Dental Education Lecture: Adult Brushing
In lecture Brushing for Kids, we discuss that every tooth should be brushed in 3 distinct areas to prevent cavities. We should apply the same principles for our adult dental care to prevent gum diseases. How do we brush? It depends on where our teeth are.
Fig.1 shows the biting view of the lower teeth, baby (A-E), adult (1-8), and the tongue in the middle. We usually do not brush the last teeth very well (#8 or E). The outside surface (buccal, next to cheek) of our teeth are brushed cleaner than the inside surface (lingual, next to tongue). Let us take a look at Fig.2. The latter reveals lower (1) and upper (2) back teeth in a cross section. The pink area represents the gums. The curved arrow below on the left points to an area we call gum groove, at the junction between the tooth and gums. This is the most dirty area if we do not pay to attention to brushing detail. Why? When we chew, food particles (several empty circles between upper and lower teeth (1 and 2) slide along tooth surfaces for self cleaning. Due to special morphology of our teeth (curvature), food particles do not enter and pass into the gum groove for the "free" cleaning (as shown in arrow on the right side of Fig.2). Therefore we should aim toothbrush at 45 degree toward the gum groove in a slow gentle stroke. We should brush 2 to 3 teeth at one time, i.e., small stroke. If we brush using excessive force and in a wrong direction (Fig.4), the gums are gradually pushed down along the root (pink area, as compared to that of Fig.3). A notch is created in the root surface (arrow, Fig.4), causing sensitivity to brushing, cold or sour food/drink. If you are interested in knowing what this type of notch looks like, see Fig. 3 in Lecture Cases of Filling. Incorrect way of brushing an lead to accumulation of plaque and tartar (calculus) (yellow) in the tooth surface next to the gum groove and the gums become inflamed and swollen (red, Fig.5).
To prevent gum recession and gingivitis, we need to brush the gum groove in 45 degree, both outside and inside surfaces of each tooth (Fig.3 and 4). The third surface needing to be brushed is the biting surface, in a 90 degree angulation, as shown in Fig.7. Do not forget brushing the last teeth in our mouth. Every time we pick up a toothbrush, we should realize that it is one of most important things to do for ourselves. Most of dental ailments can be prevented by right ways of brushing. We should concentrate upon brushing, executing precisely as described here. Forget about anything else, happy or miserable in our life, temporarily, at least two minutes. In How to Brush lecture, we use photos to show you where is the most nasty area in our teeth and how to clean up.
Although correct methods of brushing are critical, they are still not enough for overall oral health. We should use dental floss as well.
Xin Wei, DDS, PhD, MS 03/20/2010