The authors propose the use of rigid polyethylene and silicon spacers in mandibular defects as an interim measure before definitive osseous reconstruction after mandibular resections for locally aggressive benign disease. The authors point out that the current intermediate reconstruction systems provide only structural rigidity to reconstitute mandibular continuity and some degree of soft tissue support. They fail to meet the demands of maintenance of space and are not designed to facilitate re-entry and removal. Even more problematic is intermediate condylar reconstruction, which has not been intelligently designed. They propose to redesign intermediate reconstruction prosthesis to provide not only immediate structural rigidity and to support the healing of soft tissues, but also to maintain an adequate space for reconstruction while remaining technically simple to insert and remove. A virtual model using computer tomography and 3-Matic software was made that allowed three dimensional printing of a silica plaster replica of the neomandible on which a custom plate was adapted. The mandibular segment was resected through an intraoral approach and spacer introduced. The spacer consisted of a rigid condyle / ramus unit (ultrahigh molecular weight polyethylene) and a separate flexible body spacer (inert, non-toxic medical and food grade silicon rubber). The spacer was left in place for six to eight weeks and definitive reconstruction performed through an extraoral approach using coticocancellous bone graft. Thirty-eight patients were treated this way, wherein 37 patients had uncomplicated mucosal healing and only one patient (who did not adhere to follow-up protocol) had large mucosal dehiscence over the spacer. The authors argue that while primary reconstruction saves time and resources, it is seldom in the patient’s best interests and may result in compromised aesthetic and functional results that are difficult or impossible to rectify. They point out that secondary reconstruction of the mandible defect can be effected in a patient who is in physiologically optimal condition and better able to withstand reconstructive surgery. It allows the surgeon to reassess not only the adequacy of the excision but also the cosmetic outcomes of the reconstruction during healing and if necessary make changes in the final reconstructive plan to optimise the aesthetic result. Finally, grafting in an environment that is sealed from the oral cavity improves the likelihood of uncomplicated healing.
Use of spacers for mandibular defects after resection of mandible preceding definitive osseous reconstruction
Reviewed by Sampath Chandra Prasad
Interim reconstruction and space maintenance of mandibular continuity defects preceding definitive osseous reconstruction.
