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MatrixMANDIBLE Preformed Reconstruction Plates (MMPRPs) were developed to overcome laborious bending procedures of conventional reconstruction plates. The design comprises three sizes with a nonbendable centerpiece and two bendable sections (proximal and distal). According to the surgical protocol unnecessary parts are trimmed after the last used screw hole. In the present retrospective study postoperative radiographs from 130 patients (average age 63 years) that received treatment with MMPRPs were assessed. There was no statistical correlation between plate-size, location (left/right) or age. 82.98% of the small and 91.80% of the medium MMPRPs were trimmed by at least the terminal screw hole of the ramus part. In all patients receiving a large MMPRP, the terminal screw hole of the ramus was unused accordingly all inserted large MMPRPs were trimmed by at least the terminal screw hole. The majority of the bridged defects were located within the area of the body indicating a feasible plate design. With the emergence of solid free form fabrication of Ti-alloys and economic need to reduce the waste of resources this study may help to further improve the MMPRP design and prevent the loss of medical-grade titanium.

In oral and maxillofacial surgery, autologous grafts from the iliac crest remain the 'gold standard' for alveolar ridge reconstruction, whereas intraoral bone grafts are considered in smaller defects. To date, a comparison of the osteogenic potential of osteoblasts with regard to their tissue origin is missing. Primary osteoblasts have proven useful for the investigation of the tissue-specific osteogenic properties. The present study compares primary human alveolar (aHOBs) and iliac osteoblasts (iHOBs) derived from three female patients undergoing routine intraoral bone grafting. Proliferation potential of the osteoblasts was evaluated using real-time impedance monitoring. Relative gene expression of bone specific biomarkers was analyzed and quantified using quantitative polymerase chain reactions (qPCR). Immunohistochemistry and phase contrast microscopy were performed, as well as alkaline phosphatase assay and alizarin red staining to visualize morphology and mineralization capacity. A twofold faster proliferation rate of aHOBs compared with iHOBs (130 h vs. 80 h) was observed. Alkaline phosphatase activity and alizarin red staining in both HOBs indicated similar mineralization capacity. Gene expression of seven genes (BMP1, CSF-1, TGFBR1, ICAM1, VCAM1, SPP1 and DLX5) was significantly higher in iHOB than in aHOB samples. These data suggest a higher osteogenic potential of osteoblasts derived from the iliac crest compared with primary osteoblasts from the alveolar bone and may lead to a better understanding of the molecular impact of bone cells from different bone entities on bone regeneration in alveolar ridge reconstructions.

Background A prerequisite of irradiation after advanced head and neck tumour resection is the accurate localization of the tumour resection margin. The purpose of the following study is to evaluate the use of surgical clips placed in the tumour resection margins for use as radiographic markers to facilitate focussed adjuvant radiation therapy. Materials To evaluate whether the clips remain predictive for the resection margin, we analysed the deviation of each clip in two postoperative CT scans on different days. Bone registration points were used to fuse the two CT scans in the region of the primary tumour and the distances between corresponding clips were measured. Results The tumour resection margins were labelled with an average of 18 titanium clips. In total 282 clips were evaluated. Metric analysis of clip deviation between the two postoperative CT scans found a mean distance of 4.5 mm±2.5 mm with a range of 0.5–11.8 mm. No significant statistical relationship of the clip differences as a function of time, the method of reconstruction or administered radiotherapy could be demonstrated. Conclusion Placement of surgical clips in the cavity walls after complete tumour resection provides an easy and inexpensive approach for defining resection margins and allows for increased accuracy of adjuvant treatment. Clinical trial number DRKS00007534.

Long-term results of reconstructions and prosthetic rehabilitation of patients presenting severely atrophied edentulous ridges remains a challenge for clinicians. Among the various available augmentation materials there is evidence that avascular fibula bone grafts possess a reliable resistance against resorption and may thus provide a valuable source to reduce the loss of vertical bone height after reconstruction of the severely atrophied mandible and maxilla. The purpose of the present study was to assess long-term crestal bone level stability in avascular fibula bone grafts. 8 edentulous female patients (average age 70.6 years) with Class-VI-atrophy and less than 5 mm residual bone volume received onlay-grafting with avascular fibula bone grafts and were monitored with a mean observation time of 133.7 months (121-186). A total of 39 implants were placed in the maxilla and mandible. Three patients received immediate and five patients delayed implant placement 3 months after grafting. All patients were provided with bar-retained dentures. Postoperative evaluation included clinical implant success (Buser) and radiographic examinations (orthopantomogram) to quantify crestal bone resorption. Grafting was successfully performed in all patients with no regrafting necessary. All implants but one, lost 2 years after abutment connection, remained successfully integrated and fulfilled the Buser criteria, rendering to a success rate of 97%. Mean bone resorption after 10 years was mesial 1.4 mm and distal 1.4 mm at each implant-site. Maximum bone resorption occurred between postoperative and first year, thereafter no significant resorption was measured in re-examinations up to 15 years. Avascular fibula grafts are a reliable bone graft for augmentation procedures in atrophied edentulous ridges. Dental implants that integrated in the autogenous fibular bone grafts showed a stable crestal peri-implant bone level up to 15 years after implant placement.

Accurate localization of tumor resection borders is crucial for adjuvant radiotherapy. An improvement to adjuvant radiotherapy with the reduction of radiation doses to free flap reconstruction by virtual navigation procedures and titanium clips was evaluated. Thirty-three patients with oral cancer were prospectively included in the study. Following complete local excision of the primary tumor, resection borders were marked virtually using a navigation pointer and with titanium ligature clips. Postoperative delineation of tumor resection borders was examined. In five patients with microvascular free flap reconstruction a reduction of the radiation dose to the free flap reconstruction was achieved. The tumor resection borders in 30 patients were marked with titanium ligature clips. Surgical clip insertion was successful in 91%. We demonstrate a significant relationship between the reconstruction volume and the part of the target volume which will receive a reduced radiation dose. A cumulative dose of 60 Gy was administered to the target volume and a significant reduction of the administered radiation dose to the center of the flap could be demonstrated. We demonstrate an accurate delineation of the tumor resection margins. These improvements in tumor resection margin delineation allow for increased accuracy in adjuvant treatment and a reduction of radiation dose to the vascular free flap reconstruction.

The purpose of this study was to evaluate the long-term survival rate and potential influencing factors of dental implants and implant-retained prostheses in oral cancer patients who had undergone surgical tumor resection. In the present study, 157 patients (95 females and 62 males with a mean age of 53.7 years) with 830 implants were included. All patients were diagnosed with a malignant tumor in the oral cavity and had undergone ablative surgery. In 55 patients (292 implants), the surgical procedure was followed by an additional radiochemotherapy (RCT) before implant placement. Nicotine users who received RCT were excluded from this study. Patients were clinically examined every 6 or 12 months according to a standard procedure. Of the 830 examined implants, 450 were placed in the maxilla and 380 in the mandible. A total of 65 implants were lost, 36 in the maxilla and 29 in the mandible; of these, 42 implants (65 %) were documented as lost due to the patient’s death. The mean observation period was 121 months. The cumulative survival rate was 94.9 % at 3 years and 92.5 % at 7 years. With an observation period up to 20 years, the cumulative survival rate remained constant after 11 years with 90.8 %. Age, gender, and localization (maxilla/mandible) of implants did not show any influence on the survival of the implants. However, radiochemotherapy was determined as a significant factor influencing the survival rate. The results of this study demonstrate that the survival rate of implants was significantly lower in oral cancer patients who had been treated by ablative surgery and additional radiochemotherapy than in patients without RCT. Since there is no significant difference in the mortality rate of patients with additional RCT compared to patients who underwent sole ablative surgery, the higher loss ratio is due to a late failure of osseointegration. Dental implants in oral cancer patients who had been treated by ablative surgery show a high and steady cumulative survival rate after 11 years. Implant survival of patients with additional RCT is significantly lower. Non-smoking-irradiated patients seem to have a better implant survival.

Introduction The aim of this work was to analyse the suitability of mesenchymal stem cell isolation by FICOLL density centrifugation and the closed bone marrow aspirate concentrate (BMAC) system for sinus augmentation with bovine bone mineral (BBM) in the sheep model. Methods 16 sheep underwent sinus augmentation with BBM and MSCs; they were divided between two groups with survival points of 8 and 16 weeks. For the FICOLL control arm three, and for the BMAC test arm, five augmentations were performed for each time point. The derived cell numbers were counted; a colony forming unit (CFU) assay was performed; the pluripotency of the MSCs was proved; histological and histomorphometrical analysis were performed. Results The approach of using BBM and MSCs in combination with fibrin adhesive was sufficient for new bone formation as the FICOLL experiment indicated. However, due to significantly lower cell numbers isolated using the BMAC in sheep, less new bone was formed in the test arm. Conclusions The BMAC system is well suited for human MSC isolation but it needs to be optimized to fit sheep cell characteristics if it is to be used in this animal model.

Communication between the surgeon and the radiation oncologist is improved with the use of virtual models of the final tumour resection, combining three-dimensional imaging and conventional clip marking with computer-aided navigation. This investigation was designed to determine the deviation of virtual marking procedures compared to conventional marking by titanium ligature clips in oral cancer with different localizations. Seventeen patients with surgically placed clips and virtual landmarks on the resection margin after complete tumour ablation were evaluated. To determine whether the virtual landmarks remain predictive of the resection margin, the deviation of the virtual points from their corresponding clips was analyzed by measuring the distance between their centres of gravity. In total, 189 clips were evaluated. Metric analyses of the deviation between the virtual points and clips showed a deviation of 2.3 ± 0.6mm for tumours with a maxilla localization, 7.2 ± 2.5mm for tumours with a mandible localization, and 12.6 ± 3.8mm for tumours with a tongue localization. A significant statistical relationship was demonstrated in the virtual point-clip deviation as a function of tumour localization. Virtual marking of maxillary tumour resection margins allows accurate definition of the former tumour bed and could lead to novel adjuvant treatment strategies.

Purpose Novel gabapentin-lactam (GBP-L) has shown its potency in enhancing new bone formation (NBF) in vitro. The objective of the present preclinical trial was to investigate the in vivo performance of GBP-L. Materials and Methods Bilateral sinus floor augmentations in 10 adult sheep were conducted. Bovine bone mineral (BBM) and mesenchymal stem cells (MSCs) combined with novel GBP-L were placed into the test sinus of each sheep. The BBM and MSCs alone served as the control on the contralateral side. Simultaneously, 3 dental implants were inserted in each maxillary sinus. The animals were sacrificed after 8 and 16 weeks, and the amount of NBF was analyzed using histomorphometry. The osteogenic potency of the MSCs was demonstrated using the colony-forming unit and differentiation assay. Statistical evaluation was performed using the Wilcoxon signed rank test and 3-factorial nonparametric analysis of variance. Results The histologic examination showed NBF in tight contact with the original bone in the control and test groups. The NBF was not significantly different between the test and control sites (P > .05). However, a highly significant difference in NBF between the apical and coronal sites in the specimens from the control and test groups was detected (P Conclusions Bone formation is initiated from the residual alveolar crest and along the implant. The elected mode of GBP-L application did not induce faster NBF. Alternate forms of application (eg, slow release or systemic administration) might clarify the controversial in vitro findings.

Background A prevalent modality to increase the amount of available bone prior to implantation is grafting of the maxillary sinus. Multiple factors such as the surgical technique, moment of implant placement as well as grafting materials and membranes are known to affect implant survival. However, the role of different factor combinations and associated reciprocal effects remain unclear. Conventional statistical methods do not consider inconsistency of study designs and do not take covariables into account. Hence, a systematic research and meta-analysis was conducted to investigate the influence of various treatment modalities on implant survival in the grafted maxillary sinus. Materials and Methods A meta-analysis was conducted according to the PRISMA guidelines. Articles published from 1980 through January 2013 were electronically and manually searched in MEDLINE (Ovid), the Cochrane Register of Controlled Trials, the Database of Abstracts of Effects, and the Cochrane Database of Systematic Reviews. Clinical reports on single intervention sinus augmentation with root-form implants, a minimum of 10 patients and 6 months of loading were eligible for inclusion if implant survival was stated or calculable. Results were calculated by non-parametric univariate Kaplan-Meier analysis and Bayesian multivariate interval-censored Cox regression. Results A total of 122 publications on 16268 endosseous implants placed in grafted maxillary sinus were included. The treatment parameters surgical approach, grafting material and implant type showed no selective preference. However, application of membranes showed a significantly reduced hazard-ratio, independent of other co-factors. Conclusions The use of membranes is the most significant factor to achieve long-term implant survival in sinus augmentation procedures. More data exceeding 3 years follow-up are needed to address prospective confounding and improve clinical evidence.

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.