The enamel on baby teeth is thinner and softer than on permanent teeth and decay can move through it very rapidly. Some children develop decay as soon as a tooth erupts and about 50 percent of two-year-olds have at least one cavity.
Baby bottle tooth decay occurs when sugary liquids, including milk, juice, or formula, cling to the baby's teeth, particularly when the child is put to bed with a bottle. The decay occurs most often in the upper front teeth but other teeth also can be affected. If a decayed baby tooth is lost too early, the adjacent teeth may move into the space, causing crooked and overcrowded permanent teeth.
In a perfect jaw, all of the teeth fit exactly without crowding or spacing. The teeth are not rotated, twisted, or leaning forward or backward. With a perfect bite (occlusion), the teeth of the upper jaw slightly overlap those of the lower jaw. The points of the molars fit into the grooves of the opposing molars.
Few children develop perfect teeth and occlusion. More than 90 percent of children have some degree of malocclusion or poor bite. Skeletal malocclusions occur when the upper and lower jaws are not properly aligned with each other and with the skull. Dental malocclusions occur when the teeth are crowded or the upper and lower teeth are not properly aligned with each other. Malocclusions can be caused by the following:
crowded or misaligned baby teeth
premature loss of baby teeth due to decay or injury, so that the permanent first molars move forward, causing crowding and misalignment of the new front teeth
loss of permanent tooth structure due to untreated decay in the baby teeth
a tooth emerging at an angle such that it pushes on and damages an adjacent tooth
sucking that continues after the permanent teeth erupt
wisdom teeth that erupt crookedly
Some children experience mild, temporary symptoms of malocclusion resulting from a growth spurt. Severe malocclusion may require orthodontic intervention to improve appearance or to prevent problems with eating and speaking. Most alignment problems develop gradually, although they may be apparent at eruption. Symptoms of alignment problems include the following: