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The maxillary first molar is the
human tooth The human teeth function to mechanically break down items of food by cutting and crushing them in preparation for swallowing and digesting. As such, they are considered part of the human digestive system. Humans have four types of teeth: inci ...
located laterally (away from the midline of the
face The face is the front of an animal's head that features the eyes, nose and mouth, and through which animals express many of their emotions. The face is crucial for human identity, and damage such as scarring or developmental deformities may aff ...
) from both the
maxillary second premolar The maxillary second premolar is one of two teeth located in the upper maxilar, laterally (away from the midline of the face) from both the maxillary first premolars of the mouth but mesial (toward the midline of the face) from both maxillary firs ...
s of the
mouth In animal anatomy, the mouth, also known as the oral cavity, or in Latin cavum oris, is the opening through which many animals take in food and issue vocal sounds. It is also the cavity lying at the upper end of the alimentary canal, bounded on ...
but mesial (toward the midline of the face) from both
maxillary second molar The maxillary second molar is the tooth located distally (away from the midline of the face) from both the maxillary first molars of the mouth but mesial (toward the midline of the face) from both maxillary third molars. This is true only in pe ...
s. The function of this molar is similar to that of all molars in regard to grinding being the principal action during
mastication Chewing or mastication 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 a more efficient break down by enzymes. During the mastication process, ...
, commonly known as chewing. There are usually four
cusp A cusp is the most pointed end of a curve. It often refers to cusp (anatomy), a pointed structure on a tooth. Cusp or CUSP may also refer to: Mathematics * Cusp (singularity), a singular point of a curve * Cusp catastrophe, a branch of bifurc ...
s on maxillary molars, two on the buccal (side nearest the cheek) and two palatal (side nearest the
palate The palate () is the roof of the mouth in humans and other mammals. It separates the oral cavity from the nasal cavity. A similar structure is found in crocodilians, but in most other tetrapods, the oral and nasal cavities are not truly separ ...
). There may also be a fifth smaller cusp on the palatal side known as the Cusp of Carabelli. Normally, maxillary molars have four lobes, two buccal and two lingual, which are named in the same manner as the cusps that represent them ( mesiobuccal, distobuccal, mesiolingual, and distolingual lobes). Unlike the anterior teeth and premolars, molars do not exhibit facial developmental depressions. Evidence of lobe separation can be found in the central groove, which divides buccal from lingual lobes. The two lingual lobes are separated by the distolingual groove, and the two buccal lobes are divided by the buccal groove. There are great differences between the
deciduous In the fields of horticulture and Botany, the term ''deciduous'' () means "falling off at maturity" and "tending to fall off", in reference to trees and shrubs that seasonally shed leaves, usually in the autumn; to the shedding of petals, ...
(baby) maxillary molars and those of the permanent maxillary molars, even though their function are similar. The permanent maxillary molars are not considered to have any teeth that precede it. Despite being named molars, the deciduous molars are followed by permanent premolars.


Notation

Permanent maxillary first molar notation In the universal numbering system, one number is used to identify the tooth. The right permanent maxillary first molar is known as tooth "3", and the left permanent maxillary first molar is known as tooth "14". In the
Palmer notation Palmer notation (sometimes called the "Military System" and named for 19th-century American dentist Dr. Corydon Palmer from Warren, Ohio) is a dental notation (tooth numbering system). Despite the adoption of the FDI World Dental Federation not ...
, a number and symbol are used to identify the tooth. The number identifies the tooth position relative to the midline, and the symbol identifies the quadrant of the mouth. Both maxillary first molars have the same number; ''6''. However, the right molar has the symbol "┘" underneath it. The left molar has "└" underneath it. In the international system of notation two numbers are used to identify the tooth. The first number identifies the quadrant of the mouth. The second number identifies the tooth relative to the midline of the arch. The right permanent maxillary first molar is known as "16". The left permanent maxillary first molar is known as "26". Deciduous maxillary first molar notation In the universal numbering system, an uppercase letter is used to identify the tooth. The right deciduous maxillary first molar is known as "B", and the left one is known as "I". In the
Palmer notation Palmer notation (sometimes called the "Military System" and named for 19th-century American dentist Dr. Corydon Palmer from Warren, Ohio) is a dental notation (tooth numbering system). Despite the adoption of the FDI World Dental Federation not ...
, a letter and symbol are used to identify the tooth. The letter identifies the tooth position relative to the midline, and the symbol identifies the quadrant of the mouth. Both maxillary first molars have the same letter; "D". However, the right molar has the symbol "┘" underneath it. The left molar has "└" underneath it. In the international system of notation two numbers are used to identify the tooth. The right deciduous maxillary first molar is known as "54", and the left one is known as "64".


External root morphology

The maxillary first molar normally has three roots. * The mesiobuccal root is broad distobuccal and has prominent depressions or flutings on its mesial and distal surfaces. The internal canal morphology is highly variable, but the majority of the mesiobuccal roots contain two canals. * The distobuccal root is generally rounded or ovoid in cross section and usually contains a single canal. * The palatal root is more broad mesiodistally than buccolingually and ovoidal in shape but normally contains only a single canal. Although the palatal root generally appears straight on radiographs, there is usually a buccal curvature in the apical third. Depressions on the buccal and palatal surfaces of the palatal root can be present but are generally shallow. There are prominent depressions found on the distal aspect of the mesiobuccal roots. Depressions can also be found on the furcal side of the distobuccal and palatal roots. The overall average length of the maxillary first molar is 20.5 mm with an average crown length of 7.5 mm and an average root length of 13 mm.J. Craig Baumgartner MS, DDS, PHD, John I. Ingle, DDS, MSD, Leif K. Bakland, DDS, eds. 2008. Ingle's Endodontics. Hamilton, Ontario. BC Decker Inc. , .


Pathologies

The maxillary first molars are the second most common carious teeth and the second most common teeth to undergo
endodontic treatment Root canal treatment (also known as endodontic therapy, endodontic treatment, or root canal therapy) is a treatment sequence for the infected pulp of a tooth which is intended to result in the elimination of infection and the protection o ...
or
extraction Extraction may refer to: Science and technology Biology and medicine * Comedo extraction, a method of acne treatment * Dental extraction, the surgical removal of a tooth from the mouth Computing and information science * Data extraction, the pr ...
(with
mandibular first molar The mandibular first molar or six-year molar is the tooth located distally (away from the midline of the face) from both the mandibular second premolars of the mouth but mesial (toward the midline of the face) from both mandibular second molars. It ...
s the most common
disease A disease is a particular abnormal condition that negatively affects the structure or function of all or part of an organism, and that is not immediately due to any external injury. Diseases are often known to be medical conditions that a ...
d teeth). Up to 21% of all extracted teeth are maxillary first molars.


External links


Video description of Maxillary first molar


References

{{Tooth anatomy Types of teeth Human mouth anatomy