In primary dentition, a distal step is associated with a permanent molar relationship Class II.

In primary dentition, a distal step is associated with a permanent molar relationship Class II.

• A. Class I
• B. Class II
• C. Class III
• D. None

Answer: (B)

A distal step in the primary dentition signals that the lower second primary molar sits farther back relative to the upper second primary molar. As the permanent first molars erupt, this pattern tends to produce a Class II permanent molar relationship, where the upper molar is ahead of the lower molar in the arch. In other words, the way the deciduous molars are positioned sets up an eruption path that endows the maxillary first molar with a position mesial to the buccal groove of the mandibular first molar, resulting in Class II. By contrast, a mesial step would push toward Class III, and a flush terminal plane often advances to Class I with growth, though the outcome can vary.

A distal step in the primary dentition signals that the lower second primary molar sits farther back relative to the upper second primary molar. As the permanent first molars erupt, this pattern tends to produce a Class II permanent molar relationship, where the upper molar is ahead of the lower molar in the arch. In other words, the way the deciduous molars are positioned sets up an eruption path that endows the maxillary first molar with a position mesial to the buccal groove of the mandibular first molar, resulting in Class II. By contrast, a mesial step would push toward Class III, and a flush terminal plane often advances to Class I with growth, though the outcome can vary.