1 The median is the middle value of the data set. 2  The lower quartile (Q 1) is the median of the lower half of the data set. 3  The upper quartile (Q 3) is the median of the upper half of the data set. 4  The interquartile range (IQR) is the spread of the middle 50% of the data values.
Removable Essix retainers typically cost between $100-$250 for one or $200-$500 for two. They are made from a vacuum sealed clear plastic that is less noticeable but more likely to break or warp, meaning that you could be paying the price more than once for this style of retainer.
Generally, a premium, upper denture and lower Lock-Tight Denture with 4 Mini-Implant retainters costs less than $6000! However, if the patient already has a working denture, the cost will be much less. For more information, visit IMTEC's website.