Donor site morbidity after computer assisted surgical reconstruction of the mandible using deep circumflex iliac artery grafts: a cross sectional study.

BACKGROUND: Computer Assisted Design and Computer Assisted Manufacturing (CAD/CAM) have revolutionized oncologic surgery of the head and neck. A multitude of benefits of this technique has been described, but there are only few reports of donor site comorbidity following CAD/CAM surgery. METHODS: This study investigated comorbidity of the hip following deep circumflex iliac artery (DCIA) graft raising using CAD/CAM techniques. A cross-sectional examination was performed to determine range of motion, muscle strength and nerve disturbances. Furthermore, correlations between graft volume and skin incision length with postoperative donor site morbidity were assessed using Spearman's rank correlation, linear regression and analysis of variance (ANOVA). RESULTS: Fifteen patients with a mean graft volume of 21.2 ± 5.7 cm3 and a mean incision length of 228.0 ± 30.0 mm were included. Patients reported of noticeable physical limitations in daily life activities (12.3 ± 11.9 weeks) and athletic activities (38.4 ± 40.0 weeks in mean) following surgery. Graft volume significantly correlated with the duration of the use of walking aids (R = 0.57; p = 0.033) and impairment in daily life activities (R = 0.65; p = 0.012). The length of the scar of the donor-site showed a statistically significant association with postoperative iliohypogastric nerve deficits (F = 4.4, p = 0.037). Patients with anaesthaesia of a peripheral cutaneous nerve had a larger mean scar length (280 ± 30.0 mm) than subjects with hypaesthesia (245 ± 10.1 mm) or no complaints (216 ± 27.7 mm). CONCLUSIONS: Despite sophisticated planning options in modern CAD/CAM surgery, comorbidity of the donor site following  iliac graft harvesting is still a problem. This study is the first to investigate comorbidity after DCIA graft raising in a patient group treated exclusively with CAD/CAM techniques. The results indicate that a minimal invasive approach in terms of small graft volumes and small skin incisions could help to reduce postoperative symptomatology. Trial registration Retrospectively registered at the German Clinical Trials Register (DRKS-ID: DRKS00029066); registration date: 23/05/2022.

Feasibility of Implant Strain Measurement for Assessing Mandible Bone Regeneration.

Nonunion is one of the most dreaded complications after operative treatment of mandible fractures or after mandible reconstruction using vascularized and non-vascularized bone grafts. Often diagnosis is made at advanced stage of disease when pain or complications occur. Devices that monitor fracture healing and bone regeneration continuously are therefore urgently needed in the craniomaxillofacial area. One promising approach is the strain measurement of plates. An advanced prototype of an implantable strain measurement device was tested after fixation to a locking mandible reconstruction plate in multiple compression experiments to investigate the potential functionality of strain measurement in the mandibular region. Compression experiments show that strain measurement devices work well under experimental conditions in the mandibular angle and detect plate deformation in a reliable way. For monitoring in the mandibular body, the device used in its current configuration was not suitable. Implant strain measurement of reconstruction plates is a promising methodical approach for permanent monitoring of bone regeneration and fracture healing in the mandible. The method helps to avoid or detect complications at an early point in time after operative treatment.

Evaluation of computed tomography settings in the context of visualization and discrimination of low dose injections of a novel liquid soft tissue fiducial marker in head and neck imaging.

BACKGROUND: Intraoperative incorporation of radiopaque fiducial markers at the tumor resection surface can provide useful assistance in identifying the tumor bed in postoperative imaging for RT planning and radiological follow-up. Besides titanium clips, iodine containing injectable liquid fiducial markers represent an option that has emerged more recently for this purpose. In this study, marking oral soft tissue resection surfaces, applying low dose injections of a novel Conformité Européenne (CE)-marked liquid fiducial marker based on sucrose acetoisobutyrate (SAIB) and iodinated SAIB (x-SAIB) was investigated. METHODS: Visibility and discriminability of low dose injections of SAIB/x-SAIB (10 µl, 20 µl, 30 µl) were systematically studied at different kV settings used in clinical routine in an ex-vivo porcine mandible model. Transferability of the preclinical results into the clinical setting and applicability of DE-CT were investigated in initial patients. RESULTS: Markers created by injection volumes as low as 10 µl were visible in CT imaging at all kV settings applied in clinical routine (70-120 kV). An injection volume of 30 µl allowed differentiation from an injection volume of 10 µl. In a total of 118 injections performed in two head and neck cancer patients, markers were clearly visible in 83% and 86% of injections. DE-CT allowed for differentiation between SAIB/x-SAIB markers and other hyperdense structures. CONCLUSIONS: Injection of low doses of SAIB/x-SAIB was found to be a feasible approach to mark oral soft tissue resection surfaces, with injection volumes as low as 10 µl found to be visible at all kV settings applied in clinical routine. With the application of SAIB/x-SAIB reported for tumors of different organs already, mostly applying relatively large volumes for IGRT, this study adds information on the applicability of low dose injections to facilitate identification of the tumor bed in postoperative CT and on performance of the marker at different kV settings used in clinical routine.

Intraoperative marking of the tumour resection surface for improved radiation therapy planning in head and neck cancer: preclinical evaluation of a novel liquid fiducial marker.

OBJECTIVE: To evaluate a novel liquid fiducial marker for intraoperative marking of the tumour resection surface in oral cancer patients to facilitate precise postoperative delineation of the interface between the tumour resection border and reconstructed tissue for intensity-modulated radiation therapy. METHODS: A total of 200 markers were created by injecting the volumes of 10 µl, 20 µl, 30 µl, 40 µl and 50 µl of a liquid marker composed of sucrose acetoisobutyrate (SAIB) and iodinated sucrose acetoisobutyrate (x-SAIB) into the soft tissue of porcine mandible segments. Visibility of the resulting markers was quantified by threshold-based segmentation of the marker volume in CT- and CBCT imaging and by a comparison of signal intensities in MRI. RESULTS: Even the lowest volume of SAIB-/x-SAIB investigated (10 µl) resulted in a higher visibility (CTSoft tissue: 88.18 ± 13.23 µl; CTBone: 49.55 ± 7.62 µl; CBCT: 54.65 ± 12.58 µl) than observed with the incorporation of titanium ligature clips (CTSoft tissue: 50.15 ± 7.50 mm3; CTBone: 23.90 ± 3.39 mm3; CBCT: 33.80 ± 9.20 mm3). Markers created by the injection of 10 µl and 20 µl could reliably be delineated from markers created by the injection of higher volumes. CONCLUSION: SAIB/x-SAIB, which has recently become available as a Conformité Européenne (CE)-marked fiducial marker, provides an option for fast and reliable production of markers with excellent visibility in imaging modalities used in oral cancer radiation therapy (RT) planning routine.

Effects of Red Blood Cell Transfusions on Distant Metastases of Oral Squamous Cell Carcinomas.

There is no consensus on the effect of red blood cell (RBC) transfusions on patients with oral squamous cell carcinoma (OSCC). The aim of this study was to investigate the association between RBC administration and the occurrence of distant metastases (M+) after surgical treatment of OSCC. All medical records of patients who underwent primary surgery for OSCC in our department (2003-2019) were analyzed retrospectively (n = 609). Chi and Cox regression models were used to analyze the influence of transfusion on the development of M+, and survival rates. Kaplan-Meier curves were used for graphical presentation. A multitude of patient-specific factors showed a statistical impact in univariate analysis (transfusion, age, gender, diabetes, pT, pN, L, V, Pn, G, UICC, adjuvant therapy, free microvascular transplant, preoperative hemoglobin level). Transfusion status and pN stage were the only variables that showed a significant correlation to M+ in the multivariate Cox model. The hazard ratios for the occurrence of M+ were 2.42 for RBC transfusions and 2.99 for pN+. Administration of RBC transfusions was identified as a significant prognostic parameter for the occurrence of distant metastases after surgical treatment of OSCC. Hence, the administration of RBC transfusions should be considered carefully in the perioperative management.

Concentration of Penicillin G in Jawbone Affected by Antiresorptive Agent-Related Osteonecrosis Following a Single Preoperative Dose.

The aim of this study was to evaluate the concentration of penicillin G in bone affected by antiresorptive agent-related osteonecrosis of the jaw (ARONJ) following a single preoperative dose of 10 million international units (6000 mg). ARONJ is a major concern in patients administered antiresorptive agents for conditions associated with pathologically increased bone resorption. Antibiotic therapy is a key component of most treatment approaches for ARONJ and penicillin based regimens, providing a cost effective therapy option with a favorable side effect profile, are administered most frequently. In this study, high performance liquid chromatography with tandem mass spectrometry (HPLC-MS/MS) was applied to evaluate penicillin G concentration in serum and bone samples of 19 patients suffering from ARONJ and undergoing surgical treatment under perioperative intravenous (IV) antibiotic therapy. Penicillin G bone concentrations were above the limit of detection (0.1 µg/g bone tissue) in 16 out of 19 samples, with a median concentration of 2.7 µg/g (range 0.1-8.8 µg/g). Penicillin G concentrations in intraoperative serum samples were above the limit of detection in all serum samples, with a median concentration of 116 µg/mL (range 1-232 µg/mL). Thus, considering bacteria frequently found in ARONJ lesions, penicillin G at levels providing adequate antimicrobial activity was detected in the serum and 16 out of 19 osteonecrotic lesions of patients suffering from ARONJ.

Tooth extractions in patients under antiresorptive therapy for osteoporosis: Primary closure of the extraction socket with a mucoperiosteal flap versus application of platelet-rich fibrin for the prevention of antiresorptive agent-related osteonecrosis of the jaw.

PURPOSE: The aim of this study was to compare primary closure of the extraction socket to application of platelet-rich fibrin (PRF) without subsequent primary closure for the prevention of osteonecrosis of the jaw (ONJ) in patients administered antiresorptive therapy for osteoporosis. MATERIALS AND METHODS: Primary closure of the extraction socket was performed with a mucoperiosteal flap and two-layer suturing or PRF was inserted into the extraction socket without subsequent primary closure. In all patients, intra- and postoperative complications as well as the overall treatment outcome were recorded. RESULTS: The patient sample consisted of 77 patients; primary closure with a mucoperiosteal flap was performed in 39 patients (group A), and application of PRF without subsequent primary closure was performed in 38 patients (group B). There were no statistically significant differences (p > 0.05) between the two groups in terms of age and gender, duration and type of antiresorptive therapy, teeth to be extracted (number, location and type) as well as comorbidities. No intraoperative complications occurred in either of the groups. Postoperative complications were found in 6 patients in group A and in one patient in group B. Analyzing risk factors for these complications, the highest OR (6.72 with p = 0.085 in univariate analysis; 12.81 with p = 0.052 in multivariate analysis) was found for the type of procedure (group A/group B). All patients had complete mucosal coverage without any signs of antiresorptive agent-related osteonecrosis of the jaw at the final control examination 90 days postoperatively. CONCLUSION: Based on the results of this study, the use of PRF can be recommended as a preventive measure in patients requiring tooth extractions while being under antiresorptive therapy for osteoporosis.

Primary wound closure and perioperative antibiotic therapy for prevention of bisphosphonate-related osteonecrosis of the jaw after tooth extraction.

OBJECTIVES: Tooth extractions are suspected to be a major trigger for the development of bisphosphonate-related osteonecrosis of the jaw (BRONJ). Preventive measures like perioperative antibiotic therapy and primary wound closure have been found to be effective in preventing the development of BRONJ following tooth extraction. The aim of this study was to present long-term results of a treatment protocol for patients under bisphosphonate therapy requiring tooth extraction. METHOD AND MATERIALS: Between January 2008 and December 2012, 232 tooth extractions were performed in 84 patients under current or previous bisphosphonate treatment. Extractions were performed applying an atraumatic technique under prolonged intravenous antibiotic therapy. The bony edges were rounded off meticulously and the extraction sockets were covered with a mucoperiosteal flap. RESULTS: Out of 84 patients, two developed osteonecrosis of the jaw (ONJ), resulting in an incidence-rate of 2.4%. Both ONJ patients had received radiation therapy to the head and neck region following tooth extraction. The remaining 82 patients had uneventful healing and did not present any signs or symptoms of BRONJ during the follow-up period of 41.5 months. CONCLUSION: Tooth extractions, if performed under certain circumstances, would not seem to constitute a major risk factor for the development of BRONJ. The treatment protocol presented in this article seems to be highly effective in preventing development of ONJ after tooth extraction in patients under current or previous bisphosphonate therapy.

Vascularized scapula and latissimus dorsi flap for CAD/CAM assisted reconstruction of mandibular defects including the mandibular condyle: technical report and clinical results.

BACKGROUND: Reconstruction of mandibular continuity and function after tumor resection is challenging, particularly in cases including the mandibular condyle. Various approaches for reconstruction after disarticulation resection have been reported. However, the scapula flap has received little attention as a treatment option in these cases. PATIENTS AND METHODS: Three cases of computer aided design and computer aided manufacturing (CAD/CAM) assisted reconstruction after disarticulation resection using a vascularized scapula and latissimus dorsi flap are reported. All cases required reconstruction of the mandibular ramus and condyle in combination with the reconstruction of large and complex soft tissue defects. RESULTS: The surgical procedure was deemed successful in all cases. The scapula flap could be placed as preoperatively planned and patients regained their preoperative occlusion pattern and satisfying mouth opening-ranges. The large soft tissue defects could reliably be reconstructed using a latissimus dorsi flap. CONCLUSIONS: The scapula and latissimus dorsi flap can be considered a suitable option for the reconstruction of mandibular disarticulation resection defects in combination with large soft tissue defects.

Analysis of the accuracy of a novel preformed osteosynthesis plate for the reduction and fixation of zygomaticomaxillary complex fractures.

INTRODUCTION: There has been a shift toward surgical treatment of ZMC (zygomaticomaxillary complex) fractures with open reduction and subsequent fixation in the past decades. Anatomically preformed osteosynthesis plates, already used in the field of craniomaxillofacial surgery for the treatment of fractures of the mandible and the orbit, might be a suitable option for ZMC fractures as well. MATERIAL AND METHODS: A statistical shape model was created from 179 cranial CT scans. Based on this surface model, an anatomically preformed plate for the reduction and fixation of ZMC fractures was developed in 3 sizes (S, M, L). Virtual analysis of the accuracy of the plate was performed on a dataset consisting of 120 CT scans. RESULTS: Within a determined tolerance range of 0-1.5 mm, analysis revealed a high accuracy of the plate in 70-87 % of the CT scans. The S-sized plate has the highest overall accuracy, whereas the L-sized plate has highest accuracy at the "base" region which is essential for the placement of the plate. DISCUSSION: The newly developed plate can be placed via an intraoral approach and analysis of the plate has confirmed its accuracy to be sufficient to ensure an adequate fracture reduction and fixation. It thus might allow for a less extensive approach and less approaches/incisions necessary overall to reduce and fixate ZMC fractures.

Catching condyle - Endoscopic-assisted transoral open reduction and rigid fixation of condylar process fractures using an auto reposition and fixation osteosynthesis plate.

INTRODUCTION: Fractures of the mandibular condyle are reported to account for 9 %-45 % of all mandibular fractures. There has been a long lasting controversy on the superiority of different treatment options with endoscopic-assisted transoral approaches gaining increasing attention in recent years. In this article, we report the application of a newly developed osteosynthesis plate for an auto reposition, reconstruction and rigid fixation of condylar process fractures. MATERIAL AND METHODS: We present 6 cases of uni- or bilateral fractures of the condylar process treated with a transoral open reduction and rigid fixation using an auto reposition plate. Via a transoral endoscopic assisted approach the proximal condyle fragment is captured using an anatomical defined clinch of the cranial part of the plate. The reposition of the condyle is facilitated with the distal bridge of the plate ranging around the posterior part of the ascending ramus. RESULTS: The results show a sufficient reposition, rigid fixation and no facial nerve palsy or postoperative long-term occlusal disturbances. The mean operating time was 86 min. CONCLUSION: Transoral endoscopic-assisted surgery with application of an auto reposition, reconstruction and fixation plate offers a quick and convenient way for open reconstruction and rigid fixation of condylar process fractures.

Correction to: Treatment of stage II medication-related osteonecrosis of the jaw with necrosectomy and autologous bone marrow mesenchymal stem cells.

In the Original publication of the article, the co-author has been misspelled as Fabian Duttenhöfer in the article "Treatment of stage II medication-related osteonecrosis of the jaw with necrosectomy and autologous bone marrow mesenchymal stem cells" published in October 2017, Volume 105, Issue 4 of Odontology. The correct name is "Fabian Duttenhoefer".

Necrotizing fasciitis as a complication of osteonecrosis of the jaw related to oral bisphosphonate application in a patient with osteoporosis: a case report.

BACKGROUND: Necrotizing fasciitis has been reported as a complication secondary to bisphosphonate-related osteonecrosis of the jaw (BRONJ) in a low number of patients. The only report of such a case in an osteoporosis patient found in current literature was related to short-term bisphosphonate but long time corticosteroid and methotrexate treatment. CASE PRESENTATION: In this article, we report a case of necrotizing fasciitis secondary to osteonecrosis of the jaw related to long-term oral bisphosphonate treatment in an osteoporosis patient additionally suffering from poorly controlled type 2 diabetes. Diabetes mellitus not only has been reported to be a systemic risk factor regarding BRONJ but also to be the most common comorbidity in patients presenting with necrotizing fasciitis and to increase mortality of this condition. Necrotizing fasciitis and BRONJ in the patient could eventually be resolved by a surgical approach and intravenous antibiotic therapy. CONCLUSIONS: The case presented suggests diabetes mellitus potentially having been an important factor in the particularly unfavorable course of therapy. It emphasizes the importance of an adequate therapy and surveillance of modifiable systemic risk factors like diabetes mellitus in patients being at risk for development of BRONJ. If necrotizing fasciitis is suspected, early diagnosis and aggressive surgical and medical management are essential to minimize morbidity and mortality.

Sexual activity and quality of life in patients after treatment for breast and ovarian cancer.

OBJECTIVE: Sexual activity (SA) and functioning (SF) are important factors influencing quality of life (QoL). Anticancer treatment can cause or promote sexual dysfunctions. In this study we analyzed the SA, SF and QoL in patients after completion of treatment for breast cancer (BC) and ovarian cancer (OC). METHODS: In this retrospective multicenter study 396 BC patients and 93 OC patients aged between 18 and 70 years were surveyed at least 24 months after cancer diagnosis and compared to 60 healthy women. Data were collected through validated questionnaires (Sexual Activity Questionnaire, Female Sexual Function Index-d, EORTC Quality of Life Questionnaire-C30). RESULTS: 45.9% of BC patients and 56.5% of OC patients reported SA. SF and well-being of sexually active BC patients were not influenced by the type and radicality of surgery or the administration of chemotherapy. Patients who received antihormonal therapy at the time of evaluation showed a lower frequency of SA (p = 0.007), less satisfaction (p = 0.003) and more discomfort during SA (p = < 0.001) compared to healthy controls but no differences in experiencing orgasms, health status, QoL and global health status. In contrast, BC patients without antihormonal therapy showed only a higher discomfort score (p = 0.028) than healthy controls and estimated their health status and QoL significantly better than patients who received antihormonal therapy (p = 0006). In general, SA was associated with a better health status (p = 0.007), a better QoL (p = 0.004) and a better global health status (p = 0.004) in BC patients. Sexually active OC patients showed no significant differences in SF, QoL and health status compared to healthy controls. CONCLUSIONS: Compared to healthy controls BC patients showed limitations in SF with a lower SA rate and more discomfort. Antihormonal therapy was an important factor influencing SF and well-being. Breast and OC survivors reported good physical and psychical health without differences in QoL and health status compared to controls. This might be explained by a change of perspective on life difficulties and altered priorities through a life threatening disease.

Treatment of stage II medication-related osteonecrosis of the jaw with necrosectomy and autologous bone marrow mesenchymal stem cells.

Treatment strategies for medication-related osteonecrosis of the jaw (MRONJ) remain controversial. Although the AAOMS suggests a conservative approach, a surgical management with necrosectomy is often required when conservative management has failed. Moreover, recent studies have shown promising results using an early stage surgical treatment. Over the past decade, cell-based bone regeneration utilizing bone marrow mesenchymal stem cells (MSCs) received increased attention. MSCs are known to promote wound healing and induce new bone formation in compromised tissue. Accordingly, the aim of this study was to assess the role of MSCs in the management of MRONJ. This study included 6 patients referred to our department with the diagnosis of MRONJ. Upon informed consent, the patients underwent surgical resection of necrotic bone followed by MSCs grafting. The MSCs were separated from bone marrow cells aspirated from the iliac crest using a bone marrow aspirate concentrate system. The MSCs were grafted into the defect with autologous thrombin and the defect was covered with a collagen membrane. In all cases, bony edges were rounded and the wound was closed using a three-layered technique. In the follow-up from 12 to 54 months, all patients including those who had impaired conditions, sepsis, or pathological fracture, showed satisfactory healing with no signs of wound infection. This pilot study indicated that surgical management in combination with MSCs transplantation seems to be a promising treatment modality in the therapy of MRONJ.

Primary wound closure after tooth extraction for prevention of medication-related osteonecrosis of the jaw in patients under denosumab.

OBJECTIVES: Some recent reports have indicated that local infection causes osteonecrosis of the jaw and described that tooth extraction may not be a direct cause of developing medication-related osteonecrosis of the jaw (MRONJ) in patients receiving antiresorptive medications. Tooth extraction and elimination of the source of infection are expected to reduce the risk of developing MRONJ. However, there is no data regarding prevention for developing osteonecrosis of the jaw in patients receiving denosumab. Therefore, the aim of this study was to investigate the outcome of tooth extractions with proper wound closure in patients receiving denosumab. PATIENTS AND METHODS: Forty teeth in 19 patients treated with denosumab therapy were extracted under preoperative intravenous antibiotics. Patients who had already developed MRONJ in the extraction sites or who had a history of radiation therapy were excluded. During surgery, bone edges were smoothed and all wounds were closed using the double-layered technique. RESULTS: Thirty-seven extraction sites (92.5 %) in 17 out of 19 patients (89.5 %) were healed. However, three extraction sites in two patients had complications; one patient had exposed bone and developed MRONJ (stage 1) and the other developed a mucosa fistula. Additional surgical procedures were performed and all wounds were completely healed. CONCLUSIONS: Tooth extractions in patients receiving denosumab can be performed in an appropriate manner and result in good outcomes. CLINICAL RELEVANCE: This study indicated that tooth extraction with proper wound closure to avoid secondary infection may be effective for the prevention of MRONJ even in high-risk patients.

Sinusitis and oroantral fistula in patients with bisphosphonate-associated necrosis of the maxilla.

BACKGROUND: The management of bisphosphonate related necrosis of the jaw has become clinical routine. While approximately two thirds of the lesions are in the mandible, one third is located in the maxilla. In 40-50 % of maxillary necrosis the maxillary sinus is involved, leading to maxillary sinusitis and oro-antral communications. METHODS: This retrospective single center study includes all patients with diagnosis of BP-ONJ of the maxilla and concomitant maxillary sinusitis. The information collected includes age, gender, primary disease, bisphosphonate intake, involving type of bisphosphonate, route of administration and duration of BP treatment previous to surgical treatment and treatment outcome. RESULTS: A total of 12 patients fulfill the criteria of the diagnosis of maxillary sinusitis associated to maxillary necrosis, of which 6 Patients showed purulent sinusitis. All patients underwent surgical treatment with complete resection of the affected bone and a multilayer wound closure. A recurrence appeared in one patient with open bone and no sign of sinusitis and was treated conservatively. CONCLUSIONS: Purulent maxillary Sinusitis is a common complication of bisphosphonate-related necrosis of the maxilla. The surgical technique described can be suggested for the treatment of these patients.

Zoledronate induces osteonecrosis of the jaw in sheep.

INTRODUCTION: The treatment of bisphosphonate-related osteonecrosis of the jaw has become routine in maxillofacial hospitals. However, the etiopathology has not yet been fully understood. The aim of this study was to develop a large animal model for medication-related osteonecrosis of the jaw (MRONJ). MATERIAL AND METHODS: Eight Swiss mountain sheep were randomly assigned into two groups. Group I received 0.075 mg/kg zoledronate (ZOL) intravenously every third week for 16 weeks. After 16 weeks, extraction of the first and second lower left premolar was performed. Group II underwent surgery and no ZOL was administered. After surgery, Group I continued to receive ZOL infusions; after 16 weeks, all animals were euthanized. The jaw bones were investigated macroscopically, radiographically (computed tomography) and histologically. RESULTS: Osteonecrosis of the jaw was observed at all extraction sites in all the animals receiving ZOL, and at none of the sites in animals without ZOL. All ZOL-treated animals spontaneously developed exposed bone lesions in the oral cavity at sites where no surgical intervention was performed. CT imaging shows persistent alveolar extraction sockets 16 weeks after surgery in all animals of the ZOL-group, and healed alveolar extraction sockets in non-ZOL-treated animals. CONCLUSION: Sheep treated with ZOL reproducibly demonstrated osteonecrosis of the jaw after tooth extraction, and spontaneous development of exposed bone in the oral cavity at sites where no manipulation was performed. This animal model can be used for further research in the fields of BP-ONJ etiopathology, oral implantology, bone and fracture healing and periodontology.

Evaluation of bone substitute materials: comparison of flat-panel based volume CT to conventional multidetector CT.

Over the last decade tissue engineering has emerged as a key factor in bone regeneration within the field of cranio-maxillofacial surgery. Despite this in vivo analysis of tissue-engineered-constructs to monitor bone rehabilitation are difficult to conduct. Novel high-resolving flat-panel based volume CTs (fp-VCT) are increasingly used for imaging bone structures. This study compares the potential value of novel fp-VCT with conventional multidetector CT (MDCT) based on a sheep sinus floor elevation model. Calcium-hydroxyapatite reinforced collagen scaffolds were populated with autologous osteoblasts and implanted into sheep maxillary sinus. After 8, 16 and 24 weeks MDCT and fp-VCT scans were performed to investigate the volume of the augmented area; densities of cancellous and compact bone were assessed as comparative values. fp-VCT imaging resulted in higher spatial resolution, which was advantageous when separating closely related anatomical structures (i.e. trabecular and compact bone, biomaterials). Fp-VCT facilitated imaging of alterations occurring in test specimens over time. fp-VCTs therefore displayed high volume coverage, dynamic imaging potential and superior performance when investigating superfine bone structures and bone remodelling of biomaterials. Thus, fp-VCTs may be a suitable instrument for intraoperative imaging and future in vivo tissue-engineering studies.

Gorham-Stout syndrome of the facial bones: a review of pathogenesis and treatment modalities and report of a case with a rare cutaneous manifestations.

Gorham disease is a very rare condition associated with spontaneous destruction and resorption of 1 or more bones anywhere in the body. Many authors have suggested and/or implicated trauma as the initiating factor in the majority of the reported cases. It can affect almost all bones, and a combination of bones has been reported. In the maxillofacial skeleton, the first facial case was reported by Romer in 1928. Until now, only a few cases of Gorham disease affecting the maxillofacial bones, including this case report, have been reported. We present a brief review of the pathogenesis and treatment modalities of the disease and report a very rare clinical picture of the disease affecting a young and otherwise healthy patient with massive osteolysis of the mandibular bone and extensive involvement of the mouth floor and skin of the chin, which to our knowledge, is the only case report with skin manifestation affecting the maxillofacial region. Such skin manifestations play an important role for the diagnosis and add a clue for management of such condition.