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Topic

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Root canal of upper molar tooth

The root canal of the upper molar tooth is the internal cavity within the roots of maxillary molars that houses the pulp tissue, including nerves, blood vessels, and connective tissue. Each upper molar typically has three roots—two buccal (mesiobuccal and distobuccal) and one palatal—with one to three canals per root, although anatomical variations are common. The canals allow the pulp to communicate with the periapical tissues, supplying nutrients and sensory innervation. Their size, curvature, and number are highly variable, making accurate imaging and assessment essential for diagnosis, endodontic therapy, and surgical planning.

Synonyms

  • Maxillary molar pulp canal

  • Upper molar root canal system

  • Endodontic canal of upper molar

Function

  • Houses and protects dental pulp, which provides vascular supply and innervation to the tooth

  • Facilitates nutrient delivery and sensory function to the dentin and surrounding tooth structure

  • Provides a conduit for immune response within the tooth

  • Essential for tooth vitality and long-term dental health

MRI Appearance
T1-weighted images:

  • The root canal appears as a small, linear hypointense structure within the hyperintense dentin and surrounding alveolar bone

  • The pulp tissue itself may appear intermediate signal intensity, slightly lower than adjacent fat in the bone marrow

  • Pathological changes, such as pulp necrosis or inflammation, may alter the signal, appearing hypo- or hyperintense depending on the stage of pathology

T2-weighted images:

  • The pulp canal appears hyperintense relative to the surrounding dentin, allowing clear delineation of pulp chambers and canal morphology

  • Useful for identifying pulp edema, necrosis, or periapical inflammatory changes

STIR (Short Tau Inversion Recovery):

  • Suppresses fat signal in surrounding alveolar bone

  • Highlights edema, infection, or inflammatory changes within the pulp or periapical region

  • Normal pulp shows intermediate to slightly hyperintense signal, while pathological changes are bright hyperintense

CT Appearance

  • The root canal appears as a hypodense linear cavity within the hyperdense dentin and surrounding alveolar bone

  • Easily visualized in axial, coronal, and sagittal planes

  • CBCT (cone-beam CT) provides high-resolution 3D mapping of canal morphology, including accessory canals, curvatures, and apical foramina

  • CT is ideal for evaluating periapical lesions, canal calcifications, fractures, or resorption

Root canal of upper molar tooth mri sagittal image -img-00000-00000