Wednesday, October 14, 2009

Malocclusion: Disease of Civilization, Part IV

There are three periods during the development of the face and jaws that are uniquely sensitive to environmental influences such as nutrition and muscle activity patterns.

1: Prenatal Period

The major structures of the human face and jaws develop during the first trimester of pregnancy. The maxilla (upper jaw) takes form between the 7th and 10th week after conception. The mandible (lower jaw) begins two weeks earlier. The nasal septum, which is the piece of cartilage that forms the structure of the nose and divides the nostrils, appears at week seven and grows most rapidly from weeks 8 to 11. Any disturbance of this developmental window can have major consequences for later occlusion.

2: Early Postnatal Period

The largest postnatal increment in face and jaw growth occurs from birth until age 4. During this period, the deciduous (baby) teeth erupt, and the activity patterns of the jaw and tongue influence the size and shape of the maxilla and the mandible as they grow. The relationship of the jaws to one another is mostly determined during this period, although it can still change later in development.

During this period, the dental arch widens from its center, called the midpalatal suture. This ensures that the jaws are the correct size and shape to eventually accept the permanent teeth without crowding them.

3: Adolescence

The third major developmental period occurs between ages 11 and 16, depending on the gender and individual, and happens roughly at the same time as the growth spurt in height. The dental arch continues to widen, reaching its final size and shape. Under ideal circumstances, at the end of this period the arch should be large enough to accommodate all teeth, including the third molars (wisdom teeth), without crowding. Narrow dental arches cause malocclusion and third molar crowding.

Growth of the Dental Arch Over Time

The following graph shows the widening of the dental arch over time*. The dotted line represents arch growth while the solid line represents growth in body height. You can see that arch development slows down after 6 years old, resumes around 11, and finally ends at about 18 years. This graph represents the average of many children, so not all children will see these changes at the age indicated. The numbers are in millimeters per year, but keep in mind that the difference between a narrow arch and a broad one is only a few millimeters.

In the next few posts, I'll describe the factors that I believe influence jaw and face structure during the three critical periods of development.


* These data represent many years of measurements collected by Dr. Arne Bjork, who used metallic implants in the maxilla to make precise measurements of arch growth over time in Danish youths. The graph is reproduced from the book A Synopsis of Craniofacial Growth, by Dr. Don M. Ranly. Data come from Dr. Bjork's findings published in the book Postnatal Growth and Development of the Maxillary Complex. You can see some of Dr. Bjork's data in the paper "Sutural Growth of the Upper Face Studied by the Implant Method" (free full text).

21 comments:

Jack Christopher said...

I know a little girl with significant face underdevelopment. She was born with it. She's maybe 12 now. She's my little sister's friend.

I suspect her parent think it's genetic. But I haven't talked with them, I have no idea how to go about it. But I'd like to do some good.

Aaron Blaisdell said...

My older daughter is 4 years old. Last January the dentist told me that her adult teeth are likely to be crowded and that she'll likely need orthodontics. I'm waiting for your next post with baited breath to see what I can do to correct this situation before she hits puberty.

I'm already trying to give her lots of D3 (sunshine in summer, Carlson's D3 drops all year), high-vitamin fermented cod liver oil, whole-fat yogurt from grass-fed cows, and minimize grains (very tough for a girl who's favorite foods are goldfish crackers, cereal, and noodles).

Half Navajo said...

Aaron,

just find someone in your area who does functional jaw orthodontics, or preventative dentistry.

At the young of an age the maxilla bone hasn't sealed yet, so they can put a widening device in the top arch. It will widen her arch, giving the teeth all the room they need. I have friends who had this done when they were young.... there smiles are amazing, the arches are nice and wide, they didn't have to have braces, there teeth have stayed straight as can be.

troy

Aaron Blaisdell said...

@Troy,

Thanks! Funny, my brother had a maxilla widening treatment when he was a kid, but he still had to have all four wisdom teeth extracted through surgery in his late teens. Perhaps they started the widening too late (he was about 11 or 12 years old). Nevertheless, I will try to find a local functional-jaw-orthodontist for a consultation. Perhaps starting while she's only 4 or 5 years old will be critical to the success of this procedure.

LynneC said...

I'm lucky in that all my wisdoms came in, with no crowding. However, my older siblings both had much narrower arches and had to have wisdoms extracted. Nutritional?

Ken said...

What about the idea that hunter gatherers would have made room by losing some teeth by the time their wisdoms came in. Eating tough seeds ect must have resulted in some broken teeth. Even a whole grain if bitten hard on could crack a tooth.

Anand Srivastava said...

@Aaron

I hope you are also supplementing K2. It is very important for the dental growth. D3 may make Calcium available, but K2 is the one which guides it to the proper place.

Anna said...

Aaron, I think Half Navajo is totally right about consulting with a functional orthodontist for your daughter. And I'd do it sooner rather than later. They definitely have a different approach to orthodontics.

Check out http://www.facefocused.com/ for an idea of the functional orthodontics approach. It seems to be standard to offer an initial orthodontic evaluation and treatment proposal for no charge so there really isn't a good reason not to have your daughter's teeth evaluated soon by a couple of orthodontists. That way you don't risk starting treatment too late. And I do think it is good to get several opinions, hopefully from orthodontists with a range of perspectives, from conventional to functional, so you have enough different viewpoints to compare. Initially I just consulted a few on our dental network plan and they all proposed the same conventional approach (which leads to the "orthodontic teeth" teeth I see on too many teenagers and young adults. If you have dental insurance, your benefit may be different, but our small orthodontic insurance benefit seems to be the same amount for in or out of network providers, so that won't factor into my decision.

We just yesterday had an initial consult with a functional orthodontist for our son, age 11.

This one recommends a different treatment for the overbite and crowding than the three "in-network" conventional orthodontists we consulted last year (all recommended an optional preliminary short-term phase to bring in his upper front teeth to protect them from injury, but waiting until age 13-14 with secondary teeth in place, to do full braces with head gear. Something didn't feel quite right about that approach so I kept digging for more info and stumbled into the functional orthodontics.

Between having read Price's Nutrition & Physical Degeneration, Stephan's great posts, retired dentist Brian Palmer's informative website, ENT doc Steven Y. Park's website and book about facial/maxillary development's connection to breathing, sleep, & health, as well as the orthotropic and orthognastic association's websites, I think that the functional appliances that guide the jaw growth and development are probably the best approach for my son's malocclusion issues - overbite and crowding.

She took measurements and complimentary panoramic mouth & whole skull/neck profile x-rays, as well as digital photos from different angles, which made it easier to see the problems and to discuss later with my husband. Our appt was 1 hour. That's much longer and more comprehensive than the evaluations we had last year.

The treatment plan recommended for our son is to place a Herbst (fixed) appliance and an upper palate expander (Crozat and Biobloc are other types of functional appliances that guide jaw placement and growth) for about one year, followed by about 1.5 years of braces to then guide the teeth into place. Extractions won't be necessary with this approach.

However, it was clear even to me from the x-ray that his third molars (wisdom teeth)won't have enough room and will need to be removed. She recommended that the wisdom teeth come out around age 18, no later than age 21. Perhaps if we had started treatment earlier...?

I have too more consult appts with other functional orthodontists (one uses biobloc and the other uses crozat appliances) located near each other, BUT they are at least a 2-3 hour drive away (in the northern LA area). It's been hard finding more in my area.

I really wish I'd known more about this approach to orthodontics earlier, but at least we're still within the growth window to be able to use it to full advantage.

Anna said...

Aaron,

One more thought - my son put up some fuss when I cut back then eliminated cereal, pasta, bread, etc., too. I mourned the loss of cold cereal and toast for him, too, as they were easy for him to fix for himself. He was about your daughter's age when I cut my own carbs drastically; within a year I started to make reductions in his access to those foods, too. At first I just said, "we're out" or "I forgot to buy it". Later I explained that these foods didn't fit my idea things are good to eat frequently, so I wasn't going to buy or make them anymore. Four year olds won't get that, but none or ten year olds will (to a point).

The earlier you wean her off those empty sugars and starches (at least at home, where hopefully she eats most of her meals), the better IMO, so that eating without a bunch of empty carbs will seem fairly normal to her in the long run, rather than a deprivation. We are 5+ years into this (completely wheat-free since January) and I've never regretted it, I only wish I had started even earlier.

I don't even keep a stash sequestered away (except the good dark Belgian chocolate) in "secret" locations, because either I forget about it, it becomes a temptation for my husband or myself, or because now my son is old enough to go looking for it and then it will reawaken his expectation that I stock it (& make me look like a hypocrite, something that 11 yos are good at pointing out). Let's face it, kids aren't known for their moderation with the treats (nor are many adults).

I am more flexible about the sugars and starches for him when we are traveling or visiting someone else's home, except with wheat (we're both wheat-free now). So it's not like he *never* has rice krispies, or potato chips (or candy), but that's so infrequent it hardly matters. He tries some of these "long lost" treats again and loses interest when he realizes they aren't as good as he remembers.

Of course, both parents need to present a united front with this approach for it to work well. Good luck if you are alone in your efforts. ;-) But I do think it is up to the parents to decide what foods come into the home, not these "short adults-in-training".

I can guarantee your daughter won't starve if you remove the goldfish crackers, cereals, and noodles, though you might hear a lot of whining and pleading for a while (and boy, can they persist in their whining and attempts to get what they want however long it takes to get us to cave in). Just plan ahead and have some healthy offerings (& earplugs ready). And be prepared to wait it out.

Let us know how it goes when you do this! ;-)

Stephan Guyenet said...

Hi Jack,

There are legitimately genetic forms of face/jaw underdevelopment. They're rare but they do exist.

Ken,

HGs didn't generally lose teeth before their full dentition had erupted so I don't think that can account for it. They did sometimes lose teeth, but it was generally front teeth due to trauma or molars later in life due to extreme wear.

Gabriella Kadar said...

Aaron,

firstly, if your child is digit/thumb sucking, stop the habit. Same with using a soother/pacifier. Also if she is still using a baby bottle.

Secondly, palatal expansion can be done once the first permanent molars have erupted. (After age 6. Usually about age 8 or 9. Considerably sooner than age 12 when presumably the second molars are erupting/erupted.)

If your daughter has a normal bucco/palatal relationship, i.e. no crossbite, then the amount of palatal expansion required is not that much. The lower arch will follow the upper. If you expand the upper, the lower arch will have a chance to expand as well. And the mandible won't be caught/trapped up inside the maxilla.

cheers,

g.

Aaron Blaisdell said...

Wow, thanks to everyone for the feedback and advice regarding my 4yo daughter! Yes, I supplement her (and myself, my wife, and my 1yo daughter) with K2 (thorne drops) in addition to the D3. I also sneak fermented high-vitamin cod-liver oil into my 4yo's yogurt and in my 1yo's bottle of milk. Over the past year I've cut way back on the goldfish crackers (just because they're her favorite doesn't mean she gets 'em every day, and when she does, it's only a few). Her cereals are Trader Joe's Os and Puffins (both made with non or low-gluten grains). We've switched to almost exclusively using sweet-potato noodles (from 99 Ranch, a Chinese grocery store) and no longer use wheat-based noodles. She does have white bread occasionally as I cannot get her to eat the sprouted stuff. Still, she has that maybe once or twice a week at the most.

Luckily her day care does not provide meals or snacks, so I pack everything for her for the day, which usually includes some kind of chicken or meat ball with rice or sweet-potato noodles for lunch, strawberries for one snack and cottage cheese for the other. And she has eggs just about every morning. It's been a struggle, but I've been moving her in the right direction.

I'll look into those resources regarding functional orthodontics. I hope we can get by without extractions. I had 5 teeth pulled as a teenager followed by 6 years of braces (all through college!). It was no fun. My only saving grace is that three of my wisdom teeth were congenitally absent, and the fourth had plenty of room to come in normally. My current dentist keeps threatening to pull it because it's continuing to grow down and he's worried it will press down against the gum of my lower jaw when I bite because there's no lower 3rd molar to press back against it. Not sure what to think about this, but I'm sure to get a second and third opinion before letting him do it.

Thanks everyone!

Half Navajo said...

anna,

you should look up Raymond Silkman, he is in the L.A. area, he wrote a really good article a few years ago for the weston a price foundation about cranial facial development. Its what got me into functional orthodontics. I had it done... i had already had my wisdom teeth extracted when i was 19, other than that all my teeth fit in my mouth...haha... i have a well developed mandible, but my maxilla was a tad under developed. I had the the schwartz appliance that widened alittle, then an appliance that pushed my front teeth forward. This took 8 months... then i had braces for 8 months... I hated having braces, they seemed to negatively affect me in some odd way... i couldn't wait to get the metal out of my mouth by the end of it!!!

Everything worked out great though... my bite is perfect. i am glad i had it done... it cost a bit though...

troy

Helen said...

I had written a long personal saga in response to this, but it got lost, so let me just say...

Malocclusion: it happened to me.

Ken said...

Aaron Blaisdell
Infant Vitamin D Supplementation and
Allergic Conditions in Adulthood
.

Consider, if vitamin D is so very good in amounts difficult to get from normal activities Europeans (who've worn clothes for 30,000 years) would have evolved to maximize Vitamin D levels. Well they don't!
Why are Europeans white? .

Ken said...

The Growth Hormone Receptor Gene is Associated with Mandibular Height in a Chinese Population.

Ken said...

According to The History of Man by C.Coon wild animal dwarf species have proportionately smaller teeth than the full size species but animals domesticated and dwarfed by man have teeth that are very large for their jaws

Toy dogs crowded teeth. It will be argued that toy dogs have been intensively bred for a characteristic (reduced size) that had the effect of crowding their teeth whereas natural selection in the wild would make malocclusion rare; artificial selection by man that produced toy dogs is very different to the process of natural selection in the wild which improves functioning and would tend to weed out maloccusion. That is true however sexual selection can produce results that are sub-optimal if the pay off outweighs the cost. I maintain that the occurence of crowding in Europeans is largely due to the reduced size of the jaws due to sexual selection for feminine features.

The point you made about crowded teeth being less appealing than straight teeth is true; if you'll look at the women's interest magazine covers you will see that most of them have a female model showing off her excellent set of teeth.

However if you'll look at the men's interest magazine covers you will notice that their female models who are trying to look sexually appealing do not usually show their teeth.

Andy said...

Ken,

I am by no means an expert on this subject and take into consideration that these are just a couple of thoughts I had. Feel free to correct me.

I believe Europeans would have adequate vitamin D levels almost all year-round if we spent most of the days outside. I remember reading somewhere that a white male in shorts and a T-shirt in New York in July will produce about 10 000 IU of vitamin D in 30 minutes. So when we spend most of the days outside, we wouldn't need more vitamin D and hence we haven't evolved to further maximize it. Vitamin D has a half life of 1-2 months, so we probably would get through most of the winter with our reserves.

The Vieth review of vitamin D says "Ultraviolet exposure beyond the minimal erythemal dose does not increase vitamin D production further. The ultraviolet-induced production of vitamin D precursors is counterbalanced by degradation of vitamin D and its precursors. The concentration of previtamin D in the skin reaches an equilibrium in white skin within 20 min of ultraviolet exposure". They also suggest the amount of vitamin D produced from one session would be comparable to a 10 000 IU oral dose and that the time can vary depending on skin pigmentation.

Stephan showed that Caucasians in Kentucky on their natural diet didn't have malocclusion, while young people in Kentucky on a poor diet did. NAPD by Price also discusses about isolated and modernized Swiss people. The ones on a nutrient dense diet have very good occlusion, while the modernized people don't. This is the same with every other race and culture. On a good diet, no malocclusion. I can't think of a way how the theory that Europeans have high rates of malocclusion due to our genes could possibly be true when it has been shown that they have excellent occlusion on a proper diet just like every other culture.

Ryan Koch: Health Matters to Me said...

Stephan,

What are some key features to indentify an infant with optimal craniofacial development? Round face? Chubby Cheeks?

I'm attempting to compare infants raised on a raw vegan diet with infants raised on a WAPF-style diet ...

Stephan Guyenet said...

Hi Ryan,

I wish I knew the answer to that question. I do notice characteristic skeletal features of teens and adults raised on vegan diets-- a hunched posture, thin frame and narrow shoulders and hips. I can't really tell at younger ages at this point; I don't know what to look for.

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