This study aimed to analyze quantitatively videofluoroscopic (VF) images of patients with Parkinson's disease (PD), to evaluate if the predicted factors of the oral phase of swallowing deteriorated with PD progression, and to demonstrate a relationship between the abnormal movements of the tongue and food transportation. Thirty PD patients were recruited and divided into mild/moderate (Hoehn & Yahr stages II and III) and advanced (stages IV and V) groups. They underwent measurement of tongue strength and VF using 5 ml of barium gelatin jelly as a test food. We measured the speed of bolus movement and the range of tongue and mandible movements during oropharyngeal transit time. The maximum tongue pressure of the mild/moderate group was significantly larger than that of advanced group (p = 0.047). The oropharyngeal transit time of the mild/moderate group was significantly shorter than that of the advanced group (p = 0.045). There was a significant negative correlation between the speed of tongue movement and the oropharyngeal transit time (p = 0.003, R = -0.527). Prolonged mealtimes and the ejection of insufficiently masticated food from the oral cavity into oropharynx were associated with PD progression. These results indicate the importance of the oral phase of swallowing in PD patients.

Phantom bite syndrome is characterized by an uncomfortable sensation mainly affecting corrected dentition in which no abnormality is clinically detectable. Despite repeated failures of dental surgery, sufferers persist in seeking bite correction from a succession of dentists. The etiology-pathogenesis of phantom bite is unknown but some consider the syndrome to be a psychosomatic disorder. Seven patients with this syndrome were treated with the serotonin and norepinephrine reuptake inhibitor milnacipran for 4 weeks. One patient withdrew after 2 weeks because he was feeling "well". At the end of the study, 5 of the 6 patients completing the study reported significant improvements, with a mean decrease in occlusal discomfort of 55.3%, as indicated by a visual analogue scale. This result appeared to be independent of any antidepressant effect. Only minor and transient side-effects were observed. It is suggested that milnacipran may be a helpful treatment for phantom bite but this needs to be confirmed by further and longer term studies.

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Sonodynamic therapy (SDT) is a new treatment modality using ultrasound to activate certain chemical sensitizers for cancer therapy. In this study, effects of high intensity focused ultrasound (HIFU) combined with photocatalytic titanium dioxide (TiO2) nanoparticles on human oral squamous cell line HSC-2 were investigated. Viability of HSC-2 cells after 0, 0.1, 1, or 3s of HIFU irradiation with 20, 32, 55 and 73Wcm(-2) intensities in the presence or absence of TiO2 was measured immediately after the exposures in vitro. Immediate effects of HIFU (3s, 73Wcm(-2)) combined with TiO2 on solid tumors were also examined by histological study. Cytotoxic effect of HIFU+TiO2in vitro was significantly higher than that of TiO2 or HIFU alone with the tendency to increase for higher HIFU intensity, duration, and TiO2 concentration in the suspension. In vivo results showed significant necrosis and tissue damage in HIFU and HIFU+TiO2 treated samples. However, penetration of TiO2 nanoparticles into the cell cytoplasm was only observed in HIFU+TiO2 treated tissues. In this study, our findings provide a rational basis for the development of an effective HIFU based sonodynamic activation method. This approach offers an attractive non-invasive therapy technique for oral cancer in future.

BackgroundThe location of the lateral osteotomy cut during bilateral sagittal split osteotomy (BSSO) varies according to the surgeon's preference, and no consensus has been reached regarding the ideal location from the perspective of biomechanics. The purpose of this study was to evaluate the mechanical behavior of the mandible and screw-miniplate system among three lateral osteotomy designs for BSSO by using three-dimensional (3-D) finite element analysis (FEA).MethodsThe Trauner-Obwegeser (TO), Obwegeser (Ob), and Obwegeser-Dal Pont (OD) methods were used for BSSO. In all the FEA simulations, the distal segments were advanced by 5 mm. Each model was fixed by using miniplates. These were applied at four different locations, including along Champy's lines, to give 12 different FEA miniplate fixation methods. We examined these models under two different loads.ResultsThe magnitudes of tooth displacement, the maximum bone stress in the vicinity of the screws, and the maximum stress on the screw-miniplate system were less in the OD method than in the Ob and TO methods at all the miniplate locations. In addition, Champy's lines models were less than those at the other miniplate locations.ConclusionsThe OD method allows greater mechanical stability of the mandible than the other two techniques. Further, miniplates placed along Champy's lines provide greater mechanical advantage than those placed at other locations.