In situ assessment of cell proliferation at the invasive front of oral squamous cell carcinomas.

In oral squamous cell carcinoma (OSCC) the histopathological malignancy grading of the invasive front has been found to offer the most reliable prognostic parameter. In the present study we compared such tumour front grading of 100 OSCCs with the in situ growth fraction demonstrated by MIB1 immunostaining following wet autoclave antigen retrieval. MIB1 labelling indices (LIs) were estimated both at the invasive front and in the central parts of OSCCs using two different evaluation methods (overall and random counting) to investigate whether MIB1 LIs represent a possible biological background for the tumour front grading. Statistically highly significantly increased MIB1 LIs were found at the invasive tumour fronts with both counting methods compared with the centres of the same tumours. For LI estimation the classic overall counting procedure proved to be superior. However, in contrast to tumour front grading, MIB1 LIs revealed no correlation with the clinical outcome of the patients concerned. Our results demonstrate that the invasive tumour front of an OSCC is composed of (a) tumour subpopulation(s) with higher proliferative activity. However, determination of the proliferative activity by MIB1 of this tumour area offers no prognostic information.

Prognostic and predictive factors in oral squamous cell cancer: important tools for planning individual therapy?

An escalation in the incidence of oral cancer and its attributable mortality has been observed in recent decades in Europe; oral cancer is expected to become a public health problem in the foreseeable future. However, survival rates have remained at a disappointingly stable level despite significant development in the multimodality treatment of the disease. Additionally, due to the limited prognostic value of conventional prognostic factors and the uniformity of treatment strategies, several patients are still over- or under-treated with significant personal and socio-economical impact. Here we review some promising prognostic and predictive markers that can help the clinician to improve prognostic accuracy and define the most appropriate management for the individual patient with oral cancer.

The invasive front of carcinomas. The most important area for tumour prognosis?

Various molecular events of importance in tumour spread, like the gain and loss of adhesion molecules, secretion of proteolytic enzymes, increased cell proliferation, and the initiation of angiogenesis occur at the tumour-host interface (invasive front). We have hypothesised that molecular or morphological characteristics at the invasive front area of various carcinomas may reflect tumour prognosis better than other parts of the tumour. Consequently, we recently developed a simple malignancy grading system restricted to the deep invasive front area of head and neck squamous cell carcinomas. This grading system proved to have additional prognostic value over the established prognostic factors. All similar studies performed so far have confirmed the high prognostic significance of the invasive front grading in squamous cell carcinomas at different locations. In this review paper we describe the system and the hypothesis on which it has been developed. The reproducibility of the grading is acceptable for further extended studies. Interestingly, observations of similar invasive front alterations in different adenocarcinomas suggest that the invasive tumour front may underlie the biological aggressiveness of carcinomas of glandular origin, as well.

Experimental and finite element study of a human mandible.

Knowledge of the complex biomechanical behaviour of the human mandible is of great importance in various clinical situations. Various approaches can be used to evaluate the physical behaviour of bony specimens. In the course of this study, we investigated mandibular deformation under mechanical loads in an experimental setting and compared them with results derived from finite element analysis (FEA). A special apparatus was developed to apply various forces under defined conditions on an explanted human mandible in vitro. Strains on the surface of the mandible were measured with strain gauges and subsequently a voxel based finite element mesh was generated. Strain patterns of the mandible were calculated in the FE analysis and matched with the experimental data. Comparing the numerical with the experimental data, we found a good correlation between in vitro measurements and mathematical modelling (correlation coefficient = 0.992). Then the FE model was used to evaluate mandibular biomechanics relative to aspects of load transfer, stress distribution and displacements. It is concluded that the applied procedure of generating the FE model is a valid and accurate, non-invasive method to predict different parameters of the complex biomechanical behaviour of human mandibles.

Intraoral sebaceous carcinoma.

Sebaceous carcinoma in the oral cavity is extremely rare, and we have found only four previously reported cases. We describe a fifth case. A wide surgical excision seems to be the correct treatment and estimation of serum carcinoembryonic antigen (CEA) may be a useful tumour marker in the follow-up of intraoral sebaceous carcinomas.

3D evaluation of postoperative swelling using two different cooling methods following orthognathic surgery: a randomised observer blind prospective pilot study.

Orthognathic surgery is associated with side effects including severe postoperative swelling, pain, neurological dysfunction and trismus. The beneficial effects of localised cold treatment on postoperative swelling have been described. Topographical considerations make it difficult to quantify facial swelling. A new and promising method to measure facial swelling seems to be optical face scanning. This study aimed to evaluate the 3D optical scanner to measure soft tissue swelling following orthognathic surgery. Postoperative swelling was treated either with conventional cooling by cold packs or with the water-circulating cooling device Hilotherm Clinic. Secondary endpoints in each group included postoperative pain, neurological complaints, duration of hospital stay, trismus and patient satisfaction. The use of the cooling device by Hilotherm significantly reduced postoperative swelling, pain and hospital duration compared with conventional cooling. Postoperative trismus and satisfaction with the cooling method was significantly higher in the Hilotherm group compared with conventional cooling. No differences were observed concerning neurological score and outcome. In conclusion, 3D optical scanning is a simple and precise method of quantifying face swelling after orthognathic surgery. Hilotherm significantly reduces swelling and duration of hospital stay compared with conventional cooling.

Prognostic and predictive factors in oral cancer: the role of the invasive tumour front.

Most decisions for cancer patients are now made on the basis of prognostic and predictive factors. However, due to the limited prognostic value of conventional tumour/nodal/ metastasis staging and histopathological grading in oral cancer, a large group of patients are still over- or under-treated with significant personal and socioeconomical impact. Recent work indicates that morphological and functional characteristics of the invasive tumour front underlie the biological aggressiveness of oral cancer. Incorporation of these concepts into a prognostic system will better reflect the biologic diversity of oral cancer and more accurately predict clinical outcomes and responses to particular types of adjuvant therapy.

[Immunohistochemical expression of p53 protein in squamous epithelial carcinomas and normal and dysplastic epithelium of the mouth cavity]. / Immunhistochemische Expression des p53-Proteins in Plattenepithelkarzinomen und normalem und dysplastischem Epithel der Mundhöhle.

Routinely formalin-fixed and paraffin-embedded material of 123 squamous cell carcinomas of the floor of the mouth and tongue bordered by non-tumorous mucosa were immunohistochemically investigated for the expression of p53 protein using a panel of four anti-p53 antibodies (CM1, PAb 1801, DO7, PAb240) following wet autoclave antigen retrieval. p53 immunoreactivity was detected in 55-67% of the carcinomas, with the different antibodies used showing a preferential accumulation of the p53-positive tumour cells at the invasive tumour front. In dysplastic and normal epithelium focal or dispersed p53 immunopositivity could be detected in 62-72% and 57-70% of the cases, respectively, regardless of the p53 immunostatus of the carcinomas. No statistically significant correlations between p53 immunophenotype of the tumours and clinico-pathological parameters, or survival of the patients, could be detected statistically. It is concluded that immunohistochemically detectable p53 accumulation in oral cancer might indicate an early stage of carcinogenesis. The immunohistochemical detection of p53 in these tumours, however, is without prognostic significance.

[New aspects in managing mandibular fractures]. / Neue Aspekte in der Versorgung von Unterkieferfrakturen.

BACKGROUND: The aim of osteosynthetic mandibular fracture treatment is a bony bridging of the fracture gap. The gap distance and the fragment movement determine the micromovement in the gap tissue. They are known to be the main factors associated with the clinical outcome of fracture treatment. LITERATURE: The term fracture stability and the underlying mechanically modulated tissue reactions are not well described in the literature. MODEL: In this article we describe experimental results of strain related bone regenerate reactions in vivo. Additionally, in an in vitro model of osteosynthetic fracture treatment micromovements in the sense of bone strains were determined in the gap area. Implications for the osteosynthetic treatment of mandibular fractures are discussed on the basis of our biological and biomechanical results.

[Treatment of frontobasal trauma and polytrauma]. / Behandlung von frontobasalen Traumen und Polytraumen.

BACKGROUND: This paper describes the historical development as well as current concepts of frontobasal fracture treatment by maxillofacial surgeons. TREATMENT CONCEPT: Based on the experience of many years a diagnostic and therapeutic treatment concept was developed, which proved to be adequate in 320 patients with 90 frontobasal fractures in the last five years.

[Possibilities and limitations in evaluating treatment concepts in lip-jaw-palate clefts]. / Möglichkeiten und Limitationen der Evaluation von Behandlungskonzepten bei Lippen-, Kiefer- und Gaumenspalten.

BACKGROUND: Recently, government and medical practitioners have shown considerable interest in the discipline of evidence-based medicine. LITERATURE RESEARCH AND RESULTS: In this study, we investigated the literature concerning treatment concepts in cleft surgery according to criteria of evidence-based medicine. Over the last decade 996 articles on cleft patients were published, 181 of which were studies evaluating the clinical outcome of distinct treatment options. Only 57 studies proved to be classifiable due to a well-described study protocol. One treatment study of cleft patients reached the strength of evidence grade I and strength of recommendation grade A, whereas all other studies had a lower evidence rating. DISCUSSION: The reasons behind these findings seem to be due to problems faced by the specialty of this disease.

[Experimental and clinical study of the stability of an osteosynthesis plate for the atrophic mandible]. / Experimentelle und klinische Studie zur Stabilität einer Osteosyntheseplatte für den atrophen Unterkiefer.

BACKGROUND: The high rate of complications led us to develop a new osteosynthesis plate for the treatment of the fractured atrophied mandible. The development of the new so-called pencil-bone plate is based on the 2.0 mini-plate system manufactured by the Medartis Company. MATERIAL AND METHODS: Finite elements (FE) analysis of the new plate as well as flexibility experiments were undertaken, and 14 patients with 16 fractures of the atrophied mandible were treated with the pencil-bone plate between October 2000 and November 2001. RESULTS: The results clearly show that the pencil-bone plate reacted in both the FE model and the static flexibility experiment in a more stable way than a standard 2.0 plate. In 13 patients, healing proceeded without serious complications; all of the patients showed subjective, nearly unchanged chewing, speaking, and swallowing abilities and no complications occurred when wearing dentures. One patient underwent surgical intervention after a new trauma. CONCLUSION: The clinical outcome of the treated fractures confirmed the experimental results, which proved the high stability of the plate in the area of the fracture site. Due to the mini-plate format the intraoral application of the plate is possible without problems. The intraoral access allows rapid operation followed by a minimum of morbidity. A great advantage of the small dimension system is the unrestricted wearing of dentures after the application.

Natural immunity in recurrent aphthous ulceration.

In the present study we investigated immunophenotypes of peripheral blood lymphocytes, natural killer (NK) cell activity as well as spontaneous migration, ingestion, digestion and antibody-dependent cell-mediated cytotoxicity (ADCC) as effector functions of polymorphonuclear neutrophil granulocytes (PMNs) in 51 patients with acute stage recurrent aphthous ulceration (RAU), during remission, and 47 age-matched healthy individuals. Statistically significant lower B-lymphocyte (CD19) values were found between patients with acute RAU, and those during the remission period (P<0.001), when compared with those of the controls. Total T-lymphocyte (CD3) percentages were lower in patients with RAU, and also during the remission period, when compared with the controls (P<0.001). The percentages of CD4 lymphocytes were significantly lower in patients with RAU in comparison with those of the controls (P<0.001). T-suppressor cells (CD8) were unchanged in all three groups of participants. Significantly lower spontaneous migration and ingestion values were found in patients with acute RAU, when compared with those of the controls, and during the remission period (P<0.001). Digestion values differed insignificantly between the patients with acute RAU and during the remission period. During the remission period, digestion values were significantly elevated when compared with those of the controls (P<0.05). ADCC values were lower during the remission period (P<0.001), when compared with the values during acute RAU and with those of the controls. Significantly depressed NK activity (P<0.001) was observed in patients with acute RAU, when compared with that of the controls. During the remission period, values of NK activity were also lower (P<0.001) when compared with those of the controls. These results suggest either a specific or nonspecific immunological disorder in patients with RAU.

Standardized demonstration of silver-stained nucleolar organizer regions-associated proteins in archival oral squamous cell carcinomas and adjacent non-neoplastic mucosa.

Standardized silver staining and quantitation of nucleolar organizer regions-associated proteins (AgNORs) on routinely formalin-fixed and paraffin-embedded tissues has been recently established. The present study was designed to assess its applicability and reproducibility on archival oral squamous cell carcinoma specimens, with special emphasis on the invasive tumor front. Standardized image cytometric AgNOR analysis was performed at the invasive zone and central parts of the tumors as well as in adjacent dysplastic and normal oral mucosa by applying a modified silver staining on routinely processed archival tissues after wet autoclave pretreatment for protein retrieval. A statistically highly significant and reproducible difference of all of the four standardized AgNOR parameters evaluated (mean AgNOR number, mean AgNOR area, coefficient of variation (CV) of AgNOR number, and CV of AgNOR area per nucleus) was observed between the different areas assessed; there was a statistically significant gradual decrease in the CV of the AgNOR number from the invasive tumor front to central parts of the carcinomas, from dysplastic mucosa to normal epithelium. The observed increase of AgNORs at the invasive front of oral squamous cell carcinomas seems to indicate a subgroup of tumor cells with increased biosynthetic activity and malignant potential. Wet autoclave pretreatment before silver staining of AgNORs is necessary for a reliable visualization of single AgNOR dots. Second-order statistics of AgNOR features, e.g., CV values, offer a potent and highly reproducible parameter for AgNOR quantitation.

Standardized AgNOR analysis of the invasive tumour front in oral squamous cell carcinomas.

In the last decade, silver staining of nucleolar organizer region-associated proteins (AgNORs) has been widely used in tumour pathology both for diagnostic and for prognostic purposes. However, a reliable and reproducible assessment of these proteins on routinely processed archival tissues has only become possible since the recent introduction of standardized staining method and computer-aided morphometric analysis. In the present study, the AgNOR content at the invasive front of 80 squamous cell carcinomas of the floor of the mouth/tongue was investigated using this novel approach, with regard to prognosis and a variety of clinico-pathological parameters. All standardized AgNOR parameters [mean of AgNOR number, mean of AgNOR area, coefficients of variation (CV) of both AgNOR number and area] were statistically significantly associated with the clinical course. The strongest correlation was found for the AgNOR-area univariate analysis (P = 0.006). In multivariate analysis, the mean of AgNOR number could independently predict both overall (P = 0.01) and disease-free survival (P = 0.001). It is concluded that standardized staining and computer-aided analysis of AgNORs are prerequisites for an objective and reproducible AgNOR assessment, which has potential as a supplementary diagnostic and prognostic tool in oral cancer.

[Experimental study on the biomechanical stability of different internal fixators for use in the mandible]. / Experimentelle Untersuchung zur biomechanischen Stabliltät unterscheiedlicher Unterkieferosteosynthesen

BACKGROUND: Comparative studies of different forms of osteosynthesis require that biomechanical and biological criteria be observed. The conditions in experimental studies should be as close as possible to the in vivo situation. The aim of our study was to develop a fracture model that would allow determination of the micromovements in the gap tissue following different forms of internal fixation in fractured human mandibles. METHODS: Micromovements in the gap tissue of five human mandibles treated with different osteosynthetic systems (DCP, EDCP, Miniplates, 3-D systems) following osteotomy or fracture in the region of the corpus and median region were investigated by means of strain gauges. By fitting the human mandibles in plaster according to a method of our own it was possible to create fractures at predictable and comparable localizations. RESULTS: Our investigations show that the micromovements in the gap tissue of osteotomied and fractured mandibles are different and not dependent on the form of osteosynthesis applied. Physiological micromovements in the gap tissue were found under strain for all osteosynthetic systems used in fractured and congruently reset mandibles. DISCUSSION: Our fracture and osteosynthesis model allows the quantitative determination of micromovements in the gap tissue and shows the importance of ideal realignment, which has a decisive influence on micromovements in the gap tissue.

Immunohistochemical detection of p53 protein in archival tissues from squamous cell carcinomas of the oral cavity using wet autoclave antigen retrieval.

Using a panel of four anti-p53 antibodies (CM-1, PAb 1801, DO7, and PAb 240), the phenotypic characteristics of p53 protein overexpression were investigated in 22 routinely formalin-fixed and paraffin-embedded squamous cell carcinomas of the oral cavity. Conventional immunohistochemical staining without pretreatment for antigen retrieval was compared with wet autoclaving (AC) and microwave irradiation (MW). Applying AC or MW, p53 immunoreactivity was demonstrated in 9/22 cases with PAb 1801 and DO7 antibodies and in 8/22 cases with the CM-1 antibody. Immunostaining with the PAb 240 antibody after AC pretreatment showed p53 positivity in 8/22 tumours, but in only 4/22 following MW pretreatment. Immunostaining without pretreatment revealed only 2/22 p53-positive cases using CM-1, 4/22 with PAb 1801, and 3/22 with DO7. Without pretreatment, the PAb 240 antibody was consistently negative. Wet autoclave pretreatment was significantly superior for all the antibodies used in this study when compared with conventional immunohistochemistry without pretreatment (P < 0.005). It yielded better results than microwave irradiation for antigen unmasking in relation to the PAB 240 antibody (P < 0.05). Wet autoclave pretreatment is recommended as a reliable and highly reproducible method for p53 antigen retrieval in routinely processed archival material. The advantages over microwave pretreatment include simple handling and good preservation of morphology.

[Gigantic proliferating trichilemmal cyst of the scalp with central carcinoma and lymph node metastasis]. / Gigantische proliferierende Trichilemmalzyste der Kopfhaut mit zentralem Karzinom und Lymphknotenmetastasierung.

We report the case of a 77 year old woman with a giant proliferating trichilemmal cyst of the scalp and a central squamous-cell carcinoma. Six months after radical tumor-excision and dissection of the locoregionary lymph nodes the patient developed retroclavicular lymph node metastases. The tumor develops from cells of the hair matrix and tends to recur after excision; in rare cases malignant transformation may occur. We suggest radical excision and complete histological examination of the tumor. In cases of malignancy, lymph node-dissection is sometimes necessary. In these cases close postoperative follow-up of the patient is mandatory.

Immunophenotypic analysis of normal mucosa and squamous cell carcinoma of the oral cavity.

Detection of tumor-associated alterations in peritumoral normal mucosa may give insight into the molecular pathogenesis of oral cancer. In the present study, 100 archival oral squamous cell carcinomaswith adjacent nontumorous mucosa were immunohistochemically investigated with antibodies against p53, Mdm2, Bcl-2, WAF1, MIB1, epidermal growth factor receptor (EGF-R), and various CD44 isoforms. Additionally a standardized argyrophilic nucleolar organizer region (AgNOR)-associated proteins analysis was performed. No correlation was found between p53, Mdm2, Bcl-2, and WAF1 immunophenotypes of the respective tumors and adjacent mucosa. The proliferation-associated markers MIB1 and AgNORs showed a statistically significant sequential increase from normal to dysplastic mucosa to invasive carcinoma. Investigation of various CD44 adhesion molecules revealed a highly variable expression pattern in overt carcinomas with a significantly decreased expression of CD44 v4 and v9 variants and unaltered strong expression of v5 and v6 isoforms compared with normal oral epithelium. We conclude that proliferation markers (MIB1 and AgNORs), as well as selected CD44 isoforms, represent useful markers for the assessment of precancerous lesions. They may be utilized for screening patients at high risk for the development of oral cancer.

Deformation characteristics of the human mandible in low impact experiments.

A total of 11 human mandibles were subjected to physical impacts under standardised conditions. Two impact sites and directions were tested and the impact load was varied in four steps. Two occlusional strengths were applied and the influence of simulated soft tissue covering was recorded. The deformation of the bones was measured using strain gauge strips located at eight defined sites. In a series of frontal to occipital impacts the frontal areas and the collum showed the largest length changes. Increasing impact intensities led to a proportional increase of the length changes. An increase of the occlusional strength was either protective (at the collum) or it increased the deformation (frontal area). The soft tissue covering was only partly protective. Lateral impact was characterised by a compression on the side of the impact and stretching on the other side only. The intensity and speed of deformation increased with increasing distance from the site of impact. A fixed occlusion caused an increase of compression at the site of impact and an increasing stretching in the frontal part of the bone and at the opposite collum.