Supplements the maxillary first premolar in function
Less angular ,rounded crown in all aspects
Single root Smaller crown
cervico-occlusally Root length is as
great or greater
Not as long as that of the first premolar
Less pointed Mesial slope is
shorter than the distal slope
Buccal ridge of the crown may not be so prominent when compared with the first premolar
Lingual cusp is longer making the crown longer on the lingual side
Cusps of second premolar are shorter with the buccal and lingual cusps more nearly the same length
Greater distance between cusp tips-that widens the occlusal surface buccolingually
No developmental depression on the mesial surface of the crown as on the first premolar
Crown surface is convex instead No deep dev. Groove crossing the mesial
marginal ridge
Outline of the crown is more rounded or oval rather than angular
Central dev. groove is shorter and more irregular
Tendency toward multiple supplementary grooves radiating from the central groove that may extend out to the cusp ridges
Makes for an irregular occlusal surface and gives a very wrinkled appearance