The mandibular second premolar is the tooth located distally from both the mandibular first premolars of the mouth but mesially from both mandibular first molars. The function of this premolar is to assist the mandibular first molar during mastication. Mandibular second premolars have three cusps. There is one large cusp on the buccal side of the tooth. The lingual cusps are well developed and functional, which means the cusps assist during chewing. Therefore, whereas the mandibular first premolar resembles a small canine, the mandibular second premolar is more like the first molar.