When you are born do you have both sets of teeth already in your head?

Yes, you are born with tooth "buds" inside your alveolar bone (jaw bone under the gums in your upper & lower jaws. The buds grow into teeth below the surface of your gums and eventually the buds form the 20 teeth that erupt through your gums to form your baby teeth, know as your primary dentition. The term "dentition" is a collective term describing all your teeth.

Once your primary dentition has erupted, the buds of your adult teeth, known as your permanent teeth (adult teeth), begin to grow in the bone. The growth of the permanent tooth is what begins to resorb the root structure of your primary teeth. The process of resorption is similar to dissolving. The roots of the teeth are what holds them securely in your jaw bone, so during root resrobtion (as the roort is dissolving), the primary tooth beomes loose and eventually falls out. Resorption is why there are no roots on baby teeth when they fall out.

A permanent tooth then erupts in the lost primary tooth's place. Ultimately, 32 teeth (including your third molars, commonly called "wisdom teeth") erupt through your gums to form your permenent dentition.

The 20 teeth in your primary dentition are labeled with a letter. 20 teeth are lettered A through T. A-J are the top baby teeth, K-T the lower baby teeth.

The 32 teeth in your permanent dentition are labeled with numbers. The 32 teeth are numbered 1 through 31. 1-16 are the top teeth, 17-31 the bottom teeth.

To count or label teeth, you begin counting on your upper right side, go accross to your upper left side, then "drop down" to your lower left side and continue counting until you reach the end on your lower right. You start & end counting on the right side. Example on permanent teeth: Tooth number 1 is the first tooth on your UPPER right side, and tooth 32 is the last tooth on your LOWER right side.

First answer by Pjdinucci. Last edit by Pjdinucci. Contributor trust: 0 [recommend contributor]. Question popularity: 24 [recommend question]