Guided Double Auto-transplantation of Immature Molars Replacing Multiple Posterior Teeth with Extensive Invasive External Cervical Resorption - A Case Report.

This case report describes the extraction of 3 mandibular posterior teeth (teeth #19, 20 and 21) with extensive invasive external cervical resorption (ECR) followed by guided double auto-transplantation of immature mandibular third molars (teeth #17 and 32). A 17-year-old male with a history of orthodontic treatment reported with intermittent pain in the mandibular left posterior region. Clinical and radiographic examination revealed extensive tooth tissue loss in teeth #19, 20 and 21 that was diagnosed as class 3 ECR (Patel 3Dp for teeth #20 and 21, 3Bp for tooth #19). Guided double auto-transplantation of the immature molar tooth #17 was performed to replace premolar teeth 20 and 21, and tooth #32 to replace tooth #19. At the 6-month follow-up the donor tooth #32 had symptoms of pulpitis and was managed with a full pulpotomy using tricalcium silicate cement. Both teeth were followed-up for 36 months when they were asymptomatic, had no associated periodontal defects, had positive pulp sensibility tests as well as radiographic evidence of substantial periapical bony healing. The roots of tooth #17 had only a limited increase in length, with apical hard tissue barrier deposition, whereas tooth #32 (after pulpotomy) had continued root development. The 36 months follow-up of this case highlights the success of an interdisciplinary approach when integrating three-dimensional guides for double auto-transplantation of immature molars to successfully replace multiple teeth with extensive invasive ECR.