Does My Child Need An Expander, And If So, How Does It Work?



In this article, I want to share a few tips for parents to determine whether or not early expansion treatment is appropriate for their child.


In my view, only cases that exhibit a true skeletal constriction of the upper jaw should receive skeletal expansion treatment of the upper jaw. So what does that mean, exactly? It means that if your child exhibits a posterior crossbite relationship on one or both sides, then he/she would be a good candidate for early expansion treatment. A posterior crossbite relationship means that all of the upper back/side teeth on one or both sides are fitting inside the lower back/side teeth.


A posterior crossbite on one side is more common than a posterior crossbite on both sides. A unilateral posterior crossbite is often associated with a sideways shift of the lower jaw to the side where the crossbite is present. This shift occurs because when the child closes centered, he/she is not able to gain any contact of the back teeth necessary to chew food, and subconsciously figures out that by shifting the lower jaw off to one side, contact between the teeth can then be achieved in order to function.


Unfortunately, this lower jaw shift results in a muscle imbalance. The muscles on the side of the face the jaw is shifting towards are contracted while the muscles on the opposite side are being stretched. Long-term these types of muscle imbalances can lead to temporo-mandibular disorder (sore, fatigued jaw muscles, headaches, etc.), not to mention how they may be acting on a growing face. It is important to coordinate the skeletal arch widths so that the bite can be centered and muscles can be returned to a state of balance.


A palatal expander should be custom-made, cemented on the teeth and include an expansion screw to be turned with a key. In my office I prefer to use a four-banded expander (four teeth are custom fit with bands/rings) as opposed to an acrylic-bonded expander. While a banded expander requires more work and skill on the part of the orthodontist, it is more hygienic and has greater patient acceptance. An impression or dental scan (now available at Luks Orthodontics) is taken of the teeth and sent to the lab for the appliance’s fabrication. At the cementation appointment, we instruct the parent how to turn the expansion screw and at what frequency. Each turn of the screw (1/4mm/turn) opens the midline palatal bony suture to widen the upper jaw. On turning the screw, there is a momentary sensation of pressure that dissipates within seconds.


In my office, I like to assess the amount of expansion about 7 to 10 days after the appliance was cemented. It is normal to observe a good size space developing between the upper two front teeth; this is proof that the expansion is working just as expected. And not to worry, we always straighten and close the spacing of the adult upper four front teeth with four little braces while we wait for the bone cells to do their work to fill in the space between the two halves of the palate we successfully separated.


When treatment is completed, a retaining wire is custom bent in-office and cemented to the back side of the upper four front teeth.