Why do teeth grow in crooked?

The jaws of this 10-year-old are too narrow and her teeth are all tipped inwards. Early childhood asthma is the likely cause.

Crooked teeth are most often due to the jaws being too small rather than the teeth too large. Here’s an example to describe this. Imagine taking a room in your house where all of the walls were neatly lined with chairs and small sofas that were all touching. If you were to change the square feet of the room, making it smaller, all of the furniture would be bunched up and crooked instead of straight.

It is the same situation with jaws and teeth. If the jaws grow so narrowly that there is no room for the teeth, they will be bunched up and crooked. Current thought is improper breathing, diet, and pollution as a child develops causes improper growth of the jaws. If a child only breathes through their mouth, the tongue lays low so air can come through. This is not good because the tongue is needed to form the roof of the mouth and make it a U shape instead of a V shape. The U shape is developed by the tongue pushing on it during normal swallowing.

OK, so how can this be corrected?

This is an example of a bonded palate “expander”, only one type of appliance used.

With today’s dental technology, bone can actually be expanded in a way that places growing jaws into the right position, and makes them the correct size. The key to success is the age of the person who needs the procedure. If you wanted to have a unique bend or curvature of a tree in your back yard, you would need to start when the tree was a sapling, and the same holds true for people.

In our practice, when we see children at about age 7 developing jaws that are too narrow to fit the incoming adult teeth, we refer them to an orthodontist for evaluation. Children at this age do not need braces, which only move teeth, but rather appliances that help direct proper jaw growth (see the photo). These usually fit in the roof of the mouth, and sometimes on the lower jaw as well; some types are removable and some are bonded to the teeth, the type differs based on the exact dental condition. The appliances are used to put pressure on the bone of the jaws, causing it to grow wider.

Wow…doesn’t that hurt?

Kids are tough and adaptable. After the first week most kids get totally used to the appliances, and learn how to eat, talk, etc and to keep everything clean. Also, because the pressure is placed so slowly most kids don’t even feel anything happening…until a few months pass and the parents and orthodontist compare the change! We feel great about this type of treatment because we know our orthodontist will put everything in its right place, and children will develop the right jaw-to-jaw relationship for the rest of their lives.

Great for kids, but what if I am an adult needing to “expand” my jaw?

So this is where treatment gets more complicated…but also can have even greater benefits! There is a direct link between too-narrow jaws with crowded teeth and snoring or sleep apnea. Think of it this way…the roof of the mouth is actually also the “floor” of the nose. If the palate is narrow, so will the nose be narrow…and harder to breathe through as well. Adults like this are more likely to breathe through their mouths all day long, but also at night…which creates snoring sounds!

Because adults’ jaws aren’t growing anymore, the orthodontist might need the help of an oral surgeon to section the palate so an appliance like the one for children can be used to “grow” the jaw wider. The amazing this is that when pressure is placed to push the bones apart with this technique, bone is tricked into growing as though the patient were a child! This treatment can be extremely effective for patients who are diagnosed with Sleep Apnea and who use a breathing machine (called a CPAP) at night to sleep; sometimes after the jaw is widened the CPAP may no longer be necessary, or can be used at a much lower setting, making it more comfortable to use.

Are there other reasons jaws should be expanded?

Here is another reason early intervention is important and downright essential. Symmetry is beauty. The jaws and teeth make up one third of the face and if they don’t develop correctly, the face will not be symmetrical. In our office, we usually joke about it, saying “your son/daughter will be even more beautiful with wider jaws”…but it’s true! Look at the faces of those around you who you find beautiful…and I can almost guarantee they also have beautiful, wide smiles and proportional faces!

Having an evaluation for your child earlier (around age 7) can lead to minimal treatment. Most people do not have crooked teeth, they just have limited room. Make space by growing the jaws properly, and the teeth will “fit” with less help from traditional braces.