Orthodontic tooth movement relies on coordinated tissue resorption and formation in the surrounding bone and periodontal ligament. Tooth loading causes local hypoxia and fluid flow, initiating an aseptic inflammatory cascade culminating in osteoclast resorption in areas of compression and osteoblast deposition in areas of tension.
Did you get that?
Let’s translate that and explain why that is important if you are considering getting your teeth straightened and why Invisalign is so much more comfortable and in most cases, faster than braces.
The teeth sit in a socket in your bone and are attached to it by a thin membrane called the periodontal ligament. There are nerves and blood vessels in that living tissue that gives the teeth a little flexibility in this connection. When some pressure is applied to one side of the tooth, the ligament stretches slightly on one side while the compression on the other starts to restrict the blood flow there.
This reduction of available blood oxygen causes an inflammatory situation that signals the body to intervene with a cascade of events leading to the transformation of white blood cells into “bone remover” and “bone grower” cells depending on if room is needed, or room needs to be filled up.
This process takes somewhere between 10 and 14 hours to really get going, and if you release the pressure it slows to a stop. Moving teeth effectively requires the pressure be kept up. Starting and stopping really slows the process or even makes it useless. Hence, if someone advertises nighttime only wear of some appliance will work, forget it.
Applying too much pressure, such that blood flow is cut off will result in death of the tissues so compressed. Lots of inflammation and lots of pain and a delay in the process because the blood to feed the cells needed to change is not available until others can migrate in “to the rescue”. That is one of the reasons that braces so often are very painful because the adjustments cannot be controlled with much precision. Pressure tends to be in bursts every 4 to 6 weeks with the wire change.
This is why I quit using wires and brackets twenty-five years ago when Invisalign was developed. The aligner material applies gentle pressure which makes for faster movement, and the precise movements programmed into the appliances coupled with the patented aligner material prevents “bursts”. The precision of the manufacturing technology is considerably more accurate than the “eyeball” method with braces.
I find with good compliance treatment takes half the time of braces for a lower cost. After 1600 or so cases, I am confident that Invisalign is the best method for most adult and many teen cases.
Dr. Bob
