Dr. Brian's Column

Space Maintenance

The difficulty and complexity of orthodontic treatment for crowding can be reduced by proper maintenance of space in the primary and mixed dentitions. That is, we want to try to avoid crowding as much as possible, and we do have some control over a crowded permanent dentition. The primary dentition includes the baby teeth and starts at about 6 months of age and ends with the eruption of the first permanent tooth (usually the lower front teeth or central incisors). The mixed dentition contains both baby (or primary) and permanent teeth. This lasts roughly from 6-13 years of age.

In the primary dentition, the first thing that must be recognized is spacing of the baby teeth. It may seem logical that if your child has nice straight teeth, with no spaces, they are set up for an ideal permanent dentition. However, the opposite is true; it is more favorable to have extra space in the primary dentition for the erupting permanent teeth as they are larger and require more space. Therefore, spacing between the baby teeth is a very desirable situation. Seeing spaces in your child’s baby teeth should cause no reason to worry. Conversely, if your child’s teeth appear straight and there is no spacing, crowding may develop and an early orthodontic consult is probably a good idea.

As the child grows, it is critical to maximize the amount of space for the erupting permanent teeth. Things such as early loss of a tooth (usually through trauma) or extensive decay of teeth can lead to loss of space for the erupting teeth. Teeth have a natural inclination to “drift” toward the midline of the dental arches. Therefore any space left open, say from a tooth being knocked out playing baseball, will allow the teeth behind to tip into that space. The effect this will have will be to “block out” the permanent tooth for that spot. Now we have a crowding issue because that tooth has nowhere to erupt, and will start to erupt into unnatural places.

If a tooth is lost prematurely, that space can still be saved if the problem is addressed in time. The general dentist, the pediatric dentist, or orthodontist can make an appliance called a space maintainer to alleviate the problem. Space maintainers come in a variety of forms, and can be adapted to virtually any situation—and they work! They do this by holding the tooth behind an empty space in its position, preventing it from tipping forward. This will “hold” that space until the permanent tooth erupts into its natural position.

In summary, the objective of space maintenance is to allow permanent teeth the proper amount of space to erupt into their most natural position. This will undoubtedly reduce the time and complexity of any orthodontic treatment that may be needed for the child. Excess space in the permanent dentition is far easier to close than trying to create space for teeth in a crowded dentition. With proper observation and recognition of a child’s dentition the practice of space maintenance becomes an easy and practical way to ensure straighter teeth and often, much simpler orthodontic treatment, if it is needed.