Replantation of a Permanent Tooth With a Curved Root From Infected Tooth Germ: A Case Report With a Four-Year Follow-Up.

Intentional reimplantation has long been supported by many clinicians as a last resort before tooth extraction. With the accumulation of data and the development of techniques, the survival rate of reimplantation has increased. However, although there have been many reports and studies on replantation for common causes such as root fracture, root resorption, inadequate root canal treatment, perforation, and apical periodontitis, the method of replantation in unusual cases is not yet clear, and many cases result in tooth extraction. In this report, we describe a special case in which a patient requested the replantation of an infected immature tooth with an abnormally curving root. The patient, a seven-year-old boy, sustained a bruise on his anterior maxillary tooth due to a fall at the age of one year. He had been symptom-free since then, but he came to see his dentist with a chief complaint of pain in the left maxillary gingiva. An immature permanent tooth was retrogradely impacted under the left maxillary deciduous central incisor and bone permeation was observed around the tooth. After referral to our department, the deciduous incisor was extracted and drained of pus as the first step. In the second step, a permanent central incisor was replanted at the patient's request. After four years of observation of the replanted teeth, the patient's prognosis was satisfactory. The tooth was replanted under general anesthesia. This is the first report of a permanent tooth with a curved inverted, impacted, or incomplete root infection, and the patient's progress was good after over four years of follow-up.