Notation
- In the universal numbering system, the right permanent maxillary first molar is tooth 3, and the left one is tooth 14.
- In the Palmer notation, both maxillary first molars have the letter D, but the right molar has the symbol ┘ and the left molar has └.
- In the international system of notation, the right permanent maxillary first molar is known as 16, and the left one is known as 26.
- In the universal numbering system, the right deciduous maxillary first molar is known as B, and the left one is known as I.
- In the Palmer notation, both maxillary first molars have the letter D, but the right molar has the symbol ┘ and the left molar has └.
- In the international system of notation, 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 has depressions on its mesial and distal surfaces and usually contains two canals.
- The distobuccal root is rounded or ovoid in cross-section and usually contains a single canal.
- The palatal root is broad mesiodistally, ovoidal in shape, and normally contains only a single canal.
- Depressions can be found on the distal aspect of the mesiobuccal roots, as well as on the furcal side of the distobuccal and palatal roots.
- The average length of the maxillary first molar is 20.5mm, with an average crown length of 7.5mm and an average root length of 13mm.
Pathologies
- Maxillary first molars are the second most common carious teeth.
- They are also the second most common teeth to undergo endodontic treatment or extraction.
- Up to 21% of all extracted teeth are maxillary first molars.
External links
- Video description of the maxillary first molar.
References
- Ash, Major M. and Nelson, Stanley J. (2003). Wheeler's Dental Anatomy, Physiology, and Occlusion.
- J. Craig Baumgartner MS, DDS, PHD, John I. Ingle, DDS, MSD, Leif K. Bakland, DDS, eds. (2008). Ingle's Endodontics.
- Zadik Y, Sandler V, Bechor R, Salehrabi R (August 2008). Analysis of factors related to extraction of endodontically treated teeth.
This article includes a list of general references, but it lacks sufficient corresponding inline citations. (December 2008) |
The maxillary first molar is the human tooth located laterally (away from the midline of the face) from both the maxillary second premolars of the mouth but mesial (toward the midline of the face) from both maxillary second molars.
Maxillary first molar | |
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![]() Maxillary first molar | |
![]() Maxillary first molars of permanent and primary teeth marked in red. | |
Identifiers | |
FMA | 290269 |
Anatomical terminology |
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 cusps 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, 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 (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.