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Purpose The treatment of advanced stages of medication-related osteonecrosis of the jaw (MRONJ) remains challenging. In order to improve decision making concerning the therapy, we examined the change of patients’ quality of life (QoL) after surgical treatment of MRONJ stage III. Method The primary outcome variable was patients’ QoL. It was preoperative (T0), 6 weeks postoperative (T1) and 6 months postoperative (T2) assessed by the European Organisation for Research and Treatment of Cancer QoL-H&N35 (EORTC QoL-H&N35) and the Oral Health Impact Factor-G14 (OHIP-G14) questionnaire in a prospective cohort study. Other variables included location, age, sex, risk factors, and recurrence. Descriptive statistics and general multivariate regression models were calculated. Results Forty-three patients with stage III MRONJ underwent surgery. OHIP-G14 scores decreased (improvement) statistically significant (p = .001) by 52.02% (T0-T1) and 56.45% (T1–T2). EORTC QoL-H&N35 showed statistical improvement for “swallowing” (p = .007), “opening mouth” (p = .045), “painkiller” (.005), “weight loss” (.004), “pain” (p = .001), “trouble with social eating” (p = .001), “trouble with social contact” (p = .001), and “teeth” (p = .001). Patients who developed a recurrence did not show any significant higher (worse) scores in OHIP G14 or EORTC QoL-H&N35 scores compared with patients without recurrence. Twenty-nine out of 36 patients showed full mucosal healing (T2). For patients with no full mucosal healing, a downgrade to stage I was achieved. Conclusion In terms of QoL patients with stage III MRONJ do benefit from surgical treatment. The incident of a recurrence seems to have no significant impact on patients QoL.

The aim of the study was to evaluate the surgical outcome of patients with advanced medication-related osteonecrosis of the jaw (MRONJ) treated with different flaps for soft tissue closure. Only MRONJ stage III patients with a minimum follow-up of 6 months were included in our prospective study. The soft tissue closure techniques were: Mylohyoid Muscle Flap, Buccal Fat Flap and mucoperiosteal flap alone. Potential risk factors and surgical side effects were analyzed. Relapses occurred in 12 of 44 included cases and 38 reached mucosal integrity within the follow-up. Cases treated with the muscle or fat flap showed better results regarding the recurrence rate (p < 0.001) and soft tissue healing (p = 0.002): only 3 of 33 developed a relapse, and 31 of 33 reached mucosal integrity. The outcome was worse if MRONJ occurred at the front areas of the jaw (p = 0.025). Postoperative, the pain level was reduced significantly (p < 0.001). Partial hypoesthesia of the lip arose in 18 cases. An impairment of the long-term prosthetic rehabilitation has not been seen.Patients with MRONJ stage III undergoing surgery benefit from extensive soft tissue closure.

Background To evaluate predictive clinico-pathological characteristics on outcome in head and neck melanoma (HNM) in a population-based study with particular emphasis on the prognostic effect of sentinel lymph node biopsy (SLNB), Charlson comorbidity index (CCI) and distinct tumor localisations. Methods Here we primarily describe a retrospective multicenter population-based cohort study with 402 patients having undergone resection with curative intent of HNM between 2010 and 2017. SLNB was used in the diagnosis of 79 HNM patients. Outcome was analyzed, focusing on SLNB, CCI as well as tumor localisation. Overall survival (OAS) und recurrence free survival (RFS) was examined by uni- and multivariate analysis. Results Histopathologically verified lymph node metastasis according to SLNB was associated with impaired RFS in HNM patients (p = 0.004). Especially in higher tumor stages, the sole implementation of SLNB improved survival significantly in the present cohort (p = 0.042). With most of the HNM being located in the face, melanoma of the scalp and neck could be linked to deteriorated patient’s outcome in uni- as well as multivariate analysis (p = 0.021, p = 0.004). Conclusions SLNB is a useful tool in predicting development of distant metastasis after HNM resection with curative intent. Especially in higher tumor stages, performing a SLNB ameliorated survival of HNM patients. Additionally, CCI as well as a distinct tumor localisations in HNM were identified as important risk factors in our population-based cohort study.

Purpose To illustrate the influence of different socioeconomic factors on the treatment and outcome of patients in Germany with oral cancer. Methods In this retrospective single-center study, 400 patients of our department of oral and maxillofacial surgery with primary cases of oral cancer were included. Preoperative diagnostics, occupational groups, and marital and health insurance status were evaluated. Overall and disease-specific survival were analyzed. Occupations were distinguished in 5 groups (unemployed, physically light workers, physically hard worker, university graduate, and freelancer). Data were adjusted to covariables like tumor size, positive lymph nodes, age, alcohol, or tobacco abuse. Results There was no differences between private and statutory insured patients concerning overall (p = 0.858) or disease-specific survival (p = 0.431). Private insured patients received more preoperative PET-CT (p = 0.046) and had a better dental status (p = 0.006). The occupational groups showed also no differences in survival (p = 0.963). The hospitalization of freelancers was in average 2 days shorter. Physically hard workers were diagnosed with bigger tumors (p = 0.018) and consumed more tobacco and alcohol. The 5-year survival rate of married patients was approximately 20% points better than not married patients, without showing a significant difference over the entire observation time (p = 0.084). Conclusion In our cohort, socioeconomic factors have just a limited influence on the survival or treatment of patients with oral cancer. A sufficient statutory health insurance system is a reasonable explanation for this.

Objectives The aim of this retrospective study was to analyze the early postoperative swallowing outcome in oral cancer patients considering risk factors and localization. Materials and methods Four hundred patients with primary cases of oral cancer were included. Tumors’ locations were categorized into four main groups (central, lateral, anterior and posterior). Swallowing function was evaluated at day 7 after surgery. Results Ninety-eight percent (393/400) of the patients had a swallowing impairment including 41 (10.2%) patients who were unable to swallow. Strong risk factors with p values of 0.001 were tumor size, nodal stage, tracheotomy, insufficient dental status and reconstruction with a flap. The inability to swallow was increased at T1 und T2 patients, if they were reconstructed with a flap compared to patients who had a primary wound closure (p = 0.04). Decreased swallowing function was determined if the tumor was located central (OR = 1.8; p = 0.141) and additionally posterior (OR = 5.8; p = 0.110). Inability to swallow, even at that early point in time, (p = 0.001) was as significant as tumor size (p = 0.009) and nodal stage (p = 0.020), referring to overall survival. Conclusion The impact of early dysphagia should not be underestimated. By considering swallowing impairment at the primary therapy patients can profit concerning survival and comorbidity.

Objective The aim of this study was to evaluate the possible influence of denosumab and zoledronate on proliferation and osteogenic differentiation of alveolar bone stem cells. Design Mesenchymal stem cells (MSCs) and dental follicle cells (DFCs) were grown under osteogenic differentiation with concentrations from 0.25 μM to 10 μM (zoledronate) and to 20 μM (denosumab). Vitality was assessed after 7 days by CCK-8 Kit. Osteogenic differentiation was measured by alkaline phosphatase (ALP) assay and additionally by RT-qPCR of key enzymes COL1, RUNX2 and ALP. Results MSCs expressed receptor activator of NF-κB (RANK), as requirement to interact with denosumab. DFCs did not express RANK. Denosumab significantly reduced proliferation and ALP activity of MSCs in high concentrations (10 μM and 20 μM). Growth of DFCs was not influenced at all by denosumab. Zoledronate reduced proliferation of DFCs in higher concentrations (5 μM and 10 μM) (p > 0.05). Physiological and medium concentrations of denosumab (0.25 μM, 1 μM 5μM) significantly enhanced ALP activity in MSCs and COL1, RUNX2 and ALP were upregulated. Zoledronate had no effect on ALP activity in DFCs. Conclusion Our evaluations suggest receptor and dose depending effects of denosumab in MSCs. High concentrations mediate toxic effects, whereas physiological and medium concentrations enhance osteogenic differentiation.

Objectives Recently, multiple studies addressed the importance of lymph node ratio (LNR) in specifying patients’ risk of disease recurrence in various malignancies. The present study examines the prognostic significance of LNR in predicting outcome of oral squamous cell carcinoma (OSCC) patients after surgical treatment with curative intent. Methods Here, we describe a retrospective population-based cohort with 717 patients previously diagnosed with OSCC. Histopathologically verified lymph node metastasis was diagnosed in 290 patients. Among these patients, we evaluated the impact of LNR on overall survival (OAS) and recurrence-free survival (RFS) in uni- as well as multivariate analysis. Results A median cutoff (0.055) in LNR was found to significantly predict outcome in OSCC patients. Five-year OAS was 54.1% in patients with a low LNR, whereas a high LNR was associated with a 5-year OAS of 33.3% (p p = 0.002). Results were confirmed in multivariate Cox regression which substantiated the importance of LNR in predicting survival in OSCC patients. Conclusions LNR was shown to be an independent prognostic factor for outcome of OSCC in a population-based cohort in uni- as well as multivariate analysis. Hereby, a LNR ≥ 0.055 predicted a shorter OAS and RFS in our cohort. Clinical relevance Besides established histopathological factors, LNR can be used as a reliable predictor of outcome in OSCC and might therefore be further applied in evaluating adjuvant treatment after resection in curative intention.

Background Radiotherapy aggravates implant‐based prosthetic rehabilitation in patients with head and neck cancer. Purpose To evaluate the impact of radiation dose at implant and parotid gland site for prosthetic rehabilitation. Material and methods The retrospective study includes 121 irradiated head and neck cancer patients with 751 inserted implants. Radiation doses on implant bed and parotid gland site were recorded by 3‐dimensional modulated radiation plans. Implant success was clinically and radiographically evaluated according to modified Albrektsson criteria and compared to treatment‐ and patient‐specific data. Results Implant overall survival after 5 years was 92.4% with an implant success rate of 74.9%. Main reasons for implant failure were marginal bone resorption (20.9%), implant not in situ or unloaded (9.6%) and peri‐implantitis (7.5%). A mean radiation dose of 62.6 Gy was applied with a mean parotid dose of 35 Gy. Modulating radiation techniques went along with lower grades of xerostomia (p < 0.001). At implant site mean doses of 57.5, 42.0, and 32.3 Gy were recorded for oral, oropharyngeal, and hypopharyngeal/laryngeal carcinoma, respectively. Implant success inversely correlated to radiation dose at implant site. Strong predictors for implant failure in uni‐ and multivariate analysis were implant‐specific dose >50 Gy (HR 7.9), parotid dose >30 Gy (HR 2.3), bone (HR 14.5) and soft tissue (HR 4.5) transplants, bad oral hygiene (HR 3.8), nonmodulated radiation treatment planning (HR 14.5), and nontelescopic prosthetics (HR 5.2). Conclusion Radiotherapy impedes implant success in a dose‐dependent manner at implant site. Modern radiation techniques effectively reduce xerostomia favoring implant‐based prosthetic rehabilitation. Implantation in bone grafts is more critical and telescopic‐retained overdentures should be preferred.

Background: The purpose of the study was to categorize the vitality and inflammation of resected bone of patients with medication-related osteonecrosis of the jaw (MRONJ) and to correlate the grade of inflammation with the surgical success. Methods: This prospective study includes 44 patients with stage III MRONJ. Necrotic bone was resected in a block fashioned way. After demineralization and staining, histological analyses were performed by measuring the areas of necrotic, vital, and regenerative bone. Areas of chronic and acute inflammation were categorized as non, mild, moderate, and severe and were correlated with surgical success and parameters of inflammation in blood plasma (C-reactive protein and leukocytes). Results: An average area of 59.0% was necrotic in the examined specimen. Vital bone was measured with an average area of 40.9%. The stage of chronic inflammation correlated with the amount of vital bone (P < .001) and the success of surgery (P = .002). If acute inflammation was dominant, chronic inflammation areas were found less while necrotic areas were observed more (P < .001). Also, the risk of relapses, wound healing disorders, and the level of C-reactive protein were elevated if acute inflammation was severe or moderate (P = .031). Areas of bone regeneration were seen only in 11.3% of vital bone areas and occurred independently of infection stages. Conclusion: If possible, surgery should be delayed in patients with signs of severe acute inflammation. Patients may profit from prolonged pre-operative antibiotic therapy to reduce the level of acute inflammation.

Purpose This retrospective study analyzes deviations between preoperative planning and postoperative outcome in orthognathic surgery using 2D Onyx Ceph®-cephalometric analyzing and planning system. Materials and methods A total of 100 patients with a mean age 25.1 of years were included in this study. In 33 patients a bilateral sagittal split osteotomy and in seven patients a Le Fort I osteotomy was performed. A total of 60 patients were treated by a bimaxillary approach. Onyx Ceph® was used as cephalometric planning software (Onyx Ceph®), followed by mock operations. Postoperative cephalograms were obtained after 3.3 days and compared to preoperative planning cephalograms for sagittal (SNA, SNB, ANB) and vertical (ArGoMe, ML-NSL, NL-NSL) angle measurements. Real and absolute mean deviation were documented. Results Absolute mean deviation (degrees) between postoperative and planned jaw movement was lower for the sagittal parameters SNA (0.58), SNB (1.15) and ANB (1.05) compared to the vertical parameters NL-NSL (1.47), ML-NSL (1.96) and ArGoMe (3.20). SNA, SNB and ANB showed constant deviations independent from the extent of jaw movement. With regard to the vertical parameters ML-NSL, ArGoMe and NL-NSL the extent of the postoperative rotational jaw movement was not as much as planned, particularly for vertical shifts of more than 4°. Conclusion By using the 2D Onyx Ceph® cephalometric software for orthognathic surgery, the deviations between planned and actual movements are within an acceptable and predictable range. Planning of extensive vertical alterations may result in greater deviations after surgery.

The aim of this study is to investigate the influence of prognostic biomarkers on radiosensitivity and survival of advanced head and neck squamous cell carcinomas treated by primary (chemo)radiation. The clinicopathological data and immunohistochemical staining of p16, c-Met, survivin, PD-1, and PD-L1 of 82 primarily (chemo)irradiated patients with head and neck squamous cell carcinoma were analyzed. Associations with local and locoregional radiation response, overall survival (OS), disease-free (DFS), and disease-specific survival (DSS) were assessed. Complete tumor response was associated with increased patient age (p = 0.007), N0-status (p = 0.022), M0-status (p = 0.007), and p16-positivity (p = 0.022). High PD-L1 was associated with M0-status (p = 0.026) and indicated tumor response to irradiation (p = 0.057); survivin expression showed higher rates of response failure (p = 0.073). Low PD-1 was associated with increased T-stage (p = 0.029) and local recurrence (p = 0.014). High PD-1 was strongly correlated with PD-L1-positive tumor infiltrating lymphocytes (p

Objective To evaluate the prognostic effect of allogenic red blood cell transfusion (RBT) and preoperative anemia in patients with oral squamous cell carcinoma (OSCC) undergoing primary tumor resection. Methods We retrospectively analyzed a cohort of 621 patients, diagnosed with OSCC receiving tumor resection in curative intention. Preoperative anemia and perioperative RBT were evaluated according to WHO definition. Overall survival (OAS) as well as recurrence-free survival (RFS) was evaluated in transfused and non-transfused as well as in anemic and non-anemic patients. In addition, outcome parameters were calculated for distinct amounts of perioperatively administered RBTs. Data analysis was performed by uni- and multivariate statistics. Mean follow-up time was 7.3 years. Results Preoperative anemia was diagnosed in 29% of OSCC patients. Anemic patients displayed a significantly decreased five-year OAS (44%) in comparison to non-anemic equivalents (69%). 70% of non-transfused OSCC patients were alive after five years, whereas in case of RBT five-year OAS was 41%. These findings were substantiated by subgroup analysis in patients without preoperative anemia. For anemic patients however, no deleterious effect on survival in case of perioperative RBT was seen. Increasing numbers of received RBTs were shown to worsen outcome of OSCC patients in a dose-dependent manner. Conclusion Preoperative anemia and RBT are significantly associated with impaired long-term outcome of patients suffering from OSCC. Future studies are needed to evaluate differentiated effects of RBTs in anemic and non-anemic OSCC patients and accordingly providing individual transfusion strategies to ameliorate outcome of patients suffering from OSCC.

The purpose of this study was to outline lower leg vessel anatomy and to investigate reliability and limitations of magnetic resonance angiography (MRA) in patients proposed for microvascular fibula transplantation (free fibula flap (FFF)). We retrospectively investigated MRAs of 99 patients considered for FFF. Frontal MRA planes and maximal intensity projections (MIPs) were evaluated for fibula lengths, anatomical branching pattern, arterial stenoses and fibular perforator positions in both legs (n=198). Normal branching patterns were observed in 168 (85.3%) legs. Twenty-nine (14.7%) legs presented abnormal branching patterns. Once (0.5%) the anterior, 19 times (9.6%) the posterior tibial artery were absent or hypoplastic. Nine (4.6%) lower legs presented an arteria peronea magna. Average length of the tibiofibular trunk (TFT) was 3.3±0.15cm. A total of 492 perforators were found with an average of 2.5 (±0.82±0.99) perforators per leg. A mapping of perforator run-offs was illustrated true to scale. Lower limb stenoses were distributed in the anterior tibial artery (14.1%), in the posterior tibial artery (11.1%) and in the fibular artery (8.1%). Smoking (P=0.828), diabetes (P=0.727) and peripheral arterial occlusive disease (P=0.172) did not correlate with presence of stenoses. Preoperative lower limb angiography avoids postoperative complications. MRA reliably and non-invasively identifies anatomical variants and arterial stenoses without radiation. Illustration of perforator run-offs enhances incision planning for fibula harvest.

Purpose To study implant-based prosthetic rehabilitation of head and neck cancer patients with focus on implant survival and quality of life. Materials and methods The prospective observational study presents preliminary results of 29 edentulous head neck cancer patients (20 patients after radiotherapy) with 165 OsseoSpeed implants. Implant success after 1-year follow-up was evaluated by means of the Albrektsson criteria. Quality of life was analysed with the EORTC QLQ-C30, QLQ-H&N35, and OHIP 14 questionnaires. Results The overall implant survival rate after 1 year was 95.2% (157/165). Implant success measured by the Albrektsson criteria showed a lower success rate of 86.7% (143/165), mainly because of peri-implant marginal bone loss with a mean of 0.8 mm after 1 year. Xerostomia (p = 0.008), implant insertion within the radiation target volume (p = 0.09), implantation in transplanted bone (p = 0.05), and smoking (p = 0.041) were the main reasons for implant failure, followed by D4 bone quality, maxillary implant site, and insufficient primary stability. Speaking, swallowing, eating, as well as social integration and individual self-confidence had considerably improved 1 year after denture placement compared to before treatment. Conclusion Implant-based prosthetic rehabilitation of head and neck cancer patients is possible at a calculable risk and significantly improves patients' quality of life.

The purpose of this study was to analyse the impact of surgical margins on tumour recurrence and survival of patients with carcinomas of the head and neck.A cohort of 156 patients with primary squamous cell carcinoma of the head and neck treated by local resection with negative margins and neck dissection between 2004 and 2012 was investigated. Margin status in frozen sections and permanent paraffin tissues were analysed and compared to clinical and histopathological parameters as well as to tumour recurrence (local, regional and distant) and disease-specific survival (DSS).Close margins (5mm) on permanent sections were correlated to high-grade differentiation (p=0.070), lymphangiosis (p=0.009) and positive neck nodes (p=0.025) implicating regional and distant recurrence (p=0.001) as well as unfavorable DSS (p=0.002). Positive margins on initial frozen section analysis revised into negative margins during further surgery were the strongest predictor for local recurrence in uni- and multivariate analysis (p0.001, hazard ratio 3.34). However, positive frozen section margins were not significantly predictive for DSS (p=0.150). Significant predictors for DSS in univariate analysis were local recurrence (p=0.026), T-stage (p=0.02), N-stage (p0.001), grading (p=0.02) and lymphangiosis (p=0.001). Multivariate DSS analysis revealed lymph node metastasis (p=0.005) and local recurrence (p=0.017) as significant negative predictors.Close margins on permanent sections are associated with aggressive tumour characteristics, regional and distant metastasis implicating worse DSS. The accuracy of frozen section analysis seems limited as positive frozen section margins revised into negative margins bear a high risk of local recurrence.

Numerous studies analyzed lymphovascular invasion (LVI) in various malignant diseases, however, little is known about the role of lymphatic invasion (LI) as well as vascular invasion (VI) in oral squamous cell carcinoma (OSCC). The aim of this study is to illuminate the role of LI and VI in a population-based cohort study.We retrospectively analyzed 745 primarily resected OSCC patients in Eastern Bavaria for histopathologically verified LI and VI. Overall survival (OS) and recurrence-free survival (RFS) were calculated, whereas analysis was performed by uni- and multivariate statistics. Mean follow-up time was 7.4 years.LI was found in 115 patients (15.4%), VI was diagnosed in 23 cases (3.1%). LI correlated significantly with distinct anatomical sites (p = 0.004), increasing pT-classification (p 0.001), lymph node involvement (p 0.001), higher grading (p 0.001), advanced UICC-stages (p 0.001) and adjuvant therapies (p 0.001). Similar results were found for VI. Survival analysis resulted in a significantly decreased five-year OS and RFS in patients with diagnosed LI (OS: 41.1%, RFS: 38.3%) in contrast to LI-negative cases (OS: 66.8%, RFS: 59.7.7%, p 0.001). Analogous outcomes were seen for patients with VI. Additionally, LI was identified as a predictive parameter, indicating individual patients' response to adjuvant therapies.This population-based cohort study underlines the unfavorable aspect of LI and VI on outcome in OSCC. Including LI and VI in existing staging systems could help to stratify patients' risk for adverse outcome and consecutively determine adjuvant treatment in malignant disease.

Definition of implant success is unclear in prosthetic implant-based rehabilitation of head neck cancer patients. Fifty-two patients with 309 inserted implants were included in this prospective observational study. Implant survival (in situ and loaded) and implant success (modified Albrektsson criteria) at 2-year follow-up were evaluated under the influence of patient- and implant-specific variables. Thirty-nine patients with 234 implants finished the study. Overall implant survival after 2 years was 92.3% (216/234) with an osseointegration rate of 94% (220/234). Implant success was 78.6% (184/234). Main reasons for failure were “bone resorption > 1.7mm” (n = 27, 11.5%) and “implant not in situ or not loaded” (n = 18, 7.7%). Smoking (OR 3.1, p = 0.034), bone grafts (OR 2.4, p = 0.021) and radiation dose > 60 Gy (OR 3.8, p = 0.025) revealed as significant predictors for implant failure. Implant survival differs significantly from implant success in head and neck cancer patients. Implant success is mainly determined by radiographic peri-implant bone resorption. Dealing with head and neck cancer patients a higher amount of peri-implant bone resorption must be taken into account and warrants for intensified implant monitoring.

Background: In humans, there are four known G-Protein-coupled receptors (GPCRs) that sense protons: GPR4 (GPR19), TDAG8 (GPR65, T-cell death-associated gene 8), OGR1 (GPR68, ovarian cancer GPCR1), and G2A (GPR132, G2 accumulation protein). They are known to be involved in sensing changes of extracellular proton-concentrations in the acidic microenvironment of tumors, which leads to altered cancer cell proliferation, migration, metastasis, angiogenesis, apoptosis, immune cell function and inflammation. However, only little is known about the expression of proton-sensing GPCRs in the skin and especially in skin cancers. We studied the expression of proton-sensing GPCRs in selected skin cancers, that is Merkel cell carcinoma (MCC), dermatofibrosarcoma protuberans (DFSP), atypical fibroxanthoma (AFX) and pleomorphic dermal sarcoma (PDS). Methods: We did immunohistochemistry and immunofluorescence to analyze the expression of GPR4, TDAG8, OGR1 and G2A using paraffin-embedded tissue samples (n = 4, exceptions: PDS GPR4/GPR65 n = 5, AFX GPR132 n = 3) from patients suffering from MCC, DFSP, AFX and PDS. Results: (1) GPR4 was expressed on all AFX and PDS specimens. All AFX and MCC showed a positive expression of G2A. All PDS exhibited a strong positive expression of G2A. (2) MCCs neither expressed GPR4 nor TDAG8. All DFSP showed no expression of TDAG8. (3) For any other combination of GPCR and skin disease, we found positive/negative mixed results. Conclusions: These are the first results on pH - GPCRs in selected skin cancers. We provide evidence that these GPCRs are differentially expressed on the various types of skin cancers and that they can potentially be addressed as a therapeutic target in extensive disease.

Stem cells from the human dental apical papilla (SCAP) can be obtained from almost all extracted wisdom teeth with an immature tooth root. Although different stem cell lines are used for studies, it remains elusive whether specific characteristics of the dental stem cell cultures such as proliferation rates or the cell differentiation potential are related to the cell source, e.g. the donor tissue of the dental apical papilla. To answer this question, we compared two independent SCAP cell lines from the same donor and compared them with a third cell line from another donor. We investigated the expression of stem cell markers, the efficiency of colony forming units, cell proliferation and the differentiation potential. Results showed particular differences for typical stem cell attributes such as stem cell marker expression, cell proliferation and the adipogenic differentiation. These differences were regardless of the donor of the cell lines. In conclusion, we suppose that stem cell characteristics of SCAP cell cultures are independent from the donor.

The directed expression of osteogenic transcription factors via a balanced activation of signaling pathways is an important prerequisite for the development of mineralized tissues. A positive-feedback loop of the BMP2-dependent SMAD signaling pathway and the DLX3 transcription factor (BMP2/DLX3 pathway) directs the osteogenic differentiation of periodontal precursor cells from the dental follicle (DFCs). However, little is known how this BMP2/DLX3 pathway interacts with other crucial signaling pathways such as the WNT/β-catenin signaling pathway. This study investigated the interaction between the BMP2/DLX3 pathway and the WNT pathway during the osteogenic differentiation of DFCs. BMP2 induced the WNT/β-catenin pathway in DFCs and phosphorylates β-catenin via protein kinase A (PKA). Moreover, only BMP2 facilitated the binding of LEF1/SMAD4/β-catenin complex to the DLX3 promoter, while an inducer of the canonical WNT pathway, WNT3A, act as an inhibitor. Although WNT3A inhibits the osteogenic differentiation of DFCs the expression of β-catenin was crucial for both the expression of DLX3 and for the osteogenic differentiation. In conclusion, while the activation of the canonical WNT pathway inhibits the osteogenic differentiation of DFCs, β-catenin sustains the BMP2/DLX3-mediated osteogenic differentiation via the activation of PKA.

The purpose of this study was to evaluate the necessity of elective bilateral neck dissection for treating strict unilateral squamous cell carcinoma (SCC) of the tongue. A cohort of 169 patients with unilateral non-midline crossing SCCs of the tongue treated by local resection and neck dissection was investigated. Study endpoints were nodal relapse and overall survival. The mean follow-up was 7.4 years. A total of 146 (88.1%) patients were treated by neck dissection. Lymph node metastases were diagnosed in 50 (34.2%) patients. Only two (1.1%) had contralateral lymph node metastases. Risk factors for developing a primary lymph node metastasis were size of tumor (T2/T3, p = 0.03; OR = 2.2), lymphangiosis (p = 0.003; OR = 4.7), and higher-grade differentiation (p = 0.051; OR = 2.43). Metachronous lymph node metastases were detected in 23 (13.6%) patients (19 ipsilateral, one contralateral and three bilateral). The main risk factor for developing a metachronous lymph node metastasis was the presence of a primary lymph node metastasis (p = 0.004; HR = 4.65). Patients with initial neck dissection came up with lower 5-year recurrence rates (13.6%) compared to patients without neck dissection (27.3%; p = 0.014). Bilateral neck dissection showed no advantage regarding nodal relapse free and overall survival (p = 0.606) compared to unilateral neck dissection irrespective of initial N or T stage. Patients with unilateral SCC of the tongue benefit from an ipsilateral neck dissection regarding nodal relapse. The value of elective bilateral neck dissection as standard treatment seems questionable even if positive lymph nodes were diagnosed ipsilateral at primary therapy.

OBJECTIVE: Evaluating vascular autonomization of pedicled and microvascular free flaps for soft tissue reconstruction in the head and neck area by means of postoperative quantitative measurement of dynamic contrast values obtained with contrast-enhanced ultrasound. METHODS: 8/18 patients underwent lip reconstruction with a pedicle flap, 10 patients reconstruction of other parts of the head with a microvascular free transplant. Ultrasound examinations were conducted within the 1st postoperative week and 4 weeks after surgery. After the intravenous bolus of the ultrasound contrast agent, examinations were carried out for 30 sec without compression followed by 30 sec with compression of the vascular pedicle in bolus and flash kinetics. Digital cine loops were analyzed off-line with a quantification software (VueBox (TM)) to determine the Rise Time (RT) between flap tissue with and without compression. RESULTS: Measurements showed increasing autonomous perfusion, independent of the vascular pedicle. No transplant was lost, but 4/10 patients with a microvascular flap and 1/8 patients with a pedicle flap developed postoperative complications. RT values for the pedicled and microvascular flaps obtained under compression differed significantly between the 1st and the 4th week (p = 0.025). CONCLUSIONS: Reliable neovascularization was achieved 4 weeks postoperatively. CEUS showed to be a useful method for assessing the degree of autonomization of pedicle and microvascular free flaps.

The secretion of osteocalcin (OCN) is an excellent differentiation marker for the osteogenic differentiation. This study investigated the secretion of OCN during the osteogenic differentiation of DFCs. During the differentiation of DFCs the extracellular concentrations of OCN were higher in standard cell culture medium than in osteogenic differentiation medium. However, after 4 weeks in the osteogenic differentiation medium the extracellular OCN concentration decreased strongly, whereas the concentration remains high in the control medium. At this point in time DFCs formed connective tissue like structures with mineralized clusters and OCN. Real-time RT-PCR analyses and western-blot analyses proved that OCN was expressed in both cell culture media. However, the expression of the mRNA was inhibited in the osteogenic differentiation medium. These results suggest that DFCs secrete constitutively OCN into the cell culture medium and that the osteogenic differentiation medium suppresses the gene expression of OCN. Moreover, OCN imbeds into the extracellular matrix after the formation of connective tissue like structures, and the soluble OCN in the cell culture medium disappears. Hence, extracellular OCN in the cell culture medium is not a marker for the osteogenic differentiation of DFCs.

The purpose of this case-control study was to find a correlation between certain imaging findings in dental panoramic radiographs and the risk for developing a medication-related osteonecrosis of the jaw (MRONJ) in patients taking antiresorptive therapy (AT).Randomized and blinded dental panoramic radiographs of 60 patients undergoing antiresorptive drug treatment (36 patients with MRONJ, 24 patients without MRONJ) and of 60 patients without AT were analyzed by 3 experts for the following signs: sequestrum, osteosclerosis, difference in sclerosing of alveolar process and body of mandible, visible alveolar socket, enhancement and loss of lamina dura, enhancement of the oblique ridge, enhancement of the mandibular canal, proliferative periostitis and osteolytic processes at the cortex.Signs were seen significantly more often in patients undergoing AT than in the control group (CG) (osteosclerosis p-value = 0.019, visible alveolar socket p-value = 0.001, enhancement of lamina dura p-value 0.001, enhancement of the mandibular canal p-value = 0.025, proliferative periostitis p-value = 0.05 and osteolytic processes at the cortex p-value 0.001). While there is no significant difference between the CG and the group of patients with AT without manifest MRONJ for any sign, the significance increases when taking the group of patients under AT with manifest MRONJ into consideration. In addition, if medication was administered for malignant reasons, the signs visible alveolar socket, enhancement of the lamina dura and the enhancement of the mandibular canal were seen significantly more often.The radiographic findings mentioned above are not indicators for the development of MRONJ, as they are seen only in patients with manifest osteonecrosis. However, these findings could be important to assess the dimension and potency of a MRONJ.

The dental follicle is involved in tooth eruption and it expresses a great amount of the parathyroid hormone-related protein (PTHrP). PTHrP as an extracellular protein is required for a multitude of different regulations of enchondral bone development and differentiation of bone precursor cells and of the development of craniofacial tissues. The dental follicle contains also precursor cells (DFCs) of the periodontium. Isolated DFCs differentiate into periodontal ligament cells, alveolar osteoblast and cementoblasts. However, the role of PTHrP during the human periodontal development remains elusive. Our study evaluated the influence of PTHrP on the osteogenic differentiation of DFCs under in vitro conditions for the first time. The PTHrP protein was highly secreted after 4days of the induction of the osteogenic differentiation of DFCs with dexamethasone (2160.5pg/ml±345.7SD. in osteogenic differentiation medium vs. 315.7pg/ml±156.2SD. in standard cell culture medium; Student's t Test: p

Objective Human dental follicle cells (DFCs) are genuine precursor cells of cementoblasts and alveolar bone osteoblasts. MicroRNAs (miRNAs) represent a class of non-coding endogenous RNAs that silence gene expression post-transcriptionally. miRNA101 actively regulates the osteogenic differentiation of periodontal ligament cells. Therefore the aim of this study was to investigate the role of miRNA101 during the osteogenic differentiation in DFCs. Materials and methods DFCs were isolated, cultivated and osteogenic differentiated in differentiation medium. Total RNA including miRNAs was isolated and the expression of miRNA101 was examined by real-time RT-PCRs. The expression of miRNA101 was induced by miRNA101-mimic transfection and the gene expression of osteogenic transcription factors was obtained by real-time RT-PCRs. Moreover the induction of the osteogenic differentiation was evaluated by the activity of alkaline phosphatase. Results miRNA101 was regulated in DFCs during the osteogenic differentiation. After miRNA101-mimic transfection the alkaline phosphatase was increased and the gene expression of typical osteogenic transcription factors such as SP7 (osterix) was up-regulated. Conclusion Our results suggest that miRNA101 sustains the osteogenic differentiation of DFCs.

Background Periodontal ligament progenitor cells (PDLPs) and PDL stem cells (PDLSCs) are progenitor and stem cells that were isolated from PDL tissues using the outgrowth and single cell isolation methods respectively. The differences between PDLPs and PDLSCs characteristics could be observed from previous studies. However, these cells were obtained from different patients. This study was the first report to compare the characterization of PDLPs and PDLSCs from the same person. Material and Methods The characterization of PDLPs and PDLSCs includes flow cytometry analysis, cell proliferation assay and the assessment of the colony-forming unit fibroblast. The osteogenic differentiation was evaluated by alkaline phosphatase activity, biomineralization (alizarin red staining) and gene expression of osteogenic markers. The adipogenic differentiation was examined by Oil Red O staining and adipocyte-related gene expression. Results Mesenchymal stem cell marker expression and colony-forming unit fibroblast analysis of PDLPs and PDLSCs were similar. However, PDLSCs grew faster than PDLPs on days 3 and 5 of the cell proliferation assay. Both PDLPs and PDLSCs could differentiate into osteoblast and adipocyte-like cells. However, the mineralization of PDLSCs was stronger than that of PDLPs. Conclusions The characteristics of undifferentiated PDL cells in our study were not significantly impacted by the isolation method. We assumed that both PDLPs and PDLSCs are valuable cell sources for periodontal regeneration. However, PDLSCs have a possible advantage for the regeneration of alveolar bone.

Background Dental stem cells in combination with implant materials may become an alternative to autologous bone transplants. For tissue engineering different types of soft and rigid implant materials are available, but little is known about the viability and the osteogenic differentiation of dental stem cells on these different types of materials. According to previous studies we proposed that rigid bone substitute materials are superior to soft materials for dental tissue engineering. Methods We evaluated the proliferation, the induction of apoptosis and the osteogenic differentiation of dental stem/progenitor cells on a synthetic bone-like material and on an allograft product. The soft materials silicone and polyacrylamide (PA) were used for comparison. Precursor cells from the dental follicle (DFCs) and progenitor cells from the dental apical papilla of retained third molar tooth (dNC-PCs) were applied as dental stem cells in our study. Results Both dental cell types attached and grew on rigid bone substitute materials, but they did not grow on soft materials. Moreover, rigid bone substitute materials only sustained the osteogenic differentiation of dental stem cells, although the allograft product induced apoptosis in both dental cell types. Remarkably, PA, silicone and the synthetic bone substitute material did not induce the apoptosis in dental cells. Conclusions Our work supports the hypothesis that bone substitute materials are suitable for dental stem cell tissue engineering. Furthermore, we also suggest that the induction of apoptosis by bone substitute materials may not impair the proliferation and the differentiation of dental stem cells.

Signaling transduction pathways are established by interactions between growth factors, protein kinases, and transcription factors, and they play a crucial role in tooth development. Precursor cells of the dental follicle (DFCs) are used for in vitro studies about molecular mechanisms during periodontal development. Previous studies have already shown that the growth factor BMP2 and the transcription factor EGR1 are involved in the osteogenic differentiation in DFCs while interactions with protein kinase-based pathways remain elusive. In this current study, we investigated the role of the AKT kinase signaling pathway for the osteogenic differentiation in DFCs. The AKT signaling pathway was activated in DFCs after the induction of the osteogenic differentiation by BMP2. The inhibition of AKT in DFCs repressed the differentiation and the expression of the transcription factor EGR1. Interestingly, EGR1 bound to the phosphorylated form of SMAD1/5 (pSMAD). The binding of pSMAD to EGR1 was increased after the induction with BMP2. Moreover, the overexpression EGR1 increased the osteogenic differentiation of DFCs. Our results suggest that the AKT signaling pathway submits the BMP2-dependent osteogenic differentiation in DFCs via the expression of the transcription factor EGR1.

In hair follicle cells APCDD1 inhibits the canonical WNT/β-Catenin pathway and its inactivation is associated with an autosomal dominant form of hair loss. We analyzed the role of APCDD1 for the osteogenic differentiation in dental follicle cells (DFCs) and identified a new and surprising function. Contrarily to hair follicle cells APCDD1 was crucial for the expression of β-Catenin and for the activity of the TCF/LEF reporter assay in DFCs. In addition, a depletion of APCDD1 inhibits the expression of osteogenic markers such as RUNX2 and decreased the matrix mineralization. However, similar to hair follicle cells in previous studies a control cell culture with oral squamous carcinoma cells showed that APCDD1 inhibits the expression of β-Catenin and of typical target genes of the canonical WNT/β-Catenin pathway. In conclusion, our data disclosed an unusual role of APCDD1 in DFCs during the osteogenic differentiation. APCDD1 sustains the expression and activation of β-Catenin.

Background Alterations of the binding epitopes of bone morphogenetic protein-2 (BMP-2) lead to a modified interaction with the ectodomains of BMP receptors. In the present study the biological effect of a BMP-2 double mutant with antagonistic activity was evaluated in vivo. Methods Equine-derived collagenous carriers were loaded with recombinant human BMP-2 (rhBMP-2) in a well-known dose to provide an osteoinductive stimulus. The study was performed in a split animal design: carriers only coupled with rhBMP-2 (control) were implanted into prepared cavities of lower limb muscle of rats, specimens coupled with rhBMP-2 as well as BMP-2 double mutant were placed into the opposite limb in the same way. After 28 days the carriers were explanted, measured radiographically and characterized histologically. Results As expected, the BMP-2 loaded implants showed a typical heterotopic bone formation. The specimens coupled with both proteins showed a significant decreased bone formation in a dose dependent manner. Conclusion The antagonistic effect of a specific BMP-2 double mutant could be demonstrated in vivo. The dose dependent influence on heterotopic bone formation by preventing rhBMP-2 induced osteoinduction suggests a competitive receptor antagonism.