Density

INTRODUCTION:. Orthodontic treatment are potentially unstable although a number of factors can be cited as influencing long term-result. It called relapse orthodontics. Relapse Orthodontic is the return, following correction, any change from the final tooth position at the end of treatment relapse, could be a return to the original teeth position, caused by periodontal,occlusal,soft tissue factor and growth. Orthodontic relapse is a complex problem. 1,2 Studies have shown that stability and…

Osteoporosis One disease of the bones that affects over 1 million Australians is osteoporosis. This bone-thinning disease greatly increases the risk of fractures and occurs when the “…ratio of bone formation to bone break- down…” becomes out of balance, triggering osteoblast activity to slow down (Whitney, Rady Rolfes, Crow, Cameron-smith & Walsh, 2014, p. 199). Affected bones rapidly lose important minerals, such as calcium, rendering them ineffective in replacing these important minerals…

Age is a primary cause for knee and hip replacement surgeries. As we get older, our joints naturally become more susceptible to breakdowns in cartilage and a loss of bone density. Osteoarthritis, sometimes referred to as degenerative joint disease is an abnormal medical condition that causes deterioration, pain, swelling or stiffness of bones and joints. Although osteoarthritis affects all age groups, the condition is seen most often in the older population. This could be for various reasons.…

This experiment is to be used to determine the era of which the composition and thus the density of the penny changed, and what the other metal besides copper has made up the composition since 1962. First, ten pennies from three different time periods (1995-1999, 2000-2004, 2005-present) were gathered. All ten pennies from a specific time were weighed together on an analytical balance. Then, a fifty mL graduated cylinder was filled with twenty mL of water, which was recorded as the initial…

In 2013, air pollution has been characterized by the WHO as the “most widespread environmental carcinogen” (IARC, 2013). For Torontonians, the problem regarding air quality is also a big challenge upfront. Although the overall air quality has been improved for recent years, Toronto still sees over a thousand premature deaths and over three thousand hospitalization due to respiratory diseases every year. (Toronto 's Vital Signs, 2015) Moreover, Dr. David McKeown (2007), Toronto medical officer of…

loss (Taylor, 2009). “Over time, the risk of osteoporosis and fracture increases as older women lose more one than they replace” (Taylor, 2009). The removal of both ovaries, called bilateral oophorectomy, may also cause osteoporosis and low bone density in women. “In one study, this surgery caused a 54% increase in hip, spine, and wrist fractures in postmenopausal women” (Taylor, 2009). Another possible cause of osteoporosis is low testosterone in men. “Men need both testosterone and estrogen…

implant failures. The occurrence of severe skeletal loss requires the stability provided by polymethylmethacrylate (PMMA). In a biomechanical study which investigated the treatment of osteoporotic trochanteric patients, femurs which had the lowest bone density showed a significant improvement in the initial fixation stability and total displacement of the femoral head was reduced by 39% on average in the group with the modified sliding hip screw (SHS) and PMMA compared to the standard SHS group…

Women have advanced in the Armed Forces progressively since World War II. Deseret Storm was a starting point in realizing that women could be an asset, not a detriment, to demanding military positions. Still, any combat related job within each branch had a rule of no females. That all changed in December 2015 when the United States Secretary of Defense Ashton Carter stated that all roles in the military were now open to women. This allows women to try out and be a part of the elite positions…

Brazil is the largest country in South America. Its home to about 200 million people and variety of ecosystems. The connection between the society and the environment presents two major issues to the enormous country. One being the amount of poverty that floods throughout the area and the other being a crucial amount of environmental damage. This relationship can flow either way in a positive or negative aspect. Research shows that there can be a benefit rather than a detriment. Researchers in…

We live in a world of relentless change. This Earth we call our home has slowing been maturing since science can prove so. It has molded itself through many tedious reproductions to give it life to live on. Our home is approximately 4.54 billion years old (Sarfati 8); however, with the lifestyle that the human race has allowed itself to live, we have left unmistakable damage to the planet. We are now approaching an era that can possibly be a very difficult one. Earth has conducted a diverse…