Maxillary first molar
Encyclopedia
The maxillary first molar is the tooth
located laterally (away from the midline of the face
) from both the maxillary second premolar
s of the mouth
but mesial (toward the midline of the face) from both maxillary second molar
s.
The function of this molar
is similar to that of all molars in regard to grinding being the principal action during mastication
, commonly known as chewing.
There are usually four cusp
s on maxillary molars, two on the buccal (side nearest the cheek) and two palatal (side nearest the palate
). 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, mesiolineual, 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
(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.
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
, 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 1st 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 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".
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.
teeth and the second most common teeth to undergo endodontic treatment or extraction (with mandibular first molar
s the most common disease
d teeth). Up to 21% of all extracted teeth are maxillary first molars.
Tooth
Teeth are small, calcified, whitish structures found in the jaws of many vertebrates that are used to break down food. Some animals, particularly carnivores, also use teeth for hunting or for defensive purposes. The roots of teeth are embedded in the Mandible bone or the Maxillary bone and are...
located laterally (away from the midline of the face
Face
The face is a 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, eyelashes, eyes, nose, ears, cheeks, mouth, lips, philtrum, temple, teeth, skin, and...
) from both the maxillary second premolar
Maxillary second premolar
The maxillary second premolar is one of two teeth located in the upper jaw, laterally from both the maxillary first premolars of the mouth but mesial from both maxillary first molars...
s of the mouth
Mouth
The mouth is the first portion of the alimentary canal that receives food andsaliva. The oral mucosa is the mucous membrane epithelium lining the inside of the mouth....
but mesial (toward the midline of the face) from both maxillary second molar
Maxillary second molar
The maxillary second molar is the tooth located distally from both the maxillary first molars of the mouth but mesial from both maxillary third molars. This is true only in permanent teeth. In deciduous teeth, the maxillary second molar is the last tooth in the mouth and does not have a third...
s.
The function of this molar
Molar (tooth)
Molars are the rearmost and most complicated kind of tooth in most mammals. In many mammals they grind food; hence the Latin name mola, "millstone"....
is similar to that of all molars in regard to grinding 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.
There are usually four 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 on maxillary molars, two on the buccal (side nearest the cheek) and two palatal (side nearest the palate
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 separate. The palate is divided into two parts, the anterior...
). There may also be a fifth smaller cusp on the palatal side known as the Cusp of Carabelli
Cusp of Carabelli
The cusp of Carabelli, or Carabelli's tubercle, or tuberculum anomale of Georg Carabelli is a small additional cusp at the mesiopalatal line angle of maxillary first molars. This extra cusp is usually found on the first molar, and becomes progressively less likely in the second, third molars...
.
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, mesiolineual, 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
Deciduous teeth
Deciduous teeth, otherwise known as reborner teeth, baby teeth, temporary teeth and primary teeth, are the first set of teeth in the growth development of humans and many other mammals. In some Asian countries they are referred to as fall teeth as they will eventually fall out, while in almost all...
(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 1st Molar NotationIn the Universal Numbering System
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....
, 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
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 orthodontists, dental students and practitioners in the United...
, 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
FDI World Dental Federation notation
FDI World Dental Federation notation is widely used by dentists internationally to associate information to a specific tooth.Developed by the FDI World Dental Federation, World Dental Federation notation is also known as ISO 3950 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 1st Molar Notation
In the Universal Numbering System
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....
, 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 International System of Notation
FDI World Dental Federation notation
FDI World Dental Federation notation is widely used by dentists internationally to associate information to a specific tooth.Developed by the FDI World Dental Federation, World Dental Federation notation is also known as ISO 3950 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 buccolingually 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.
Pathologies
The maxillary first molars are the second most common cariousDental caries
Dental caries, also known as tooth decay or a cavity, is an irreversible infection usually bacterial in origin that causes demineralization of the hard tissues and destruction of the organic matter of the tooth, usually by production of acid by hydrolysis of the food debris accumulated on the...
teeth and the second most common teeth to undergo endodontic treatment or extraction (with mandibular first molar
Mandibular first molar
The mandibular first molar or six-year molar is the tooth located distally from both the mandibular second premolars of the mouth but mesial from both mandibular second molars...
s the most common disease
Disease
A disease is an abnormal condition affecting the body of an organism. It is often construed to be a medical condition associated with specific symptoms and signs. It may be caused by external factors, such as infectious disease, or it may be caused by internal dysfunctions, such as autoimmune...
d teeth). Up to 21% of all extracted teeth are maxillary first molars.