Struys et al. Journal of Medical Case Reports 2010, 4:328 http://www.jmedicalcasereports.com/content/4/1/328 Page 4 of 5 Figure 4 Electron microscopic images of the transplanted PDL. (a) Shows fully developed blood vessels. (b) Shows the electron microscopic aspect of the enlarged ERM. Figure 5 Electron microscopic image of the re-innervation of the ERM in the autotransplanted PDL. seen as an attempt to direct PDL remodeling and re-inner- vation. The innervation of the ERM suggests that this whole process is directed by the nervous system. Conclusion One of the key elements necessary for a successful auto- transplantation is the conservation of the periodontal ligament. These results suggest that the extraction should be as atraumatic as possible in order to conserve the periodontal ligament and minimalise the damage brought to the ERM. Consent Written informed consent was obtained from the patient for publication of this case report and accompanying images. A copy of the written consent is available for review by the Editor-in-Chief of this journal. Abbreviations ERM: epithelial rests of Malassez; ERSH, epithelial root sheath of Hertwig; IPC, inflammatory paradental cyst; PDL, peridontal ligament; TEM, transmission electron microscope. Acknowledgements The skilful technical assistance of Mr Marc Jans is gratefully acknowledged. Author details 1Biomedical Research Institute, Hasselt University, Campus Diepenbeek, Diepenbeek, Belgium. 2Department of Maxillo-Facial Surgery, Hospital of East Limburg (ZOL), Genk, Belgium. 3Oral Imaging Center, Catholic University Leuven, Leuven, Belgium. 4Department of Maxillo-Facial Surgery, Gent University, Gent, Belgium.