Primary Teeth

diagram of primary teeth.

There are ten primary teeth on the maxillary and ten primary teeth on the mandibular. There are central and lateral incisors and two canines in each arch. There are no premolars in the primary dentition and there are only two molars in each quadrant instead of three.

The following chart outlines the eruption and exfoliation dates for each of the primary teeth.

Primary Eruption Date (Avg.) Exfoliation Date (Avg.)
Central Incisor 8-12 Months 6-7 Years
Lateral Incisor 9-13 Months 7-8 Years
Canine 16-22 Months 10-12 Years
1st Molar 13-19 Months 9-11 Years
2nd Molar 25-33 Months 10-12 Years
Central Incisor 6-10 Months 6-7 Years
Lateral Incisor 10-16 Months 7-8 Years
Canine 17-23 Months 9-12 Years
1st Molar 14-18 Months 9-11 Years
2nd Molar 22-31 Months 10-12 Years

Our six-year-old patient, Sara, has come to Blue University Dental School’s Pediatric Clinic. Jamie, the dental assisting student, has been assigned to Sara to collect data, work on oral hygiene and assist the dental student treating Sara.

dentist helping young patient.

Jamie to Sara (and her parents): "Hi Sara, my name is Jamie and I am going to be helping you today. After I talk with your parents (about health data), we are going back to my special room so you can sit in my big, fancy chair where I can talk to you about your teeth and how to have a big, bright, happy smile."

After the parents complete the medical and dental history and Jamie reviews it with them, she takes Sara back to the treatment room. She explains to Sara’s parents that she will come and get them prior to any treatment.

Sara has no significant health problems, takes no medications and is healthy overall. Her parents are concerned because they think she might have cavities and she does not like to brush her teeth.

Jamie to Sara: "Sara, I am going to look in your mouth, count your teeth and then put some information in my computer about your teeth. It is pretty dark inside your mouth. I know you are a big helper and can open your mouth really wide so I can see in there. Open wide - that is perfect Sara."

Sara still has all of her primary teeth (20) but has two teeth, the mandibular central incisors, that are loose.

After collecting the oral health data on Sara, Jamie calls the dental student in for the examination of the patient. At this point, Jamie asks Sara's parents to come into the treatment room. The dental student begins by reviewing the data collected by Jamie and then begins the examination. He does find a small area of decay on the occlusal surface of Sara's mandibular first molar. He points this out and begins to explain how he examined her mouth and the way a cavity is formed and how dental decay progresses.