Which arch generally sheds first?

• A. Maxillary
• B. Mandibular
• C. Both equally
• D. Neither

Answer: (B)

Exfoliation of primary teeth follows a typical sequence tied to the eruption of the permanent successors. The lower (mandibular) arch tends to shed first, with the mandibular central incisors usually the first to loosen and shed around ages 6–7. This happens because the permanent tooth beneath each deciduous tooth begins to erupt earlier in the mandible, and as its crown moves into position, it resorbs the root of the corresponding deciduous tooth from below upward. The resorption progresses from the root apex toward the crown, leading to loosening and eventual shedding. After the lower central incisors, the corresponding upper (maxillary) incisors shed, followed by other teeth in a generally similar pattern. While there can be individual variation, this mandibular-first shedding sequence is the common general trend.