Occlusal plane orientation in complete denture construction

Guides to the orientation of the occlusal plane in complete denture construction are reviewed and the current opinions of some British dentists are reported.

It is concluded that this element of complete denture construction owes less to the intelligent application of scientific principles than to a form of guesswork.     

Ludwig''s Angina. The anaesthetic management of nine cases

We reviewed nine patients with Ludwig's angina who required surgical drainage over a 24-month period. This represents the largest series reported in world literature. All of these patients were managed successfully by a combination of tracheal intubation and early surgical intervention. None required tracheostomy, which is the previously recommended procedure of choice for airway management.     

Oxidative stress,antioxidant defenses,and schizophrenia

Schizophrenia is a complex neuropsychiatric disorder with a prevalence of nearly 1% of the world population. Accumulating evidence suggests that increase in production of reactive oxygen species (ROS) along with decrease in antioxidants and antioxidant enzymes (superoxide dismutase, glutathione peroxidase and catalase) may be closely associated with the pathogenesis of schizophrenia. Genes associated with glutamate transmission, dopamine transmission, synaptic plasticity, mitochondrial function, oxidative stress, lipid metabolism, and neuroinflammation have been closely linked to schizophrenia. Proteins encoded by many of the above genes affect the level of ROS, and lipid mediators that regulate signaling in the brain through cross‐talk among glutamate, dopamine, and eicosanoid receptors. Under physiological conditions, this refines the communication between neurons, glial cells and vascular cells, but in schizophrenia, the cross‐talk might initiate and promote oxidative stress‐mediated abnormal neuronal signaling responsible for symptoms of the disease.     

Comparison of a photostimulable phosphor system with film for dental radiology

This study compared the imaging performance of a photostimulable phosphor system with E speed film for dental radiography. The response of each imaging system was measured as a function of radiation exposure. Measurements were also made of imaging performance in terms of the limiting spatial resolution and low contrast detectability. Photostimulable phosphors had a wider dynamic range in comparison with film. The limiting spatial resolution of the photostimulable phosphor was approximately 6.5 lp/mm and independent of image magnification. For film, the limiting spatial resolution was in the range 11 to 20 lp/mm depending on image magnification. At the same radiation exposure, low contrast detectability of the photostimulable phosphor was superior to that of film. Major benefits of photostimulable phosphor systems include the elimination of chemical processing and an improved low contrast detectability performance.     

In vivo retrospective study of cement thickness under crowns

Purpose. This study evaluated the cement thickness under crowns cemented with zinc phosphate cement that had been in clinical use for at least 10 years.Material and methods. A total of 97 teeth were extracted because of periodontal disease as part of a new treatment plan. Teeth were sectioned and the cement thickness measured at predetermined points on the occlusal and axial walls with a measuring microscope at ×150 magnification.Results. Mean cement thicknesses on buccal and lingual walls were similar (116 μm and 109 μm, respectively), but much smaller than on occlusal walls (310 μm). Cement thicknesses at occlusal locations were significantly thicker in molars than in premolars. Poor correlations existed between cement thicknesses on buccal and lingual walls (0.26) and between these and the occlusal walls (0.35) implying that incomplete seating is strongly related to tilting or oblique seating.Conclusion. Under clinical conditions where more inherent difficulties exist, special measures must be taken to alleviate the consequences of cement fluid dynamics. (J Prosthet Dent 1998;79:621-5.)