In the described progression order of caries, which tooth group is listed as the second stage?

• A. Upper incisors
• B. First molars (mandibular primary molars)
• C. Second molars (maxillary primary molars)
• D. Upper canines

Answer: (B)

Cars in the primary dentition tend to follow the order of eruption and where plaque tends to collect most. The mandibular first primary molars come in relatively early and have prominent pits and fissures on their biting surfaces that trap food and plaque, making them especially prone to rapid decay. Because they are among the first posterior teeth to erupt and are harder to clean in toddlers, they frequently show caries after the initial stage, placing them as the second stage in the described progression. The other options either erupt later or have surfaces that are less prone to early decay in this sequence, so they don’t fit as the second stage.