List of metropolitan areas by population. One concept which measures the world's largest cities is that of the metropolitan area, which is based on the concept of a labor market area and is typically defined as an employment core (an area with a high density of available jobs) and the surrounding areas that have strong commuting ties to the core.
Average Costs. In treatment year 1, the average costs per patient diagnosed with PTSD ($8,300), TBI ($11,700), or both ($13,800) were much higher than the average costs for those with neither PTSD nor TBI ($2,400) (see Table 2 and Figure 3 on page 20).
As of 2017, our cost range from $85 for gingivitis treatment to about $4,500 for a full mouth laser periodontal treatment on patients with severe periodontal infection. This includes the cost of local anesthesia and follow visits. The cost for a regular dental cleaning, called prophylaxis, averages between $75 and $85, while the average cost for periodontal scaling and root planing (deep cleaning) is between $175 and about $900. Periodontal maintenance costs after undergoing periodontal treatment average $115.