We all remember as kids, the way are teeth came, left, and then came again. However, we never really understood the how and why of this remarkable process. We remember the fear of losing teeth. We remember the pain and the wondering of why. We remember the fairy tales that surround losing teeth as a child. This article will help illustrate how the process works from a highly medical standpoint. Genetics plays an important role in the existence and development of teeth. It determines when teeth come in and what they look like. Additional environmental factors and the mother's condition during the nine month pregnancy have an effect. Other than that, what you see is what you get. Baby Teeth They are known as primary or deciduous teeth. Generally, the lower teeth appear before the upper teeth. The primary front teeth are called central and lateral incisors and usually arrive by the time the child is one. The next teeth to arrive are the primary first molars followed by the primary cuspids and then the primary second molars. All twenty baby teeth usually arrive by the time a child reaches three years of age. Adult Teeth They are known as secondary or permanent dentition. The permanent front central and lateral incisors emerge shortly after the primary front teeth fall out. This usually occurs between the ages of six and eight. Prior to this, permanent first molars arrive around ages six or seven. The primary molars are replaces with permanent premolars between the age of ten and twelve. Adult cuspids arrive between the ages of nine and twelve. Permanent second molars arrive between the ages of eleven and thirteen. No-Show Teeth They are teeth that never develop. Common missing teeth are the adult laterals incisors, bicuspids and third molars. Wisdom Teeth They are known as third molars. They may or may not emerge from the gums, depending upon their position. If they grow sideways or angled, they may not appear at all because they are impacted. If they grow straight and there is enough room in the mouth to accommodate them, they can appear between the age of seventeen and twenty-one. Supernumary Teeth They are extra teeth. Usually found in the middle of the upper central teeth. This is called mesiodens. As with any issues involving teeth, please consult with an experienced dentist in your local area. There is no substitute for highly skilled dental care. Failure to seek immediate care may have detrimental effects.