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Bone volume changes following vascularized bone flaps and possible confounding factors over time are described in the literature with some controversy. The purpose of this study was to evaluate the bone volume behavior of two frequently used free flaps.Computed tomography (CT) scans were examined with regard to bone volume using the software program ITK-SNAP for all patients who required mandibular reconstruction with a free fibula flap (FFF, conventionally vs assisted by computer-aided design/computer-aided manufacturing (CAD/CAM)) or iliac crest flap (DCIA) following mandibular resection because of benign or malign processes, between August 2010 and August 2015. Clinical data, complication rates, and CT scans were analyzed retrospectively. Additionally, complication rates (microvascular revision, flap loss, postoperative fistula or dehiscence, and postoperative bone exposure) were compared within early (≤30 days), late (31st-100th day), and overall (≤100th day) postoperative time intervals.113 cases, comprizing 89 FFF and 24 DCIA cases, were included. FFF showed superior bone volume behavior over the DCIA flap. Multivariable regression models assessed the relationships between the following and bone volume behavior: interval between operation and CT scan (p 0.683), age (p = 0.004), gender (p = 0.006), BMI (p = 0.400), adjuvant radiation therapy (p = 0.334), reconstruction with DCIA flap (p 0.0001), number of segments (p = 0.02), and incidence of dental implant insertion (p = 0.45).The bone volume of FFFs remains stable. DCIA flaps show a higher bone volume reduction, but the postoperative course might be associated with fewer complications. Time interval between operation and CT scan, age, gender, reconstruction with DCIA flap, and number of fibula segments contributed significantly to bone volume behavior.

Background Intimal injury in microvessels due to common risk factors such as atherosclerosis or inadequate manipulation are known to have a major impact on developing thrombosis and eventually vascular obstruction. Understanding of these injuries is therefore of great significance to prevent far-reaching consequences such as flap loss in free tissue transfer. It was the aim of this study to evaluate artificially induced intimal lesions with focus on alteration in size and configuration. Methods Intimal defects were created surgically in the abdominal aorta of 30 male Wistar rats. After planimetric measurement of the defect sizes, configuration of defects were classified as round, horizontal, or vertical. Seven days postoperatively, the rats underwent a second-look surgery. Finally, the abdominal aorta was harvested, and the endothelial defects were reevaluated concerning size and configuration using a defined pattern. Results The mean defect size created intraoperatively was 1.68 ± 0.6 mm2. The classification of the defects configurations resulted in 43.3% round, 20% horizontal, and 36.7% vertical defects. Reevaluation at 7 days after surgery showed defect shrinkage in 96.7% in total and 42.8% averaging due to reendothelialization. A shift in defect configuration was detected in 56.7%, the strongest being in vertical defect configurations (100%). Vascular occlusion did not occur in any of the specimen. Conclusion Intimal injuries undergo a fast repair process in terms of size reduction and configuration modification due to reendothelialization. Especially vertical defects, representing a great risk for thrombus formation, convert into lower risk horizontal defect configurations. In high-flow vessels such as the rat aortas, small endothelial damage seems to have no significant impact to produce complete vascular occlusion. Still, all efforts should be made to avoid any kind of intimal injury.

Introduction The amount of fluids administered intraoperatively seems to influence the postoperative outcome, and especially the transfusion of red blood cell concentrates (RBC) are known to have an increased risk of postoperative complications. This prospective study focuses on patients planned with microvascular free flap reconstruction and investigates the effect of various types and amounts of volumes given intraoperatively and on the intensive care unit with regard to overall postoperative complications. Material and methods In this prospective study, 52 consecutive patients planned for reconstruction with microvascular free flaps were included. Intraoperatively administered volumes including blood products were documented by the anesthesiologists as well as volumes given during the intensive care unit stay. Postoperative complications were registered for the entire hospital stay. Statistical analysis was carried out correlating the amount and type of volumes with the incidence of postoperative complications. Results The intraoperative use of RBC showed a close to statistically significant increased risk of postoperative complications (mean/SD concentrates: 0.5/1.1 [no complications] vs. 1.0/1.4 [complications], p = 0.058). In a multivariate analysis with stepwise selection the use of human albumin, gelatin, or Ringer's acetate showed no correlation with complications. The overall blood loss, however, had no significant influence on the incidence of complications (mean/SD ml: 1187/761 [no complications] vs. 1004/600 [complications], p = 0.37). The use of noradrenalin during reconstructive surgeries with microvascular flaps bears statistically no increased risk of failure (mean/SD μg/kg/min: 36/23 [no flap loss] vs. 22/15 [flap loss], p = 0.289) or complications (mean/SD μg/kg/min: 34/22 [no complications] vs. 35/23 [complications], p = 0.807). Conclusion In our investigation, the use of crystalloids and colloids seems to have no influence on the postoperative outcome, but the use of RBC may have an increased overall incidence of postoperative complications. A careful hemostasis to limit the use of RBC remains essential despite available options of substitutions. The use of infusion-pump-administered noradrenaline seems valuable to sustain a stable circulation during surgeries with microvascular free flaps and may have no negative impact on postoperative complications.

Systematic assessment of computed tomography (CT) scans and clinical symptoms is necessary to quickly indicate the correct treatment of zygomatico-orbital (ZMO) fractures. For this purpose, a clinical scoring system (=Clinical Score) was developed and correlated with CT scans to analyse its validity. Every operated, isolated, and unilateral ZMO fracture between January 2012 and December 2016 was screened retrospectively, including patient and treatment data. All available CT scans were analysed, and the grade of dislocation was measured for each case and plane. Four hundred and sixty-one cases were included and showed a median surgery time of 66.0 min (5.0–361.0) and a median postoperative hospital stay of three days (0–25). The distribution of gender, aetiologies and age groups was significantly different (each p = 0.001), and the aetiology had a significant influence on the Clinical Score (p = 0.038). The degree of dislocation in the coronary and sagittal planes correlated significantly with the Clinical Score with regard to the orbital involvement (p < 0.001, ρ = 0.566; p < 0.001, ρ = 0.609). The simple, quick, and easy-to-apply Clinical Score showed a significant correlation with the most important planes in CT scans as well as with the clinical course. It may facilitate fast risk stratification of the patient. However, the validity of the proposed score in determining indications must now be evaluated in a prospective setting, including both operated and non-operated fractures.

The objective of this clinical study was to compare and assess the clinical performance of tooth-supported and implant-supported zirconia single crowns with sintered veneering caps. In this prospective study, 118 patients with a total of 220 single crowns placed on 106 teeth (69 vital teeth, 37 endodontically treated teeth) and 114 implants in molar and premolar regions were examined during a mean observation period of 42 months. The restorations were evaluated for technical failures such as veneering porcelain fractures (chipping), surface quality, marginal fit, and the interface quality of the coping and sintered veneering. The soft tissue status was assessed using the modified Silness and Loe’s plaque and gingival index (mPI) and the modified Muhlemann sulcus bleeding index (mSBI). Tooth-supported crowns were checked for secondary caries and hypersensitivity during the follow-up period. Recalls were performed every 6 months. The 3-year Kaplan-Meier success probability was 98.2% and 100% for implant- and tooth-supported crowns, respectively. A significant difference could be detected between the implant-supported and tooth-supported zirconia single crowns, in terms of their chipping rate (p = 0.039). Veneering material fractures were recorded on two implant-supported restorations (1.8%). No veneering fractures occurred on tooth-supported single crowns. The plaque and gingival index and sulcus bleeding index showed stable and healthy soft peri-implant and periodontal tissues. Neither loss of vitality nor secondary caries occurred on tooth-supported crowns. Zirconia-based single crowns with a sintered veneering cap showed promising clinical results on both tooth and implant abutments; however, the dental implants were more prone to complications. In terms of clinical significance, high-strength ceramic with a sintered veneering cap can be recommended for prosthetic treatment of both tooth- and implant-supported single crowns in molar regions. This study provides valuable information for further application of all-ceramic restorations.

Background The accuracy of computer-assisted biopsies at the lower jaw was compared to the accuracy of freehand biopsies. Methods Patients with a bony lesion of the lower jaw with an indication for biopsy were prospectively enrolled. Two customized bone models per patient were produced using a 3D printer. The models of the lower jaw were fitted into a phantom head model to simulate operation room conditions. Biopsies for the study group were taken by means of surgical guides and freehand biopsies were performed for the control group. Results The deviation of the biopsy axes from the planning was significantly less when using templates. It turned out to be 1.3 ± 0.6 mm for the biopsies with a surgical guide and 3.9 ± 1.1 mm for the freehand biopsies. Conclusions Surgical guides allow significantly higher accuracy of biopsies. The preliminary results are promising, but clinical evaluation is necessary.

Objectives The purpose of this study was to evaluate the incidence of complications following mandibular reconstruction and to analyse possible contributing factors. Materials and methods Clinical data and computed tomography scans of all patients who needed a mandibular reconstruction with a reconstruction plate, free fibula flap (FFF) or iliac crest (DCIA) flap between August 2010 and August 2015 were retrospectively analysed. Results One hundred and ninety patients were enrolled, encompassing 77 reconstructions with reconstruction plate, 89 reconstructions with FFF and 24 reconstructions with DCIA flaps. Cutaneous perforation was most frequently detected in the plate subgroup within the early interval and overall (each p = 0.004). Low body mass index (BMI) and total radiation dosage were the most relevant risk factors for the development of analysed complications. Conclusions Microvascular bone flaps have overall less skin perforation than reconstruction plates. BMI and expected total radiation dosage have to be respected in choice of reconstructive technique. Clinical relevance A treatment algorithm for mandibular reconstructions on the basis of our results is presented.

Introduction Microvascular surgery following tumor resection has become an important field of oral and maxillofacial surgery (OMFS). Following the results from management of T1/T2 floor-of-mouth and tongue squamous cell carcinoma (SCC) in German-speaking countries, Europe, and worldwide, this paper presents specific concepts for the management of resection and reconstruction of T3/T4 SCC of the maxillary and mandibular alveolar process and tongue. Methods The DOSAK questionnaire was distributed in three different phases to a growing number of maxillofacial units worldwide. Within this survey, clinical patient settings were presented to participants and center-specific treatment strategies were evaluated. Results A total of 188 OMFS units from 36 different countries documented their treatment strategies for T3/T4 maxillary and mandibular alveolar process and tongue SCC. The extent of surgical resections and subsequent reconstructions is more consistent than with T1/T2 tumors, although the controversy surrounding continuity resections and mandible-sparing procedures remains. For continuity resection of the mandible the fibula free flap is the most frequently used bone replacement, whereas maxilla reconstruction concepts are less consistent, ranging from locoregional coverage concepts and different microvascular reconstruction options to treatment via obturator prosthesis. Conclusion Results from treatment strategies for T3/T4 tumors underline the limited evidence for the appropriate amount of resection and subsequent reconstruction process, especially in cases involving the mandible. Prospective randomized trials will be necessary in the long term to establish valid treatment guidelines.

Modern surgical strategies aim to reduce trauma by using functional imaging to improve surgical outcomes. This reviews considers and evaluates the importance of the fluorescent dye indocyanine green (ICG) to visualize lymph nodes, lymphatic pathways and vessels and tissue borders in an interdisciplinary setting. The work is based on a selective search of the literature in PubMed, Scopus, and Google Scholar and the authors' own clinical experience. Because of its simple, radiation-free and uncomplicated application, ICG has become an important clinical indicator in recent years. In oncologic surgery ICG is used extensively to identify sentinel lymph nodes with promising results. In some studies, the detection rates with ICG have been better than the rates obtained with established procedures. When ICG is used for visualization and the quantification of tissue perfusion, it can lead to fewer cases of anastomotic insufficiency or transplant necrosis. The use of ICG for the imaging of organ borders, flap plasty borders and postoperative vascularization has also been scientifically evaluated. Combining the easily applied ICG dye with technical options for intraoperative and interventional visualization has the potential to create new functional imaging procedures which, in future, could expand or even replace existing established surgical techniques, particularly the techniques used for sentinel lymph node and anastomosis imaging.Moderne chirurgische Strategien zielen auf Reduktion von Trauma mit Nutzung funktioneller Darstellungsmethoden zur Verbesserung chirurgischer Ergebnisse. Die Relevanz von Indocyaningrün (ICG) als Fluoreszenzfarbstoff, zur Darstellung von Lymphknoten, Lymphbahnen, Gefäßen und Gewebegrenzen, wird in dieser Übersichtsarbeit interdisziplinär dargestellt und kritisch bewertet. Diese Arbeit basiert auf einer selektiven Literaturrecherche in PubMed, Scopus, Google Scholar und den klinischen Erfahrungen der Autoren. Aufgrund der einfachen, strahlungsfreien und komplikationsarmen Anwendung hat sich ICG in den letzten Jahren als eine wichtige klinische Indikatorsubstanz etabliert. In der onkologischen Chirurgie wird ICG zur Markierung von Sentinellymphknoten intensiv und mit vielversprechenden Ergebnissen genutzt und zeigt zum Teil verbesserte Detektionsraten im Vergleich mit den etablierten Verfahren. Durch Visualisierung und Quantifizierung von Gewebedurchblutungen kann ICG zu einer Verringerung von Anastomoseinsuffizienzen und Transplantatnekrosen führen. Die Darstellung von Organgrenzen, Grenzen von Lappenplastiken sowie deren postoperativer Vaskularisierung sind auch Gegenstand der wissenschaftlichen Evaluation. Die Kombination des leicht anwendbaren Farbstoffs ICG mit den technischen Möglichkeiten der intraoperativen und interventionellen Visualisierung hat das Potenzial, neue funktionelle Darstellungen zu ermöglichen und die bisher etablierten operativen Techniken, insbesondere die Sentineltechniken und Anastomosetechniken, zu erweitern und möglicherweise zukünftig abzulösen.

Orbital exenteration (OE) is considered to be a mutilating surgical procedure reserved for relentlessly progressive neoplastic disorders or extensive facial trauma with unfavourable eye involvement. Malignant tumours, accounting for the majority of ablative orbital surgeries, may be caused by primary orbital tumours or secondarily by neoplasias from the surrounding skin, the maxillary sinus or intracranial malignomas. Orbital exenteration following trauma is mostly caused by penetrating globe defects or extended infections with the danger of intracranial effects. Thoughtful resection planning, the exploitation of reconstructive possibilities as well as the consideration of adjuvant therapy are essential to provide the patient with the best available treatment. As a multitude of reconstructive procedures exist, it is of crucial importance to offer a disease-tailored treatment to achieve a successful patient outcome. After retrospective analysis of 45 orbital exenteration cases within the last decade, we developed a defect-driven classification for ablative orbital therapy followed by a guideline for reconstructive procedures. The classification as well as the reconstruction guideline will help the surgeon to restore anatomic boundaries and to promote physiological and psychological recovery for the patient.

Background The mainstay of treatment in adenoid cystic carcinoma (ACC) of the head and neck is surgical resection with negative margins. The purpose of this study was to define the margin status that associates with survival outcomes of ACC of the head and neck. Methods We conducted univariate and multivariate analyses of international data. Results Data of 507 patients with ACC of the head and neck were analyzed; negative margins defined as ≥5 mm were detected in 253 patients (50%). On multivariate analysis, the hazard ratios (HRs) of positive margin status were 2.68 (95% confidence interval [CI], 1.2-6.2; p = .04) and 2.63 (95% CI, 1.1-6.3; p = .03) for overall survival (OS) and disease-specific survival (DSS), respectively. Close margins had no significant impact on outcome, with HRs of 1.1 (95% CI, 0.4-3.0; p = .12) and 1.07 (95% CI, 0.3-3.4; p = .23) for OS and DSS, respectively, relative with negative margins. Conclusion In head and neck ACC, positive margins are associated with the worst outcome. Negative or close margins are associated with improved outcome, regardless of the distance from the tumor. © 2017 Wiley Periodicals, Inc. Head Neck 39: 1008-1014, 2017.

With the introduction of microsurgery, even patients with severe defects due to trauma, tumor, infections, or deformities can be treated successfully with the concept of dental rehabilitation by using implants. In the past, concepts including obturator prosthesis or reconstruction plates limited the possibilities of full dental rehabilitation including a sufficient quality of life. Since the use of different microvascular bone grafts, patients can be treated reliably by individual perfused bone containing additional healthy tissue for coverage and reconstruction of form and function. In the following chapter, we would like to present the operative procedures with examples illustrating the key steps of each free flap presented. Although microvascular free flap surgery containing bone is complex, the important points are emphasized and explained.

Although several donor sites are available for maxillofacial bone reconstruction, the use of iliac crest bone grafts, either with spongiosa or bone blocks, is still one of the main choices in the clinical treatment, especially if a large amount of bone is required to correct severe bone defect of the jaw. The correct surgical approach, as well as the individual plan for the site of augmentation considering the prosthetic concept preoperatively, makes this type of bone very reliable. Its use offers several options even in complicated cases. In the following chapter, different types of bone grafts are illustrated and explained in detail for the use in daily clinical treatments.

Introduction The superficial musculoaponeurotic system (SMAS) is a controversial functional fibro-adipose layer that connects the mimic muscles to the skin and is involved in a variety of facial mimic expressions. The presence of muscle fibers within SMAS fibrous septa is hypothetical. The present study analyzed SMAS fibrous septa composition for the existence of striated muscle cells. Methods Histological serial sections of the sample borders (n = 107) of 19 in sano-resected and diagnosed cutaneous tumors of the midfacial region were investigated. Immunohistochemical (actin and myosin) and hematoxylin and eosin staining were performed to detect striated muscle cells in SMAS fibrous septa. Results A fibro-neuro-musculo-vascular functional unit within SMAS fibrous septa was demonstrated. SMAS striated muscle cells were morphologically independent from preparotideal and periorbital mimic muscles. Intraseptal blood vessels draining the superficial and deep SMAS vascular system were described. Conclusions Striated muscle cells were demonstrated within SMAS fibrous septa. Nerve cells and vascular tissue together with the SMAS fibro-muscular meshwork demonstrated an autonomous operating functional unit that hypothetical modulated individual mimic expression contributing to the diversity of mimic expression. The SMAS develops with mimic muscle contractions as a synergetic effect during facial crease and fold formation processes.

To explore the preventive effect of a prophylactic oral and maxillofacial treatment to reduce bisphosphonate associated necrosis of the jaws (BRONJ) in metastatic prostate cancer (PC) patients treated with zoledronic acid (4.0 mg i.v./months).253 PC patients with bone metastases were prospectively randomized. All patients received baseline assessments including a dental panoramic tomogram. Group A was monitored and treated where deemed necessary by the patient's dentist and were re-evaluated once a year. In group B patients were monitored and treated where necessary by the authors at 12 week intervals. We compared the incidence rate per year (IR) and incidence proportion (IP) in both cohorts and assessed independent risk factors for BRONJ.Patients in group A were evaluated 3.2 (range 2-4) vs. 6.8 times (range 4-24) in group B. A significantly higher proportion of dental extractions was performed in group B vs. A (26.7% vs. 22.7%, p = 0.006). A BRONJ was detected with an IP of 23.3% vs. 2.2% in group A vs. B, revealing a 2.59 fold higher relative risk for group A (p = 0.01, 95% CI 0.01-0.56). The IR in group A was 0.073 cases/year while the IR in group B was significantly decreased by 82% to 0.0131 (p 0.001). Extraction therapy was the only independent risk factor for BRONJ (p 0.0001; 95% CI 21.22-189.06).Preventive oral and maxillofacial treatment before bisphosphonate application combined with 3-monthly dental follow-ups significantly reduces the occurrence and risk of BRONJ in PC patients. Therefore this approach should be implemented in the specific treatment algorithms.

The technical process has no associativity from the design area to the machine tool. In the chipping area, we need for an essential and continuous optimization in the whole process data’s from the machine tool. If we habe the possibility to optimize the components on design area, then we improve the complete process from the customer order entry to the delivery. Based on this information, it’s possible to reduce the time to market. On technical level, we have a functional revolution based on new workflows, processes to reduce the effort in the planning process, the product costs and manufacturing costs. The change process is also affected by the worflow from the production environment to the planning area.The design department defines approximately 70% of the product cost [Heimsoth 2006] - by modern connection technology it’s possible to receive in the CAD-system resource information of the production to optimize the whole process. So, it's helpful to derive preliminary cost estimation, based on 3D analytics which results based on the optimized technological data's. A manufacturable design is the basis for an optimized total process - the work plan for the ERP system can be generated already, too. It is also ensured that parts which have been designed under using analysis would be easy to produce.Based on the 3D-CAD-models the NC program can be created via feature-oriented automated rules (dependence of the CAM programming system), so that NC programs for alternative machines can be derived. This is necessary that we obtained the higher flexibility in production and reduction on process times.Based on machine signals, we send back the information’s over the machine connectors to the data-analytics database. So, it's implemented a holistic approach in the field of logistics, as well as in the technical field. With PDCA (continuous improvement process) it's ensured a steady optimization.The effects on real time data are implemented in the technical area within the reporting, interfaces and visualization. The decision-making process shows the importance of employees in the total chain.The benefits based on the realization of the Karlsruhe Institute of Technology (KIT) - Institute for Information Management in Engineering (IMI).

The radial forearm flap is still the most commonly used free flap for the reconstruction of intraoral soft tissue defects. Flap raising can be performed in two ways: with or without integrating the fascia antebrachii into the flap.A prospective randomized study was performed, comparing the outcomes of 25 subfascial and 25 suprafascial radial forearm flaps. Flap viability was assessed clinically and by measuring flap perfusion parameters. Additionally, donor site morbidity was evaluated for 3 months after surgery.Hemoglobin concentration was significantly higher in suprafascial flaps, whereas no difference in flap success rate was observed. No significant differences in donor site morbidity were found. Shrinkage of the full-thickness skin graft was tendentially higher in the subfascial group. Our results do not support the suggestion that subfascial flaps are associated not only with higher success rates but also with a higher donor site morbidity than suprafascial flaps. Despite relevant differences in flap perfusion, neither the flap success rate nor the donor site morbidity differed significantly.Both supra- and sub-fascial dissection techniques are reliable methods of radial forearm flap raising, with little clinical difference between them.

Introduction Microvascular free flaps have become an essential part of reconstructive surgery following head and neck tumour ablation. The authors' aim was to investigate the influence of cardiovascular risk factors, preoperative irradiation, previous operations and metabolically active medication on free flap loss in order to predict patients at risk and to improve their therapy. Materials and methods All patients who underwent reconstructive surgery with microvascular free flaps in the head and neck region between 2009 and 2013 were retrospectively analysed. Uni- and multivariate logistic regressions were performed to determine the association between possible predictor variables for free flap loss. Results We included 451 patients in our analysis. The overall free flap failure rate was 4.0%. Multivariate regression analysis revealed significantly increased risks of free flap failure depending on prior attempts at microvascular transplants ( p p = 0.007, OR = 1.05). Conclusions With consistently low rates of flap failure, microvascular reconstruction of defects in the head and neck region has proven to be highly reliable, even in patients with comorbidities. The expertise of the operating team seems to remain the main factor affecting flap success. The only discerned independent predictor was previously failed attempts at microvascular reconstruction.

The decision to re-operate on a potentially ischemic free flap remains challenging. Indocyanine green videoangiography (ICG) with the FLOW(®) 800 tool is a method which allows an immediate qualitative conclusion about the patency of an anastomosis. Is it also able to predict the outcome of potentially compromised vascular free flaps?An epigastric flap was raised and repositioned in 79 rats. Intraoperative fluorescence angiography was performed using ICG videoangiography and the FLOW(®) 800 tool was applied. Six regions of interest were positioned systematically over the flap, changes of the ICG fluorescence were color coded with respect to time and 474 measurements were performed. The flap was clinically monitored for one week and the resulting necrotic areas were correlated with the ICG/FLOW(®) 800 results.Mean intensity of clinically vital areas was 83.39 ± 50.96 arbitrary units (AU) and 37.33 ± 15.14 AU in necrotic areas. The receiver operating characteristic curve and Youden-Index analysis revealed that the optimal cutoff for the maximal intensity of ICG after FLOW(®) 800 analysis was 61.733 for the prediction of flap survival (P< 0.0001; 95% CI = 0.85-0.91; Youden-Index: 0.67). The maximal intensity of ICG angiography had a specificity of 96.1% and sensitivity of 71.4%. The positive predictive value was 97.46% and the corresponding negative predictive value was 61.34%.This demonstrates the potential additional value of ICG videoangiography including FLOW(®) 800 analyses in the postoperative monitoring of transplanted flaps. © 2016 Wiley Periodicals, Inc. Microsurgery 37:235-242, 2017.

The technical and commercial planning areas are today not fully connected.Through horizontal and vertical integration of the areas we'll receive new effects in a fully integrated optimization.The design department defines approximately 70% of the product cost - by modern connection technology it’s possible to receive in the CAD-system resource information of the production to optimize the whole process. So, it's helpful to derive preliminary cost estimation, based on 3D analytics which results based on the optimized technological data's. A manufacturable design is the basis for an optimized total process - the work plan for the ERP system can be generated already, too. It is also ensured that parts which have been designed under using analysis would be easy to produce.Based on the 3D-CAD-models the NC program can be created via feature-oriented automated rules (dependence of the CAM programming system), so that NC programs for alternative machines can be derived. This is necessary that we obtained the higher flexibility in production and the reduction the process times.On the base of the machine signals we send back the information’s over the machine connectors (big data) in turn in the tool management. So, it's implemented a holistic approach in the field of logistics, as well as in the technical field. With PDCA (continuous improvement process) it's ensured a steady optimization.Holistic networking enables a significantly optimized process in the construction, as well as in the production. The methodology for the optimization with data from the machine (big data) is represented.The effects on real time data are implemented from different systems within the reporting and visualization. The decision-making process shows the importance of employees in the total chain.The benefits based on the networking of various systems are represented on the realization of the Karlsruhe Institute of Technology (KIT) - Institute for Information Management in Engineering (IMI).

BackgroundFree flap transplantation may not be feasible in patients with inadequate or absent recipient vessels. We report successful mandibular composite reconstructions without anastomosis in three consecutive patients with vessel-depleted neck. Based on clinical reports describing early neovascularisation, temporary extracorporeal perfusion of flaps was maintained until the flaps had become independent from the extracorporeal blood supply.MethodsA blood transfusion bag filled with the patients' arterialised blood was connected to the flap artery and set under rhythmic compression to ensure continuous blood supply to the flap. The returning venous blood was collected but not reinfused. Extracorporeal circulation was sustained for 10–13 days until flaps had become independent from the external blood supply. Flap viability was assessed every 2 h using combined laser Doppler flowmetry and remission spectroscopy.ResultsSuccessful bony reconstructions were achieved in all three consecutive patients substantiated by MRI-, CT-scan or bone scintigraphy. Neovascularisation occurred within the soft tissues of all flaps with the exception of one skin paddle, which later developed necrosis. Systemic transfusion of 12–25 units of packed red cells was necessary to compensate for the blood loss.ConclusionsWith this technique, transplantation of composite free flaps becomes feasible even in the absence of recipient vessels, opening up new treatment options to a broad range of complex surgical problems. Blood reinfusion should be pursued in the future to avoid excessive blood transfusions. The trial is registered with ClinicalTrials.gov, number NCT02449525.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Background Indocyanine green (ICG) videoangiography is routinely used to evaluate skin and organ perfusion and to assess patency rates of microvascular anastomoses. This study uses ICG angiography as a novel approach to qualitatively and quantitatively evaluate bone perfusion of microvascular fibula grafts intraoperatively and to assess the effect of fibula segment length and number of osteotomies on bone perfusion. Methods All patients planned for mandible reconstruction using a microvascular fibula graft between January 2013 and May 2017 were considered for this study. ICG videoangiography of cancellous bone perfusion was performed using a handheld ICG camera. Videos were analyzed, and a perfusion curve was generated. Peak enhancement, time to peak, slope, and wash-in area under the curve were extracted; rise time, wash-in rate (WiR), and wash-in perfusion index were calculated. Results were statistically analyzed with regard to distal fibula segment length and number of osteotomy sites. Results Thirty-nine patients (age 59 ± 8 years) were included in the study. Mandible reconstruction was achieved with 1 (n = 15), 2 (n = 13), or 3 (n = 11) fibula segments. The WiR was 6.4 ± 2.3 and 4.4 ± 0.2 before and after proximal osteotomy, respectively. The wash-in perfusion index was 114.2 ± 48.4 before and 84.4 ± 20.0 after proximal osteotomy. Bone perfusion was significantly reduced after additional proximal osteotomies. Both the segment length and number of proximal osteotomies correlated with bone perfusion, with longer segments and fewer osteotomies showing higher perfusion. Conclusion This study demonstrates the feasibility of cancellous bone perfusion analysis using ICG and can serve as a basis for future bone perfusion studies. Additional osteotomies and short segment length negatively affects cancellous bone perfusion of the distal fibula segment in free fibula flaps. The extent to which the observed decrease in arterial inflow to the distal fibula segment affects the further course of healing needs to be addressed in future studies.

Tissue glues are a useful tool for hemostasis and a potential tool for microvascular anastomosis. The hemostatic power and thrombotic risk of these surgical aids have been the subject of debate, but studies regarding thromboembolic risks of tissue glues are lacking.The authors compared the thromboembolic risk of three different tissue glues (six interrupted sutures complemented with fibrin, FloSeal, or TachoSil) against a control group (12 interrupted sutures) in the aorta-filter model in the rat. Each group consisted of 10 rats, examined 4 hours and 14 days postoperatively (total n = 80) using a structured protocol to assess the patency and condition of the filter, amount of thromboembolic material, and histologic appearance of the vessel wall.In total, 160 anastomoses were performed in 80 rats. The overall patency rate for the groups was 90 percent (control), 35 percent (fibrin glue), 25 percent (FloSeal), and 10 percent (TachoSil). All experimental groups had significantly faster mean anastomotic times and less blood loss compared with the control group. Patency rates were reduced and thromboembolic material was significantly increased in all experimental groups. Histologically, the use of tissue glue reduced the incidence of irritation of the internal elastic lamina and was associated with an increased incidence of fibrocyte infiltration of the media, hypercellularity of the adventitia, and adventitial neovascularization and lymphangiogenesis.The application of tissue glues in microvascular anastomosis reduces the time needed for anastomosis but was associated with a statistically significant increase in thromboembolism.

Patient reported outcomes following head and neck cancer are of great importance, given the functional, psychological, and social impacts of the disease and its treatment. In addition, not only is the number of publications on health-related quality of life (HRQOL) increasing in a variety of specialties, but there is also a growing awareness of the potential role of HRQOL in practice. Therefore, we aimed to investigate the HRQOL of head and neck cancer patients following different oncologic interventions, using an internationally established test. In this cross-sectional study, we included three different groups of 32 patients each. Participants had histologically confirmed invasive oral squamous cell carcinoma (OSCC) in the anterior floor of the mouth. Group allocation was based on treatment modality, as follows: only surgery (group 1), operation and adjuvant radiotherapy (XRT) (group 2), and the additional presence of osteoradionecrosis (ORN) (group 3). All patients were questioned about their HRQOL, using the standardized University of Washington Quality of Life Questionnaire (UW-QOL). Surveys for groups 1 and 2 were conducted at least 24 months after the end of tumor-related treatment, in cases of ORN (group 3) 12 months after completion of disease-related treatment. A total of 96 patients were included into this study. The mean age was 62.79 ± 8.93 years. The patients in groups 1 and 2 revealed a reduced quality of life, of a greater magnitude after radiation therapy. Patients felt that radiotherapy was much worse than surgery; however, half of the patients stated that they would repeat radiation therapy if necessary. The subjective evaluation of the HRQOL after surgery and radiotherapy was a valuable instrument for assessing the rehabilitation of patients in the context of their function and quality of life. Radiation therapy can be considered a trigger of functional limitations and emotional distress that contributes to decreased HRQOL in patients with head and neck cancer.

The recurrence rate following the treatment of oral squamous cell carcinoma (OSCC) by primary surgery is about 10%-26%. The earliest possible diagnosis of residual tumour, recurrence of local tumour disease, and subsequent metastasis is essential for an improvement of the overall survival and of the survival period for affected patients. No international consensus exists for a post-therapeutic surveillance schedule for OSCCs. Based on a review of the literature, existing guidelines, and our institutional experience, we have established an algorithm for the follow-up of these patients regarding the timing and techniques of postoperative imaging. We recommend a follow-up interval of 6 weeks during the first half-year after discharge from hospital by single clinical and alternating clinical check-ups combined with computed tomography (CT) or magnetic resonance imaging (MRI), followed by an interval of 3 months in the second half-year, with clinical and radiological check-ups. In year 2, we recommend a follow-up interval of 3 months with single clinical and alternating clinical check-ups combined with CT or MRI. In year 3, we recommend screening every 6 months, both clinically and via imaging, because of the decreased risk of recurrence. From year 5 onwards, our recommendation is a clinical and imaging-based examination every 6-12 months, depending on patient risk factors and disease progression. Four standard imaging techniques, namely positron emission tomography (PET), CT, MRI, and ultrasound (US), are discussed concerning their range of application, sensitivity, and specificity. Furthermore, the technical aspects of our institutional protocols are described in detail. In highly frequented head and neck cancer centres, PET and US are of secondary importance, since CT and MRI are nowadays highly efficient tools in primary diagnostic and post-therapeutic surveillance.

The subject of the presented study was to monitor and compare problems and outcomes of reconstructive surgery with microvascular free flaps in the head and neck region between groups of patients treated with perioperative antibiotics and a group of patients without antibiotics. Patients requiring oral reconstructive surgery following cancer resections with microvascular free flaps were prospectively evaluated (2007-2012). Antibiotic therapy was started 30 min before the operation and administered for 10 days. Three hundred and fifty patients were included (208 male, 59.4%; 142 female, 40.6%; mean age 59.8 ± 13.2 years). 330 patients received perioperative antibiotics. Twenty patients (5.7%) who received no antibiotics for specific reasons served as the control group. Wound infections developed in 33 of 122 patients (27%) who received benzylpenicillin, 17 of 88 patients (19.3%) who received amoxicillin combined with sulbactam and 25 of 120 patients (20.8%) who received cefuroxime. Ten patients (50%) who did not receive antibiotics developed wound infections. Receiving no antibiotics or penicillin showed no benefit (P = 0.11). Those receiving cefuroxime showed significantly lower incidence of wound infections (P = 0.034; risk decreased by the factor 2.88). The use of amoxicillin combined with sulbactam showed the lowest rate of wound infections (P = 0.018; risk decreased by the factor 3.46). The use of amoxicillin combined with sulbactam appears to be the most appropriate prophylactic antibiotic followed by cefuroxime in oral microsurgical free flap reconstructions. These data may serve as a guide until a controlled multicenter prospective trial is performed comparing newer antibiotics against current standards.

Introduction Microvascular sutured anastomosis remains the gold standard in microvascular flap surgery but is technically challenging, time-consuming, and sometimes unreliable. The goal of our study has been to develop a microvascular stenting system that can be used for microvascular anastomosis, even without the use of a microscope. Materials and methods Custom-made stainless-steel stents were used to re-establish vessel continuity after the severance of the abdominal aortic vessel in nine rats. At 30 min after re-opening the blood flow, Doppler flowmetry and indocyanine green (ICG) angiography were used to assess vessel patency, and vessels were inspected microscopically for signs of thrombosis. Results Eight of the nine animals survived the procedure. In one case, the abdominal aorta was torn during balloon dilation of the stent. Four out of the nine stent anastomoses showed an excellent fit. In the remaining four cases, a collagen membrane and fibrin glue were successfully used to stop vascular leakage. However, these additional steps might have had a negative impact on vessel patency, and thrombus formation impaired blood flow completely in one case. Conclusion Microvascular stent anastomosis is feasible and might in some cases be superior to standard sutured anastomosis. However, a number of technical difficulties remain to be addressed, and long-term results are not yet available.

Ketamine-xylazine is a frequently used combination for anesthesia in microsurgically operated rats and can be administered by intraperitoneal (IP) or intravenous (IV) injection. Both methods are associated with relatively high misadministration rates. In the present study, we want to introduce a femoral vein access that requires microsurgical cannulation but enables a 100% administration rate.In this study, the maximal time of anesthesia was analyzed, time to response, latency time, and the total need for anesthetic agents in IP (n = 200) and IV (n = 40) anesthesia in Wistar rats for the purpose of microvascular operations. IV injections were achieved with an inserted microcatheter that was applied via a microsurgical femoral vein access.The time needed for the placement of the microcatheter was 5.76 ± 0.89 minutes. Maximal time of anesthesia (IP vs. IV) was 7.02 ± 1.92 versus 21.78 ± 5.77 hours (p0.0001), time to response was 137.5 ± 3.91 versus 18 ± 2.18 seconds (p0.0001), latency time 35.53 ± 3.21 versus 27.8 ± 2.88 minutes (p0.0001), and total volume of anesthetic 1.42 ± 0.39 versus 2.78 ± 0.73 mL (p0.0001), respectively.IV administration using the microsurgical femoral vein access is a feasible method with a quicker response rate and a 100% administration rate. Furthermore, it enables longer anesthesia, for example, complex microsurgical or other experimental procedures in the rat.

Introduction Microvascular surgery following tumor resection has become an important field of oral maxillofacial surgery (OMFS). Following the results on general aspects of current reconstructive practice in German-speaking countries, Europe and worldwide, this paper presents specific concepts for the management of resection and reconstruction of T1/T2 squamous cell carcinoma (SCC) of the anterior floor of the mouth and tongue. Methods The DOESAK questionnaire was distributed in three different phases to a growing number of maxillofacial units worldwide. Within this survey, clinical patient settings were presented to participants and center-specific treatment strategies were evaluated. Results A total of 188 OMFS units from 36 different countries documented their treatment strategies for T1/T2 anterior floor of the mouth squamous cell carcinoma and tongue carcinoma. For floor of mouth carcinoma close to the mandible, a wide variety of concepts are presented: subperiosteal removal of the tumor versus continuity resection of the mandible and reconstruction ranging from locoregional closure to microvascular bony reconstruction. For T2 tongue carcinoma, concepts are more uniform. Conclusion These results demonstrate the lack of evidence and the controversy of different guidelines for the extent of safety margins and underline the crucial need of global prospective randomized trials on this topic to finally obtain evidence for a common guideline based on a strong community of OMFS units.

Background Different advantages of virtually planned and guided mandibular reconstructions have been described. Functional analyses and comparisons with conventionally reconstructed patients. Methods We retrospectively analyzed 30 cases of mandibular reconstructions that involved virtually planned or conventional microvascular, fibular free flaps that occurred between April 2011 and December 2014 at a single center. The results were also compared with a healthy cohort of 30 participants. Axiographic measurements were performed postoperatively, and uni- and multivariate regressions analyses were performed to determine the association between possible predictor variables on functional outcome. Results Operation time, hospital stay, number of osteotomies, incidence of postoperative temporomandibular joint pain, noise, and tension did not differ significantly between the conventional and computer-aided design/computer-aided manufacturing (CAD/CAM) groups (each p > 0.05). Mouth opening and protrusion and laterotrusion also did not differ significantly (each p > 0.05) but were significantly reduced compared with the healthy group. Univariate analysis showed a significant influence of postoperative irradiation on mouth opening and laterotrusion in the conventional group (p = 0.047 and p = 0.028). In addition, multivariate analysis showed a significant influence of indication and number of osteotomies on laterotrusion (p = 0.005 and p = 0.043). Uni and multivariate analyses revealed a significant influence of indication, preoperative irradiation, and number of osteotomies on protrusion and mouth opening in the CAD/CAM group (p = 0.016, p = 0.044, and p = 0.028). Conclusion CAD/CAM-assisted reconstructions of the mandible give comparable functional results with those of the conventional technique, but no functional superiority has been established. Nevertheless, the integration of virtual planning and guided surgery is definitely of significant value but should be indicated individually case by case.

Introduction Microvascular surgery following tumour resection has become an important field of oral maxillofacial surgery (OMFS). This paper aims to evaluate current microsurgical practice in Europe. Methods The questionnaire of the DOESAK collaborative group for Microsurgical Reconstruction was translated into English, transformed into an online based survey and distributed to 200 OMFS units with the aid of the European Association for Cranio-Maxillo-Facial Surgery (EACMFS). Results 65 complete and 72 incomplete questionnaires were returned. Hospitals from the United Kingdom, France, Italy, the Netherlands, Spain, Belgium, Greece, Slovenia and Lithuania participated. 71% of contributing centres were university hospitals, 87% out of these perform microvascular tumour surgery at least on a two-weekly base. Overall complication rate was at around five percent. Most frequently used transplants were the radial forearm flap and the fibular flap. The perioperative management varied widely. Success factors for flap survival, however, were uniformly rated, with the surgical skill being the most important factor, followed by the quality of postoperative management. Medication seems to play a less important role. Conclusion Within Europe microvascular surgery is a common and safe procedure for maxillofacial reconstructive surgery in the field of OMFS. While there is a major accordance for the surgical procedure itself and the most frequently used flaps, perioperative management shows a wide variety of protocols with low presumed impact on surgical outcome.

The TNM classification is used to assess cancers of the oral cavity, and advancements in imaging techniques have revealed clear variations in tumor volume at presentation. This study therefore aimed to clarify whether preoperative imaging, with exact measurements of the tumor, could affect post-surgery survival after controlling for demographic, clinical, and tumor characteristics. We included 437 patients with histologically confirmed, stage T1–4, N1–3, M0, invasive squamous cell carcinoma of the tongue. Participants were assessed for recurrence every 3 months for the first 2 years, every 6 months for another 2 years, and annually thereafter; routine computed tomography was performed annually. Associations were determined using the Kaplan–Meier estimator, univariate log-rank test, and Cox proportional hazards regression models. The mean survival of all patients was 68.1 ± 48.2 months. The 2- and 5-year overall survival rates were 82.2 and 66.7 %, respectively. The mean primary tumor volume was 7.14 cm3 with a range of 1.3–24.21 cm3. The ROC curve and Youden Index analysis revealed that the optimal cutoff volume was between ≤5.9 and ≤18.3 cm3 for three different volume groups (p

Background The purpose of this study was to characterize the incidence, pattern of spread, and prognostic correlation of nerve invasion in patients with adenoid cystic carcinoma (ACC). Methods Using 3 different pathological categories of perineural invasion, intraneural invasion, and perineural inflammation, we investigated the prognostic value of nerve invasion in a total of 495 ACCs from 9 international patient cohorts with median follow-up 90 months (range, 12–288 months). Results Of 239 patients (48%) with nerve invasion, 174 (73%) had perineural invasion, 65 (27%) intraneural invasion, and 37 (15%) perineural inflammation. Multivariate Cox regression analysis identified tumor site (p = .008; hazard ratio [HR] = 1.8; 95% confidence interval [CI] = 0.07–3.7) and intraneural invasion (p < .001; HR = 5.9; 95% CI = 0.8–12.3) as independent prognostic markers for both overall survival (OS) and disease-specific survival (DSS), but not of distant metastases. Conclusion Although perineural invasion has no impact on survival, intraneural invasion is an independent predictor of poor prognosis. Recognition of intraneural invasion may help optimize treatment of patients with head and neck ACC. © 2014 Wiley Periodicals, Inc. Head Neck 37: 1038–1045, 2015

Background The patterns of regional metastasis in adenoid cystic carcinoma (ACC) of the head and neck and its association with outcome is not established. Methods We conducted a retrospective multicentered multivariate analysis of 270 patients who underwent neck dissection. Results The incidence rate of neck metastases was 29%. The rate observed in the oral cavity is 37%, and in the major salivary glands is 19% (p = .001). The rate of occult nodal metastases was 17%. Overall 5-year survival rates were 44% in patients undergoing therapeutic neck dissections, and 65% and 73% among those undergoing elective neck dissections, with and without nodal metastases, respectively (p = .017). Multivariate analysis revealed that the primary site, nodal classification, and margin status were independent predictors of survival. Conclusion Our findings support the consideration of elective neck treatment in patients with ACC of the oral cavity. © 2014 Wiley Periodicals, Inc. Head Neck 37: 1032–1037, 2015

The objective of the study was to find out if human amniotic membrane could be used for corrective surgery after trauma to the orbital wall. Because of its proposed antiadhesive qualities, it seemed to be potentially suitable. We studied 8 men (mean age 37 (range 19-74) years) who had deficient ocular movement after fractures of the orbital floor. Five of them had already been operated on. Inclusion criteria were trauma dating back more than 4 months and a soft tissue stricture in the orbital floor diagnosed by magnetic resonance imaging. Patients were treated secondarily with lysis of adhesions and insertion of allogeneic human amniotic membrane laminated on to polyglactin 910/polydioxanone foil, which functioned as the carrier material. Patients were followed up for 3 months, by which time disorders of motility of the ocular bulb had disappeared completely in 5. Two patients had improved motility and a reduction in both their subjective and objective symptoms. One patient had no improvement. The considerable reduction in adhesions and scarring after insertion of the membrane confirms previous assumptions, according to which the epithelial side of the human amniotic membrane has an antiadhesive effect because of its smooth surface.

We did biomechanical loading tests to compare the quantity and quality of interfragmentary movement in fractured human cadaver mandibles that had been reconstructed with iliac crest using 3 different osteosynthesis systems. Eighteen mandibles from human cadavers with a 4.5 cm paramedian L-type defect were reconstructed with bone from the iliac crest using 3 different osteosynthesis systems and continuously loaded on the "Mandibulator" test bench. Six mandibles each had the bones joined together using 2 monocortical non-locking plates, 2 monocortical locking plates, or a single bicortical locking plate/fracture gap. Macroscopic deformation, failure mechanisms, and movement of the fracture gap in all 3 dimensions were assessed and quantified over increasing loading by PONTOS(?) optical measurement systems. Final mechanisms of failure were excessive deformation of the plate, fracture of the mandibular fragments, and failure of the iliac crest graft. The plate became deformed mainly in the miniplate group. The iliac crest graft failed in all the specimens in which osteosynthesis was performed by a 6-hole TriLock(?) plate. Interfragmentary movement was minimised in the miniplate group. All three osteosynthesis systems provided sufficient stability for reconstruction when mechanically loaded up to 100 N. The miniplate allowed less movement in the gap and gave better stability than the two TriLock(?) plate systems. The superiority of the miniplate was significant when compared with the 4-hole TriLock(?) plate. The transplant failed mainly in the 6-hole TriLock(?) group, which suggests that the iliac crest graft works better with the miniplate as a more malleable osteosynthesis system. The British Association of Oral and Maxillofacial Surgeons.