Age Range

What's Typically Happening

What to Watch For

0 – 3 years

Primary (baby) teeth erupting and settling in

Prolonged thumb-sucking or pacifier use

4 – 6 years

Primary dentition complete; first permanent molars/incisors beginning to erupt

Persistent habits; mouth breathing or snoring

6 – 7 years

Mixed dentition begins

First orthodontic evaluation recommended around this age

7 – 11 years

Mixed dentition continues; jaw growth active

Crossbite, significant overjet, or notable crowding — candidates for interceptive treatment

11 – 13 years

Most permanent teeth erupting or in place

Comprehensive treatment (braces/aligners) becomes appropriate if needed

13+ years

Permanent dentition; adolescent growth spurt tapering

Comprehensive treatment continues; retention planning begins