There are a total of 32 permanent or adult teeth that erupt in the human mouth. With the exception of the third molars, which come through a few years after all the others, most of these will have pushed through the gums by the time a child reaches the age of 13 or so. As this transition happens, proper dental care is critical, and many children have to make adjustments to what and how they eat.
General Guideline
Typically, kids get their adult teeth in the same order they got their baby ones. They usually come in from front to back, with the exception of the first molars, and in general, the ones in the lower jaw tend to show up just slightly ahead of their counterparts in the upper jaw. The order of appearance is usually first molars and central incisors, lateral incisors, canines and premolars, second molars and third molars. It takes about six or seven years for all of them to erupt, not including the third molars.
Order of Loss
The central incisors are typically the first to come in. This typically happens around age six or seven, and in most cases, the lower ones appear first. At the same time, as the mouth expands, it makes room for the first molar teeth, which often appear between the ages of six and eight.
Following the first molars and central incisors come the lateral incisors. Kids usually lose the lower ones when they're about seven or eight, followed by the uppers a year or so later. The lower canines emerge at around nine or 10, as well, followed by the upper first premolars, also called first bicuspids, between 10 and 11. The lower first premolars and upper second premolars show up any time between 10 and 12 years of age, while the lower second premolars and upper canines appear when kids are around 11 or 12.
Next to erupt are the second molars, which generally appear when children are 11 – 13 years old. The lower set usually come through first. After this, kids get a bit of a break. They don't get their third molars until they're between 17 and 21.
Teeth Function and Eating Issues
Each type of tooth in the mouth has a specific function in terms of helping a person chew their food. The eight incisors — four on the top and four on the bottom — are the ones in front, and they cut and chop. The canines, which are next to the incisors, are meant to tear, so they are usually are pointy. Premolars grind and crush, while molars help move food around, mixing and squishing it before a person swallows.
With these roles clearly defined, it's very common for kids to have trouble with certain kinds of foods at different points. Apples and carrots, for instance, can be a problem when the incisors are loose or missing, and later on, when the premolars are emerging, chewing bites thoroughly is more of an issue. The fact that kids have a mixture of baby and permanent teeth between six to 13 years old also can create general difficulty, simply because the teeth are not all the same size or height, and because it can feel so different to chew on one side versus the other. Children sometimes have to adjust how they are eating to make things work, and they usually need to step up brushing and flossing to make sure that food particles don't get trapped in gaps.
The Dentist's Role
Most of the time, adult teeth push the baby ones, which essentially are placeholders, out of the way without any problems. Occasionally, however, the first set might develop issues, such as cavities, that if left untreated, can cause premature loss. Children also sometimes have smaller-than-normal jaws, which means there is limited space for development. It is important for children to see a dentist regularly for these reasons, as he can perform routine cleaning and take x-rays to determine if everything is forming correctly. Most professional dental organizations recommend starting care very early because of how baby teeth later can affect the permanent ones, with the general guideline being to bring in children in six months after their first baby tooth comes in, and no later than when they start school.
Considerations
Not all children develop the same way. Some begin to get their first adult teeth as early as four or five, and some are still getting them in when they're 14 to 15. Similarly, the molars are somewhat fickle — sometimes they come in, and sometimes they don't. Parents don't necessarily need to worry if their children are a little off the normal schedule, and with proper dental care, any abnormalities that do show up are usually fixable. The main things to look at as the permanent set comes in, therefore, are whether each tooth is coming in straight, and whether it is functioning well without pain.