10 X Actual Size
1. INTRODUCTION TO MICROSCREWS:
Example 1: Retraction
Example 2: Cant Correction
Screw Loosens
Screw Breaks
Screw Hits tooth root
Who should place the screw?
What type of anesthesia is needed?
Does it hurt?
Will it hurt after the anesthesia wears off?
Is it hard to remove?
Should I resist use of a microscrew if other options exist?
How much should it cost for the screw?
INTRODUCTION TO MICROSCREWS:
Microscrews are also know as Temporary Anchorage Devices (TAD). They have been used in health care for almost a century. Screws and pins have been utilized to fix fractures of bones, or to reconnect tendons to bones.
Orthodontics started utilizing microscrews (or bone plates) since the mid 1990's. The benefit of microscrews in orthodontics is centered around the concept of "anchorage."
"Anchorage Requirement" refers to the need to hold certain teeth stable while pulling/pushing other teeth. For example, if you need to pull the front teeth back, traditionally you need to use the back teeth as an "anchor." As such, the back teeth WILL move forward somewhat. The question is how much can you allow the back teeth to move forward? Maybe only a little, maybe alot, or maybe not at all.
In the case that the back teeth cannot move forward AT ALL, the orthodontist needs absolute anchorage requirements. As such, something other than a tooth must be utilized. Enter: Microscrew.
Microscrews are bone screws that provide "absolute anchorage." Once integrated into the bone, the screws do not move at all in response to orthodontic forces. This is a very useful tool for the orthodontist in maximum/absolute anchorage situations.
EXAMPLES:
Example 1: Retraction
In the image below, the front teeth need to move back significantly and the back teeth cannot move at all (the back teeth already fit perfectly). As such, the microscrew is being utilized to exact retraction forces on the front teeth.
Example 2: Cant Correction
In the image below, the upper molars are at different heights relative to the face. As such, the smile is "crooked" or "angled" or more precisely, "canted." It is no simple task to correct a jaw cant (even a small amount). It is similar to moving a home (even a small amount). In order to pursue such correction, microscrew technology is usually employed as shown below.
PROBLEMS WITH SCREWS:
Screw Loosening
Sometimes a screw gets loose after it is placed. This situation is more common in the upper jaw than the lower jaw, because the bone of the upper jaw is much less dense that that of the lower jaw. As such, many orthodontists prefer to place these screws either high up on the upper jaw (zygomatic region) or on the lower jaw.
If a screw gets loose, it will need to be repositioned into an area of denser bone.
Screw Breakage
While very rare, a screw may break during placement or removal. If this happens, the screw is usually removed by a small surgical approach to extract the screw. The screw may also simply be abandoned in place without any negative consequences.
Screw Hits Tooth Rooth
Studies have been done to determine the consequences of root contact with a microscrew during placement. These studies indicate that there are no long term sequelae, especially when the screw is placed using a manual thin screw-driver (rather than a machine driver or ratcheting-wrench).
FREQUENTLY ASKED QUESTIONS:
A. Who should place the screw?
While it is not that significant who places the screw, studies have shown that orthodontists are overall better equipped to place a microscrew, because only the orthdontist knows the ideal location and orientation of the screw for maximum orthodontic utility.
B. What type of anesthesia is needed?
Local anesthesia (aka. Novocaine) at the site of screw placement.
C. Does it hurt?
Minimal to no pain is perceived. The entire procedure usually takes less than 10 minutes (from anesthesia application to completion of procedure).
D. Will it hurt after the anesthesia wears off?
Most people feel minor soreness or no discomfort at all.
E. Is it hard to remove?
No. In fact, generally microscrews are removed even without local anesthesia.
F. Should I resist use of a microscrew if other options exist?
No. Microcsrcews are simple but powerful solutions for certain orthodontic problems. If you orthodontist is suggesting its use for your orthodontic needs, you probably do not have a more conservative option.
G. How much should it cost for the screw?
Screw placement should not cost more than $500.00 each. In fact, some people charge as little as 250.00 when more than one is placed at a time.
