external root resorption was observed following traumatic intrusion. A 10-year-old boy was referred to the Department of Pediatric Dentistry 3 days after having fallen at school. Intraoral examination revealed intrusive luxation and an enamel-dentin crown fracture of the maxillary left central incisor (Tooth 21). The tooth was not sensitive to percussion and responded positively to electric pulp test. Radiographic examination indicated that the tooth had an open apex and had been intruded approximately 3-4 mm relative to the cemento-enamel junction of the adjacent right central incisor. The tooth was left for possible spontaneous re-eruption. The crown fracture was temporarily restored using glass ionomer cement, and the patient was scheduled for recall in 2 weeks, at which time intraoral examination revealed spontaneous re-eruption of the tooth. However, radiographic examination also showed inflammatory external root resorption. The root canal was accessed and filled with a calcium hydroxide paste; however, follow-up examination indicated continuing resorption after 1 month. Calcium hydroxide plus points (CHPP) was chosen as an alternative treatment. At the end of 6 months of CHPP treatment, examination showed no further progression of external resorption and complete apexification of the tooth. After a 24-month follow-up period, no signs of pathosis were observed.