Mandibular second premolars

• There are two types of mandibular second premolars: 2 cusp or 3 cusp type
• The cusp height difference is not very noticeable
• The buccal cusp is less pointed and shorter, and the buccal ridge is less prominent compared to the first premolar
• Proximally the outline is rhomboidal, but the lingual inclination is less prominent
• The two cusp type second premolar has a more oval outline occlusally, with a slight lingual convergence, while the first premolar is more diamond shaped and has a sharper lingual convergence
• The lingual cusp tip is shifted more mesially for the two cusp type and the distal fossa is greater than the mesial fossa
• The three cusp type has buccal, lingual, and distal cusps
• The three cusp type has a Y shaped central developmental groove
• The three cusp type has a more squarish outline
• For the three cusp type, the mesiolingual cusp is wider and higher than the distolingual cusp