The Value of Surveillance Imaging of Oral Squamous Cell Carcinoma.

The evaluation of surveillance imaging of OSCC patients is a difficult task physicians have to face daily. Multiple patients experience a recurrence of this disease, which underlines the importance of regular patient monitoring programs. Our study analysed the value of surveillance imaging, such as computed tomography (CT) and nuclear magnetic resonance imaging (NMRI), as a patient monitoring programme and its effectiveness in achieving improvement in early recurrence detection. The study comprised 125 patients, out of which 56 (n = 56) showed radiological and 69 (n = 69) showed clinical and radiological conspicuous patterns in domestic follow-ups, respectively. The use of CT and NMRI showed a significant dependence on the histological result (p = 0.03). However, the different groups showed no significant dependence on the histological result (p = 0.96). The distribution of the histological biopsies, which were taken due to radiological changes, were prone to wrong positive diagnoses (false positives) in 71 percent. To conclude, imaging modalities should be chosen for each patient individually to reduce false positives, improve the early detection of recurrence, and increase the cure rate.

YBX1 integration of oncogenic PI3K/mTOR signalling regulates the fitness of malignant epithelial cells.

In heterogeneous head and neck cancer (HNC), subtype-specific treatment regimens are currently missing. An integrated analysis of patient HNC subtypes using single-cell sequencing and proteome profiles reveals an epithelial-mesenchymal transition (EMT) signature within the epithelial cancer-cell population. The EMT signature coincides with PI3K/mTOR inactivation in the mesenchymal subtype. Conversely, the signature is suppressed in epithelial cells of the basal subtype which exhibits hyperactive PI3K/mTOR signalling. We further identify YBX1 phosphorylation, downstream of the PI3K/mTOR pathway, restraining basal-like cancer cell proliferation. In contrast, YBX1 acts as a safeguard against the proliferation-to-invasion switch in mesenchymal-like epithelial cancer cells, and its loss accentuates partial-EMT and in vivo invasion. Interestingly, phospho-YBX1 that is mutually exclusive to partial-EMT, emerges as a prognostic marker for overall patient outcomes. These findings create a unique opportunity to sensitise mesenchymal cancer cells to PI3K/mTOR inhibitors by shifting them towards a basal-like subtype as a promising therapeutic approach against HNC.

Detection of HPV infection in head and neck cancers: Promise and pitfalls in the last ten years: A meta-analysis.

The current controversial discussion on the disease-specific survival of patients with human papillomavirus (HPV)-positive (+) and -negative (-) squamous cell carcinoma (SCC) of the head neck region was the motivation for the present meta-analysis. Different detection methods for HPV are available, though these often lack sensitivity. As a consequence, there may be false interpretation of HPV positivity. A bias concerning HPV status and therefore also survival rates is serving a non-durable relevance in the discussion of tailored therapies. A literature search was performed via the online database PubMed/NCBI, and data extraction and statistical analysis were conducted. A total of 139 studies published between 2004 and 2014 were evaluated in the present meta-analysis. The HPV detection methods, patient characteristics, tumor localizations and stages, as well as (neo-) adjuvant therapies and survival times were analyzed. The average incidence rates of HPV+ patients with oropharyngeal tumors were higher than those of patients with cancers of other regions of the head and neck. Upon evaluating the results of different detection methods no significant differences were identified. We have compared the HPV incidence rates of each detection method, when studies have used more than one. Regarding overall survival, the pooled adjusted hazard ratio (HR) for oropharyngeal SCC was 0.31 [95% confidence interval (CI)=0.27-0.36]. Unfortunately, only 3 equivalent studies were available on nonoropharyngeal tumors, for which the pooled adjusted HR was 1 (95% CI=0.73-1.36). Overall, the evaluation demonstrated that the survival rates reported in numerous studies were not evaluated multifactorially and important confounders were excluded from the statistics. The HPV detection methods used were often not sufficient in representing HPV positivity. In addition, oropharyngeal and oral SCCs were assessed together in the localization. The widely differing number of HPV+ patients in each of the various studies may be explained by insufficient detection methods and by a lack of localization distinction. The considerations of a tailored therapy according to HPV status should be rejected based on the present information. The previously published studies should be read critically and do not represent a basis for therapeutic decisions.

Skeletal-versus soft-tissue-based cephalometric analyses: is the correlation reproducible?

OBJECTIVES: Dentofacial deformities can be analyzed by skeletal and soft tissue cephalometric analysis (CA). The aim was to evaluate the difference in reproducibility between both methods. MATERIALS AND METHODS: Lateral cephalograms of 112 patients (65 females and 47 males, 27.7 ± 9.0 years) were oriented in natural head position (NHP) and digitized. The distances of skeletal (SNA, SNB, SnPog) and soft tissue (A', B' and Pog') landmarks relative to the respective norm values and the angles between the Nasion Sella line (NSL) and Frankfurt horizontal (FH) to NHP were measured for statistical evaluation and compared with respective data of an adult control group (CG) with class I occlusion and harmonic facial balance. RESULTS: The mean differences (mm ± SD) of skeletal and soft tissue landmarks were -2.4 ± 4.4 (A), -7.0 ± 9.3 (B), -6.3 ± 11.2 (Pog), -0.9 ± 1.8 (A'), -4.7 ± 6.2 (B'), and -6.1 ± 7.8 (Pog'), respectively. Pearsons's correlation (r) between the measurements of SNA/A', SNB/B' and SNPog/Pog' were r = .158 (p = .092), r = .662 (p < .001) and r = .655 (p < .001), respectively. The mean (±SD) angles between NSL and FH to NHP were -9.8° ± 5 and 0.0° ± 3.9, respectively. CONCLUSION: Variability of cranial-based measurements could give a possible explanation for the high variation and the low reproducibility of skeletal cephalometric analysis with soft tissue measurements. Soft-tissue cephalometric analysis would probably improve facial analysis and treatment planning.

Composition and Clinical Impact of the Immunologic Tumor Microenvironment in Oral Squamous Cell Carcinoma.

Immunotherapy shows promising results and revolutionizes treatment of oral squamous cell carcinoma (OSCC). The immunologic microenvironment might have prognostic/predictive implications. Morphologic immunologic parameters (inflammatory infiltrate, stromal content, and budding activity [BA] [potentially indicating epithelial-mesenchymal transition]) were evaluated in 66 human primary therapy-naive OSCCs. Intraepithelial/stromal tumor-infiltrating lymphocytes (TILs; CD3+/CD4+/CD8+/CD4+FOXP3+/IL-17A+) were quantified, and ratios were calculated. HLA class I in tumor cells was evaluated immunohistochemically. mRNA in situ hybridization to detect IFN-γ was performed. Analysis was performed within invasive front (IF) and tumor center (TCe). Decreased HLA expression was associated with low TIL density, pronounced stromal content, and high BA; IFN-γ in TILs was correlated with high-density TILs; and IFN-γ in tumor cells was correlated with absence of BA (p < 0.05). Heterogeneity of parameters (TCe/IF) was rare. Low density of stromal CD4+FOXP3+ TILs within TCe and IF was identified as an independent prognostic factor for poor overall, disease-specific, and disease-free survival (p ≤ 0.011). Refining prognostication in OSCC with high-density CD4+FOXP3+ infiltrate within TCe and/or IF, high FOXP3:CD4 ratio was significantly correlated with favorable outcome in this subgroup. Furthermore, high-stromal CD8:CD4 ratio was found to be an independent favorable prognostic factor. In summary, immunologic parameters were closely intertwined. Morphologic correlates of epithelial-mesenchymal transition were associated with downregulation of HLA and decreased inflammation. Heterogeneity was infrequent. Low-density stromal CD4+FOXP3+ infiltrate within TCe and IF was an independent poor prognostic factor. Stratification of cases with high-density CD4+FOXP3+ TILs by FOXP3:CD4 ratio enables refinement of prognostication of this subgroup. CD8:CD4 ratio was identified as an independent prognostic factor.

ALDH1 as a prognostic marker for lymph node metastasis in OSCC.

Long-term survival in cases of head and neck squamous cell carcinoma, particularly oral squamous cell carcinoma (OSCC), remains a rare achievement in the field of clinical oncology. In recent years, the theory of cancer stem cells (CSCs) has emerged and been used to offer explanations for tumour recurrence and metastasis. The present aim was to investigate the role of aldehyde dehydrogenase 1 (ALDH1) as a CSC-marker for OSCC and to determine the role of p16ink4a, which is also a surrogate marker of human papilloma virus (HPV), in the expression of ALDH1. The study cohort comprised of 186 surgically-treated cases of OSCC. The primaries were located in the oral cavity. The expression of the CSC marker (CSCM) ALDH1 was evaluated via immunohistochemistry (IHC) of a tissue microarray. HPV detection was performed by polymerase chain reaction and an HPV Array kit. Furthermore, the IHC expression of p16ink4a was also analysed. Risk regression models as the Kruskal Wallis test was used to assess the association of CSCM and p16ink4a expression with tumour size and lymph node metastasis, and cox proportional hazards were analysed. Additionally, coexpression of the markers ALDH1 and p16ink4a was analysed with regard to associations with tumour classification. Overall, high expression of ALDH1 in lymph nodes was significantly associated with Union for International Cancer Control (UICC) stage IV (P=0.044) and T4 stage cancer (P=0.03). p16ink4a positivity, in cases of HPV negativity, was associated with worse survival rate compared with that of the total cohort (P=0.048). Collectively the data indicate that ALDH1 expression may be suitable for detection of unfavourable prognosis in OSCC patients, based in part on its apparent role as a marker of metastasis. HPV status was not statistically predictive of patient outcome or CSCM expression; however, p16ink4a remains a potential marker in HNSCC Further in vitro studies with ALDH1 and p16ink4a should be performed to evaluate the expression of ALDH1 and HPV in cell culture and to clarify the role of ALDH1 as a marker for increased invasiveness of OSCC cells.

Immunohistochemical expression of CD44 in oral squamous cell carcinoma in relation to histomorphological parameters and clinicopathological factors.

AIMS: Oral squamous cell carcinoma (OSCC) is characterised by its variable clinical course. In addition to the routinely used TNM and Union for International Cancer Control systems, patient-specific prognostic/predictive biomarkers are needed. Promising biomarkers include the determination of the cancer stem cell compartment, which can be identified by CD44 expression (among other things). The aim of this study was to evaluate the impact of CD44 in OSCC in terms of correlation with histomorphology, especially targeting features of EMT, and its influence on patient prognosis. METHODS AND RESULTS: A well-characterised cohort of 108 therapy-naive OSCCs with complete long-term follow-up and matched lymph node metastases were evaluated for CD44 expression by immunohistochemistry. CD44 expression was correlated with histomorphological characteristics (including tumour differentiation and tumour budding), clinicopathological parameters, and follow-up data. Overexpression of CD44 was detected in 37% of OSCCs within the tumour centre, in 39% of OSCCs at the invasive margin, and in 16% of lymph node metastases. CD44 overexpression at the invasive margin was significantly correlated with poor histopathological differentiation, and specifically with high tumour budding activity and single-cell invasion as signs of epithelial-mesenchymal transition (EMT). CD44 overexpression within the tumour core region and in lymph node metastases was identified as an independent prognostic factor for poor overall, disease-specific and disease-free survival in subsets of patients with advanced OSCC. CONCLUSION: Our study demonstrates the association of CD44 with tumour aggressiveness and EMT, as well as the independent prognostic impact of CD44 in a subset of OSCCs, which underlines the role of tumour cell stemness as a key factor in malignant behaviour in this disease.

Comparison of contact radiographed and stained histological sections for osseointegration analysis of dental implants: an in vivo study.

OBJECTIVES: Histology is still regarded as the gold-standard to determine bone implant contact (BIC) as a parameter representing implant stability. As the further processing of cut slices for contact radiography (CR) to stained and polished histological sections is time consuming and error prone, our aim was to assess agreement between CR and Giemsa-eosin (GE) stained sections with regard to dental implants. STUDY DESIGN: Threaded dental titanium implants (n = 54) from the maxillae of Goettingen minipigs were evaluated. After 28 and 56 days, BIC and the ratio of bone volume to total volume (BV/TV; 1000 µm) were determined on the same sections by using CR and GE staining, and the results were compared. RESULTS: Moderate differences for BIC (0.6%; P = .53) and BV/TV (1.3%; P = .01) between the methods were determined, in which CR overestimated BIC and BV/TV. A strong correlation was seen between the modalities concerning BIC (28 days: r = 0.84; 56 days: r = 0.85; total: r = 0.85) and BV/TV (r = 0.96; r = 0.94; r = 0.96; all: P < .0001). CONCLUSIONS: CR enabled determination of the bone-to-implant interface in comparison with GE-stained sections. BIC and BV/TV were slightly overestimated but correlated strongly between the methods. Therefore, if BIC and BV/TV are sufficient endpoints, CR is adequate and no further preparation and staining are necessary.

EGFR and Cortactin: Markers for potential double target therapy in oral squamous cell carcinoma.

Survival periods of patients following surgical therapy of oral squamous cell carcinoma (OSCC) have previously been demonstrated to decrease over recent decades. Epidermal growth factor receptor (EGFR) and Cortactin are molecular markers that are important in tumour progression and development, and interact within the EGF pathway. Although EGFR antibody therapy exists, sufficient efforts for increased survival are still lacking due to the present limited response rates. The aim of the present study was to examine the association between EGFR and Cortactin expression on survival rates of OSCC patients and to determine whether EGFR and Cortactin expression levels are associated with advanced tumor sizes and lymphnode-metastases. In total, 222 OSCC patients were included in the study. EGFR and Cortactin expression in tumor tissue was evaluated by immunohistochemistry. Cox regression was used for survival analysis. Categories were tested for associations by using cross tabs (Chi-square test). Groups were compared by the non-parametric Mann Whitney U-test. Probabilities of less than 0.05 were considered significant and significant expression of Cortactin was observed in Advanced Union Internationale Contre le Cancer stage (P=0.032), including advanced tumour stage (P=0.021) and lymph node metastasis (P=0.049). High Cortactin expression was significantly associated with poorer survival rates (P=0.037). Further Cortactin expression was not associated with extracapsular spread, however EGFR exhibited a significant association (P=0.034). Neither EGFR nor Cortactin expression was correlated to grading. EGFR and Cortactin co-expression was demonstrated to be significantly associated with poorer survival rates in OSCC patients, suggesting that identification of predictive biomarkers for adjuvant therapies are of primary concern in OSCC. In particular, efficient dual-target therapy may act as an appropriate therapy to improve survival time for patients at advanced OSCC tumor stages.

Mammary analogue secretory carcinoma of salivary glands: diagnostic pitfall with distinct immunohistochemical profile and molecular features.

Mammary analogue secretory carcinoma (MASC) is a newly defined entity among salivary gland malignancies which has just been established in the 4th edition of the WHO classification of head and neck tumors. MASC (synonym: secretory carcinoma) are characterized by a specific rearangement of the ETV6 gene locus. Here, we present a series of 3 MASC cases including clinical data with follow-up for up to 26 months. All tumours immunhistochemically displayed strong positivity for cytokeratin 7, and mammaglobin, focal positivity for S100, cytokeratin 5/6 and muc-4. In contrast, immunhistochemical stainings against cytokeratin 14, hormon receptors, Her2/neu, androgen receptor and prostate-specific antigen were consistently negative. FISH analysis showed translocation of the ETV6 gene locus in the majority of tumour cell nuclei. During clinical follow-up, no local relapse or metastasis was detected. As these carcinomas are clinically and radiologically indistinguishable from other salivary gland tumours and as therapeutic approaches and prognosis might differ, we need to be able to diagnose MASC correctly.

Fully automated segmentation of callus by micro-CT compared to biomechanics.

BACKGROUND: A high percentage of closed femur fractures have slight comminution. Using micro-CT (µCT), multiple fragment segmentation is much more difficult than segmentation of unfractured or osteotomied bone. Manual or semi-automated segmentation has been performed to date. However, such segmentation is extremely laborious, time-consuming and error-prone. Our aim was to therefore apply a fully automated segmentation algorithm to determine µCT parameters and examine their association with biomechanics. METHODS: The femura of 64 rats taken after randomised inhibitory or neutral medication, in terms of the effect on fracture healing, and controls were closed fractured after a Kirschner wire was inserted. After 21 days, µCT and biomechanical parameters were determined by a fully automated method and correlated (Pearson's correlation). RESULTS: The fully automated segmentation algorithm automatically detected bone and simultaneously separated cortical bone from callus without requiring ROI selection for each single bony structure. We found an association of structural callus parameters obtained by µCT to the biomechanical properties. However, results were only explicable by additionally considering the callus location. CONCLUSIONS: A large number of slightly comminuted fractures in combination with therapies that influence the callus qualitatively and/or quantitatively considerably affects the association between µCT and biomechanics. In the future, contrast-enhanced µCT imaging of the callus cartilage might provide more information to improve the non-destructive and non-invasive prediction of callus mechanical properties. As studies evaluating such important drugs increase, fully automated segmentation appears to be clinically important.

Evaluating tumour after care in oral squamous cell carcinoma: Insights into patients' health related quality of life.

INTRODUCTION: Tumour aftercare (tac) is an essential tool in oncology. The main aim of these follow ups is to diagnose recurrence and second tumours from the beginning. Tac appointments can create a special environment for patients' further concerns. The purpose of the current study was to evaluate tac of patients diagnosed with OSCC and to investigate their health related quality of life (hrql). MATERIAL AND METHODS: A German questionnaire was created by two maxillo-facial surgeons with several years of tac experience. It was handed out to 100 German-speaking OSCC patients during tac. Results were statistically evaluated with SPSS (SPSS version 21.0; SPSS, IBM; Chicago, IL, USA). The inclusion criterion was that diagnosis and surgery were performed at our department and that the patients attended our tac regularly. RESULTS: Side effects such as difficulties in speaking and swallowing were evaluated as being significantly higher in cases who were administered adjuvant radiochemotherapy (art) compared with the surgical therapy group (stg) (p = 0.03). Anxiety occurred in 80% of all female patients (p = 0.02), 90% of them with a high psychological strain because of the cancer diagnosis (p = 0.04). DISCUSSION: To date, tac is a rare topic in literature. Moreover, only a few trials have focused on hrql in OSCC. A main result of the current study is that during tac, OSCC patients should be regularly questioned about their symptoms and mental state. Further, the need of the majority of OSCC patients for coping therapies can concomitantly be evaluated. CONCLUSION: The evaluation of tac is of high relevance. The results of the current study have encouraged us to establish this questionnaire as a routine tool in our tac.

Micro-CT vs. Whole Body Multirow Detector CT for Analysing Bone Regeneration in an Animal Model.

OBJECTIVES: Compared with multirow detector CT (MDCT), specimen (ex vivo) micro-CT (µCT) has a significantly higher (~ 30 x) spatial resolution and is considered the gold standard for assessing bone above the cellular level. However, it is expensive and time-consuming, and when applied in vivo, the radiation dose accumulates considerably. The aim of this study was to examine whether the lower resolution of the widely used MDCT is sufficient to qualitatively and quantitatively evaluate bone regeneration in rats. METHODS: Forty critical-size defects (5mm) were placed in the mandibular angle of rats and covered with coated bioactive titanium implants to promote bone healing. Five time points were selected (7, 14, 28, 56 and 112 days). µCT and MDCT were used to evaluate the defect region to determine the bone volume (BV), tissue mineral density (TMD) and bone mineral content (BMC). RESULTS: MDCT constantly achieved higher BV values than µCT (10.73±7.84 mm3 vs. 6.62±4.96 mm3, p<0.0001) and consistently lower TMD values (547.68±163.83 mm3 vs. 876.18±121.21 mm3, p<0.0001). No relevant difference was obtained for BMC (6.48±5.71 mm3 vs. 6.15±5.21 mm3, p = 0.40). BV and BMC showed very strong correlations between both methods, whereas TMD was only moderately correlated (r = 0.87, r = 0.90, r = 0.68, p < 0.0001). CONCLUSIONS: Due to partial volume effects, MDCT overestimated BV and underestimated TMD but accurately determined BMC, even in small volumes, compared with µCT. Therefore, if bone quantity is a sufficient end point, a considerable number of animals and costs can be saved, and compared with in vivo µCT, the required dose of radiation can be reduced.

Impact of HPV infection on oral squamous cell carcinoma.

BACKGROUND: Head and neck squamous cell carcinomas (HNSCC) are often divided by their aetiology. Noxae associated collectives are compared with the human papilloma virus (HPV)-associated group, whereas different localisations of oral (OSCC) and oropharyngeal (OPSCC) squamous cell carcinomas are mostly discussed as one single group. Our aim was to show that classification by aetiology is not appropriate for OSCC. RESULTS: HPV DNA was detected by PCR in 7 (3.47%) patients, and we identified 12 (5.94%) positive (+) cases by p16INK4a immunostaining. Only 4 (1.98%) of the p16INK4a+ cases were + for HPV using PCR. Our homogenous collective of OSCC allowed us to compare HPV+ and HPV negative (-) patients without creating bias for tumour localisation, age, gender or tumour stage. MATERIALS AND METHODS: After testing OSCC samples for HPV positivity, we compared the results of two commonly used HPV detection methods, p16INK4a immunostaining and HPV DNA-related PCR, on 202 OSCC patients. HPV subtypes were determined with an HPV LCD Array Kit. Clinicopathological features of the patients were analysed, and the disease specific survival rates (DSS) for HPV+ and HPV- patients were obtained. CONCLUSIONS: p16INK4a immunostaining is a not a reliable HPV detection method for OSCC. Positive p16INK4a immunostaining did not agree with + results from PCR of HPV DNA. Furthermore, the influence of HPV-related oncogenic transformation in OSCC is overestimated. The significance of HPV infection remains clinically unclear, and its influence on survival rates is not relevant to OSCC cases.

A biomechanical, micro-computertomographic and histological analysis of the influence of diclofenac and prednisolone on fracture healing in vivo.

BACKGROUND: Non-steroidal anti-inflammatory drugs (NSAIDs) have long been suspected of negatively affecting fracture healing, although numerous disputes still exist and little data are available regarding diclofenac. Glucocorticoids interfere in this process over a similar and even broader mechanism of action. As many previously conducted studies evaluated either morphological changes or biomechanical properties of treated bones, the conjunction of both structural measures is completely missing. Therefore, it was our aim to evaluate the effects of diclofenac and prednisolone on the fracture callus biomechanically, morphologically and by 3-dimensional (3D) microstructural analysis. METHODS: Femura of diclofenac-, prednisolone- or placebo-treated rats were pinned and a closed transverse fracture was generated. After 21 days, biomechanics, micro-CT (µCT) and histology were examined. RESULTS: The diclofenac group showed significantly impaired fracture healing compared with the control group by biomechanics and µCT (e.g. stiffness: 57.31 ± 31.11 N/mm vs. 122.44 ± 81.16 N/mm, p = 0.030; callus volume: 47.05 ± 15.67 mm3 vs. 67.19 ± 14.90 mm3, p = 0.037, trabecular thickness: 0.0937 mm ± 0.003 vs. 0.0983 mm ± 0.003, p = 0.023), as confirmed by histology. Biomechanics of the prednisolone group showed obviously lower absolute values than the control group. These alterations were confirmed in conjunction with µCT and histology. CONCLUSIONS: The inhibiting effects of both substances were not only mediated by absolute parameters (e.g. breaking load, BV), but we have shown, for the first time, that additional changes occurred in the microstructural bony network. Especially in patients at risk for delayed bone healing (arteriosclerosis, diabetes mellitus, smoking), the administration of these drugs should be weighed carefully.

CD274/PD-L1 gene amplification and PD-L1 protein expression are common events in squamous cell carcinoma of the oral cavity.

Immunomodulatory therapies, targeting the immune checkpoint receptor-ligand complex PD-1/PD-L1 have shown promising results in early phase clinical trials in solid malignancies, including carcinomas of the head and neck. In this context, PD-L1 protein expression has been proposed as a potentially valuable predictive marker. In the present study, expression of PD-L1 and PD-1 was evaluated by immunohistochemistry in 80 patients with predominantly HPV-negative oral squamous cell carcinomas and associated nodal metastasis. In addition, CD274/PD-L1 gene copy number status was assessed by fluorescence in situ hybridization analysis. PD-L1 expression was detected in 36/80 (45%) cases and concordance of PD-L1 expression in primary tumor and corresponding nodal metastasis was present in only 20/28 (72%) cases. PD-1 expression was found in tumor-infiltrating lymphocytes (TILs) but not in tumor cells. CD274/PD-L1 gene amplification was detected in 19% of cases, with high level PD-L1 amplification present in 12/80 (15%), and low level amplification in 3/80 (4%). Interestingly, CD274/PD-L1 gene amplification was associated with positive PD-L1 immunostaining in only 73% of cases. PD-L1 copy number status was concordant in primary tumor and associated metastases. Clinically, PD-L1 tumor immunopositivity was associated with a higher risk for nodal metastasis at diagnosis, overall tumor related death und recurrence. Based on our findings we propose to include PD-L1 copy number status in addition to protein status in screening programs for future clinical trials with immunotherapeutic strategies targeting the PD-1/PD-L1 axis.

Oral soft tissue infections: causes, therapeutic approaches and microbiological spectrum with focus on antibiotic treatment.

INTRODUCTION: Intraoral soft tissue infections (OSTI) are a common problem in dentistry and oral surgery. These abscesses are mostly exacerbated dental infections (OIDC), and some emerge as postoperative infections (POI) after tooth extraction (OITR) or apicoectomy (OIRR). The main aim of this study was to compare OIDC with POI, especially looking at the bacteria involved. An additional question was, therefore, if different antibiotic treatments should be used with OSTI of differing aetiologies. The impact of third molars on OSTI was evaluated and also the rates of POI after removal of third molars were specified. MATERIAL AND METHODS: Patient data was collected from the patients' medical records and the results were statistically evaluated with SPSS (SPSS version 21.0; SPSS, IBM; Chicago, IL, USA). The inclusion criterion was the outpatient treatment of a patient with an exacerbated oral infection; the exclusion criteria were an early stage of infiltration without abscess formation; and a need for inpatient treatment. RESULTS: Periapical exacerbated infections, especially in the molar region were the commonest cause of OIDC. In the OITR group, mandibular tooth removal was the commonest factor (p=0.016). Remarkably, retained lower wisdom teeth led to significant number of cases in the OITR group (p=0.022). CONCLUSIONS: In our study we could not define differences between the causal bacteria found in patients with OIDC and POI. Due to resistance rates we conclude that amoxicillin combined with clavulanic acid seems to be the antibiotic standard for exacerbated intraoral infections independent of their aetiology.

Current and future options of regeneration methods and reconstructive surgery of the facial skeleton.

Musculoskeletal defects attributable to trauma or infection or as a result of oncologic surgery present a common challenge in reconstructive maxillofacial surgery. The autologous vascularized bone graft still represents the gold standard for salvaging these situations. Preoperative virtual planning offers great potential and provides assistance in reconstructive surgery. Nevertheless, the applicability of autologous bone transfer might be limited within the medically compromised patient or because of the complexity of the defect and the required size of the graft to be harvested. The development of alternative methods are urgently needed in the field of regenerative medicine to enable the regeneration of the original tissue. Since the first demonstration of de novo bone formation by regenerative strategies and the application of bone growth factors some decades ago, further progress has been achieved by tissue engineering, gene transfer, and stem cell application concepts. This review summarizes recent approaches and current developments in regenerative medicine.