A Pediatric Dentist Explains The Journey of a Tooth


bottom and top jaw with teeth

Everyone knows the basics of tooth development, they grow in, fall out, grow back in, and sometimes fall back out again. What most people don’t know is that there is a system and it starts months before that first little friend pops through the gum line. Teeth begin to develop in the embryonic stage at about 3-6 weeks. There the soft tissue forms and creates small translucent tooth nubs. At 3-4 months hard tissue starts to develop around the tooth and thin translucent roots will start to grow down. By the time of birth, there are 20 fully developed teeth buried under the gums. In some rare cases, babies will be born with partially erupted teeth.

Baby’s teeth will start to erupt between 3-6 months, this stage is commonly called teething. Since every child develops at a different rate it’s hard to say exactly when and what teeth will come in, fall out, and come back in. However, they typically erupt in this order: 

Lower Central Incisors (middle teeth): Between 3 and 6 months

Adult Tooth Growth Chart
Adult Tooth Growth Chart

Upper Central Incisors: Between 8 and 12 months

Upper Lateral Incisors (next to middle teeth): Between 9 and 13 months

Lower Lateral Incisors: Between 10 and 18 months

Upper 4 molars: Between 13 and 25 months

Lower 4 molars: Between 14 and 23 months

Upper and lower cuspids (canine): Between 16 and 23 months

Now, when the baby teeth are ready to fall out the brain sends special cells to eat away at the baby tooth root. As this is happening the adult teeth are slowly starting to push the baby teeth up and out! While your baby teeth typically fall out in the order they erupt in, adult teeth are more sporadic. The adult upper and lower Central Incisors come in at 6-7 years. This is followed by the Lateral Incisors at 8-9 years. Next comes the Cuspids at 9-12, then the 1st and 2nd Premolars at 7-11 years. Finally the 1st and 2nd come in at 7-12 years.

Sometimes permanent and primary teeth can grow in crooked. This can be caused by: 

  • thumb sucking
  • pacifier or bottle use
  • tongue thrusting
  • mouth breathing
  • misaligned jaw
  • having a baby tooth knocked out too early

These can cause jaw alignment issues. To fix these problems braces or other teeth alignment equipment may be used. Sometimes, they use what's called 2 phase orthodontics. Typically after all 4 of the permanent central incisors and molars come in, the first phase will begin. Then after the last permanent tooth comes in, phase 2 will start. This can be used to correct abnormalities that otherwise can’t be corrected in adults.

If your tooth falls out as an adult and is not cracked or broken, immediately put it in cold milk and call your dentist right away. The dentists can sometimes reinsert the tooth. Please do not attempt to put the tooth in yourself, you can cause damage to your gums. This can make it impossible for the dentist to successfully reattach the tooth to the root.

Remind those kiddos to brush twice and floss once daily to keep those pearly whites clean and healthy. Keep your kids on a healthy track, call and schedule their next dental exam today!