Hygiene Atlas

Atlas · Plate II · Dental Anatomy and Tooth Morphology · 02

Eruption of the primary teeth

The 20 primary teeth begin erupting at about 6 months, usually led by the mandibular central incisors. The order is central incisor, lateral incisor, first molar, canine, then second molar, which arrives last at roughly 23-33 months. The primary dentition period lasts until about age 6, when the mixed dentition begins and runs to about 12.

High-yield facts · 9

  1. Primary teeth: 20 in all, beginning to erupt at about 6 months; mandibular central incisors usually come first.S6
  2. Mandibular primary central incisor erupts 6-10 months; maxillary central 8-12 months.S6
  3. Primary lateral incisors erupt 9-13 months (maxillary) and 10-16 months (mandibular).S6
  4. Primary first molars erupt 13-19 months (maxillary) and 14-18 months (mandibular).S6
  5. Primary canines erupt 16-22 months (maxillary) and 17-23 months (mandibular), after the first molars.S6
  6. Primary second molars erupt last: 23-31 months (mandibular) and 25-33 months (maxillary).S6
  7. Primary eruption order: central incisor, lateral incisor, first molar, canine, second molar.S6
  8. Shedding: central incisors 6-7 years, lateral incisors 7-8 years, first molars 9-11 years, canines 9-12 years, second molars 10-12 years.S6
  9. Primary dentition period runs from about 6 months to 6 years; mixed dentition from about 6 to 12 years.S43

Facts are written in our own words; each tag links to its source. Values marked "sources vary" differ between references, so check the one your program uses.