Malignant minor salivary gland tumors: a retrospective study of 27 cases

PURPOSE: Malignant tumors of the intra-oral minor salivary glands are uncommon. The aim of this study was to give information concerning the clinical features of these tumors, the distribution of location, treatment opportunities, and outcome. METHODS: Twenty-seven patients with malignant salivary gland tumors that were treated between January 1999 and December 2008 were evaluated retrospectively. RESULTS: Of the 27 minor salivary gland carcinomas, 48.1% were adenoid cystic carcinomas (ACC), 29.7% mucoepidermoid carcinomas (MEC), 22.2% adenocarcinomas (ADCA). The most common first symptom was a painless swelling in 60% of the cases, with the second most common symptom being ulcers (28%). Four recurrences and two metastases were found. No recurrence was observed in ADCA. All four patients experiencing a recurrence developed it in the first 3 years after treatment. CONCLUSION: Wide excision with a clinical margin of 1 cm and in large tumors, positive surgical margins or perineural infiltration and postoperative radiotherapy (RT) can be recommended; but in order to give exact information concerning the possible benefit from postoperative RT, it needs large prospective multicenter studies. Long-term follow-up controls and in particularly longer than 5 years in ACC including yearly chest X-rays should be offered to these patients because of late metastasis and recurrences

Measuring velocity of sound with nuclear resonant inelastic x-ray scattering

Nuclear resonant inelastic x-ray scattering is used to measure the projected partial phonon density of states of materials. A relationship is derived between the low-energy part of this frequency distribution function and the sound velocity of materials. Our derivation is valid for harmonic solids with Debye-like low-frequency dynamics. This method of sound velocity determination is applied to elemental, composite, and impurity samples which are representative of a wide variety of both crystalline and noncrystalline materials. Advantages and limitations of this method are elucidated

Precise screw positioning at the mandibular angle: computer assisted versus template coded

BACKGROUND: Buried intraoral devices for distraction osteogenesis in mandibular deformities have numerous advantages, but success depends on the precise positioning of these devices. Although most centers nowadays use template-guided techniques for precise positioning, computer navigation has been described as a promising technique. Surgical navigation during device placement could become a viable method because it affords certainty in defining a device position. METHODS: A clinical situation was simulated by means of mounting a mandible model inside a phantom head. Screws were positioned according to a preoperative plan through transoral and transbuccal approaches, with both template-coded and freehand computer navigation. RESULTS: With template-coded navigation, the medium deviation from the planned position was 0.63 mm (range, 0.00-1.24 mm). With commercial freehand surgical computer navigation, the medium deviation was significantly higher at 0.98 mm (range, 0.00-3.13 mm). CONCLUSIONS: Computer-assisted surgery can provide a high level of accuracy in the region of the mandibular angle where precision is crucial for buried intraoral distraction devices. However, template-coded guidance does provide a significantly higher level of accuracy and therefore represents the gold standard

Pressure-dependence of electron-phonon coupling and the superconducting phase in hcp Fe - a linear response study

A recent experiment by Shimizu et al. has provided evidence of a superconducting phase in hcp Fe under pressure. To study the pressure-dependence of this superconducting phase we have calculated the phonon frequencies and the electron-phonon coupling in hcp Fe as a function of the lattice parameter, using the linear response (LR) scheme and the full potential linear muffin-tin orbital (FP-LMTO) method. Calculated phonon spectra and the Eliashberg functions $\alpha^2 F$ indicate that conventional s-wave electron-phonon coupling can definitely account for the appearance of the superconducting phase in hcp Fe. However, the observed change in the transition temperature with increasing pressure is far too rapid compared with the calculated results. For comparison with the linear response results, we have computed the electron-phonon coupling also by using the rigid muffin-tin (RMT) approximation. From both the LR and the RMT results it appears that electron-phonon interaction alone cannot explain the small range of volume over which superconductivity is observed. It is shown that ferromagnetic/antiferromagnetic spin fluctuations as well as scattering from magnetic impurities (spin-ordered clusters) can account for the observed values of the transition temperatures but cannot substantially improve the agreeemnt between the calculated and observed presure/volume range of the superconducting phase. A simplified treatment of p-wave pairing leads to extremely small ($\leq 10^{-2}$ K) transition temperatures. Thus our calculations seem to rule out both $s$- and $p$- wave superconductivity in hcp Fe.Comment: 12 pages, submitted to PR

Validation of a new three-dimensional imaging system using comparative craniofacial anthropometry

Abstract Background The aim of this study is to validate a new three-dimensional craniofacial stereophotogrammetry imaging system (3dMDface) through comparison with manual facial surface anthropometry. The null hypothesis was that there is no difference between craniofacial measurements using anthropometry vs. the 3dMDface system. Methods Facial images using the new 3dMDface system were taken from six randomly selected subjects, sitting in natural head position, on six separate occasions each 1 week apart, repeated twice at each sitting. Exclusion criteria were excess facial hair, facial piercings and undergoing current dentofacial treatment. 3dMDvultus software allowed facial landmarks to be marked and measurements recorded. The same measurements were taken using manual anthropometry, using soluble eyeliner to pinpoint landmarks, and sliding and spreading callipers and measuring tape to measure distances. The setting for the investigation was a dental teaching hospital and regional (secondary and tertiary care) cleft centre. The main outcome measure was comparison of the craniofacial measurements using the two aforementioned techniques. Results The results showed good agreement between craniofacial measurements using the 3dMDface system compared with manual anthropometry. For all measurements, except chin height and labial fissure width, there was a greater variability with the manual method compared to 3D assessment. Overall, there was a significantly greater variability in manual compared with 3D assessments (p < 0.02). Conclusions The 3dMDface system is validated for craniofacial measurements

Chronischer Gesichtsschmerz unterschiedlicher Genese. Ein Fallbericht

INTRODUCTION: Therapy of chronic orofacial pain (OFP) is often a challenge since OFP can be triggered by numerous medical conditions. Pulpitis is frequently related to acute OFP, only in rare cases pulpitis elicits chronic OFP e. g. due to a cracked tooth. Hypertrophy of masticatory muscles can also cause pain. While this pathosis is easily diagnosed, hypertrophy of masticatory muscles is challenging to treat. METHODS: The presented case demonstrates a combination of a cracked tooth and a symtomatic hypertrophy of the masseteric muscle in a 19-year old patient. The patient suffered from diffuse chronic OFP for more than four month. After diagnosis an interdisciplinary step-by-step treatment plan was realized with re-evaluation and adjustment. RESULTS: After physiotherapy and medicamentous pain control intramuscular injection of Botolinum toxin type-A was performed with remission of the muscle hypertrophy but only partial success regarding pain control. After root canal treatment of a cracked tooth the patient was free of symptoms. CONCLUSION: The high degree of specialization in dental medicine requires a multidisciplinary approach for OFP not thoroughly responding to therapy. Stepwise diagnostics and treatments are recommended to clarify the pathology and to address multiple causes of disease

Commodity price fluctuations and the EROI of oil - How the availability of surplus energy affects non-fuel commodity prices

We study the long-term effect of a changing energy return on investment (EROI) of oil on non- fuel commodity prices. Compared to economic growth, interest rates and uncertainty, the EROI of oil is the main driver of commodity price variations since 1938. A change in the EROI of oil accounts for up to 30% of the variation in commodity prices. We show that over the past 100 years, periods of low EROI have been correlated with higher commodity prices and vice versa. Commodity prices thus depend on the amount of surplus energy available for society. As renewables show substantially lower EROI values than fossil fuels used decades ago, the energy transition poses major challenges not only to our society but also to resource-intensive companies. The adoption of new business practices like the circular economy fosters the development of strategies increasing the EROI and reducing the large demand for external sources of energy and raw materials

Oblique high resolution tomography. The ideal plane for visualisation of the gonial section of the mandibular canal and its related structures?

A new radiologic technique is introduced in this paper for reducing the risk of nerve damage as a result of surgical removal of the mandibular third molar (wisdom tooth). The gonial part of the mandibular canal is obliquely scanned with tomograms on a plane parallel to this part of the mandibular canal. This procedure can be performed with the patient either prone or supine. The scans obtained cover a much longer section of the canal than the axial or coronal plane. Therefore, the scan provides more precise information on the spatial relationship between the mandibular canal and the surrounding structures with fewer images and, therefore, a lower radiation dose. Due to the oblique plane metal artifacts from dental restorations do not impair visualization of the mandibular canal Clinical cases demonstrating the advantages of this new technique are presented