Mandibular second premolar

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Human Teeth
Maxillary teeth
Incisor Central incisor Lateral incisor Canine Premolar First premolar Second premolar Molar First molar Second molar Third molar
Mandibular teeth
Incisor Central incisor Lateral incisor Canine Premolar First premolar Second premolar Molar First molar Second molar Third molar
Mandibular second premolar
Mandibular second premolars of permanent teeth marked in red. There are no premolars in primary teeth.

The mandibular second premolar is the tooth located distally (away from the midline of the face) from both the mandibular first premolars of the mouth but mesial (toward the midline of the face) from both mandibular first molars. The function of this premolar is assist the mandibular first molar during mastication, commonly known as chewing. Mandibular second premolars have three cusps. There is one large cusp on the buccal side (closest to the cheek) of the tooth. The lingual cusps (located nearer the tongue) are well developed and functional (which refers to cusps assisting during chewing). Therefore, whereas the mandibular first premolar resembles a small canine, the mandibular second premolar is more alike to the first molar. There are no deciduous (baby) mandibular premolars. Instead, the teeth that precede the permanent mandibular premolars are the deciduous mandibular molars.

Sometimes, premolars are referred to as bicuspids. Even though the terms are synonymous, "bicuspid" refers to having two functional cusps, and the mandibular second premolar is an example of a premolar with three functional cusps. Thus, "biscupid" is technically not as accurate as "premolar".

In the universal system of notation, the permanent mandibular premolars are designated by a number. The right permanent mandibular second premolar is known as "29", and the left one is known as "20". In the Palmer notation, a number is used in conjunction with a symbol designating in which quadrant the tooth is found. For this tooth, the left and right second premolars would have the same number, "5", but the right one would have the symbol, "┐", over it, while the left one would have, "┌". The international notation has a different numbering system than the previous two, and the right permanent mandibular second premolar is known as "45", and the left one is known as "35".

It is a very common condition in orthodontics for a patient to have one or both mandibular second premolars congenitally absent.

[edit] References

• Ash, Major M. and Stanley J. Nelson, 2003. Wheeler’s Dental Anatomy, Physiology, and Occlusion. 8th edition.