Influence of Sex, Age and Presence of Functional Units on Optical Density and Bone Height of the Mandible in the Elderly

OBJECTIVES: Mandibular bone height and density were compared with age, sex and the number and type of functional dental units, as represented by Eichner index. MATERIAL AND METHODS: A sample of 150 elderly patients of the Dental Clinic were divided into three age groups, examined and orthopantomograms/OPG/ taken. The OPGs were taken with the copper stepwedge in order to enable computer-assisted calculation of mandibular optical density and calibration of dimensional measurements by specially designed software. RESULTS:Eichner class III was found in 62% of patients. The presence of functional units was positively correlated with age (r=0.67) and bone height values (r=0.88, p<0.05). Optical density and bone height values of measurements performed at the same locations on mandibles showed no significant correlation (r=0.24, p<0.05). Intra-subject measurement showed that the eminentia piriformis region had significantly higher optical density values compared to 1st molar and mental foramen regions (p<0.05). Women had significantly lower bone height values than men (p<0.05), but no significant sex difference was found in optical density values. CONCLUSION: The presence of functional units has significant influence on bone height, although, like age or sex of the patient, it has no influence on mineral content of the mandible. The eminentia piriformis is not susceptible to bone mineral content or height change

Comparative Investigation of Dynamic Loading Resistance of Teeth with Prefabricated and Cast Metal Posts and Cores

Loss of a part or complete clinical crown of tooth results in functional and aesthetic impairment of dental arch and complete stomatognathic system. Such teeth, as well as endodontically treated teeth, during reconstructive prosthodontic therapy need to be treated with posts and cores. The aim of the investigation was to measure and compare the dynamic loading resistance of endodontically treated teeth with cast metal and prefabricated posts and cores, under dynamic loading fatigue of 800N-1000N, with specific regard to variable root preparation width. The investigation included 48 human lower second premolars of similar dimensions, divided in 4 groups according to type of post and core system (each 6mm long) which they received. 1) prefabricated narrow post and core (Maillefer Switzerland, Size 1) 2) prefabricated wide post and core (Maillefer Switzerland, Size 3B) 3) cast metal narrow post and core 4) cast metal wide post and core. Modified Voss & Meiners dynamic loading tests were performed within a field of 800N-1000N in high frequency pulsator. Teeth with prefabricated narrow posts demonstrated the highest average dynamic loading resistance of 9.050.622 cycles under 800N until fracture, while teeth with cast metal wide posts demonstrated the lowest average dynamic loading resistance of 3.522.611 cycles under 1000N until fracture. Significant influence of root preparation width on dynamic loading resistance for all types of posts was determined by ANOVA (p<0.05), with narrow posts demonstrating more fracture resistance. Prefabricated posts and cores demonstrate stable dynamic loading resistance and better intraradicular retention than cast metal posts and cores

Type And Material of Fixed Prosthodontic Appliances in Patients Living in the Region of Metković

The aim of this study was to evaluate the type and the aesthetic material in relation to age, gender, level of education, employment, socio-economic status and frequency of visits to the dentist. The examination was performed on 212 patients who had a fixed prosthodontic appliance for more than a year (55% males and 45% females, age 18-80 yrs.). The following conclusions were made: 1. The older patients and retired patients had significantly more bridges than crowns (p0.05). Patients who visit their dentist regularly have significantly more crowns than bridges than patients who visit their dentist irregularly or when in pain (p0.05). 2. Almost all fixed prosthodontic appliances older than 10 years were made of porcelain (98%), while acrylic veneer crowns were more frequent in appliances older than 10 or 15 years (p0.05). Patients older than 60 years had more acrylic material compared to younger patients. While patients younger than 39 years had almost exclusively ceramic appliances (p<0.01). Less educated patients had more acrylic veneer appliances. Employed patients had significantly more ceramic appliances than retired patients

Seasonal Aspects of Radiative and Advective Air Temperature Populations: A Canadian Perspective

Canadian high-frequency temperature time series exhibit physical heterogeneity in the coexistence of radiative and advective populations in the total air temperature sample. This work examines forty-five Canadian hourly air temperature records to study seasonal characteristics and variability of radiative and advective population counts and their corresponding temperature biases and trends. The Linear Pattern Discrimination algorithm, conceptualized in a previous study, was adjusted to seasonal analysis on the equinox-to-equinox time scale. Count analysis of radiative and advective days supports the existence of two distinct thermal regimes, Spring&ndash;Summer and Fall&ndash;Winter. Further, seasonal advective counts for the majority of examined stations typically decrease in numbers. The consistently warmer winter radiative temperature extrema points to the critical role of the advective population in control of the overall temperature magnitude. Canadian northwest warming trends are found to be the highest, indicating the amplifying effect of decreasing advective counts with rapidly increasing temperatures that weaken the advective population&rsquo;s moderating ability to control the magnitude of the total temperature population

Diurnal Extrema Timing&mdash;A New Climatological Parameter?

We address the following question: Are turning points of daily air temperature function a piece of relevant climatological information worth recording and analyzing? Diurnal Extrema Timing (DET) are daily occurrence times of air temperature minimum and maximum. Although unrecognized and unrecorded as a meteorological variable, the exact timing of daily temperature extrema plays a crucial role in the characterization of air temperature variability. In this study, we introduce the DET concept and assess the plausibility of this potential parameter in detecting temperature extrema timing changes. Conceptualization of the DET parameter has, for a primary goal, the supplementation of vital spatial information to the daily measurements of air temperature extrema. The elementary analysis of annual trends of daily DET examines the significance of this parameter in describing changes in the time domain of air temperature variability. The introduction of the new Climate Parameter Sensitivity Index (CPSI) for evaluating the susceptibility of climate parameters to climate change directs attention to the importance of the systematic acquisition of the timing of daily extrema in climate observations. The results of this study reveal the timing of daily air temperature maximum as the most vulnerable to climate change among temperature and timing extrema indices