Magnetic resonance imaging [MRI] for disc dysfunction of the temporomandibular joint

MRI is a new imaging technique that has been adapted to evaluate the T.M.J. disorder and aid in the plane of treatment presurgically. In this study ten T.M.Js of twenty patients suffering from disc dysfunction and subjected for surgical treatment were selected from Oral Surgery Department. The affected sides were imaged by MRI technique care 1.5 Telsa magnet and using surface coil which provide a high resolution of tissues contrast, the results revealed that MRI provide an accurate modality in detection of disc displacement with or without reduction comparing with the normal joint which act as control. MRI can be visualized all soft tissue components of TMJ than do radiographic methods. Also, patients are not exposed to ionizing radiation and there are no biological hazards effect

Effect of laser irradiation and acid etching on human dental enamel using scanning electron microscopy

This study was performed on forty samples of human dental sound enamel surfaces by using carbon dioxide laser irradiation and 50% phosphoric acid. By scanning electron microscopy, it was found that pits, cracks, craters and blisters were the common topological feactures in lased enamel. While the preferential loss of inter crystal porosity were the characteristic feature's of acid etching. The globular and frequently coalesced enamel rods and crystals of lased enamel were differ from the spicular nature of these structures exposed by acid etching. So, these topological features have a great role in retention of the restorative materials to the structures

Effect of radiotherapy on salivary inorganic electrolytes concentrations

Radiotherapy have direct effect on the head and neck tumors and indirect harmful effect on the adjacent salivary glands which reflects on salivary secretion and composition. This study was performed on 20 old patients and 10 volunteers [control group 1]. The patients divided into two groups: Prospective [group 2] and retrospective [group 3]. The concentrations of the salivary inorganic electrolytes were measured. The results revealed that the level of sodium ion is the only salivary electrolytes that elevate in group 2. The remaining salivary electrolytes [K, Mg and Ca] concentrations were nearly similar to that of control group