title: Mandibular reconstruction with a bioactive-coated cementless Ti6Al4V modular endoprosthesis in Macaca fascicularis.
abstract: The titanium mandibular modular endoprosthesis fixed with polymethylmethacrylate cement in the medullary space of the mandible has been introduced in previous studies. However, the internal parts of these devices have been found to be prone to loosening and wound dehiscence. The current study introduces a newly designed bioactive-coated cementless modular mandibular endoprosthesis, which was used for reconstruction in Macaca fascicularis. The devices were coated with hydroxyapatite (HA) and hydroxyapatite/bioglass (HA/BG) and implanted in unilateral mandibular segmental defects in nine monkeys for 6 months. Biomechanical testing found the reconstructed mandible to have a mean stiffness value of 110.43 N/mm. Histologically, there were both fibrous capsule and woven bone around the device body, and histomorphology analysis showed 64.17% bone contact to device stem surface. The percentage bone volume calculated from micro-computed tomography analysis around the stem surface was found to be superior to that reported in previous studies of cemented mandibular endoprostheses. Intermodular connection screw loosening has also been resolved with the dovetail interconnection. In conclusion, the current bioactive-coated cementless mandibular endoprosthesis is feasible for use in mandibular segmental reconstruction. However, insufficient load-bearing capability and a high rate of intraoral wound dehiscence were found in the majority of the study animals. Further device modifications and improvements in the surgical technique need to be addressed in future studies.
authors: Department of Oral and Maxillofacial Surgery, National Dental Centre, Singapore. Electronic address: cnattharee@yahoo.com.
authors: N
authors: N
authors: Chanchareonsook
authors: Department of Oral and Maxillofacial Surgery, National Dental Centre, Singapore.
authors: H
authors: H
authors: Tideman
authors: Department of Oral and Maxillofacial Surgery, National Dental Centre, Singapore.
authors: S
authors: S
authors: Lee
authors: Department of Biomedical Engineering, College of Engineering, University of Michigan, Ann Arbor, MI, USA.
authors: S J
authors: SJ
authors: Hollister
authors: Department of Biomedical Engineering, College of Engineering, University of Michigan, Ann Arbor, MI, USA.
authors: C
authors: C
authors: Flanagan
authors: Department of Biomaterials, Radboud University Nijmegen Medical Centre, The Netherlands.
authors: J A
authors: JA
authors: Jansen
mesh_terms: D000497:Alloys; D000818:Animals; D020099:Coated Materials, Biocompatible; D008252:Macaca fascicularis; D008297:Male; D008341:Mandibular Prosthesis; D063175:Mandibular Reconstruction / Q000295:instrumentation*; D011474:Prosthesis Design; D014025:Titanium
chemical_list: D000497:Alloys; D020099:Coated Materials, Biocompatible; C031462:titanium alloy (TiAl6V4); D014025:Titanium
keywords: bioactive; bioglass (BG); cementless endoprosthesis; hydroxyapatite (HA); mandible; modular endoprosthesis; reconstruction