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Topic

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Superior second molar tooth

The superior second molar is the second posterior tooth in the maxillary dental arch, located between the first and third molars. It typically has three roots (mesiobuccal, distobuccal, and palatal) and four cusps (mesiobuccal, distobuccal, mesiolingual, and distolingual), though variations can occur. The crown exhibits a large occlusal surface with prominent grooves and fissures, facilitating mastication. The superior second molar contributes to posterior occlusion, chewing efficiency, and maintenance of arch continuity. Its roots are closely related to the maxillary sinus floor, which is important for imaging and surgical procedures. The tooth is covered by enamel, with underlying dentin and pulp cavity housing the neurovascular bundle.

Synonyms

  • Maxillary second molar

  • Upper second molar

  • Tooth #2 in dental notation (universal system)

Function

  • Provides mastication of food, particularly grinding

  • Maintains posterior occlusion and arch continuity

  • Supports buccal and palatal soft tissue architecture

  • Plays a role in dental alignment and occlusal stability

MRI Appearance
T1-weighted images:

  • Enamel appears very low signal (dark) due to high mineral content

  • Dentin shows intermediate signal

  • Pulp cavity appears hyperintense, reflecting the vascularized soft tissue

  • Surrounding periodontal ligament is thin and hypointense, while adjacent alveolar bone shows intermediate signal

T2-weighted images:

  • Enamel remains signal void, dentin is intermediate, and pulp is bright hyperintense

  • Pathology such as pulpitis or periapical lesions appears hyperintense, especially in STIR sequences

  • Periodontal ligament space may appear slightly hyperintense due to fluid content in disease states

STIR (Short Tau Inversion Recovery):

  • Suppresses surrounding fat signal, enhancing detection of periapical inflammation, edema, or abscesses

  • Normal pulp appears intermediate, while pathologic changes appear bright hyperintense

CT Appearance

  • Enamel appears hyperdense, dentin slightly less dense, and pulp cavity hypodense

  • Roots are clearly visualized, including root morphology, canal configuration, and relationship to the maxillary sinus

  • Surrounding alveolar bone is hyperdense, with trabecular pattern visible in high-resolution scans

  • Ideal for evaluating impacted teeth, fractures, periapical lesions, and pre-surgical planning for extractions or implants

MRI images

Superior second molar tooth mri axial image -img-00000-00000

MRI images

Superior second molar tooth mri sag image -img-00000-00000