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Maxillary right first molar
The largest tooth of the maxillary arch, with four major cusps and three roots: mesiobuccal, distobuccal and palatal.
- FDI
- 16
- Universal
- 3
- Palmer
- UR6
- Roots
- Three (mesiobuccal, distobuccal, palatal)
- Root canals
- Three or four — a second mesiobuccal canal (MB2) is frequently present
- Eruption
- About 6–7 years
Form and anatomy
Seen from the occlusal side, the crown is rhomboid and wider buccopalatally than mesiodistally. Of its four main cusps, the mesiopalatal is the largest, followed by the mesiobuccal, distobuccal and the small distopalatal cusp. A prominent oblique ridge joins the mesiopalatal and distobuccal cusps and separates the central fossa from the distal fossa. Many teeth carry an extra cusp or tubercle on the palatal surface of the mesiopalatal cusp, the cusp of Carabelli. The three roots spread widely from a common root trunk: the palatal root is the longest, the mesiobuccal root is broad and usually curves distally, and the distobuccal root is the smallest. This tripod of roots gives the tooth strong anchorage, and the furcation between them is a key landmark in periodontal assessment.
Function
Primary grinding tooth; a key determinant of the occlusal relationship between the jaws.
Clinical relevance
The mesiobuccal root frequently contains a second canal (MB2), which is easily missed in root canal treatment. Its roots lie close to the floor of the maxillary sinus.
Neighbouring teeth
- Mesial neighbour
- Maxillary right second premolar
- Distal neighbour
- Maxillary right second molar
- Same tooth, other side
- Maxillary left first molar
- Opposing tooth
- Mandibular right first molar
This text is a draft and has not yet been reviewed by a dental professional. Educational reference only, not for diagnosis or treatment.