The permanent maxillary right second molar is the second permanent molar located in the upper right quadrant of the dental arch, designated as tooth #2 in the Universal Numbering System and tooth 1.7 in FDI World Dental Federation notation. It erupts between approximately ages 11 and 13, following the first permanent molar, and functions as a primary load-bearing tooth for mastication throughout adult life.
Anatomical Features
The crown is slightly smaller than the maxillary first molar and typically presents four main cusps: the mesiobuccal, distobuccal, mesiolingual, and distolingual. The occlusal surface displays a characteristic rhomboidal outline, with the mesiolingual cusp being the largest. The cusp of Carabelli — an accessory cusp sometimes found on the mesiolingual surface of the first molar — is absent or poorly expressed on the second molar.
Three roots support this tooth, each with distinct clinical relevance:
- Mesiobuccal root — the most anatomically complex, frequently containing two root canals (MB1 and MB2), a critical consideration during endodontic treatment
- Distobuccal root — shorter and more rounded, typically housing a single canal
- Palatal root — the longest of the three, with a broad, well-defined single canal
The furcation zone, where the roots diverge from the root trunk, is an essential landmark during periodontal evaluation. Furcation involvement in this area signals significant alveolar bone loss and complicates both non-surgical and surgical management.
Clinical Significance
The permanent maxillary right second molar absorbs considerable occlusal forces during chewing, making its enamel and underlying dentin susceptible to wear, fracture, and carious lesions. Its posterior position in the arch presents access challenges for both patient hygiene and clinical instrumentation. Key considerations include:
- Thorough canal identification — particularly the MB2 — to prevent missed anatomy during root canal therapy
- Careful monitoring of the periodontal ligament for attachment loss, especially at furcation sites
- Assessment of third molar positioning, as a mesially angulated wisdom tooth can impede or deflect second molar eruption
- Isolation challenges during restorative procedures due to proximity to the pterygomandibular space and soft palate
Loss of the permanent maxillary right second molar carries cascading consequences — the opposing mandibular second molar can supraerupt and adjacent teeth may drift mesially — making early intervention and long-term preservation a priority in any comprehensive treatment plan.