Clinically obscure venous malformation in the sub mandibular triangle: A rare presentation.

Vascular lesions have been classified as hemangiomas or vascular malformations depending on the presence of cellular proliferation. These lesions have been known to cause significant morbidity and even mortality in both children and adults. Confusing nomenclature, relative rarity of these lesions, inappropriate diagnosis, lack of precise imaging studies and deficiency of multidisciplinary approach are some of the factors which result in ineffective treatment of such patients. Here, we report a rare case of venous vascular malformation presenting as a mass in the sub mandibular region with no clinical stigmata which was diagnosed with the help of various imaging techniques and subsequently treated by surgery.

Trigeminal neuralgia secondary to posterior fossa tumor.

Trigeminal neuralgia (TN) is by no means an uncommon entity presenting as typical or atypical pain syndrome with a standard treatment protocol consisting of medical and surgical therapies. The diagnosis of TN is mainly dependent on the characteristics of symptoms conveyed by the patient and the clinical presentation. Careful history taking, proper interpretation of the signs and symptoms and cranial nerve assessment are necessary for proper diagnosis. Here, we report a case of TN, treated for dental problems and then for neuralgia with only short-term relief. Subsequently, the patient underwent neuroimaging and was found to be having an uncommon space-occupying lesion in the posterior cranial fossa.

Layered inorganic-organic clay-like nanocomposites rearrange to form silsesquioxanes on acid treatment.

The formation of talc-like compounds by the condensation of organotrialkoxy silanes with magnesium hydroxide has been recently reported. These represent layered hybrid nanomaterials that have a layer thickness of around 1 nm, have organic moieties covalently linked to the layer surfaces, and are called "organoclays." We show that such compounds are sensitive to acid treatment. When a phenylclay is treated with hydrochloric acid, magnesium leaches out, destroying the layered structure. The extent to which magnesium is leached out is a function of the time of the acid treatment and the concentration of the acid used. Magnesium leaches out rapidly when the concentration of acid used to treat the phenyl-clay is higher, and the extent of structural magnesium that is leached out is also higher for higher acid concentrations. Removal of the magnesium rearranges the structure of the phenyl-clay to form oligomeric phenylsilsesquioxanes. FTIR and NMR suggest that the silsesquioxanes formed by acid treatment of the phenyl-clay comprise a mixture of ladderlike and cagelike structures.