Dental Education Lecture: Brushing for Kids

Dental cavities are common in children.  Toothbrushing is one of the most effective ways to prevent cavities.  We are going to use illustrations to show how to brush their teeth in right manners.  Basically we need to brush teeth in three distinct surfaces in two angulations.

Fig.1 shows the biting surface view of the lower teeth (one side) of a 6-year-old child: A-E: baby teeth, whereas 6: adult 1st molar, A-C: baby front teeth, D-E: baby molars.  There are several grooves (shown as crosses) in the biting surfaces of the molars (D,E,6).  Food and plaque (germ film) are easily trapped in these grooves to cause cavities.  Fig.2 is a cut (along the red dashed line in Fig.1) surface (seen side way as indicated by an arrow) of three molars.  At that time, the permanent 1st molar (6) is erupting (breaking through the gums), causing a little discomfort (red spots).  It is lower than the neighboring teeth, which makes it difficult to clean there.  Because of discomfort with eruption, the kid is afraid to brush the area.  Food and plaque (yellow, Fig.3) is accumulating in the biting groove.  Dental cavity (black, Fig.4) may form even before the molar is completely coming in place. If you are careful enough, you may note the cavity in the biting surface (Fig.5).  To prevent cavities mentioned above, the kid should be encouraged to brush the biting surface as back as possible (Fig.6).   In spite of a little discomfort associated with tooth eruption, we still need to brush gently.  Contrary to our thought, gum inflammation will subside (pink in Fig.6 as compared to red in Fig.2,3).  In brief,  the bite surface is the first area that  needs to be brushed thoroughly and at the right angle (90 degree).

If children do not brush the second (buccal, outside) and third (lingual, inner) surfaces properly, food debris and plaque (yellow) deposit near gum lines of lower (1) and upper (2) teeth, causing gum swelling and redness (Fig.7)   There are also developmental grooves in the areas as shown in Fig.8, susceptible to cavities (black spots).  While we should brush the biting surface in a right angle (Fig.6), the buccal and lingual surfaces of the teeth should be cleaned in a 45 degree (as indicated by arrows in Fig.9).  Once the plaque is removed, the gums return to their normal color (pink).  Cavities in these areas are also preventable.

The developmental grooves in the biting, buccal and lingual surfaces are our tooth weak points.  Another way to prevent cavities in these surfaces is placement of sealant.  The biting, buccal and lingual surfaces are the area that can be kept clean by brushing, whereas the region between the teeth is not accessible to toothbrush.  We should use dental floss as well.  You can check here for more description of brushing for adults.

Xin Wei, DDS, PhD, MS 03/20/2010