Analysis of Genes Related to Invadopodia Formation and CTTN in Oral Squamous Cell Carcinoma-A Systematic Gene Expression Analysis.

Successful treatment for any type of carcinoma largely depends on understanding the patterns of invasion and migration. For oral squamous cell carcinoma (OSCC), these processes are not entirely understood as of now. Invadopodia and podosomes, called invadosomes, play an important role in cancer cell invasion and migration. Previous research has established that cortactin (CTTN) is a major inducer of invadosome formation. However, less is known about the expression patterns of CTTN and other genes related to it or invadopodia formation in OSCC during tumor progression in particular. In this study, gene expression patterns of CTTN and various genes (n = 36) associated with invadopodia formation were analyzed to reveal relevant expression patterns and give a comprehensive overview of them. The genes were analyzed from a whole genome dataset of 83 OSCC samples relating to tumor size, grading, lymph node status, and UICC (Union for Internatioanl Cancer Control). The data revealed significant overexpression of 18 genes, most notably CTTN, SRC (SRC proto-onocogene, non-receptor tyrosine kinase), EGFR (epidermal growth factor receptor), SYK (spleen associated tyrosine kinase), WASL (WASP like actin nucleation promotion factor), and ARPC2 (arrestin beta 1) due to their significant correlation with further tumor parameters. This study is one of the first to summarize the expression patterns of CTTN and related genes in a complex group of OSCC samples.

Mesenchymal-epithelial transition in lymph node metastases of oral squamous cell carcinoma is accompanied by ZEB1 expression.

BACKGROUND: Oral squamous cell carcinoma (OSCC), an HPV-negative head and neck cancer, frequently metastasizes to the regional lymph nodes but only occasionally beyond. Initial phases of metastasis are associated with an epithelial-mesenchymal transition (EMT), while the consolidation phase is associated with mesenchymal-epithelial transition (MET). This dynamic is referred to as epithelial-mesenchymal plasticity (EMP). While it is known that EMP is essential for cancer cell invasion and metastatic spread, less is known about the heterogeneity of EMP states and even less about the heterogeneity between primary and metastatic lesions. METHODS: To assess both the heterogeneity of EMP states in OSCC cells and their effects on stromal cells, we performed single-cell RNA sequencing (scRNAseq) of 5 primary tumors, 9 matching metastatic and 5 tumor-free lymph nodes and re-analyzed publicly available scRNAseq data of 9 additional primary tumors. For examining the cell type composition, we performed bulk transcriptome sequencing. Protein expression of selected genes were confirmed by immunohistochemistry. RESULTS: From the 23 OSCC lesions, the single cell transcriptomes of a total of 7263 carcinoma cells were available for in-depth analyses. We initially focused on one lesion to avoid confounding inter-patient heterogeneity and identified OSCC cells expressing genes characteristic of different epithelial and partial EMT stages. RNA velocity and the increase in inferred copy number variations indicated a progressive trajectory towards epithelial differentiation in this metastatic lesion, i.e., cells likely underwent MET. Extension to all samples revealed a less stringent but essentially similar pattern. Interestingly, MET cells show increased activity of the EMT-activator ZEB1. Immunohistochemistry confirmed that ZEB1 was co-expressed with the epithelial marker cornifin B in individual tumor cells. The lack of E-cadherin mRNA expression suggests this is a partial MET. Within the tumor microenvironment we found immunomodulating fibroblasts that were maintained in primary and metastatic OSCC. CONCLUSIONS: This study reveals that EMP enables different partial EMT and epithelial phenotypes of OSCC cells, which are endowed with capabilities essential for the different stages of the metastatic process, including maintenance of cellular integrity. During MET, ZEB1 appears to be functionally active, indicating a more complex role of ZEB1 than mere induction of EMT.

Reduction of CT Artifacts Using Polyetheretherketone (PEEK), Polyetherketoneketone (PEKK), Polyphenylsulfone (PPSU), and Polyethylene (PE) Reconstruction Plates in Oral Oncology.

PURPOSE: Surgical reconstruction after segmental mandibulectomy in patients with oral cancer commonly requires implantation of titanium plates, which cause metallic artifacts in CT examinations detrimental for image quality. Therefore, the aim of the present study was to evaluate CT artifacts and image quality of the polymer plate materials polyetheretherketone (PEEK), polyetherketoneketone (PEKK), polyphenylsulfone (PPSU), and polyethylene (PE) in mandible reconstruction. METHODS: Five plates (titanium, PEEK, PEKK, PPSU, and PE) were successively surgically inserted in a human cadaveric specimen using eight (1) titanium and (2) zirconium oxide screws. Streak and blooming artifacts were assessed in 1 mm CT scans with and without metallic artifact reduction algorithms (MAR) in this cross-sectional study. The different plate materials were analyzed for their effect on Hounsfield unit (HU) values resulting in streak artifacts. Blooming artifacts were measured as virtual growth of plates compared to actual size. Subjective image quality was assessed by 3 independent observers. Statistics were conducted by multifactorial ANOVA and Bonferroni's post hoc test. RESULTS: Titanium (182.42 HU; SD ± 3.09) was associated with significantly more streak and blooming artifacts compared to the polymers PEEK (86.41 HU; SD ± 1.72; P < .001), PEKK (85.50 HU; SD ± 2.75; P < .001), PPSU (85.51 HU; SD ± 1.97; P < .001), and PE (85.52 HU; SD ± 3.33; P < .001) implants. No significant differences could be seen between the screw types (titanium vs zirconium oxide) (P = .75) or the activation or inactivation of MAR (P = .85). Image quality was best for PE and worst for titanium implants in combination with zirconium oxide screws. CONCLUSIONS: Polymers plate materials PEEK, PEKK, PPSU, and PE significantly reduce CT artifacts and improve image quality facilitating the radiological interpretation of implant surrounding tissues. This effect is beneficial for radiological tumor follow-up and CT-based planning of adjuvant radiotherapy.

[Updated S2k AWMF guideline on obstructive sialadenitis]. / Aktualisierte AWMF-S2k-Leitlinie zur obstruktiven Sialadenitis.

The update of this guideline was an important step to define standards for the use of sialendoscopy and other emerging minimally invasive techniques for the therapy of sialolithiasis and other obstructive salivary gland diseases. The current actualization was necessary to adapt the diagnostic and therapeutic algorithms to the current scientific knowledge. In this article they are presented in a shortened version with a focus on conservative therapeutic measures which are especially relevant for daily practice.

Removal of stones from the superficial lobe of the submandibular gland (SMG) via an intraoral endoscopy-assisted sialolithotomy.

OBJECTIVES: Sialolithiasis is the most common cause of chronic sialadenitis of the submandibular gland (SMG). Symptomatic superficial lobe stones are often treated by submandibulectomy. A gland preserving operation allows for transoral stone removal through endoscopically assisted sialolithotomy. Herein, we provide clinical and sonographical follow-up data in patients who underwent sialolithotomy under general anesthesia. MATERIALS AND METHODS: Sixty patients treated at the Department of Oral and Maxillofacial Surgery at Düsseldorf University Hospital for superficial lobe sialolithiasis of SMG were included in this study. All received transoral sialolithotomy under general anesthesia. Follow-up was conducted via standardized patient questionnaires, clinical examination, and B-mode and color Doppler sonography. RESULTS: Mean patient age was 48.9 years. 56.6% of right and 43.4% of left SMG were affected. Mean follow-up was 45 months. Fifty-five of 59 detected stones could be removed. Mean operation time was 71 min. 3.3% of patients reported recurrent episodes of postoperative pain and 10% felt recurrent episodes of gland swelling. Persistent postoperative lingual nerve hypesthesia was described in one patient. No facial nerve damages occurred. Salivary flow rates remained reduced in most of the affected glands upon stone removal. Sonographical follow-up data of the previously affected SMG after intraoral endoscopy-assisted sialolithotomy showed a regular gland size in 70.8% of cases, a parenchyma free of inflammation in 93.8%, and without signs of fibrosis in 72.9% of cases. 68.7% of patients showed a regular structure of Wharton's duct at time of follow-up. In total, 89.6% of patients were diagnosed stone-free within both glands on follow-up. No case required subsequent submandibulectomy. CONCLUSIONS: Sialolithotomy of Wharton's duct for removal of stones from the SMG's superficial lobe is a promising alternative to submandibulectomy. CLINICAL RELEVANCE: Reduction of postoperative morbidity through endoscopically assisted sialolithotomy for removal of superficial lobe stones from SMG. TRIAL REGISTRATION: Ethics Committee of Heinrich-Heine-University Düsseldorf (no. 5586).

Minimal Residual Disease in Head and Neck Cancer and Esophageal Cancer.

Malignant epithelial tumors of the upper digestive tract are a major cause of cancer-related death worldwide. The most common of these cancers are head and neck squamous cell carcinomas (HNSCC) and esophageal cancers (EC), which are both characterized by early dissemination and poor prognosis. Although patients with early detected cancers can be subjected to multimodal therapies with curative intention, they are endangered by lethal relapses that frequently occur. These relapses originate from minimal residual cancer (MRD) cells that can only be traced by highly sensitive molecular methods as rare disseminated tumor cells (DTC). The aim of this chapter is to comprehensively inform the reader about the detection, the mode of spread, the clinical relevance, and the biology of DTCs in HNSCC and EC. A better understanding of DTCs will be key to suppress progression of the upper digestive tract cancers more effectively.

Immunohistochemical detection of lymph node-DTCs in patients with node-negative HNSCC.

This study was performed to systematically assess the prevalence, topography and prognostic impact of disseminated tumor cells (DTCs) in lymph nodes (LN) of patients with primary, regional and distant metastasis-free head and neck squamous cell carcinoma (HNSCC) who underwent resection with elective neck dissection. From the routinely processed resection specimen, we could prospectively analyze a total of 1.137 exactly mapped LNs of 50 pN0-HNSCC patients, classified as tumor free by routine histopathology. Three immunohistochemistry (IHC) assays using antibodies directed against CK5/14, a broad spectrum of CKs (1-8, 10, 14-16 and 19), and CD44v6, respectively, were applied on 4.190 LN sections to detect DTCs. The IHC results were correlated with clinicopathologic parameters and clinical follow-up data. We detected seven micrometastases (MM) in five patients and 31 DTCs in 12 patients. Overall, 15 (30%) patients were positive for DTCs or MMs. Strikingly, the anatomical distribution of LN affected with DTCs was not random, but was dependent on the lateralization of the primary tumor and clustered significantly most proximal to the primary tumor. None of the investigated patients developed loco-regional lymphatic or distant metastasis during the mean follow-up period of 71 months. Our results reveal clinically occult tumor cell dissemination as an early and frequent event in HNSCC. Considering that higher rates of recurrences in therapeutic LN dissection concepts have been reported than in elective neck dissection strategies, our DTC-data support to perform elective neck dissections, since they appear to be effective in preventing loco-regional lymphatic recurrence from LN DTCs or MMs.

Diagnostic leukapheresis enables reliable detection of circulating tumor cells of nonmetastatic cancer patients.

Circulating tumor cells (CTCs) are promising biomarkers for diagnosis and therapy in systemic cancer. However, their infrequent and unreliable detection, especially in nonmetastatic cancer, currently impedes the clinical use of CTCs. Because leukapheresis (LA) targets peripheral blood mononuclear cells, which have a similar density to CTCs, and usually involves processing the whole circulating blood, we tested whether LA could substantially increase CTC detection in operable cancer patients. Therefore, we screened LA products generated from up to 25 L of blood per patient in two independent studies, and found that CTCs can be detected in more than 90% of nonmetastatic breast cancer patients. Interestingly, complete white blood cell sampling enabled determining an upper level for total CTC numbers of about 100,000 cells (median, 7,500 CTCs) per patient and identified a correlation of CTC numbers with anatomic disease spread. We further show that diagnostic leukapheresis can be easily combined with the US Food and Drug Administration-approved CellSearch system for standardized enumeration of CTCs. Direct comparison with 7.5 mL of blood revealed a significantly higher CTC frequency in matched LA samples. Finally, genomic single-cell profiling disclosed highly aberrant CTCs as therapy-escaping variants in breast cancer. In conclusion, LA is a clinically safe method that enabled a reliable detection of CTCs at high frequency even in nonmetastatic cancer patients, and might facilitate the routine clinical use of CTCs as in the sense of a liquid biopsy. Combined with technologies for single-cell molecular genetics or cell biology, it may significantly improve prediction of therapy response and monitoring of early systemic cancer.

Genomic high-resolution profiling of single CKpos/CD45neg flow-sorting purified circulating tumor cells from patients with metastatic breast cancer.

BACKGROUND: Circulating tumor cells (CTCs) are promising surrogate markers for systemic disease, and their molecular characterization might be relevant to guide more individualized cancer therapies. To enable fast and efficient purification of individual CTCs, we developed a work flow from CellSearch(TM) cartridges enabling high-resolution genomic profiling on the single-cell level. METHODS: Single CTCs were sorted from 40 CellSearch samples from patients with metastatic breast cancer using a MoFlo XDP cell sorter. Genomes of sorted single cells were amplified using an adapter-linker PCR. Amplification products were analyzed by array-based comparative genomic hybridization, a gene-specific quantitative PCR (qPCR) assay for cyclin D1 (CCND1) locus amplification, and genomic sequencing to screen for mutations in exons 1, 9, and 20 of the phosphatidylinositol-4,5-bisphosphate 3-kinase, catalytic subunit alpha (PIK3CA) gene and exons 5, 7, and 8 of the tumor protein p53 (TP53) gene. RESULTS: One common flow-sorting protocol was appropriate for 90% of the analyzed CellSearch cartridges, and the detected CTC numbers correlated positively with those originally detected with the CellSearch system (R(2) = 0.9257). Whole genome amplification was successful in 72.9% of the sorted single CTCs. Over 95% of the cells displayed chromosomal aberrations typical for metastatic breast cancers, and amplifications at the CCND1 locus were validated by qPCR. Aberrant CTCs from 2 patients harbored mutations in exon 20 of the PIK3CA gene. CONCLUSIONS: This work flow enabled effective CTC isolation and provided insights into genomic alterations of CTCs in metastatic breast cancer. This approach might facilitate further molecular characterization of rare CTCs to increase understanding of their biology and as a basis for their molecular screening in the clinical setting.

Diagnostic accuracy of ultrasound, ¹8F-FDG-PET/CT, and fused ¹8F-FDG-PET-MR images with DWI for the detection of cervical lymph node metastases of HNSCC.

OBJECTIVE: This study aimed to compare (18)F-fluorodesoxyglucose positron emission tomography/MRI ((18)F-FDG-PET-MRI) fusion images, including diffusion-weighted imaging (DWI), (18)F-FDG-PET/CT, and ultrasound (US) regarding their performance in nodal staging of patients with head and neck squamous cell carcinoma (HNSCC). MATERIALS AND METHODS: Eighteen patients prospectively underwent ultrasound examination, (18)F-FDG- PET/CT, and MRI before oral tumor resection and bilateral neck dissection. PET data sets were fused with contrast-enhanced T1-weighted MR images. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy for nodal detection were calculated for all the imaging modalities. Furthermore, the accuracy of the correct N-staging was calculated for all methods. Detailed histopathology served as the standard of reference. RESULTS: The sensitivity, specificity, PPV, NPV, and accuracy for detection of lymph node metastases were 63, 99, 86, 96, and 95 % for ultrasound; 30, 97, 56, 92, and 90 % for (18)F-FDG-PET/CT; 52, 96, 59, 94, and 91 % for (18)F-FDG-PET-MRI; and 53, 97, 67, 95, and 92 % for (18)F-FDG-PET-MRI plus DWI, respectively. There was no significant difference in the diagnostic accuracy for lymph node metastasis detection between (18)F-FDG-PET-MRI and (18)F-FDG-PET/CT (p = 0.839) and between (18)F-FDG-PET-MRI plus DWI and (18)F-FDG-PET/CT (p = 0.286), respectively. US was significantly more accurate than (18)F-FDG-PET/CT (p = 0.009), whereas no significant difference was seen between (18)F-FDG-PET-MRI and US (p = 0.223) or (18)F-FDG-PET-MRI plus DWI and US (p = 0.115). The nodal stage was correctly rated by (18)F-FDG-PET-MRI in eight patients, (18)F-FDG-PET-MRI plus DWI in nine patients, US in 12 patients, and (18)F-FDG-PET/CT in five out of 18 patients. CONCLUSION: Software-based fusion of (18)F-FDG-PET-MRI and (18)F-FDG-PET-MRI plus DWI may not increase nodal detection and N-staging performance in patients with oral malignancies compared to US and (18)F-FDG-PET/CT. CLINICAL RELEVANCE: Surgical staging of cervical lymph nodes will not be replaced even by advanced imaging modalities in the near future.

Tissue expanders for soft tissue reconstruction in the head and neck area--requirements and limitations.

OBJECTIVES: The repair of skin defects in the head and neck region still poses a significant problem for many clinicians. Tissue expansion is described as a treatment option providing good color, texture, and thickness match of the expanded skin. Unfortunately, the complication rates for tissue expansion range from 0 to 48 %. Therefore, the purpose of this study was to investigate risk factors for the use of tissue expanders in head and neck reconstructions. MATERIALS AND METHODS: Forty-nine patients with skin deficits in the head and neck area underwent tissue expansion. Sixty-two implanted expanders were analyzed regarding the various complications and the success rate. RESULTS: The success rate of treated patients was 37 (75.5 %) of all 49 included patients. The most frequent cause for the skin deficit was a tumor resection near the tip of the nose followed by skin deficits resulting after craniectomy. Interestingly, a higher number of expanders and a larger volume were significantly associated with a worse outcome. There was a trend of association between larger defect size and failure, too. CONCLUSIONS: The internal tissue expansion is a suitable technique for skin reconstruction in the head and face area. Compared to distant or free flaps, it often offers a better cosmetic outcome. In very large defects (>100 cm(2)) or when more than two expanders are needed, the failure rate increases. In these cases, other treatment options are recommended. CLINICAL RELEVANCE: The internal tissue expansion is a suitable technique for skin reconstruction in the head and face area.

Metallic Artifact Reduction in Midfacial CT Scans Using Patient-Specific Polymer Implants Enhances Image Quality.

Midfacial reconstruction after tumor resection surgery is commonly conducted by using autologous bone grafts or alloplastic implants. Titanium is the most frequently used osteosynthesis material in these cases but causes disturbing metallic artifacts in CT imaging. The purpose of this experimental study was to evaluate whether the use of midfacial polymer implants reduces metallic artifacts in CT imaging to improve image quality. Zygomatic titanium (n = 1) and polymer (n = 12) implants were successively implanted in a human skull specimen. Implants were analyzed for their effect on Hounsfield Unit values (streak artifacts) and virtual growth in CT images (blooming artifacts) as well as image quality. Multi-factorial ANOVA and Bonferroni's post hoc test were used. Titanium (173.7 HU; SD ± 5.1) and hydroxyapatite containing polymers (155.3 HU; SD ± 5.9) were associated with significantly more streak artifacts compared to all other polymer materials. There was no significant difference in blooming artifacts between materials. The metallic artifact reduction algorithm showed no significant difference. Image quality was slightly better for polymer implants compared to titanium. Personalized polymer implants for midfacial reconstruction significantly reduce metallic artifacts in CT imaging which improves image quality. Hence, postoperative radiation therapy planning and radiological tumor aftercare around the implants are facilitated.

Development and Integration of DOPS as Formative Tests in Head and Neck Ultrasound Education: Proof of Concept Study for Exploration of Perceptions.

In Germany, progress assessments in head and neck ultrasonography training have been carried out mainly theoretically and lack standardisation. Thus, quality assurance and comparisons between certified courses from various course providers are difficult. This study aimed to develop and integrate a direct observation of procedural skills (DOPS) in head and neck ultrasound education and explore the perceptions of both participants and examiners. Five DOPS tests oriented towards assessing basic skills were developed for certified head and neck ultrasound courses on national standards. DOPS tests were completed by 76 participants from basic and advanced ultrasound courses (n = 168 documented DOPS tests) and evaluated using a 7-point Likert scale. Ten examiners performed and evaluated the DOPS after detailed training. The variables of "general aspects" (6.0 Scale Points (SP) vs. 5.9 SP; p = 0.71), "test atmosphere" (6.3 SP vs. 6.4 SP; p = 0.92), and "test task setting" (6.2 SP vs. 5.9 SP; p = 0.12) were positively evaluated by all participants and examiners. There were no significant differences between a basic and advanced course in relation to the overall results of DOPS tests (p = 0.81). Regardless of the courses, there were significant differences in the total number of points achieved between individual DOPS tests. DOPS tests are accepted by participants and examiners as an assessment tool in head and neck ultrasound education. In view of the trend toward "competence-based" teaching, this type of test format should be applied and validated in the future.

Structured Reporting of Head and Neck Sonography Achieves Substantial Interrater Reliability.

Purpose Ultrasound examinations are often criticized for having higher examiner dependency compared to other imaging techniques. Compared to free-text reporting, structured reporting (SR) of head and neck sonography (HNS) achieves superior time efficiency as well as report quality. However, there are no findings concerning the influence of SR on the interrater reliability (IRR) of HNS. Materials and Methods Typical pathologies (n=4) in HNS were documented by video/images by two certified head and neck ultrasound instructors. Consequently, structured reports of these videos/images were created by n=9 senior physicians at departments of otolaryngology or maxillofacial surgery with DEGUM instructors on staff. Reports (n=36) were evaluated regarding overall completeness and IRR. Additionally, user satisfaction was assessed by a visual analog scale (VAS). Results SR yielded very high report completeness (91.8%) in all four cases with a substantial IRR (Fleiss' κ 0.73). Interrater agreement was high at 87.2% with very good user satisfaction (VAS 8.6). Conclusion SR has the potential to ensure high-quality examination reports with substantial comparability and very high user satisfaction. Furthermore, big data collection and analysis are facilitated by SR. Therefore, process quality, workflow, and scientific output are potentially enhanced by SR.

Adjuvant Radiotherapy in Patients with Squamous Cell Carcinoma of the Oral Cavity or Oropharynx and Solitary Ipsilateral Lymph Node Metastasis (pN1)-A Prospective Multicentric Cohort Study.

(1) Background: Evaluation of impact of adjuvant radiation therapy (RT) in patients with oral squamous cell carcinoma of the oral cavity/oropharynx (OSCC) of up to 4 cm (pT1/pT2) and solitary ipsilateral lymph node metastasis (pN1). A non-irradiated group with clinical follow-up was chosen for control, and survival and quality of life (QL) were compared; (2) Methods: This prospective multicentric comprehensive cohort study included patients with resected OSCC (pT1/pT2, pN1, and cM0) who were allocated into adjuvant radiation therapy (RT) or observation. The primary endpoint was overall survival. Secondary endpoints were progression-free survival and QL after surgery; (3) Results: Out of 27 centers, 209 patients were enrolled with a median follow-up of 3.4 years. An amount of 137 patients were in the observation arm, and 72 received adjuvant irradiation. Overall survival did not differ between groups (hazard ratio (HR) 0.98 [0.55-1.73], p = 0.94). There were fewer neck metastases (HR 0.34 [0.15-0.77]; p = 0.01), as well as fewer local recurrences (HR 0.41 [0.19-0.89]; p = 0.02) under adjuvant RT. For QL, irradiated patients showed higher values for the symptom scale pain after 0.5, two, and three years (all p < 0.05). After six months and three years, irradiated patients reported higher symptom burdens (impaired swallowing, speech, as well as teeth-related problems (all p < 0.05)). Patients in the RT group had significantly more problems with mouth opening after six months, one, and two years (p < 0.05); (4) Conclusions: Adjuvant RT in patients with early SCC of the oral cavity and oropharynx does not seem to influence overall survival, but it positively affects progression-free survival. However, irradiated patients report a significantly decreased QL up to three years after therapy compared to the observation group.

Prospective Evaluation of Two Wall Orbital Fractures Involving the Medial Orbital Wall: PSI Reconstruction versus PDS Repair-Worth the Effort?

Proper treatment of the two-wall fractured orbit is still controversial. Specifically, there is no consensus on the issue of the necessity of medial orbital wall repair. With anatomically critical structures at risk during the surgical approach, surgeons' view on the necessity of medial orbital wall repair often is restricted and an aesthetically disturbing enophthalmos is more likely to be accepted. Therefore, treatment options range from leaving the medial wall without repair to reconstruction with autogenous tissue or alloplastic materials, which can lead to moderate to severe side effects. However, emerging technologies such as patient-specific implants (PSI) offer a reliable and anatomically correct reconstruction of the bony orbit. This study aimed to evaluate the outcome of full orbital reconstruction using PSIs compared to only orbital floor repair using PDS (bioresorbable polydioxanone) foils leaving the medial orbital wall untouched in traumatic two-wall orbital fractures. Of all patients treated at the University Hospital of Düsseldorf between 2017 and 2019 who suffered from traumatic orbital fracture, only patients with a two-wall orbital fracture involving both the orbital floor and the medial wall (n = 68) were included. Patients were treated either with a PSI (n = 35) or a PDS foil (n = 33). Primary outcome parameters were ophthalmological disturbances analyzed via clinical investigation and intra-orbital angles, volumes and implant position analyzed with radiological 3D-datasets. While a two-wall reconstruction using PSIs led to a significant improvement of the enophthalmos, the rate of postoperative enophthalmos was significantly increased in cases of only orbital floor repair with PDS foils. Radiologically, a significant reconstruction of the three-dimensional bony orbit succeeded with the simple use of PSIs leading to a significant reduction in the traumatically enlarged orbital volume. PSI also led to a significant reduction in the traumatically enlarged medial angle of the orbit. This was not the case for single-floor repair with PDS foil. The results of this study suggest that complex orbital fractures can be reconstructed at an even higher degree of accuracy with selective laser-melted PSIs than PDS foils. In order to achieve a true to original reconstruction of the bony orbit, surgical treatment of the medial orbital wall can be advocated for in the long term depending on the indication.

Analysis of Spontaneous and Induced Osteogenic Differentiation in 3D-micromasses of Human Multipotent Stem Cells.

BACKGROUND/AIM: Craniofacial reconstruction of extensive bone defects causes high morbidity to patients. Contemporary reconstructive surgery aims at restoring lost bone with either autogenous bone or substitutes. Multipotent unrestricted somatic stem cells (USSC) show a potential for osteoblast differentiation and are increasingly used in tissue engineering. The osteogenic potential of USSC micromasses influenced by dexamethasone, ascorbic acid and ß-glycerophosphate (DAG) seems promising. The present study evaluated the effects of DAG and MAPK, ERK and PI3K/Akt-pathway inhibitors on growth and mineralization of USSC micromasses. MATERIALS AND METHODS: Cells: i) USSC-18 (female, Passage 8), ii) USSC-8 (female Passage 9), and iii) USSC-8/17 (male, Passage 8), all cultured in 350 ml DMEM, with 150 ml fetal bovine serum, 5 ml penicillin/streptomycin and 5 ml L-glutamine. Differentiation was induced using 50 µM dexamethasone in DMEM, 50 mM ascorbic acid in PBS and 1 M ß-glycerolphosphate in PBS. Microtome slices were dyed with OsteoImage™ and analyzed under fluorescence microscopy. RESULTS: Significant increase in size and mineralization of DAG-treated micromasses was found on days 3 (p<0.001), 6 (p<0.001) and 7 (p<0.001). The ERK-pathway inhibitor, FR180204, significantly reduced micromass growth and mineralization in non-DAG treated cells (p<0.001) but showed increased mineralization in DAG-treated cells (p=0.014). The PI3K/Akt-pathway inhibitor, LY294002, did not significantly affect micromass growth but significantly decreased mineralization (p<0.001). The MAP-kinase inhibitor, U0126, significantly reduced micromass growth (p=0.001) and mineralization (p=0.001) of DAG-treated cells. CONCLUSION: DAG is a strong initiator of osteogenic differentiation. The PI3K/Akt-pathway inhibitor and the ERK-pathway inhibitor, FR180204, control osteogenic differentiation of 3D-micromasses. These results may facilitate preconditioning of cell cultures in guided tissue regeneration.

Influence of Xenogeneic and Alloplastic Carriers for Bone Augmentation on Human Unrestricted Somatic Stem Cells.

Alloplastic and xenogeneic bone grafting materials are frequently used for bone augmentation. The effect of these materials on precursor cells for bone augmentation is yet to be determined. The aim of this study was to ascertain, in vitro, how augmentation materials influence the growth rates and viability of human unrestricted somatic stem cells. The biocompatibility of two xenogeneic and one alloplastic bone graft was tested using human unrestricted somatic stem cells (USSCs). Proliferation, growth, survival and attachment of unrestricted somatic stem cells were monitored after 24 h, 48 h and 7 days. Furthermore, cell shape and morphology were evaluated by SEM. Scaffolds were assessed for their physical properties by Micro-CT imaging. USSCs showed distinct proliferation on the different carriers. Greatest proliferation was observed on the xenogeneic carriers along with improved viability of the cells. Pore sizes of the scaffolds varied significantly, with the xenogeneic materials providing greater pore sizes than the synthetic inorganic material. Unrestricted somatic stem cells in combination with a bovine collagenous bone block seem to be very compatible. A scaffold's surface morphology, pore size and bioactive characteristics influence the proliferation, attachment and viability of USSCs.

Mechanical Fatigue Performance of Patient-Specific Polymer Plates in Oncologic Mandible Reconstruction.

Mandible defects are conventionally reconstructed using titanium plates. However, titanium causes metallic artifacts which impair radiological imaging. This study aims at evaluating mechanical fatigue of radiolucent fiber-reinforced polyetheretherketone (f-PEEK), polyetheretherketone (PEEK), polyetherketoneketone (PEKK), and polyphenylsulfone (PPSU) polymer plates for mandible reconstruction. A total of 30 plates (titanium [n = 6], f-PEEK [n = 6], PEEK [n = 6], PEKK [n = 6], PPSU [n = 6]) were implanted in synthetic mandibulectomized polyurethane mandibles. Servo-pneumatic mechanical testing with cyclic application of 30−300 N at 3 Hz was conducted. Bite forces were 70% on the unresected and 30% on the resected side. Total number of cycles was set to 250,000. Testing was aborted in case of plate or screw failure. Axial load to failure was tested with a speed of 1 mm/s. Kruskal−Wallis and Dunn's post hoc tests were used. Titanium, f-PEEK, and PEEK showed no failure in fatigue testing and PPSU (p < 0.001) failed against titanium, f-PEEK, PEEK, and PEKK. Titanium allowed the highest load to failure compared to f-PEEK (p = 0.049), PEEK (p = 0.008), PEKK (p < 0.001), and PPSU (p = 0.007). f-PEEK, PEEK, and PEKK withstood expected physiological bite force. Although titanium plates provided the highest fatigue strength, f-PEEK and PEEK plates showed no failure over 250,000 chewing cycles indicating sufficient mechanical strength for mandible reconstruction.