Mandibular second molars

• The mandibular second molars have four cusps and two roots
• The proximal outline is trapezoidal
• There is a developmental groove running between the mesiobuccal and distobuccal cusps, which may end in a buccal pit
• The mesiobuccal cusp is longer than the distobuccal cusp
• The roots are more divergent than the mandibular first molar
• The lingual cusps are more pointed than the buccal cusps
• The root trunk is short with a developmental depression
• Mesially, the outline is rhomboidal with a lingual inclination
• There is a longitudinal depression on the mesial surface of the mesial root
• Mesially, the mesial marginal ridge has a concave appearance and the root is quite big, obscuring the distal root