In figure "A" below, identify the tooth, the number of cusps, and groove pattern.

Question

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Figure "A" depicts a mandibular second premolar. In the second premolar the mesial and distal marginal ridges are almost at a right angle to the buccal and lingual surfaces. Conversely, in the first premolar the mesial and distal marginal ridges converge sharply toward the lingual side of the tooth. (Marginal ridges appear more "straight" in mandibular second premolars as compared to the first.) This tooth has two cusps, a buccal and a lingual, and a "U" groove pattern. Note that in the two-cusp variety of mandibular second premolars, the groove pattern can have either a "U" or an "H" groove pattern. Also, the "U" pattern is sometimes described as "C".

In Figure "A" Below, Identify the Tooth, the Number of Cusps