Möglichkeiten und Chancen der Gewebechiptechnologie bei Kopf-Hals-Tumoren

Oral squamous cell carcinomas (OSCC) are malignant tumors with a poor prognosis and low long-term survival rates, even when using modern adjuvant and neoadjuvant therapy forms in addition to surgery. For the clinical estimation of each tumor, it is necessary to define stage-dependent molecular and/or cellular parameters as it is known that OSCC develop along a multistep pathway including the loss of tumor suppressor genes and the amplification of oncogenes which result in changes in protein expression. In order to establish a reliable pattern of molecular and cellular biomarkers, a large number of tumor specimens from different stages of the disease need to be analysed. In this study, biopsies of a collective of 293 OSCC in different stages were screened with the novel technique of tissue chip microarrays by fluorescence in situ hybridization (FISH) and immunohistochemistry (IHC). FISH-analysis was performed on the oncogene cyclin D1 and IHC-analysis on the proteins cyclin D1, p53, p16, cdk4, bcl2, mdm2 and rb. Tissue chip technology was shown to facilitate rapid screening for molecular and cellular alterations in different stages of OSCC and revealed reliable and reproducible results that may allow the definition of a multistep pathway model for tumor progression in OSCC.     

Die FAMI-Schraube für die temporäre intermaxillare Fixation

The aim of this study was to demonstrate the suitability of the FAMI screw (fixation and adaptation in mandibular injuries) for maxillomandibular fixation in the maxillofacial area in orthognathic and trauma surgery. This FAMI screw was used in 28 patients for maxillomandibular fixation with wiring or elastics. The screw is inserted into the labial or buccal surfaces of the alveolar process without predrilling. Adequate intermaxillary fixation with balanced occlusion was created intraoperatively in all patients. In comparison with conventional splinting methods, this technique was far less time-consuming. The use of the FAMI screw has the advantage of being quick and simple, particularly if only a brief period of maxillomandibular immobilization is planned. Furthermore, the risk to the surgeon of sustaining a puncture injury from wire ligatures is distinctly reduced. Screws can be removed without local anesthesia. The above-mentioned method is minimally traumatic, effective, timesaving, and hence inexpensive. It can be used for maxillomandibular immobilization in dentate as well as in edentulous patients.     

Magnetic Field Interactions of Orthodontic Wires during Magnetic Resonance Imaging (MRI) at 1.5 Tesla

AbstractBackground: Orthodontic appliances pose a potential risk during magnetic resonance imaging (MRI) due to forces on metallic objects within the static magnetic field of MRI systems. The aim of the present investigation was to measure forces on orthodontic wires caused by the static magnetic field of a 1.5-Tesla MRI system, and to assess the safety hazards associated with these forces.Materials and Methods: Thirty-two different orthodontic wires (21 arch wires, eight ligature wires and three retainer wires) were investigated in a 1.5-Tesla MRI system (Magnetom Symphony, Siemens Medical Solutions, Erlangen, Germany). The translational forces were measured using the deflection angle test (ASTM F2052-02); rotational forces were assessed on a 5-point qualitative scale.Results and Conclusion: All retainer wires and the steel arch wires (the Noninium^® arch wire being the exception) were subjected to considerable rotational and translational forces within the MRI system’s magnetic field. Translational forces were from 9.1- to 27.6-times as high as gravitational forces on these objects. Steel ligature wires and arch wires made of cobalt chromium, titanium molybdenum, nickel-titanium, and brass alloys showed no or negligible forces within the magnetic field. The translational and rotational forces within the MRI magnetic field should pose no risk to carefully-ligated arch wires. Steel retainer wire bonds should be checked to ensure secure attachment prior to an MRI investigation.* both authors share first authorship     

Erythema multiforme: a review and contrast from Stevens-Johnson syndrome/toxic epidermal necrolysis

Erythema multiforme and Stevens-Johnson syndrome/toxic epidermal necrolysis are separate diseases. Recent evidence suggests that they have different etiologies and require different treatments. This article provides an overview of the two conditions with emphasis on the differences between them. An outline of the diagnosis and management of the diseases is included.     

Preemptive rofecoxib and dexamethasone for prevention of pain and trismus following third molar surgery *

Objective The goal of this preliminary randomized prospective clinical trial was to compare the analgesic efficacy and the reduction in trismus of preoperative rofecoxib, intraoperative dexamethasone, and both rofecoxib and dexamethasone following third molar extraction surgery. Study design Thirty-five subjects requiring surgical removal of at least 1 partial bony impacted mandibular third molar were invited to participate in this double-blind and double-dummy placebo-controlled clinical trial. Subjects were randomly assigned into 1 of 4 treatment groups: (1) placebo po preoperatively and placebo IV intraoperatively; (2) rofecoxib 50 mg po preoperatively and placebo IV intraoperatively; (3) placebo po preoperatively and dexamethasone10 mg IV intraoperatively; and (4) rofecoxib 50 mg po preoperatively and dexamethasone 10 mg IV intraoperatively. Subjects completed a diary assessing postoperative pain onset and intensity using categorical and visual analogue scales. Interincisal opening was assessed 1, 2, 3, and 7 days postoperatively using a Therabite ruler. Results This randomized controlled clinical trial enrolled 35 subjects. Two subjects did not meet the inclusion criteria and 4 did not return completed diaries. The mean age of the remaining 29 subjects (11 males, 18 females) was 22.8 years (+/- 0.6 year). The active treatments tended to delay the need for initial pain medication. When compared to other active treatments and to placebo, the combination of preoperative rofecoxib and intraoperative dexamethasone significantly reduced initial pain intensity ( P < .05). Baseline interincisal opening was 52.6 mm (+/- 6.2). The greatest decrease in interincisal opening was 43.3% for the placebo group at 24 hours. Preoperative rofecoxib alone showed a decrease in interincisal opening of 42.3% ( P = ns) at 24 hours. Intraoperative dexamethasone alone showed a decrease in the interincisal opening of 24.1% of baseline ( P < .05 vs placebo). The group receiving the combination of rofecoxib and dexamethasone showed a decrease in interincisal opening of 23.7% of baseline ( P < .05 vs placebo). Conclusions The results of this trial indicate that the use of intraoperative dexamethasone is an effective therapeutic strategy for limiting trismus following surgical removal of impacted third molars. The combination of preoperative rofecoxib 50 mg and intraoperative dexamethasone 10 mg was most effective in minimizing pain and trismus following third molar surgery.     

Intracanal temperature rise evaluation during the usage of the System B: replication of intracanal anatomy

AIM: To evaluate and determine intracanal temperature rises at 2 and 4 mm from the working length (WL) necessary to obtain proper replication of intracanal anatomy with gutta-percha (GP) using the System B heat source during vertical condensation. METHODOLOGY: A split-tooth model was prepared and artificial shallow depressions were cut in the buccal canal wall 2 and 4 mm from the WL. At the same level on the palatal wall holes were drilled to adapt two thermocouples. The canal was filled using GP in a vertical condensation technique by placing the System B plugger at 2 and 4 mm from the WL in groups A and B, respectively. Two control groups in which no GP was used were carried out placing the plugger 2 and 4 mm from the WL (groups A.c and B.c, respectively) and activating the heat source. Recording of temperature rise was carried out during the filling procedure for groups A and B and during activation for control groups A.c and B.c; the highest temperatures were recorded. After each filling was completed, 3 min were allowed for the GP to cool and the model divided to reveal the filling. Images of the GP were taken with a CCD camera to evaluate the presence of replication of artificial round depressions. In control groups, the temperature was recorded for 20 s after a 3 s activation of the heat source. The rise in temperature was compared between the groups individually at each level (2 or 4 mm) and statistically analysed using one-way anova and Fisher PLSD tests at 5% of significance level (P < 0.05). RESULTS: Mean temperature rises of 14 +/- 3 and 12 +/- 2 degrees C at 2 and 4 mm from the WL, respectively, were observed in group A fillings, and 4 +/- 1 and 6 +/- 1 degrees C at 2 and 4 mm, respectively, in group B fillings. Recordings at 2 mm showed significantly (P < 0.05) higher temperature rises with group A.c when compared with groups B and B.c. Replication of intracanal anatomy with GP was always found in group A fillings at both levels but only 4 mm from the WL in group B fillings. CONCLUSIONS: Positioning the plugger close to WL and a temperature rise of 6 degrees C were necessary to obtain replication of intracanal anatomy. A mean temperature rise of 4 degrees C at 2 mm from WL (group B) resulted in no replication of intracanal anatomy. Further studies simulating clinical conditions are necessary.     

Intraoperative imaging of zygomaticomaxillary complex fractures using a 3D C-arm system

After preclinical studies and evaluation of radiation exposures, intraoperative three-dimensional (3D) C-arm based imaging is now available for the facial skeleton. Fourteen patients admitted for surgical treatment of zygomaticomaxillary complex (ZMC) fractures were included in the study. Preoperative diagnostics and surgical treatment were performed as usual. Intraoperatively, after open reduction, a cone-beam computed tomography (CBCT) dataset was generated using the SIREMOBIL Iso-C3D (Siemens Medical Solutions, Erlangen, Germany). After DICOM-import in eFilm Workstation axial, coronal and sagittal reconstructions were evaluated by five examiners with the help of six defined criteria. In our study, secondary reconstructions were available after 6 min, excluding the time needed for the evaluation of the images. Especially the positioning of the isocentre of the SIREMOBIL Iso-C3D proved to be uncomplicated. Because of the size of the datasets, assessment of the symmetry of the malar projection proved difficult. Best scoring results were found regarding the visualization of the fragment position, bony anchorage of the screws and the fitting of the plates. Remarkable was the low level of metal artefacts in primary and secondary reconstructions. In conclusion, our results demonstrate intraoperative CBCT using the SIREMOBIL Iso-C3D suitable for assessment of postoperative results following ZMC reduction.     

Dendritic-NK cell interactions in P. gingivalis-specific responses

Patients with localized aggressive periodontitis have type-1 cytokines in gingival crevicular fluid and high titers of IFN-gamma-dependent IgG2 reactive with P. gingivalis in gingival crevicular fluid and serum. Localized aggressive periodontitis monocytes spontaneously differentiate into dendritic cells that can stimulate IFN-gamma production by NK cells. These relationships prompted the hypothesis that P. gingivalis-dendritic cell-NK cell interactions might promote type-1 cytokine responses. Although P. gingivalis is not a potent inducer of Th1 responses, it stimulated strong IL-12 responses by monocyte-derived dendritic cells in the presence of IFN-gamma, and IFN-gamma was produced by NK cells within 24 hrs in the presence of dendritic cells. Anti-P. gingivalis IgG2 responses were enhanced by dendritic cells, and removal of NK cells reduced IFN-gamma- and P. gingivalis-specific IgG2. Thus, P. gingivalis-dendritic cell-NK cell interactions apparently resulted in reciprocal stimulation and increased type-1 cytokine production by both dendritic cells and NK cells, and increased P. gingivalis-specific IgG2.     

Double-blind study on materials testing with applied kinesiology

Applied Kinesiology (AK) is a scientifically unproven method used in complementary medicine to recognize the (in)tolerance of dental materials. Test-retest reliability of AK was examined. The working hypothesis was the assumption that the reliability of AK would not exceed random chance. Two dentists qualified in AK examined 112 volunteers to determine individual (in)tolerance toward two dental composite materials. After the first examination, 31 subjects were excluded from further testing. At the end of the open test phase, 34 of 81 participants had been classified as "tolerant", and seven as "intolerant" to both materials. The remaining 40 individuals showed a combination of either tolerant (to material I)/intolerant (to material II), or the reverse (n = 20 each). Retrieval rate was tested under blind conditions. In 14 cases, the results of the open and blinded tests matched, whereas in 26 cases they did not (95% confidence interval, 21%-52%; p = 0.98). This outcome confirmed our working hypothesis.