Fixed functional appliances

Herbst / CBJ / Hanks/ Forsus Appliance

One of the most common problems orthodontists are asked to treat is the discrepancy that occurs when the upper teeth protrude beyond the lower. Ordinarily when we see a patient with the upper teeth protruding, we tend to think that the upper jaw and teeth are too far forward; but, more often than not, this condition is due to a small lower jaw that is further back than it should be. With these patients, the orthodontist would like to encourage the lower jaw to catch up in growth, and braces like the Herbst appliance help this happen.

How does it work?

Smiling Wide Orthodontics uses the Herbst appliance to enhance the growth of the lower jaw in a forward direction. A tube and rod work together similar to a shock absorber to connect the upper and lower jaws. This does not interfere with opening and closing the mouth or with eating, however side to side movement is somewhat restricted. The Herbst appliance is cemented on the back molars and is in place and active 24 hours a day. It is generally worn full time for up to 8 months along with front braces. Once it is removed, braces are added to the side teeth to complete tooth alignment.

At first, your mouth will feel unusually full and speaking will be awkward. But if you practice reading aloud, your ordinary speech will return quickly. You may also notice more saliva than normal, but this will decrease as you become accustomed to the appliance. The appliance may irritate the inside of your cheeks at first but soon the tissue will toughen up to the appliance and not be a problem.

As the Herbst Appliance makes corrections to the jaw relationship, most patients will notice that the back teeth will not meet, making initial chewing difficult. This is normal and necessary for the progression of treatment. The teeth will gradually come together so that chewing becomes more normal after about a week.

Potential concerns

  • If the rod slides out of the tube while opening, open wide again and guide the rod back into the tube as you close.
  • If a screw or crown comes loose, save all pieces and call the orthodontist's office so they can repair the appliance. Bring all the pieces with you to the orthodontist.

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