Long-term skeletal, cephalometric, and volumetric changes in two Helsinki bimaxillary face transplant patients.

Analysis of skeletal, cephalometric, and volumetric changes and occlusion during long-term follow-up was performed for two patients who underwent bimaxillary facial transplantation (FT). The study material consisted of the follow-up data of two bimaxillary composite FT performed in Helsinki University Hospital, one in 2016 and the other in 2018. Serial three-dimensional computed tomography scans obtained during follow-up (6 years for patient 1, 4 years for patient 2) were analyzed. The position of the maxilla remained stable in both patients. At 4 and 6 years, the changes in the anterior maxilla were ≤1 mm, while the anterior mandible had moved 2.6-4 mm anteriorly and the mandibular midline 0.4-3.7 mm to the left side. Patient 1 underwent re-osteosynthesis 4 months after transplantation due to mandibular non-union. Patient 2 had a sagittal mandibular osteotomy at 15 months after FT due to lateral crossbite and tension created by temporomandibular joint rotation. Thereafter both patients had a stable occlusion. A continuous bone volume reduction in the mandible was noticed in both patients (6% and 9% reduction of the transplanted volume). The volume of the transplanted maxilla decreased during the early postoperative period but increased back to the original transplanted volume during the follow-up.

Craniomaxillofacial osteosarcoma - The role of surgical margins.

BACKGROUND: Osteosarcomas (OS) in the craniomaxillofacial (CMF) region are typically diagnosed at later age than long-bone OS, but they are reported to have better 5-year survival. Curative treatment warrants wide surgical resection, which is often not possible in the CMF region. The purpose of this article is to present a nationwide series of CMF in Finland to discuss the role of surgery. PATIENTS AND METHODS: All 21 CMF OS patients managed in Finland from 1992 to 2009 were included. The mean age was 40 years (range 15-72). Data on patient and tumor characteristics, treatment modalities, and survival were recorded. All patients had a minimum follow-up of 5 years or until death. RESULTS: OS was evenly represented in the mandible and maxillary bones, which together constituted 76% of all sites. Surgery with curative intent was carried out in 20 patients. Clear margins were achieved in only five cases. Eight (40%) of these 20 patients died due to OS, and their average survival time was 1.3 years. Seven (35%) out of the 20 patients received radiotherapy due to close/intralesional surgical margins, and four of them did not develop recurrences during the follow-up. CONCLUSIONS: The results suggest that postoperative radiotherapy may alter the prognosis in CMF OS, particularly in cases with close or intralesional margins. This may increase the survival rates achieved by prompt action in performing radical surgery.

Primary reconstruction of orbital fractures using patient-specific titanium milled implants: the Helsinki protocol.

Preoperative virtual planning and the use of patient-specific implants enable exact reconstruction of orbital fractures. We present our results and experience of reconstruction of isolated orbital fractures with patient-specific implants, according to the Helsinki protocol, in 15 patients who were followed up for at least three months postoperatively. The mean (range) difference between the positions of virtually planned, and postoperative, implants was 1.9 (0.5-5.6) mm. The postoperative volume of the fractured orbit was 1.34ml less than that of the non-fractured side, but this was not clinically relevant. None of the patients required reoperation and none had any implant-related complications during follow up. We conclude that patient-specific implants are an adaptable and reliable treatment for primary orbital trauma, and that the Helsinki protocol may have wider applications in the treatment of facial fractures.

Novel maxillary reconstruction with ectopic bone formation by GMP adipose stem cells.

Microvascular reconstruction is the state-of-the-art in many fields of defect surgery today. Currently, reconstruction of large bony defects involves harvesting of autologous bone causing donor site morbidity and risk of infection. Specifically, utilizing autologous adipose stem cells (autoASCs), large quantities of cells can be retrieved for cell therapy applications and the risk of tissue rejection is diminished. The authors describe the first case report of a microvascular custom-made ectopic bone flap employing good manufacturing practice (GMP) level ASCs. The patient underwent a hemimaxillectomy due to a large keratocyst. After 36 months of follow-up, the defect was reconstructed with a microvascular flap using autoASCs, beta-tricalcium phosphate and bone morphogenetic protein-2. ASCs were isolated and expanded in clean room facilities according to GMP standards and were characterized in vitro. After 8 months of follow-up, the flap had developed mature bone structures and vasculature and was transplanted into the defect area. Postoperative healing has been uneventful, and further rehabilitation with dental implants has been started. The in vitro characterization demonstrated multipotentiality and mesenchymal stem cell characteristics in ASCs. This is the first clinical case where ectopic bone was produced using autoASCs in microvascular reconstruction surgery and it will pave way for new clinical trials in the field.

Tyrosine derived polycarbonate membrane is useful for guided bone regeneration in rabbit mandibular defects.

Standardized bilateral through-and-through defects (12x6 mm) were created extraorally in the mandibular angle of 18 New Zealand White rabbits. Animals were divided in to three groups (n=6) according to the intended healing time. On the left side, defects were covered with a poly(desaminotyrosyl-tyrosine-ethyl ester carbonate) (PDTE carbonate) membrane wrapped around the inferior border of the mandible and fixed with bioabsorbable sutures. On the right side, the defects were filled with a mesh made of bioactive glass 13-93 and 3 wt% chitosan. The defects were covered with the same membranes. Periosteal flap was sutured over the membrane. Radiographically, bone ingrowth was seen in all specimens at 12 weeks postoperatively. At 24 weeks, completely ossified area remained approximately at the same level as at 12 weeks, but the non-ossified area decreased to almost zero. However, the bioactive glass mesh did not improve the results. Nevertheless, enveloping the defect with PDTE carbonate membrane seemed to play a crucial role in new bone formation. Based on these results, we conclude that tyrosine polycarbonate is a promising new material for guided bone regeneration.