Quantification of histological changes after calibrated crush of the intraorbital optic nerve in rats.

BACKGROUND: Traumatic optic nerve lesions (TONL) are probable but unpredictable consequence after severe midface or skull base trauma. Based on a previously described rat model, the authors developed a new model in order to simulate optic nerve crush during trauma on the optic canal. METHODS: To achieve a calibrated TONL, a microinjuring device was designed that made it possible to assess the correlation between a defined trauma and the neuronal degeneration in the rat retinal ganglion cell (RGC) layer. This device is based on a small dynamometer mounted onto a conventional micromanipulator. The supraorbital approach was chosen to expose the extracranial optic nerve. RESULTS: In this rat model (n=100, Wistar strain) the parameters of "force" and "time" could be precisely monitored during the experiment. The decrease in the mean number of retinal neurons (N) according to the pressure exerted (2-30 cN x mm(-2)) on the optic nerve was linear for 1, 6, and 15 minutes of injuring time; the decrease in N for varying injuring forces also appears to be nearly linear. CONCLUSION: The results show that this model provides a reliable method for studying quantitatively the anatomical effects of TONL on the RGC layer and the optic nerve itself, and may allow the design of treatment strategies following TONL.

Making bone: implant insertion into tissue-engineered bone for maxillary sinus floor augmentation-a preliminary report.

Autologous, allogenic and alloplastic materials for bony reconstruction in the cranio-maxillofacial area have many drawbacks thus stimulating the on-going search for new (bio-)materials. Whereas cultivated skin and mucosa are already in clinical routine use in head and neck reconstruction, so far there has been no successful clinical application to the best of our knowledge of periosteum-derived, tissue-engineered bone for augmentation of the edentulous posterior maxilla. In a pilot study, augmentation of the posterior maxilla was carried out using a bone matrix derived from mandibular periosteal cells on a polymer fleece. This paper demonstrates fabrication of the matrix, clinical application, and the histological results in two patients. The results suggest that periosteum-derived osteoblasts on a suitable matrix form lamellar bone within 4 months which allows reliable implant insertion.

Angiogenic factors in squamous cell carcinoma of the oral cavity: do they have prognostic relevance?

INTRODUCTION: Angiogenesis is a cascade-like mechanism which is essential for tumour growth and metastasis. Therefore the existence of angiogenic molecules and the density of activated endothelial cells in individual tumours is of major interest. MATERIAL/PATIENTS: In order to evaluate the prognostic significance of these molecules, the distribution pattern was studied of vascular endothelial growth factor (VEGF) and activated endothelial cells in tumours and normal, healthy oral mucosal specimens from 51 consecutive patients with primary oral squamous cell carcinoma. STUDY DESIGN: Frozen sections (vascular endothelial growth factor) and paraffin-embedded sections (endoglin, CD105) were investigated quantitatively by immunohistochemistry. The Pearson correlation, the non-parametric Mann-Whitney test, the non-parametric Wilcoxon rank sum test with multiple comparisons and the non-parametric Kruskal-Wallis test with multiple comparisons were used for statistical analyses. RESULTS: Endoglin expression in tumour tissue was significantly higher than in normal healthy mucosa (P<0.001). T1 tumours showed a significantly lower staining for endoglin compared with T2, T3 and T4 tumours but there was no increase with each T stage. No statistical correlation was found between VEGF expression and endoglin staining. CONCLUSIONS: Even though there is controversy about the prognostic relevance of VEGF, our results suggest that the factor is not suitable to decide prognosis in oral cancer. Endoglin may have a significant role in the development of squamous cell carcinoma of the oral cavity and might be relatively more specific than commonly used endothelial markers.

Tissue-engineered bone for maxillary sinus augmentation.

PURPOSE: Autologous, allogenic, and alloplastic materials for bony reconstruction in the craniomaxillofacial region have specific drawbacks stimulating the ongoing search for new materials. Cultivated skin and mucosa grafts are in clinical routine use in head and neck reconstruction but so far, to the best of our knowledge, no successful clinical application has been described of periosteum-derived tissue-engineered bone for augmentation of the edentulous posterior maxilla. PATIENTS AND METHODS: In a clinical study, augmentation of the posterior maxilla was carried out using a bone matrix derived from mandibular periosteum cells on an Ethisorb (Ethicon, Norderstedt, Germany) fleece. In this report, we show the fabrication of the matrix, clinical application, and results in 27 patients. RESULTS: In 18 patients, an excellent clinical, radiologic, and histologic result could be proved 3 months after augmentation. Histologically, the bone biopsy samples from these patients revealed mineralized trabecular bone with remnants of the biomaterial. An unsuccessful result was found in 8 cases with a more extended augmentation procedure. The clinical inspection 3 months after augmentation showed almost no formation of new bone. In contrast, a replacement resorption with connective tissue was found. This may be the result of failure of the initial supply of the cells embedded within large cell-polymer constructs with sufficient oxygen and nutrients to sustain their survival and proliferation and allow for the integration of the developing tissue within the surrounding tissue. CONCLUSION: Our achieved results suggest that periosteum-derived osteoblasts on a suitable matrix can form lamellar bone within 3 months after transplantation and provide a reliable basis for simultaneous or secondary insertion of dental implants.

Endoglin (CD105) expression in squamous cell carcinoma of the oral cavity.

BACKGROUND: Increasing evidence suggests that endoglin (CD105) is a new powerful marker of neovascularization in solid malignancies. To explain the rating of CD105 expression in 51 squamous cell carcinoma of the oral cavity (SCCOC) we analyzed CD105 expression in tumor tissue and adjacent normal healthy mucosa. METHODS: Mean CD105 density was quantitated by counting the number of CD105-immunostained blood vessels. The results were compared with clinical parameters like T and N stage, grading, tumor localization, and specific characteristics of patients by means of statistical analysis. RESULTS: Endoglin expression in tumor tissue was significantly higher than in normal healthy mucosa (p <.001). With the exception of T3 (n = 2), a higher T stage was correlated with higher endoglin expression. No statistical correlation was found in the analysis of patient's age, gender, and tumor localization. CONCLUSIONS: Endoglin expression is up-regulated in SCCOC compared with normal healthy oral mucosa. Endoglin may have a significant role in the development of SCCOC and might be relatively more specific than commonly used endothelial markers.

Soft tissue and hard tissue engineering in oral and maxillofacial surgery.

Autologous, allogenic and alloplastic materials for bony reconstruction in the cranio-maxillofacial area have specific drawbacks, thus stimulating the ongoing search for new (bio-) materials. Cultivated skin and mucosa grafts are in routine clinical use in head and neck reconstruction but so far, to the best of our knowledge, no successful clinical application has been described of periosteum-derived tissue-engineered bone for augmentation of the edentulous posterior maxilla. In a pilot clinical study, augmentation of the posterior maxilla was carried out using a bone matrix derived from mandibular periosteum cells on an Ethisorb fleece. In this paper we demonstrate the fabrication of the matrix, its clinical application, and histological results in two patients. Our results suggest that periosteum-derived osteoblasts on a suitable matrix can form lamellar bone within four months after transplantation and provide a reliable basis for implant insertion.

Pain, function, and psychologic outcome before, during, and after intraoral tumor resection.

PURPOSE: The aim of the present study was to determine the quality of life of patients with respect to pain before, during, and after ablative intraoral tumor surgery. PATIENTS AND METHODS: The Bochum Questionnaire on Rehabilitation was used to determine 147 items including the morphologic, functional, and psychosocial aspects of rehabilitation. One thousand six hundred fifty-two of 3,500 patients (47.2%) (413 women and 1,239 men) completed the questionnaire. The statistical investigation was carried out using 2-sample (independent) and paired (dependent) t tests. RESULTS: Pain and the functional impairment of chewing and swallowing are the most important parameters before treatment. Immediately after surgical treatment, other variables, such as speech intelligibility and mobility disorders in the head, neck, and shoulder regions, became more apparent. Pain was reported in the shoulder region in 38.5% and in the neck in 34.9% of patients after surgery. The temporomandibular joint was painful in 20.1%, the oral cavity in 18.7%, and the face in 8.2%. Pain was described by 7.4% of patients in other regions of the head. Seventy-five percent of 1527 patients were not taking pain medications during the investigation. The rate of physiotherapy consequently applied after surgery was less than 10%. CONCLUSIONS: Quality of life after ablative intraoral surgery is not greatly affected by pain. Because functional disorders play the dominant role in the impairment of postoperative quality of life, functional reconstruction, using microvascular techniques, and early rehabilitation, including physiotherapy, should be intensified.