Dear Dr. Mady: 
My six year old is going to lose one of his baby molars because of a large cavity. Our dentist wants to pull it out and replace it with something called a space maintainer. What is it and is it really needed? Natashia M. on the internet in Grosse Pointe Mi.

Dear Natashia,
Primary teeth usually stay in position until they are pushed out by an erupting permanent tooth with it’s roots two-thirds formed. Primary molars specifically remain until about the age of eleven or twelve years. If a baby tooth is lost early from decay or trauma, a space maintainer basically holds the space open for the permanent tooth to erupt into proper position.

Without it, the teeth behind the empty space usually want to drift mesially or forward and can obstruct the path of the adult teeth. This may result in an un-erupted permanent tooth and/or what is known as malocclusion or an improper bite due to improper positioning of the teeth. The space maintainer also promotes and encourages normal development of the jaw bones and muscles, in addition to saving space for future teeth.

In the case of your six year old, your dentist is making the right choice. If the baby molar is extracted, the space absolutely should be maintained. If the space is not maintained, surrounding and opposing teeth will attempt to fill the space by drifting, tilting, or even by extruding (hypererupting) up or down. The permanent tooth, if it does come in, may come in causing crowding or misalignment. If this occurs, the end result could be the need for oral surgery, or orthodontics beyond the normal realm.

Space maintainers are oral appliances that can be made of plastic (acrylic) or metal or a mixture of both. The most common type is known as a “band and loop” type that is made of a band similar to the ones used in orthodontics with a soldered wire or loop in front of the band. The band is usually cemented around the tooth directly posterior (behind) the space and the loop usually rests against the tooth in front of the space.

If it is desired to hold space open on both sides of the dental arch, then the appliance is known as bilateral. In your child’s case, a unilateral type is required. The appliance will be custom fit to your child’s mouth and will take no time at all to get accustomed to. The appliance will be easily removed when the permanent tooth is seen erupting properly. The procedure is much more affordable and easier on your child than braces. Even if orthodontics are required later, the time spent wearing braces may be decreased from wearing the space maintaining appliance.

While wearing a space maintainer, have your child avoid hard sticky foods or candies. Practising good oral hygiene is imperative and adding a daily fluoride rinse will help tremendously in preventing decalcification around the band. Remember that if the band comes loose or comes out, don’t wait. Contact your dentist immediately because surrounding teeth can begin moving within hours if allowed!

Any questions for Dr. Mady can be e-mailed to drmady@drmady.com and also visit his blog at www.dentalden.com (dental education network)

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This column is reprinted with the permission of the author and The Windsor Star. “Ask the Dentist” is written by Windsor dentist (and ECDS member), Dr. David Mady Jr.. The column appears the first Thursday of each month in the Windsor Star. Readers with questions can write to “Ask The Dentist”, c/o The Windsor Star, 167 Ferry St., Windsor Ontario, N9A 4M5