Search

Abstract Background Cleft surgery in infants includes special risks due to the kind of the malformation. These risks can be attributed in part to the age and the weight of the patient. Whereas a lot of studies investigated the long-term facial outcome of cleft surgery depending on the age at operation, less is known about the complications arising during a cleft surgery in early infancy. Methods We investigated the incidence and severity of perioperative complications in 174 infants undergoing primary cleft surgery. The severity and the complications were recorded during the intraoperative and the early postoperative period according to the classification by Cohen. Results Our study revealed that minor complications occurred in 50 patients. Severe complications were observed during 13 operations. There was no fatal complication in the perioperative period. The risk of complications was found to be directly correlated to the body weight at the time of the surgery. Most of the problems appeared intraoperatively, but they were also followed by complications immediately after the extubation. Conclusion In conclusion, cleft surgery in infancy is accompanied by frequent and sometimes severe perioperative complications that may be attributed to this special surgical field.

Abstract Background Intermediary filaments are involved in cell motility and cancer progression. In a variety of organs, the expression of distinct intermediary filaments are associated with patient prognosis. In this study, we seeked to define the prognostic potential of cytokeratin and vimentin expression patterns in squamous cell carcinomas (SCC's) of the oral cavity. Methods 308 patients with histologically proven and surgically treated squamous cell carcinomas of the oral cavity were investigated for the immunohistochemical expression of a variety of intermediary filaments including high- and low-molecular weight cytokeratins (Ck's), such as Ck 5/6, Ck 8/18, Ck 1, CK 10, Ck 14, Ck 19 and vimentin, using the tissue microarray technique. Correlations between clinical features and the expression of Cytokeratins and vimentin were evaluated statistically by Kaplan-Meier curves and multivariate Cox regression analysis. Results The expression of Ck 8/18 and Ck 19 were overall significantly correlated with a poor clinical prognosis (Ck 8/18 p = 0.04; Ck19 p < 0.01). These findings could also be reproduced for Ck 8/18 in primary nodal-negative SCC's and held true in multivariate-analysis. No significant correlation with patient prognosis could be found for the expression of the other cytokeratins and for vimentin. Conclusion The expression of Ck 8/18 in SCC's of the oral cavity is an independent prognostic marker and indicates a decreased overall and progression free survival. These results provide an extended knowledge about the role of intermediary filament expression patterns in SCC's.

Abstract Background Besides the color of the teeth the color of the alveolar gingiva plays a crucial role in esthetic rehabilitation in dento-alveolar treatment. Whereas nowadays the color of the teeth can be determined exactly and individually, the specific influence of the red color of the gingiva on treatment has not been assessed yet. The aim of this study was to evaluate the vascularization as the basis for gingival esthetics. Methods Standardized photographs of defined areas of the alveolar gingiva in operated and non-operated patients were taken and assigned to groups with same characteristics after color comparisons. In addition, histologic and immunohistologic analyses of gingival specimens were performed for qualitative and quantitative assessment of vessels and vascularization. Finally, colors and number of vessels were correlated. Results Our results demonstrated three different constellations of colors of the alveolar gingiva in healthy patients. The operated patients could not be grouped because of disparate depiction. There was a clear correlation between color and vessel number in the alveolar gingiva. Conclusion Our investigations revealed the connections between vascularization and gingival color. Recommendations for specific change or even selection of colors based on the results cannot be given, but the importance of vascularly based incision lines was demonstrated.

Abstract Background Hypoxia-inducible factor 1 (HIF-1) is a transcription factor, which plays a central role in biologic processes under hypoxic conditions, especially concerning tumour angiogenesis. HIF-1α is the relevant, oxygen-dependent subunit and its overexpression has been associated with a poor prognosis in a variety of malignant tumours. Therefore, HIF-1α expression in early stage oral carcinomas was evaluated in relation to established clinico-pathological features in order to determine its value as a prognostic marker. Methods 85 patients with histologically proven surgically treated T1/2 squamous cell carcinoma (SCC) of the oral floor were eligible for the study. Tumor specimens were investigated by means of tissue micro arrays (TMAs) and immunohistochemistry for the expression of HIF-1. Correlations between clinical features and the expression of HIF-1 were evaluated by Kaplan-Meier curves, log-rank tests and multivariate Cox regression analysis. Results HIF-1α was frequently overexpressed in a probably non-hypoxia related fashion. The expression of HIF-1α was related with a significantly improved 5-year survival rate (p < 0.01) and a significantly increased disease free period (p = 0.01) independent from nodal status and tumour size. In primary node negative T1/T2 SCC of the oral floor, absence of HIF-1α expression specified a subgroup of high-risk patients (p < 0.05). Conclusion HIF-1α overexpression is an indicator of favourable prognosis in T1 and T2 SCC of the oral floor. Node negative patients lacking HIF-1α expression may therefore be considered for adjuvant radiotherapy.

Background: To cope with the COVID-19 outbreak in Germany, the government imposed a lockdown, which led to restrictions and lifestyle changes for the population., Purpose: This study aimed to evaluate the impact of the lockdown on activities causing trauma and the consultation in emergency rooms., Material and Methods: All consecutive trauma patients consulting the Emergency Department of the Marienhospital Stuttgart (MHS), Germany, during the 6 weeks preceding the lockdown, during and after the lockdown were included. The time and type of consultation, treatment received, Manchester triage score, type of trauma, the anatomical region of the injury as well as demographic data were reported and compared., Results: The study included 551 cases during lockdown, 943 cases before and 783 cases after the lockdown. We observed a reduced caseload during the lockdown of 41.6% compared to before and of 29.7% compared to after (p < 0.001). Patients were on average older in the observation group than in both control groups (before : 51.5 years, lockdown: 56.1 years, after: 51.6 years) (p < 0.001). Injuries to the head and neck were constant (25.0%, 25.4%, 25.5%). We noticed lower limb injuries decreasing (26.1%, 22.3%, 22.7%) and upper limb injuries increasing (25.5%, 31.8%, 30.1%). A decrease in sports injuries (11.1%, 5.1%, 9.1%) and work accidents (16.1%, 10.7%, 12.8%) resulted in more domestic accidents (30.4%, 52.5%, 31.8%). Self-referral decreased (67.7%, 53.2%, 60.3%) while referral via paramedics increased (28.3%, 38.7%, 35.6). Blunt trauma was the most common cause of injury (55.6%, 61.0%, 55.3%). Indications for surgery were higher (16.8%, 21.6%, 14.0%)., Conclusion: The lockdown and restrictions in personal life and daily routine had an impact on the frequency, etiology and management of trauma patients in Stuttgart., (© 2021. Springer Medizin Verlag GmbH, ein Teil von Springer Nature.)

Purpose: Thermal inhalation injury is a common, life-threatening problem in burned patients. Whether or not this single event of damage to the oral integrity causes long term health problems is yet to be examined., Material and Methods: All consecutive burn patients between 2014 and 2017 of Marienhospital Stuttgart (MHS), Germany, with at least 10% of burned skin surface were included and compared. The Periodontal Screening Index as well as Vitamin D levels were examined. Vitamin D has been suspected to contribute to the genesis of periodontitis. Risk factors and subjective oral life quality were prompted., Results: We included a total of 32 patients, 15 of which had an inhalation injury in their medical history. Risk factors were examined via Renatus' questionnaire. While risk factors were equally distributed in both groups we saw a remarkable difference in periodontal integrity, with the Periodontal Screening Index (PSI) per sextant differing drastically (with inhalation injury: 2.40, without inhalation injury: 1.10, p < 0.001). Patients with an inhalation injury had a mean of 5.2 out of 6 possible sextants with a pathologic PSI (with the median being 6/6), while patients without an inhalation injury had a mean of 1.83 out of 6 (median: 1/6), p < 0.001. The oral health impact profile showed a difference as well, albeit without statistical significance (with inhalation injury: median = 11, without: median = 3.5, p = 0.414). A correlation between Serum Vitamin D levels and periodontal integrity could not be seen in this group., Conclusion: Inhalation injury is a possible cause for periodontitis and hence impacts the quality of life of burned patients., (Copyright © 2021 Elsevier Ltd and ISBI. All rights reserved.)

Background: Squamous cell carcinomas (SCCs) are the most prevalent malignant tumours within the head and neck. Evidence exists that distinct genes are differentially regulated in SCCs of the oral cavity compared to other head and neck regions. Given this background, the aim of this study was to investigate whether such tumour site-specific gene expression can also be observed in different localizations within the oral cavity., Methods: Using tissue microarrays (TMAs), we investigated 76 SCCs of the floor of the mouth, 49 SCCs of the tongue and 68 SCCs of other anatomic regions within the oral cavity. The expression of 17 genes involved in cell cycle and growth control (p16, p21, p27, p53, cyclin D1, EGFR, c-kit, bcl-6), cell adhesion (alpha-, beta-, and gamma-catenin), and apoptosis/stress response genes (Hif-1-alpha, Glut 1, CA IX, caspase, hsp70, XIAP) were investigated by means of immunohistochemistry. The data were subjected to chi 2 , interdependency and Kaplan-Meier analysis., Results: Our study suggests a remote difference in the site-specific gene expression patterns of oral cancer. X-linked inhibitor of apoptosis (XIAP) showed a significantly higher expression (p <0.05) in SCCs of the floor of the mouth compared to SCCs of the tongue and other locations within the oral cavity. The increased XIAP expression was further associated with significantly decreased overall survival in all cases of SCCs of the oral cavity (p <0.05). Expression levels of p53, CA IX, beta-catenin, Hif-1-alpha, and c-kit were also observed to be inversely related between SCCs of the floor of the mouth and those of the tongue respectively, although these differences did not reach statistical significance. Overall and event-free survival did not differ in patients with T1/T2/N0 SCCs according to tumour localization., Conclusion: In summary, the protein expression patterns of SCCs of the oral cavity suggest the existence of a molecular and morphological spectrum of SCCs in the oral cavity. In particular the expression pattern of XIAP indicates distinct gene expression patterns between carcinomas of the floor of the mouth and oral tongue cancer. Further studies are needed to identify possible tumour site-specific factors that influence patient prognosis and management.

Squamous cell carcinoma (SCC) of the oral cavity is a morphological heterogeneous disease. Various cytokeratin (CK) expression patterns with different prognostic values have been described, but little is known concerning the underlying biological cell mechanisms. Therefore, the present study investigated 193 cases of oral SCCs using immunohistochemistry for α/β/γ-catenin, glucose transporter 1, caspase-3, X-linked inhibitor of apoptosis protein, hypoxia inducible factor-1α, carbonic anhydrase 9, heat shock protein (hsp) 70, mast/stem cell growth factor receptor, p21, p27, p16, p53, B-cell lymphoma 6, epidermal growth factor receptor, cyclin D1 and CK1, 5/6, 8/18, 10, 14 and 19. Expression patterns were analyzed with biomathematical permutation analysis. The present results revealed a significant association between the expression of low-molecular weight CK8/18 and 19 and a high-tumor grade, β and γ-catenin expression, deregulated cell cycle proteins and a predominant localization of the tumor on the floor of the mouth. By contrast, expression of high-molecular weight CK1, 5/6, 10 and 14 was significantly associated with the expression of p21 and hsp70. In conclusion, the current study presents evidence for the existence of two parallel pathogenetic pathways in oral SCCs, characterized by the expression of low- and high-molecular weight CKs. Additional studies are required to demonstrate the extent that these results may be used to improve therapeutic regimens.

Purpose: To explore the presence of differentially expressed proteins in OSCC for discrimination of tumour and normal mucosa to establish potential biomarkers and therapeutic targets., Experimental Design: Paired protein samples of 12 individuals (tongue cancer and non-cancerous mucosa) were separated by two-dimensional polyacrylamid gel electrophoresis. The protein patterns were compared pairwise and protein spots were quantified. We identified about 70 regulated proteins which we subsequently identified by MALDI-TOF mass spectrometry., Results: Cancerous and non-cancerous tissues could be most precisely distinguished by a panel of proteins. They include the heat shock proteins (hsp)70 and 90, keratins (ck) 5, 6, 13, 14, 16, 17 and 19, beta globin, alpha-2-actin, stratifin, tropomyosin, calreticulin precursor, beta-2-tubulin, galectin7, thioredoxin, involucrin, adenylyl-cyclase-associated protein, disulfide isomerase-associated protein, thyrosine 3-monooxygenase, MYL2 and the s100 calcium binding protein. MYL3, cardiac muscle alpha actin 1 proprotein and transferrin were under-represented in OSCC. Six biomarkers, ck6 und ck13, beta globin, alpha-2-actin, hsp70 and hsp90 discriminated best between cancerous and non-cancerous oral tissues. All over-expressed proteins were analysed by STRING-analysis to highlight experimentally determined and computationally predicted interactions between the proteins. Especially involucrin, hsp70, calreticulin precursor, stratifin, (ck) 5, 6, 14, 19, tyrosine 3-monooxygenase, beta-2-tubulin and disulfide isomerase associated protein showed multiple relations., Conclusion: We identified six proteins which are differentially expressed in most OSCC compared to healthy tissues. Of those, by string analysis, multiple interaction partners are assumed for hsp70. This protein is supposed to be the most promising candidate as marker molecule and target for OSCC therapy., (© 2010 John Wiley & Sons A/S.)

Intermediate filaments are involved in cell migration and intracellular signal transduction pathways. In a variety of organs, the expression of distinct intermediary filaments are further associated with distinct steps of malignant transformation. In this study, we seeked to define the cytokeratin (Ck) expression pattern in oral leukoplakia and oral squamous cell carcinoma (OSCC). One hundred and ninety-two patients with OSCC, 117 patients with oral leukoplakia without dysplasia (OL) and 23 with oral leukoplakia with dysplasia (squamous intraepithelial neoplasia) (OLD) of the oral cavity were investigated for the immunohistochemical expression of Ck 5-6, Ck 8/18, Ck 1 Ck 10, Ck 14, Ck 19 using the tissue microarray technique. Correlations between clinical features and the expression of cytokeratins were evaluated statistically by chi2 tests. The expression of Ck 8/18, Ck 19 and Ck 1 was seen in 3.1% (Ck 8/18), 12.5% (Ck 19), 75.4% (Ck 1) of all leukoplakias, 1.0% (Ck 8/18), 9.4% (Ck 19), 76.8% (Ck 1) in OL, 13.0% (Ck 8/18), 27.3% (Ck 19), 68.4% (Ck 1) in OLD and was significantly associated with the degree of dysplasia (Ck 8/18 p<0.01; Ck 19 p<0.01; Ck 1 p<0.01) and the acquisition of invasive growth properties. The highest frequencies were observed in invasive squamous cell carcinomas. The expression of Ck 8/18 and Ck 19 in transformed oral lesions can be regarded as an early feature in the pathogenesis of invasive OSCC. However, the aberrant expression of Ck 8/18 and Ck 19 in an even higher frequency in invasive carcinomas characterizes the expression of typical glandular cytokeratins as a general progression marker in squamous cell carcinomas. These results can be interpreted as first hints that oral leukoplakias with an expression of Ck 8/18 or 19 independent of dysplasia, should be resected totally since they might indicate an increased progression potential.

Background: Cleft surgery in infants includes special risks due to the kind of the malformation. These risks can be attributed in part to the age and the weight of the patient. Whereas a lot of studies investigated the long-term facial outcome of cleft surgery depending on the age at operation, less is known about the complications arising during a cleft surgery in early infancy., Methods: We investigated the incidence and severity of perioperative complications in 174 infants undergoing primary cleft surgery. The severity and the complications were recorded during the intraoperative and the early postoperative period according to the classification by Cohen., Results: Our study revealed that minor complications occurred in 50 patients. Severe complications were observed during 13 operations. There was no fatal complication in the perioperative period. The risk of complications was found to be directly correlated to the body weight at the time of the surgery. Most of the problems appeared intraoperatively, but they were also followed by complications immediately after the extubation., Conclusion: In conclusion, cleft surgery in infancy is accompanied by frequent and sometimes severe perioperative complications that may be attributed to this special surgical field.

Cyclin-dependent kinases (CDKs) and cyclin-dependent kinase inhibitors (CDKIs), such as p21 and p27, exert a direct control on the cell cycle. p21 and p27 are negative regulators of cyclin-dependent kinases and in this function they are negative check-point regulators of the cell cycle. We therefore aimed to evaluate p21 and p27 expression in oral squamous cell carcinomas (OSSC) to determine the value as a prognostic marker. One hundred and ninety-two patients with histologically proven, surgically treated squamous cell carcinoma of the oral cavity were eligible for the study and investigated for the expression of p21 and p27 by means of tissue microarrays (TMAs). Immunohistochemical screening under identical condition were carried out with antibodies against p21 and p27. Correlations between clinical features and the expression of the respective antibodies were evaluated statistically by Kaplan-Meier curves, log-rank and chi(2) tests. The expression of p21 correlated significantly with an increased prognosis in the log-rang test (p=0.01). No significant correlation was found between the expression of p27 and the overall survival rate. In multivariate Cox analysis, p27 was indicated as independent predictor of survival prognosis in the subgroup of nodal positive carcinomas, p27 positive tumours showed a significantly better survival prognosis (p=0.03). p21 and p27 in carcinoma of oral cavity seem to be predictive parameter in regulation and prognosis of squamous cell carcinomas. A p21 negative subgroup of OSCC may benefit from additional radio or radiochemotherapy.

Background: Intermediary filaments are involved in cell motility and cancer progression. In a variety of organs, the expression of distinct intermediary filaments are associated with patient prognosis. In this study, we seeked to define the prognostic potential of cytokeratin and vimentin expression patterns in squamous cell carcinomas (SCC's) of the oral cavity., Methods: 308 patients with histologically proven and surgically treated squamous cell carcinomas of the oral cavity were investigated for the immunohistochemical expression of a variety of intermediary filaments including high- and low-molecular weight cytokeratins (Ck's), such as Ck 5/6, Ck 8/18, Ck 1, CK 10, Ck 14, Ck 19 and vimentin, using the tissue microarray technique. Correlations between clinical features and the expression of Cytokeratins and vimentin were evaluated statistically by Kaplan-Meier curves and multivariate Cox regression analysis., Results: The expression of Ck 8/18 and Ck 19 were overall significantly correlated with a poor clinical prognosis (Ck 8/18 p = 0.04; Ck19 p < 0.01). These findings could also be reproduced for Ck 8/18 in primary nodal-negative SCC's and held true in multivariate-analysis. No significant correlation with patient prognosis could be found for the expression of the other cytokeratins and for vimentin., Conclusion: The expression of Ck 8/18 in SCC's of the oral cavity is an independent prognostic marker and indicates a decreased overall and progression free survival. These results provide an extended knowledge about the role of intermediary filament expression patterns in SCC's.

Background: Besides the color of the teeth the color of the alveolar gingiva plays a crucial role in esthetic rehabilitation in dento-alveolar treatment. Whereas nowadays the color of the teeth can be determined exactly and individually, the specific influence of the red color of the gingiva on treatment has not been assessed yet. The aim of this study was to evaluate the vascularization as the basis for gingival esthetics., Methods: Standardized photographs of defined areas of the alveolar gingiva in operated and non-operated patients were taken and assigned to groups with same characteristics after color comparisons. In addition, histologic and immunohistologic analyses of gingival specimens were performed for qualitative and quantitative assessment of vessels and vascularization. Finally, colors and number of vessels were correlated., Results: Our results demonstrated three different constellations of colors of the alveolar gingiva in healthy patients. The operated patients could not be grouped because of disparate depiction. There was a clear correlation between color and vessel number in the alveolar gingiva., Conclusion: Our investigations revealed the connections between vascularization and gingival color. Recommendations for specific change or even selection of colors based on the results cannot be given, but the importance of vascularly based incision lines was demonstrated.

Background: Hypoxia-inducible factor 1 (HIF-1) is a transcription factor, which plays a central role in biologic processes under hypoxic conditions, especially concerning tumour angiogenesis. HIF-1alpha is the relevant, oxygen-dependent subunit and its overexpression has been associated with a poor prognosis in a variety of malignant tumours. Therefore, HIF-1alpha expression in early stage oral carcinomas was evaluated in relation to established clinico-pathological features in order to determine its value as a prognostic marker., Methods: 85 patients with histologically proven surgically treated T1/2 squamous cell carcinoma (SCC) of the oral floor were eligible for the study. Tumor specimens were investigated by means of tissue micro arrays (TMAs) and immunohistochemistry for the expression of HIF-1. Correlations between clinical features and the expression of HIF-1 were evaluated by Kaplan-Meier curves, log-rank tests and multivariate Cox regression analysis., Results: HIF-1alpha was frequently overexpressed in a probably non-hypoxia related fashion. The expression of HIF-1alpha was related with a significantly improved 5-year survival rate (p < 0.01) and a significantly increased disease free period (p = 0.01) independent from nodal status and tumour size. In primary node negative T1/T2 SCC of the oral floor, absence of HIF-1alpha expression specified a subgroup of high-risk patients (p < 0.05)., Conclusion: HIF-1alpha overexpression is an indicator of favourable prognosis in T1 and T2 SCC of the oral floor. Node negative patients lacking HIF-1alpha expression may therefore be considered for adjuvant radiotherapy.

Aim: There is an ongoing controversy about indications for prophylactic removal of third molars. The purpose of this retrospective study was to clarify the risk of preservation of lower third molars., Material and Method: In a 5-year period, 316 patients were registered who had received in-patient treatment for deep abscess formation, cyst formation or mandibular angle fracture in relation to lower third molars. A radiological analysis (panoramic radiographs) was performed to determine whether major pathological changes associated with lower wisdom teeth are related to their position. Third molar positions were studied in this in-patient group and in an out-patient group. The latter consisted of 300 consecutive patients with prophylactically removed impacted third molars without any pathology. The relationship between the positions and the different pathological changes associated with impacted lower wisdom teeth was analysed statistically using a new 'position score'., Results: The study revealed that the highest 'position scores' corresponding to a leading aberrant position correlated significantly with cyst formation. Lower scores corresponding to moderately aberrant or slightly irregular position were found with angle fractures, abscess formation, and in the control group as a whole., Conclusion: This study indicates that prophylactic third molar surgery for teeth with high and strongly elevated 'position scores' is appropriate in order to prevent cyst formation or mandibular angle fractures in a population at risk for facial trauma. In addition to other factors, 'position score' data could be useful for development of a model for predicting severe complications related to (removal of) impacted lower wisdom teeth.

Besides its immunoregulatory effects, interleukin-4 (IL-4) has growth inhibitory activity on cells from human solid tumors, and IL-4 receptors are present on tumor cells including cells from head and neck squamous cell carcinomas. We have conducted a phase I/II trial in patients with oral squamous cell carcinomas of T(4), N(+) (1 exception) stage to assess safety and therapeutic activity of recombinant human (rh) IL-4 applying the drug intratumorally 3 times a week with dose escalation for a duration of 4 weeks. A total of 7 patients entered the study using doses of 1, 3, and 5 microg/kg. There was no reduction of tumor size with 1 patient showing clear progression of the tumor after 4 weeks of treatment. This, and the observation of limiting toxicity occurring as local pain at the injection site, led to study termination. Therefore, rhIL-4 cannot be recommended as an antitumor drug in this disease using monotherapy with the schedules applied in this trial.

The osseointegration process of dental implants depends on the tissue reaction at the tissue-implant interface. Osteoblasts are the main cells responsible for the regulation of osteoinduction. The manner and kinetics of the tissue reaction crucially depend on the interaction between osteoblasts and the morphology of the implant surface. The aim of this study was to investigate osteoblast behaviour on different implant surfaces (smooth, microgrooved, SLA) under standardized conditions. For this in vitro investigation we used primary bovine osteoblasts. Attachment kinetics, proliferation rate and synthesis of bone-associated proteins were used as parameters for cell reaction. The results demonstrate that both attachment and adhesion strength of the primary cell surface interaction was higher on the microgrooved surfaces than on SLA surfaces. The proliferation rate of cells and the synthesis of bone-specific proteins were higher on microgrooved surfaces in contrast to SLA surfaces. Ultrastructural analysis revealed phenotypic osteoblast-like cells on smooth and microgrooved surfaces, whereas cells on SLA surfaces showed a more fibroblastic appearance. This study demonstrates that the morphology of the implant surface determined the subsequent osteoblast reaction. An optimal cell reaction was found at surfaces which are smooth in the microenvironment of osteoblasts.

Purpose: The treatment of patients with early or immediately loaded dental implants has renewed interest in the behavior of osteoblasts at the implant surface under load. A newly designed dental implant indicated for immediate loading was tested in vivo for early stages of osteoblast behavior at the implant surface., Materials and Methods: Thirty-two implants were placed in the mandibles of 8 minipigs. Half of the implants (n = 16) were immediately loaded under occlusal contacts, and implants placed in non-occlusal relations served as a control., Results: All implants, except 1 that showed signs of tissue infection, healed uneventfully and were stable throughout the experimental period. Ultrastructural analysis of mandibular specimens revealed an intimate attachment of osteoblasts to the material surface beginning as early as day 1. Application of either occlusal or non-occlusal load did not alter the phenotypic morphology of the attached osteoblasts. Transmission electron microscopy and x-ray diffraction analysis demonstrated a direct contact of bone-like minerals over the whole implant surface with no signs of crestal hard tissue alteration. Electron diffraction analysis showed a slight release of titanium from the implant side., Discussion: These results indicate that immediate loading of specially designed dental implants can be performed without disruption of the titanium/bone interface or disturbance of osteoblast physiology in the early loading phase., Conclusion: Immediate loading protocols can be performed without disturbance of normal bone biology.

The amplification and overexpression of the erbB-2 oncogene and its involvement in tumorigenesis makes this receptor an appropriate target for specific agents directed towards tumor cells. The purpose of this study was to evaluate the in vitro effect of the bacterially produced recombinant immunotoxin scFv(FRP5)-ETA on the protein synthesis and adenosine triphosphate (ATP) reduction in oral squamous cell carcinoma (OSCC) cells. This agent recognizes the erbB-2 receptor and inhibits protein synthesis in receptor-overexpressing cells. OSCC cells were selected for this study, and amplification and expression levels of the erbB-2 receptor were determined. Cell suspensions were cultured for 6 d with various concentrations of scFv(FRP5)-ETA (1-1000 ng/ml). A431 and MDA-MB468 cell lines were used as controls. Chemosensibility of tumor cells was measured by [3H]leucine incorporation assay and by an ATP luminescence assay. In OSCC cells with amplification and overexpression of erbB-2 inhibition, up to 92% of protein synthesis and 90% of ATP reduction was observed when cells were exposed to 1,000 ng/ml immunotoxin. In OSCC cells showing a deletion of erbB-2 and in erbB-2-negative MDA-MB468 cells, protein synthesis was inhibited by 22% and 8%, respectively. These results indicate that the effectiveness of a recombinant immunotoxin targeting erbB-2 receptors in OSCC cells depends on the level of erbB-2 amplification and expression, that it is highly specific for tumor cells expressing these receptors, and that a dose-dependency can be observed.