The Optimal Daytime Usage Pattern For Adult Oral Expansion Appliances

I’ve been wearing my Vivos mRNA appliance for just over two weeks now, and so far things are going well. I can speak with the device in, but it’s difficult and I sound ridiculous so I use basic sign language to order at the supermarket deli when I’m wearing it. I don’t wear it during online lectures or tutorials where I might need to speak.

I have turned all 5 expansion screws twice and each time the device feels quite tight in my mouth straight afterwards, but it’s not painful. At least, not that part.

I’m finding the appliance a little less comfortable than my SomnoMed mandibular advancement device was, principally because the interlocking wings, their mounts and adjusting screws on the lower part of the mRNA are all exposed metal whereas on the SomnoMed the equivalent parts are all acrylic. Maybe they can do that because their appliance doesn’t have to accomodate expansion over time but I wish Vivos would consider doing something similar.

When my cheek gets caught in between the wing and the body of the device during the day, it really hurts. That said, the device takes up about the same space in my mouth and I haven’t had any more difficulty sleeping with it than I did with the SomnoMed, or sleeping with my CPAP machine alone.

Initially I wan’t organising my time sufficiently well to get the recommended 16 hours per day, so I created a spreadsheet to help me track my appliance usage. I’ve averaged just over 16 hours per day for the last week since. I can’t say I’ve noticed any spectacular results yet, but it’s early days. I did have a lecturer at university say that I looked different, but he didn’t elaborate and it could just be a coincidence.

My dentist is great, but he’s relatively new at this and wasn’t specific about how I should wear the appliance during the day, other than to aim at wearing it for 16 hours each day. I didn’t ask initially for more details regarding the optimal usage pattern; I just wanted to get started.

At first I was attempting to stick to a simple 9-to-5 pattern where I removed the device at 9am in the morning, put it back in at 5pm in the afternoon and didn’t take it out again until the next day. I figured this would be the easiest to track even though it meant having my main meal early and not eating in the evening. This is supposed to be better for your body anyway, because intermittent fasting is good for health and longevity.

However, it’s rather inflexible and I kept running late each day with getting my evening meal finished by 5pm. Also, some days I have lectures that run until 6pm so I need to be more flexible and still get my 16 hours up.

Then I saw this video shared in the Adult non-surgical palate expansion Facebook group where Dr Ben Miraglia from Airway Health Solutions suggests that intermittent daytime usage is actually better because the repeated cycling of tension causes bone growth, whereas constant use is more likely to cause teeth to move through the bone instead. The whole video is relevant to DNA appliance users, but the discussion about daytime use pattern starts at 39:50:

https://www.youtube.com/watch?v=AE3ZLbDEWHM&t=39m50s

The short summary is to wear the appliance for an hour or two at a time during the day.

In another article, I presented the science supporting my hypothesis that the DNA appliance works via bone remodelling by applying a low load over a long period of time so that the bone behaves as a viscous material. In his Masters of Philosophy Orthodontics thesis Quantifying the effects of mechanical vibration on the volume of the midpalatal suture, Dr Adrian Lok from The University of Sydney, writes in Chapter 5: Oscillating Mechanical Stimulation, Section 5.3: Importance of Mechanical Loading in the Growth of the Craniofacial Sutures:

“According to a study investigating the mechanobiology of craniofacial sutures, sutural osteogenesis is likely modulated by microscale shear stresses induced by the tension or compression forces. This study demonstrated that fibroblastic cells in sutures increase proliferation and matrix synthesis following induction of mechanical stresses with cyclic strains having the greatest effect. It has been proposed that the fluid flow in bone which is modified and induced by the strain rate and oscillatory bone strain is responsible for triggering mechanotransductive responses, whereas constant forces have no ability to induce fluid movement. As a consequence, amplitude of bone strain above a certain strain likely has no influence upon the rate of bone deposition compared to strain rate and energy”.

In other words, for fluid bone flow to occur, you need cyclic forces below the level at which bone begins to act brittle.

Here are some animal experiments that also show that cyclic forces cause greater bone growth at sutures:

• In Rats: Stretch force guides finger-like pattern of bone formation in suture and Effects of vibration forces on maxillary expansion and orthodontic tooth movement
• In Pigs: Cyclic Loading Effects on Craniofacial Strain and Sutural Growth in Pigs
• In Rabbits: Suture Growth Modulated by the Oscillatory Component of Micromechanical Strain

The pig study in particular concluded:

“Daily spurts of cyclic load caused sutural strain throughout the skull. The regime likely enhances suture growth and may be therapeutically useful.”

The lowest frequencies in these studies are a few Hz; much higher than the hourly cycles Dr Miraglia is suggesting, which translates to less than 0.00014 Hz. This is 4 orders of magnitude smaller so it’s not entirely clear how the research translates to oral expansion appliances, but at worst it’s unlikely to be a bad thing. There is a thread discussing this on The Great Work Forum; thanks to @sinned, @toomer and Aimann Rashee for the research links above.

Dr Dave Singh discusses the use of cyclic intermittent forces with a DNA Appliance in this presentation at 19:45:

Dr Theodore Belfor also discusses the importance of cyclic intermittent forces, claiming that the unilateral bite block on the Homeoblock and breathing also stimulate growth, in this presentation at 50:30:

Another DNA appliance user I’ve been in touch with said that when he started repeatedly inserting and removing his appliance during the day, it no longer felt so tight after adjustment either. Plus it’s more convenient to put the appliance in and out around my schedule depending on when I need to be able to speak coherently. It seems like a better approach all round.

When I don’t have the appliance in my mouth and I’m not eating, I chew mastic gum continually. I find this reduces sensitivity when I first remove the device, suspect it helps promote bone growth, and read somewhere that it reduces the risk of teeth tipping.

I asked my dentist his thoughts on the video and he recommended I make sure to wear the device in the evenings when growth hormone is highest. So now I put it in and out every hour or two during the day, and leave it in after dinner until breakfast the next day. It has been a little challenging getting the recommended 16 hours up each day but the appliance usage tracking spreadsheet is definitely helping and I’m currently averaging just under 16 hours/day.