114 research outputs found
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
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
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
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
Profiling microRNAs in individuals at risk of progression to rheumatoid arthritis
Background: Individuals at risk of rheumatoid arthritis (RA) demonstrate systemic autoimmunity in the form of anti-citrullinated peptide antibodies (ACPA). MicroRNAs (miRNAs) are implicated in established RA. This study aimed to (1) compare miRNA expression between healthy individuals and those at risk of and those that develop RA, (2) evaluate the change in expression of miRNA from "at-risk" to early RA and (3) explore whether these miRNAs could inform a signature predictive of progression from "at-risk" to RA. Methods: We performed global profiling of 754 miRNAs per patient on a matched serum sample cohort of 12 anti-cyclic citrullinated peptide (CCP) + "at-risk" individuals that progressed to RA. Each individual had a serum sample from baseline and at time of detection of synovitis, forming the matched element. Healthy controls were also studied. miRNAs with a fold difference/fold change of four in expression level met our primary criterion for selection as candidate miRNAs. Validation of the miRNAs of interest was conducted using custom miRNA array cards on matched samples (baseline and follow up) in 24 CCP+ individuals; 12 RA progressors and 12 RA non-progressors. Results: We report on the first study to use matched serum samples and a comprehensive miRNA array approach to identify in particular, three miRNAs (miR-22, miR-486-3p, and miR-382) associated with progression from systemic autoimmunity to RA inflammation. MiR-22 demonstrated significant fold difference between progressors and non-progressors indicating a potential biomarker role for at-risk individuals. Conclusions: This first study using a cohort with matched serum samples provides important mechanistic insights in the transition from systemic autoimmunity to inflammatory disease for future investigation, and with further evaluation, might also serve as a predictive biomarker
Evaluation of the effects of the low-level laser therapy on swelling, pain, and trismus after removal of impacted lower third molar
Die Rolle der Röntgendiagnostik in der Abklärung dentaler Herde
Dentale Herde sind potentielle Infektionsquellen und müssen - neben ihrer lokalen Bedeutung - oftmals auch aus allgemeinmedizinischen Gründen gesucht und saniert werden. Nach Anamnese und klinischer Untersuchung sind Röntgenstrahlen seit ihrer nobelpreisgewürdigten Entdeckung durch Wilhelm Conrad Röntgen am 8. November 1895 [1, 2] die dritte diagnostische Säule in der Medizin und Zahnmedizin. Der vorliegende Artikel soll die Möglichkeiten und Grenzen der verschiedenen radiologischen Untersuchungsmodalitäten aufzeigen und dem Behandlungsteam eine Orientierungshilfe zur Auswahl der jeweils optimalen radiologischen Technik geben
Nutzen-Risiko-Abwägung: Darf ich bei einer Schwangeren Röntgenbilder anfertigen?
Gelegentlich wird der Zahnarzt mit der Frage konfrontiert, ob er eine Schwangere röntgen darf oder nicht. Eine einfache und pauschale Antwort gibt es nicht. Es soll aber hier der Versuch unternommen werden, gewisse Klarheit über die Schädigungswahrscheinlichkeit zu verschaffen, damit der Zahnarzt eine einzelfallbezogene evidenzbasierte Entscheidung treffen kann
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