AAPD notesResources
AAPD notesResources
Dental Growth and Development
- Source revision:
- adaptation dated 2003, based on a 1933 developmental reference
Board takeaway
- Assess: Use dental chronology to interpret development, then assess the individual child.
- Separate events: Mineralization, crown or root completion, eruption, and shedding are separate events: an erupted permanent tooth may still have immature roots.
- Limits: The chart allows normal variation outside its age ranges and supplies no age-only threshold for imaging, extraction, or orthodontic treatment.
Timeline: first permanent molar development
Loading diagram…
These are distinct developmental events, not diagnostic or intervention deadlines. In both arches, eruption at 5.5–7 years precedes listed root completion at 9–10 years. Interpret the ranges with the chart's normal-variation caveat.
Primary teeth
- Calcification begins in the fourth fetal month for every primary tooth group.
- The chart labels completion as formation, without separately listing crown and root completion.
- In the tables below, paired values are maxillary / mandibular; mo = months, y = years.
Scroll across to view all columns
| Tooth | Formation complete | Eruption, mo | Exfoliation, y |
|---|---|---|---|
| Central incisor | 18–24 mo | 6–10 / 5–8 | 7–8 / 6–7 |
| Lateral incisor | 18–24 mo | 8–12 / 7–10 | 8–9 / 7–8 |
| Canine | 30–39 mo | 16–20 / 16–20 | 11–12 / 9–11 |
| First molar | 24–30 mo | 11–18 / 11–18 | 9–11 / 10–12 |
| Second molar | 36 mo | 20–30 / 20–30 | 9–12 / 11–13 |
Permanent teeth
- First molar mineralization begins at birth; later eruption does not imply later initiation of development.
- Crown completion and root completion have separate schedules.
Scroll across to view all columns
| Tooth | Calcification starts | Crown complete | Roots complete | Eruption, y: maxillary / mandibular |
|---|---|---|---|---|
| Central incisor | 3–4 mo | 4–5 y | 9–10 y | 7–8 / 6–7 |
| Lateral incisor | Maxillary 10–12 mo; mandibular 3–4 mo | 4–5 y | Maxillary 11 y; mandibular 10 y | 8–9 / 7–8 |
| Canine | 4–5 mo | 6–7 y | 12–15 y | 11–12 / 9–11 |
| First premolar | 18–24 mo | 5–6 y | 12–13 y | 10–11 / 10–12 |
| Second premolar | 24–30 mo | 6–7 y | 12–14 y | 10–12 / 11–13 |
| First molar | Birth | 30–36 mo | 9–10 y | 5.5–7 / 5.5–7 |
| Second molar | 30–36 mo | 7–8 y | 14–16 y | 12–14 / 12–14 |
| Third molar | Maxillary 7–9 y; mandibular 8–10 y | Not provided | Not provided | 17–30 / 17–30 |
Eruption order
- The source's numbered sequence places first molars first, then mandibular and maxillary central incisors, followed by mandibular and maxillary lateral incisors.
- Next: mandibular canine → maxillary first premolar → mandibular first premolar → maxillary second premolar → mandibular second premolar → maxillary canine → second molars → third molars.
- These sequence labels accompany age ranges; they do not establish mandatory deadlines.
Common board traps
Answer aloud
Does eruption of a first permanent molar mean its roots are complete?
No. Eruption and root completion are separate events.
Scroll across to view all columns
| First permanent molar event | Listed timing |
|---|---|
| Calcification starts | Birth |
| Crown complete | 30–36 months |
| Eruption, either arch | 5.5–7 years |
| Roots complete | 9–10 years |
- Interpret the chart with its normal-variation caveat; these ages alone do not decide treatment.
How does permanent canine eruption differ between arches?
Mandibular canines are listed earlier: 9–11 years versus 11–12 years for maxillary canines.
- Root completion is listed at 12–15 years.
- Eruption does not imply completed roots; these ranges allow normal variation.
Does missing a chart age prove abnormal development?
No. Assess the clinical context rather than diagnose from age alone.
- The chart describes expected chronology with normal variation.
- It supplies neither a diagnostic cutoff nor an imaging, extraction, or orthodontic-treatment threshold.