Some people have a narrow palate for a variety of reasons:

• thumbsucking
• pacificer use
• low tongue posture
• birth defects like a cleft
• mouth breathing
• unknown reasons

Depending on how the narrow palate formed, the treatment will include some intervention such as surgery for a cleft or a habit treatment.  But almost every treatment will include an appliance to widen the narrow palate if there is  a cross bite.

Crossbites are the upper teeth biting inside the lower teeth.  See this discussion of crossbites for more details of the various kinds of crossbites.

Although both sides can be in crossbite, most crossbites occur only on one side, a unilateral crossbite.  These cause the lower jaw to swing toward one side so the lower midline is moved toward the crossbite side. 

Because the lower jaw is made out of one bone, it is harder to change shape.  The upper jaw is made of two bones that can be moved more easily and effectively.  An appliance to widen the upper jaw usually works in 6 weeks and then stays as a retainer for another 4 months.

I like to use an expander that covers the posterior teeth because it helps prevent the downward movement that is usually found with expansion of the upper jaw due to biting force.

This expander is bonded to the teeth to seal out plaque and to get a very firm hold on the teeth so that they do not tip and they move the bones apart more effectively.

This bonded palatal expander moves the jaw bones relatively rapidly compared with a removable one that takes many months to widen the upper teeth (and that mostly moves the teeth rather than the bones) so it is called a Rapid Palatal Expander or RPE for short.

A RPE will almost always spread the maxilla or upper jaw bones enough to make a temporary space between the upper front incisors.  The gingiva or gums are full of stretchy collegen fibers that connect the teeth and act like rubber bands to close the space between the front teeth rather quickly.

 After correction of the crossbite, the lower jaw will move back to center the midline and the non-crossbite side moving backwards to match the joint on the now corrected crossbite side.  This is according to: Changes in condylar position and occlusion associated with maxillary expansion for correction of functional unilateral posterior crossbite in American Journal of Orthodontics and Dentofacial Orthopedics, Volume 111, Issue 4, Pages 410-418 by K. Hesse, J. Årtun, D. Joondeph, D. Kennedy.

What this tells me is that because the non-crossbite side cannot easily move backward (due to the structure of the joint), the other side has to move out of position downward and forward.  Once the upper jaw is expanded to the correct width, the lower jaw can resume the correct position and the corrected side joint will move up and back to match the crossbite side.

Overall, the RPE is a relatively quick and effective way to expand your palate for both unilateral and bilateral posterior crossbites.

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Expanding Your Palate

• crossbite
• cross-bite
• cross bite

An anterior crossbite involves the front teeth and a posterior crossbite involves the back teeth.

Rarely, the upper posterior teeth bite completely outside the lower teeth in a condition called a scissor bite. 

A posterior crossbite can involve either one side, called a unilateral crossbite, or both sides, called a bilateral crossbite.

Now that all the definitions are out of the way, lets look into why they are a problem.

All crossbites cause a shifting of normal chewing patterns.  The lower jaw works best to chew food if it is free to move not just up and down but side to side and front to back.  Think of a cow chewing its cud with the exaggerated jaw movements and you will get the idea.

When the upper jaw has one or more teeth that hang down inside the lower teeth, the full movement is not possible and a more up and down chewing movement results. 

Upper front teeth can also look bad if they are in crossbite and the lower teeth rub the front of the upper teeth.

Most seriously, the lower front teeth are much more likely to have gingival recession or other gum and periodontal problems if they are pushed forward by upper teeth in crossbite.

How can crossbites be corrected?

Anterior crossbites are corrected with an appliance that attaches to the permanent molars and pushes or pulls the upper front teeth forward.  Usually this is a rather quick procedure that might take a few months. 

Once an anterior crossbite is corrected, it will usually stay corrected if the upper teeth cross over the lower teeth enough vertically.

Posterior crossbites are usually corrected by expanding the palate, but sometimes by just moving one or two teeth. See the article on Expanding Your Palate for more on this.

Correcting scissor bites are a bit more difficult and usually requires some braces, at a minimum on the involved teeth and the opposing teeth with  a rubber band stretched vertically.  More often, braces on all the top and bottom teeth  in the area are more effective.

As you can see, crossbites can be a problem but can also be fixed  with relatively little work.

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Crossbites

The primary baby teeth are important for chewing and biting and speaking and especially for maintaining the space needed for the future permanent adult teeth.

Luckily, missing front teeth do not seem to have as much trouble with space loss as missing back teeth.  A gap-toothed grin in a kid is much cuter than in an adult!

But when a primary molar is lost by infection or trauma, the gingival gum fibers and the angle of the jaws closing together make for a strong tendency for the adjacent teeth to move into the newly open space.

In other words, the space will be lost.

While initially the loss of a primary tooth does not seem like such a terrible thing, the future consequences could be the loss of a permanent tooth, extensive and expensive orthodontic appliances, and even an uncomfortable bite that causes abnormal wear on the poorly positioned teeth.

We routinely make a small appliance that spans the gap to keep the the space open.  This is called a band – loop space maintainer.  It is made with a metal orthodontic band with a wire stretching across the missing tooth’s space.

Adults need to have an artificial tooth made to replace missing permanent teeth because the teeth on the other jaw can over erupt.  Children are growing so much and their adult teeth will come in soon enough that this is usually not a problem for them.  An artifical tooth is not needed.

If more than one tooth is missing, a better way to save the space is to use an appliance that goes from a permanent tooth on one side to one on the other side of the mouth.  These are called a lower lingual arch to replace bottom teeth or a transpalatal arch to replace upper teeth.

If teeth are crowded, sometimes teeth must be extracted to make room for the others to line up.  Often a lower lingual arch or transpalatal arch can keep the room that remains, and even stretch the space.

Taking care of them is easy with only minor restrictions of not playing with them and keeping them clean.  These appliances will stay in place until the permanent teeth erupt.  Usually braces are needed after all the permanent teeth erupt but the treatment will be easier.

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Saving Space

Usually dentists prefer to treat infected root canal pulps before they start to hurt because this is the most comfortable way to go.  Waiting for a tooth to hurt before starting root canal treatment is usually less comfortable.

Permanent teeth with infected pulps need root canal treatment. 

The steps of root canal treatment:

• Numb the tooth with local anesthestic, usually 4% articaine or 2% lidocaine instead of novacaine.
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• Stretch a rubber dam over the tooth to keep saliva from re-infecting the cleaned root canal.
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• Remove any decay with a handpiece drill and remove the infected pulp. 
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• Use extremely small wire files to scrape the tissue from the canals in the roots.
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• Measure the length of the files to know exactly how far it is to the end of the root.
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• Rinse the infected material from the root canals with disinfectants, often sodium hypochlorite.
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• Soak triple antibiotics in the cleaned, shaped, and smooth canals to fight infection.
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• Pack pink, rubbery gutta percha into the root canals all the way to the tip, with runny sealer to fill in any gaps.
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• Place a filling in the hole and plan on a crown to hold the weakend tooth together.

Primary teeth with infected pulps are treated differently than permanent teeth. 

Primary molars last until about age 11 or 12 so we like to save them with root canal treatment, if we can, instead of pulling them out and placing a space maintainer.

Because primary teeth roots need to dissolve away when the permanent teeth start to grow in, the root canal material used for baby teeth should be dissolveable or not go all the way down the root canals.

Most of the  time, primary teeth with infected pulps are treated with a partial pulp removal called a pulpotomy.

The pulpotomy procedure:

• Numb the tooth with 4% articaine or 2% lidocaine (almost always with 1:100,000 epinepherine).
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• Stretch the rubber dam around the infected tooth to seal out infected saliva.
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• Use a handpiece to drill away infected tooth and cut the infected tooth pulp in the top coronal pulp chamber. 
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• Stop any bleeding with ferric sulfate, then swab out the chamber with diluted formocresol.
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• The infection is often only in the top of the tooth so using medicines like formocresol or ferric sulfate will treat painful nerves and kill the germs in the remaining pulp tissue.
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• Fill the pulp chamber with zinc oxide and eugenol filling to form a tight seal and prevent bacterial entry.
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• Place a tightly fitting stainless steel crown or a composite filling.

These pulpotomies are very successful for teeth that have not infected the bone supporting the tooth.  If the bone gets infected, then all the pulp tissue must be removed, even the root canal tissue, in a pulpectomy.

A pulpectomy procedure is similar to the adult root canal treatment in that files are used to clean and shape but the filling is much different.

The root canal filling material for primary teeth must be resorbable or dissolvable.  I use a material called Vitapex (a mixture of calcium hydroxide, iodoform, and silicone lubricant) with great success healing abscessed teeth. 

Pulpectomy treatment  for primary teeth is mostly reserved for only the most important teeth: the second primary molars before the eruption of the permanent molars.

When faced with the options of a painful toothache, a root canal, or an extraction, most people will be pleasantly surprised that those root canals are the best option and not an “OUCH!” after all.

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Treating Portland Pulps & Root Canals

Some orthodontists recommend treating crooked teeth or teeth that do not occlude (bite together properly) in two phases or treatment steps.  The first phase usually starts around second or third grade and a second phase around sixth grade.

Treating jaw problems early has not been well supported with excellent randomized controlled clinical trials.  These studies show that equivalent results are achieved with either one or two phases of treatment but that two treatment phases usually costs more and takes longer.

I believe that there ARE tooth alignment or spacing problems that are best treated early; before the back primary teeth come out. 

Reasons to treat early:

• Congenital problems such as cleft lips are best treated very early, then off and on for many years.
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• Thumb or finger sucking, pacificer use or tongue thrusting all can move teeth and even bend the jaw bones. 
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• Appliances to treat these problems early are very appropriate if other methods fail.
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• Upper teeth that stick out very far risk being broken in an accident so braces can help pull these back to safety.
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• Upper teeth that bite inside lower teeth are called crossbite teeth and should be treated early.
•  
• Narrow upper jaws are best treated early when the bones are most flexible.
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• Very crowded teeth may need to be extracted to make room for the others to straighten up.
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• Holding space is always a good idea with primary tooth loss.
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• Because the lower primary molars are usually much larger than the permanent premolars that replace them, holding this space with a metal wire appliance can usually save space for alignment without extractions.

Reasons to wait until later for orthodontic appliances:

• Two sets of braces costs more than one set.
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• The novelty of braces  wears off quickly so they are not so fun to wear any longer than necessary.
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• Putting braces on, getting straight, taking off, wearing retainers, putting braces on, getting straight, taking off, wearing retainers: just takes longer.
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• The longer braces are on, the more difficult it is to keep them clean and avoid cavities.
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• Braces come off when the second molars are straight, usually after age 12. 
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• Retainers for life follow orthodontic appliances so the sooner you start, the longer you will need to have retainers.

As you can see, there are some reasons to start early but if your child has crowded teeth and can wait until middle school, you and your child will be better off for waiting.

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When to Start Kids Braces?

We move teeth with brackets glued to teeth and wires between them.  The trick to moving teeth orthodontically is to have the gentle forces continue for a long enough time.

Wires are where the forces come from.  Orthodontic wires get bent into the crooked teeth and as they straighten, they pull the teeth straight also.

Relatively new super wires are able move teeth faster and more comfortably. They can be soft with cooler temperatures and stiffer with warmer temperatures.

The advantage of changing stiffness with temperature is that they can be cooled to bend them into the braces easily then they move the teeth more quickly as they warm up to body temperature.

These thermally sensitive orthodontic wires come in many different shapes:

• simple round wires
• braided round wires
• square wires
• combination wires with rectangular and round in others
• rectangular wires
• wires with different strengths in different areas

Orthodontic wires also come in several different materials and a huge variety of thicknesses.

Which super wire  to use is dependent on how crooked the teeth are and if teeth roots need to be moved or not.  Extremely crooked teeth will usually need small diameter braided round wires.  Less crooked teeth will use solid round wires.

If only the front teeth are twisted but the back teeth are not, then we consider using a wire with different stiffnesses in the front and the back.

Rectangular wires are used to move tooth roots.  The slot in the orthodontic bracket is rectangular so a rectangular wire will be able to twist and torque the tooth roots in the proper directions.

These super orthodontic wires are made of an alloy of  nickel, titanium, and copper.  Other wires are made of nickel and titanium but heat treated differently to make different metal crystals with different flexibility properties.

When we get close to the end of treatment, we need to bend the wires.  These wires are made of stainless steel or titanium alloys.  The bends compensate for the brackets being slightly out of position since it is impossible to get them perfectly placed when first glued on.

Orthodontic wires are hard to clean and sometimes pokey but they are the work horses that get your teeth straight.

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Super Orthodontic Wires

Icy hills are lots of fun to slide down but those smiles can quickly turn to frowns and tears with a bad fall.

If your child gets into an accident that damages teeth, follow these steps:

• Check that there are no skull, neck, or back injuries first.
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• Cuts / scrapes on the head will bleed heavily so control any bleeding with pressure.
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• Look at the eyes and nose for anything unusual.
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• Move the jaw to see if there is any strange movement or lack of movement.
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• Lips are frequently scraped and swollen.  Apply cold clothes to reduce swelling.
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• Look at the tongue and inside of lips and cheeks for bites or tears.  Call the doctor if bleeding will not stop.
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• Make sure the teeth come together as before and call the dentist if there are changes.
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• If permanent teeth are knocked out of position or out of the mouth, put them back where they came from as soon as possible.  Then call the dentist immediately.
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• Chipped teeth can be fix fairly easily.  If a large piece is found, keep it moist and bring to the dentist.
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• We do not usually worry about baby teeth that get knocked out but an x-ray will often be needed to see if all is well.
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• Teeth commonly get knocked slightly loose with bleeding around the gums.  Do not worry about this.  Watch for future color changes.
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• If you can take ibuprofen, do so.  It is a good pain reliever and an anti-inflammatory swelling reducer too.

If you see any major changes, call your doctor or dentist.

Dental treatment that your child may require:

• Evaluation for concussion or spinal cord injury.
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• Teeth out of the mouth must be replaced and held in place IMMEDIATELY.
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• Cuts or scrapes will have to be cleaned out and possibly stitched.
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• Large chips off teeth can sometimes be glued back on so bring the piece into the dentist.
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• If the nerve is exposed, you will most likely need a root canal treatment some day.
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• If the whole top of the tooth is broken off below the gums, the root may have to be extracted.
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• Reduce swelling by alternating ice in a washcloth on 3 minutes, off 3 minutes.
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• Take an anti-inflammatory medicine.

Prevention is always better than restoration.  Always wear a helmet and consider getting an inexpensive mouth guard from the sporting goods store before going sledding, boarding, or skiing.  

Avoid sledding head first.  People with front teeth that stick out or who have difficulty closing their lips over their teeth should be especially careful to avoid injury.

Have fun this winter and show off your pearly whites safely.

Post from: Great Grins

Icy Tooth Accidents in Oregon

Dental plaque is a thick sticky waterproof cream-colored coating that develops on teeth over time.  It is made up of bacteria and their wastes with saliva components. 

Sticky mucopolysaccharides are the mortar of dental plaque.  They protect the bacteria by gluing the whole colony to tooth enamel and making them resistant to washing off with normal eating and drinking.

If you start with perfectly clean teeth, very quickly a glycoprotein coating called pellicle will coat the enamel.  Because bacteria are still present in your mouth and will immediately stick to this pellicle on your tooth enamel. 

The bacteria grow and grow until there are literally trillions of them.  Usually it takes about 24 hours before there are enough to damage your teeth or gums.

After one to three days, another group of bacteria will stick to the first ones.  This makes the plaque more complex with the wastes of some being the food of others.

After plaque has been on teeth for about a week, the dental plaque changes color and texture.  Usually bacoming a dark yellow or light orange color, this plaque is very stiff and may need to be scraped off with a toothpick or dental instrument.

Lactic acid builds up in dental plaque and over time can dissolve the enamel surface of teeth.  Cleaning off the dental plaque gives the enamel access to the minerals present in saliva that can restore enamel strength.

Streptococcus mutans is the most prevalent bacterium in dental plaque.  This bacteria is especially good at converting sugars and starches into lactic acid and so it is responsible for most peoples cavities.

Other bacteria present in dental plaque above the gumline are:

• Streptococcus sanguis
• Actinomyces viscosus
• Actinobacillus actinomycetemcomitans
• Capnocytophypa species
• Eikenella corrodens

Bacteria only found below the gums to avoid oxygen are:

• Porphyromonas gingivalis
• Fusobacterium nucleatum
• Prevotella intermedia
• Bacteroides forsythus
• Campylobacter rectus

This links to an excellent discussion of dental plaque.

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Plaque in Portland

Some parents tell me that they have heard that it is impossible to get cavities from mother’s breast milk.

My experience shows me that although nursing is the best way to feed your infant, it is possible to get cavities while nursing.  I have seen one year old children with cavities who have only drank mother’s milk.

All the infants with cavities on their upper teeth who never had a bottle did sleep with their mothers and nursed as often as they wanted, usually suckling all night long.

This continuous exposure to sweet milk can overcome the natural cavity-fighting abilities of milk proteins and allow bacteria to grow rapidly and help dissolve away the teeth.

Sleeping with your baby can be harmful to them in other ways too.  Sudden Infant Death Syndrome, SIDS, is also increased when infants sleep in the same bed as their parents.

The best way to nurse your baby is to keep them out of your bed, perhaps in a bassinet close by, and encourage them to feed very well with plenty of time to sleep and digest before another feeding.

Cavities can start forming as soon as the teeth erupt into the mouth.  Everyone has bacteria in their mouth that came from the people around them, usually their mother.

The type of bacteria that cause cavities (Streptococcus mutans) make a waterproof coating that sticks them to the tooth surface.

Because bacteria cause cavities, not sugar or milk, brushing the bacteria off of teeth is the most important of the cavity prevention strategies:

• brushing & flossing
• receiving optimum dietary fluoride
• limiting time exposed to sugar and starch

So make sure that you massage your baby’s gums with a soft cloth before they get teeth and use a soft bristle toothbrush to clean off their teeth when they erupt.

The La Leche League has some good articles and  I especially liked this one on preventing cavities while nursing your infant.

Post from: Great Grins

Cavities from Breast Feeding?

When I looked at it, I noticed that there was an infection around the last molar, next to where the permanent tooth develops. 

Since it could be either an infection of the tooth that spread to the gingiva (gums) or an infection of the gums that could affect the developing teeth, we took an x-ray.

The x-ray showed no tooth infection but a big infection next to the growing permanent molar.  Feeling around, I could tell that the gums were very infected because lots of food was stuck under the gums, in particular a popcorn kernel. 

Popcorn kernels are almost the same shape as a tooth and can easily slip under the gums and start an infection.

After cleaning out the infection, I gave the boy a plastic syringe that can easily fit under the gums.  His mother will mix salt with warm water and gently irrigate the infected area several times daily for a week.

Salt tastes bad and is uncomfortable in wounds but it is especially uncomfortable for bacteria.  Germs do not like it so salt water rinses help heal infections.  Rinsing sores with salt water is an old home remedy, but it works!

Of course, other medicines work with gum infections too.  Listerine has alcohol and plant oils that have been shown to kill germs. 

A prescription mouthwash that works great has chlorhexidine in it.  Rinsing or brushing with chlorhexidine has a dramatic improvement in gum health.

The basics of brushing and flossing gets rid of most mouth bacteria that cause gum infections and bad breath but mouthwash will only help.

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Gum Infections in Portland