How frequently should the DNA/Homeoblock get Expanded?


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The short answer is once the jaw has grown larger the DNA appliance needs to be expanded. The appliance needs to be expanded to keep up with an increase in jaw size. Assuming the DNA appliance has been worn 10-16 hours per day, the expansion adjustments will usually need to be done every 2-4 weeks.

Many dentists advocate expanding the appliances one time per week. The 1x per week recommendation is popular among many Vivos providers. That is far too fast and may lead to bad outcomes in our opinion. Usually at an interval of 1x per week the pressure will be too great and the appliance will begin to cause significant pressure and maybe even some pain. Heavy pressure and pain will lead to bad outcomes such as tipping of the teeth and gum recession. Avoid bad outcomes and do not adjust your appliance more than every 2-4 weeks. And you should never feel pain. Pain means the force is so great that is it moving your teeth rather than growing the bone.

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  3. How to Clean the DNA Appliance


No Exact Schedule to Adjust DNA Appliance


The best rule of thumb is to only adjust the DNA appliance when it is passive. Wear the appliance for 3-4 weeks without adjusting it. Memorize how it feels “passive.” After adjusting the appliance, do not adjust it again until it is passive again. Once the jaw has grown bigger to the new size of the expanded appliance of course it will be loose and passive.


What if the Homeoblock Appliance Feels too Tight


dna appliance adjustment


DNA appliances are designed to promote bone growth in the direction the jaws are too small. The DNA exerts a small amount of pressure in the direction the appliances are designed to grow bone. Each time the appliance is adjusted, it gets 1/4 of a millimeter bigger in the direction of the expansion mechanism. If the appliance increases in size too quickly, it will put too much pressure and the DNA will begin to feel excessively tight. And it may even hurt.


Does the DNA Appliance Cause Teeth Tipping and Movement


Yes but only if the appliance is expanded too quickly and/or not worn for 10-16 hours per day. If the DNA is being worn often enough and expanded properly, teeth will not tip or move. Prior too getting movement of teeth, there will usually be pain coming from orthodontic pressure. Heavy pressure moves teeth and light pressure stimulates bone growth. DNA appliances should never cause pain or excessive pressure that persists for tens of minutes. If pain or high pressure is felt, the appliance adjustment should be reversed and not expanded until the DNA is passive.


Adjusting the Lower DNA/Homeoblock compared to the Upper


Upper jaws are usually smaller than upper jaws. Lower jaw bone is also more dense and grows at a slower rate. The upper and lower DNA devices are not usually going to be adjusted at the same time because the bones are growing at different rates. The upper jaw will usually get more growth as well. The lower DNA will usually get turned 1/2 to 3/4 as often as the upper appliance.


How Often does Upper and Lower DNA Appliance get Expanded?


In the usual course of treatment, the upper appliance usually gets turned every 1.5-3 weeks and the lower appliance every 2.5 – 4 weeks. At the beginning of treatment the appliances may become passive faster and turned a little bit more frequently. It is always better to go slower than faster. And remember, do not turn the appliances until they are passive.


How to Adjust the DNA or Homeoblock


On the day the DNA is to be adjusted, place the appliance into the mouth for 10 minutes until it comes in and out very easily. Sometimes during the day the teeth can shift on the microscopic level. The appliance is worn for 10 minutes to account for this movement. After 10 minutes, expand all the mechanisms and put the appliance back into the mouth.


What to Do if the DNA Device is too Tight after Expansion?


If the DNA is too tight after an adjustment it can be turned back 1/2 a turn. Some people find it more comfortable to adjust the appliance 1/2 turns at a time instead of a full adjustment. If adjusting 1/2 turns at a time, the same suggestions apply – only adjust the appliances when they are passive and now the appliances need to be adjusted more often. The upper gets adjusted every 7 – 14 days and the lower every 10 – 14 days if doing 1/2 turns.


How Often Does the DNA get Adjusted by the Dentist?


Once the bite is comfortable and the patient knows how to use the appliance, we see our adult patients every 3-4 months. During that time we expect the upper DNA to be expanded 5-6 full turns per mechanism and the lower appliance to be expanded 3-5 full turns. At the end of treatment the rate of growth will slow down and we emphasize to only turn the appliance when they are passive.


Does the DNA appliance cause Gum Recession?


No as long as the patient is not adjusting the appliance too quickly and the DNA is being worn 10-16 hours per day. The patient also need to have regular teeth cleanings and verified to not have active gum disease.

The two most common causes of recession are bone loss from gum disease and trauma. Trauma is usually excessive pressure from braces and teeth clenching. The DNA appliance addresses the root cause of TMJ and teeth clenching. The DNA usually improves gum recession or at least prevents it from getting any worse. Again provided the appliance is not adjusted too quickly or not worn 10-16 hours per day.


Why Did my DNA Appliance Stop Fitting?


DNA appliances stop fitting for a few reasons. People stop wearing the for a period of time. For example, if there is a common cold or flu, someone may stop wearing the DNA. During this period the teeth can move and the appliance may stop fitting. The DNA may not be getting worn properly. If the appliance is not inserted all the way, it will slowly stop fitting and then one day not fit at all. Especially after expanding it a few times in combination with not inserting it all the way. What happens is the appliance changes shape and the teeth and jaws change to a different shape.

Regardless of why the appliance is not fitting, you need to go see the dentist and have it re-fitted. Do not delay. If enough time passes, the appliance may need to be totally remade.


DNA Appliance does not Fit After Expanding


If the DNA device does not fit after expanding it, then you should turn the appliance back to the original position. After reversing the adjustment, try the appliance back in to verify it still fits. Some devices have two expansion mechanisms – one in the front and one in the back. Try only expanding one of the two expanders and see if the appliance fits. If so, it may be better to turn the different mechanisms on a different schedule. For example, adjust the expansion mechanism in the front on week 1 and the mechanism in the back on week 2.


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