Mandibular first premolar

The mandibular first premolar is the tooth

Tooth

Teeth are small, calcified, whitish structures found in the jaws of many vertebrates that are used to tear, scrape, and chew food. Some animals, particularly carnivores, also use teeth for hunting or defense. The roots of teeth are covered by gums...

 located laterally (away from the midline of the face

Face

The term face refers to the central sense organ complex, for those animals that have one, normally on the ventral surface of the head, and can depending on the definition in the human case, include the hair, forehead, eyebrow, eyes, nose, ears, cheeks, mouth, lips, philtrum, teeth, skin, and chin....

) from both the mandibular canine

Mandibular canine

The mandibular canine is the tooth located distally from both mandibular lateral incisors of the mouth but mesially from both mandibular first premolars...

s of the mouth

Mouth

The mouth, buccal cavity, or oral cavity is the first portion of the alimentary canal that receives food and begins digestion by mechanically breaking up the solid food particles into smaller pieces and mixing them with saliva...

 but mesial (toward the midline of the face) from both mandibular second premolar

Mandibular second premolar

The mandibular second premolar is the tooth located distally from both the mandibular first premolars of the mouth but mesial from both mandibular first molars. The function of this premolar is assist the mandibular first molar during mastication, commonly known as chewing...

s. The function of this premolar

Premolar

The premolar teeth or bicuspids are transitional teeth located between the canine and molar teeth. In humans, there are two premolars per quadrant, making eight premolars total in the mouth. They have at least two cusps. Premolars can be considered as a 'transitional tooth' during chewing, or...

 is similar to that of canines in regard to tearing being the principal action during mastication

Mastication

Mastication or chewing is the process by which food is crushed and ground by teeth. It is the first step of digestion and it increases the surface area of foods to allow more efficient break down by enzymes. During the mastication process, the food is positioned between the teeth for grinding by...

, commonly known as chewing. Mandibular first premolars have two cusp

Cusp (dentistry)

A cusp is an occlusal or incisal eminence on a tooth.Canine teeth, otherwise known as cuspids, each possess a single cusp, while premolars, otherwise known as bicuspids, possess two each. Molars normally possess either four or five cusps...

s. The one large and sharp is located on the buccal side (closest to the cheek) of the tooth.

The mandibular first premolar is the tooth

Tooth

Teeth are small, calcified, whitish structures found in the jaws of many vertebrates that are used to tear, scrape, and chew food. Some animals, particularly carnivores, also use teeth for hunting or defense. The roots of teeth are covered by gums...

 located laterally (away from the midline of the face

Face

The term face refers to the central sense organ complex, for those animals that have one, normally on the ventral surface of the head, and can depending on the definition in the human case, include the hair, forehead, eyebrow, eyes, nose, ears, cheeks, mouth, lips, philtrum, teeth, skin, and chin....

) from both the mandibular canine

Mandibular canine

The mandibular canine is the tooth located distally from both mandibular lateral incisors of the mouth but mesially from both mandibular first premolars...

s of the mouth

Mouth

The mouth, buccal cavity, or oral cavity is the first portion of the alimentary canal that receives food and begins digestion by mechanically breaking up the solid food particles into smaller pieces and mixing them with saliva...

 but mesial (toward the midline of the face) from both mandibular second premolar

Mandibular second premolar

The mandibular second premolar is the tooth located distally from both the mandibular first premolars of the mouth but mesial from both mandibular first molars. The function of this premolar is assist the mandibular first molar during mastication, commonly known as chewing...

s. The function of this premolar

Premolar

The premolar teeth or bicuspids are transitional teeth located between the canine and molar teeth. In humans, there are two premolars per quadrant, making eight premolars total in the mouth. They have at least two cusps. Premolars can be considered as a 'transitional tooth' during chewing, or...

 is similar to that of canines in regard to tearing being the principal action during mastication

Mastication

Mastication or chewing is the process by which food is crushed and ground by teeth. It is the first step of digestion and it increases the surface area of foods to allow more efficient break down by enzymes. During the mastication process, the food is positioned between the teeth for grinding by...

, commonly known as chewing. Mandibular first premolars have two cusp

Cusp (dentistry)

A cusp is an occlusal or incisal eminence on a tooth.Canine teeth, otherwise known as cuspids, each possess a single cusp, while premolars, otherwise known as bicuspids, possess two each. Molars normally possess either four or five cusps...

s. The one large and sharp is located on the buccal side (closest to the cheek) of the tooth. Since the lingual cusp (located nearer the tongue) is small and nonfunctional (which refers to a cusp not active in chewing), the mandibular first premolar resembles a small canine. There are no deciduous

Deciduous teeth

Deciduous teeth, otherwise known as milk teeth, baby teeth, temporary teeth and primary teeth, are the first set of teeth in the growth development of humans and many other mammals. They develop during the embryonic stage of development and erupt—that is, they become visible in the mouth—during...

 (baby) mandibular premolars. Instead, the teeth that precede the permanent

Permanent teeth

Permanent teeth are the second set of teeth formed in humans. There are thirty-two permanent teeth, consisting of six maxillary and six mandibular molars, four maxillary and four mandibular premolars, two maxillary and two mandibular canines, four maxillary and four mandibular incisors.The first...

 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 first premolar is an example of a premolar with only one functional cusp. Thus, "biscupid" is technically not as accurate as "premolar".

In the universal system of notation

Universal numbering system (dental)

The Universal numbering system is a dental notation system for associating information to a specific tooth, and is commonly used in the United States.The designations "left" and "right" on the chart correspond to the patient's left and right, respectively....

, the permanent mandibular premolars are designated by a number. The right permanent mandibular first premolar is known as "28", and the left one is known as "21". In the Palmer notation

Palmer notation

Palmer notation is a system used by dentists to associate information to a specific tooth. Although supposedly superseded by the FDI World Dental Federation notation, it overwhelmingly continues to be the preferred method used by dental students and practitioners in the United Kingdom.It was...

, a number is used in conjunction with a symbol designating in which quadrant the tooth is found. For this tooth, the left and right first premolars would have the same number, "4", 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 first premolar is known as "44", and the left one is known as "34".