Management of the temporomandibular joint after ablative surgery

Management of the temporomandibular joint in ablative head and neck surgery is controversial with no standardized approach. The aim of the study was to establish risk-based guidelines for the management of the temporomandibular joint after ablative surgery. Analysis of all patients' records receiving ablative surgery involving the temporomandibular joint in the Department of Cranio-Maxillofacial and Oral Surgery, University Hospital of Zürich, from 2001 to 2012, was performed, identifying 15 patients and 14 reconstructive procedures. A literature search was done identifying all relevant literature on current approaches. Applicable cohorts were constructed, and relevant risks were extrapolated. Evaluated studies are not uniform in their reporting with nonhomogeneous patient groups. A diverse approach is used in the management of these patients with complications such as infection, ankylosis, limited mouth opening, plate penetration in the skull base, and plate loosening. Risk factors for complications appear to be radiation, costochondral graft, disk loss, and plate use alone. Clinical data suggest use of a plate with metal condyle reconstructions and previous radiation therapy as potential risks factors. Employing literature evidence and cumulated clinical data, a risk-based flowchart was developed to assist surgical decision making. Risk factors such as radiation, disk preservation, and soft tissue conditions are important complication-associated factors when planning surgery. Free vascularized fibula grafts appear to have the least complications that must be weighed against donor site morbidity.

Bone regeneration by the osteoconductivity of porous titanium implants manufactured by selective laser melting: a histological and micro computed tomography study in the rabbit

The treatment of large bone defects still poses a major challenge in orthopaedic and cranio-maxillofacial surgery. One possible solution could be the development of personalized porous titanium-based implants that are designed to meet all mechanical needs with a minimum amount of titanium and maximum osteopromotive properties so that it could be combined with growth factor-loaded hydrogels or cell constructs to realize advanced bone tissue engineering strategies. Such implants could prove useful for mandibular reconstruction, spinal fusion, the treatment of extended long bone defects, or to fill in gaps created on autograft harvesting. The aim of this study was to determine the mechanical properties and potential of bone formation of light weight implants generated by selective laser melting (SLM). We mainly focused on osteoconduction, as this is a key feature in bone healing and could serve as a back-up for osteoinduction and cell transplantation strategies. To that end, defined implants were produced by SLM, and their surfaces were left untreated, sandblasted, or sandblasted/acid etched. In vivo bone formation with the different implants was tested throughout calvarial defects in rabbits and compared with untreated defects. Analysis by micro computed tomography (μCT) and histomorphometry revealed that all generatively produced porous Ti structures were well osseointegrated into the surrounding bone. The histomorphometric analysis revealed that bone formation was significantly increased in all implant-treated groups compared with untreated defects and significantly increased in sand blasted implants compared with untreated ones. Bone bridging was significantly increased in sand blasted acid-etched scaffolds. Therefore, scaffolds manufactured by SLM should be surface treated. Bone augmentation beyond the original bone margins was only seen in implant-treated defects, indicating an osteoconductive potential of the implants that could be utilized clinically for bone augmentation purposes. Therefore, designed porous, lightweight structures have potential for bone regeneration and augmentation purposes, especially when complex and patient-specific geometries are essential.