Primary and Permanent Dentition Eruption Sequences

Primary Dentition Eruption Sequence

The primary dentition starts to erupt at around 6 months of age, beginning with the mandibular central incisors and ending with the eruption of the maxillary second primary molars between 25-33 months (2-2.75 years).⁷ Table 1 outlines the eruption sequence for the primary dentition.⁷ The primary dentition consists of 20 teeth including 4 central incisors (E, F, O, P), 4 lateral incisors (D, G, N, Q), 4 canines (C, H, M, R), 4 first molars (B, I, L, S), and 4 second molars (A, J, K, T) distributed equally between the two dental arches (Figures 10‑11).

Figure 10.

Figure 10.

Periapical radiograph of primary mandibular anterior teeth.

Figure 11.

Figure 11.

Bitewing radiograph of primary posterior teeth.

The mixed dentition is composed of a combination of primary and permanent teeth (Figure 12). As the child matures, the primary teeth begin to exfoliate and are replaced by the permanent dentition. The mandibular central incisors and the first molars are the first to erupt, replacing their primary predecessors while the third molar teeth are the last to erupt in the late teen to early adult years.⁷ The permanent dentition consists of 32 teeth including 4 central incisors (8, 9, 24, 25), 4 lateral incisors (7, 10, 23, 26), 4 canines (6, 11, 22, 27), 4 first premolars (5, 12, 21, 28), 4 second premolars (4, 13, 20, 29), 4 first molars (3, 14, 19, 30), 4 second molars (2, 15, 18, 31), and 4 third molars (1, 16, 17, 32) distributed uniformly between the maxilla and mandible. The primary first and second molars are replaced by the premolar teeth and the permanent molar teeth erupt posterior to the primary molars. Table 2 outlines the eruption sequence of the permanent dentition.⁷

Figure 12. Panoramic radiograph of a mixed dentition.

Figure 12. Panoramic radiograph of a mixed dentition.

Permanent Dentition Eruption Sequence