First Tooth Eruption in Babies
The first primary tooth typically erupts at around 6-8 months of age, with the lower central incisors appearing first. 1
Normal Eruption Timeline
Primary teeth begin erupting at approximately 6-8 months of age, starting with the mandibular (lower) central incisors, followed by a predictable sequence that continues until all primary teeth have emerged by 24-30 months of age. 1
The median age of eruption is 7.1 months for males and 7.6 months for females for the lower central incisors, followed by upper central incisors at 8.7-9.2 months. 2
The normal eruption sequence begins with mandibular central incisors, then maxillary central incisors, followed by maxillary lateral incisors (10.0-10.3 months) and mandibular lateral incisors (10.4-10.8 months). 2
Clinical Implications for Timing
The first dental examination should occur within 6 months of the first tooth erupting, but no later than 12 months of age, as recommended by the American Academy of Pediatric Dentistry. 3, 1
This early timing is critical because by 3 years of age, poor oral hygiene or improper feeding habits may have already compromised oral health if preventive intervention is delayed. 3
Oral hygiene should begin immediately with first tooth eruption, including twice-daily brushing with fluoridated toothpaste (rice grain-sized portion for children under 36 months). 1
Variations in Eruption Timing
Indigenous children may experience earlier primary tooth eruption compared to other populations, which may contribute to earlier colonization by cariogenic bacteria and increased caries risk. 1
Premature infants may experience delayed eruption, particularly those with birthweight <1000g or gestational age ≤30 weeks, with delays related to severity of neonatal illness, duration of oral intubation, and nutritional factors. 4
When evaluating preterm infants, corrected age (adjusted for prematurity) should be used, though some studies show eruption may still occur earlier than expected even when corrected. 2
Important Caveats
Natal teeth (present at birth) and neonatal teeth (erupting within the first month) are rare phenomena occurring in approximately 1:3,400 births, most commonly involving lower incisors. 5
Parents typically observe tooth eruption earlier than dentists document at checkups, as daily observation captures the initial breakthrough through the gingiva rather than full clinical eruption. 2
The "window of infectivity" for cariogenic bacteria (Streptococcus mutans) occurs between 19-31 months, making early preventive intervention essential once teeth are present. 6