A case of tooth autotransplantation after long-term cryopreservation using a programmed freezer with a magnetic field.

This case report describes the treatment of a skeletal Class III malocclusion with autotransplantation of a cryopreserved tooth. To gain an esthetic facial profile and good occlusion, extraction of bimaxillary premolars and surgical therapy were chosen. The patient had chronic apical periodontitis on the lower left first molar. Although she did not feel any pain in that region, the tooth was considered to have a poor prognosis. Therefore, we cryopreserved the extracted premolars to prepare for autotransplantation in the lower first molar area because the tooth would probably need to be removed in the future. The teeth were frozen by a programmed freezer with a magnetic field (CAS freezer) that was developed for tissue cryopreservation and were cryopreserved in -150°C deep freezer. After 1.5 years of presurgical orthodontic treatment, bilateral sagittal split ramus osteotomy was performed for mandible setback. Improvement of the facial profile and the occlusion were achieved in the retention phase. Six years after the initial visit, the patient had pain on the lower left first molar, and discharge of pus was observed, so we extracted the lower left first molar and autotransplanted the cryopreserved premolar. Three years later, healthy periodontium was observed at the autotransplanted tooth. This case report suggests that long-term cryopreservation of teeth by a CAS freezer is useful for later autotransplantation, and this can be a viable technique to replace missing teeth.

Treatment of a horizontal open bite with an invisible multiloop appliance in a girl with tooth trauma.

This case report presents the treatment of a girl with a Class II horizontal open bite and severe crowding with an invisible appliance. She had been in a severe traffic accident at 5 years 10 months of age. Her teeth, especially the mandibular right lateral incisor, canine, and first premolar had ankylosed, and their roots were severely resorbed and fused to the alveolar bone. Orthodontic treatment started at the age of 12 years. The mandibular left first premolar and both maxillary first premolars were extracted to reduce overjet and crowding. The left first premolar was extracted and transplanted to the extracted position of the right first premolar. Because the patient wanted an invisible appliance, we selected the Fujita lingual bracket system for her treatment. During the final stage of treatment, a multiloop mushroom archwire was placed to correct the open bite in the maxillary arch with vertical elastics. Six years after retention, her occlusion remained stable, and the transplanted premolar was functioning normally.