Topics

Topic

design image
Superior first premolar tooth

The superior first premolar, also known as the maxillary first premolar, is located between the canine and second premolar in the maxillary dental arch. It typically has two cusps (buccal and palatal) and one or two roots, with a single root being most common but a bifurcated root present in a significant percentage of cases. This tooth is primarily responsible for tearing and grinding food, bridging the functional role between anterior canines and posterior molars. Its crown morphology, root anatomy, and pulp chamber configuration are essential considerations in endodontics, restorative dentistry, and orthodontics.

Synonyms

  • Maxillary first premolar

  • Upper first premolar

  • 1st premolar tooth (maxilla)

Function

  • Facilitates mastication, particularly tearing and grinding of food

  • Supports dental arch integrity and occlusion

  • Transmits occlusal forces to alveolar bone, contributing to jaw stability

  • Serves as a guide for orthodontic alignment and prosthodontic planning

MRI Appearance
T1-weighted images:

  • The tooth enamel appears very low signal (hypointense) due to its high mineral content

  • Dentin shows intermediate signal, and the pulp chamber appears hyperintense due to soft tissue content

  • Surrounding alveolar bone marrow is intermediate in signal, with adjacent fat hyperintense, creating contrast

  • Pathologies such as caries or pulpitis may appear as altered signal intensity within the enamel or pulp

T2-weighted images:

  • Enamel remains very low signal, dentin is intermediate, and pulp chamber appears bright (hyperintense)

  • Useful for detecting endodontic pathology, pulp inflammation, or periapical lesions

STIR (Short Tau Inversion Recovery):

  • Suppresses fat signal in surrounding alveolar bone and soft tissue

  • Edema, inflammation, or cystic lesions within the tooth or periapical region appear bright hyperintense, while enamel and dentin remain hypointense

CT Appearance

  • Tooth enamel appears hyperdense, making the crown easily distinguishable

  • Dentin shows slightly lower density, while the pulp chamber is hypodense, filled with soft tissue

  • Root morphology, number, and orientation are clearly visualized

  • Surrounding alveolar bone appears intermediate to high density, while the air of the oral cavity is hypodense, providing natural contrast

  • CT is particularly useful for evaluating root anatomy, caries, fractures, periapical lesions, and planning implants or orthodontic treatment

MRI images

Superior first premolar tooth mri axial image -img-00000-00000

MRI images

Superior first premolar tooth mri sag image -img-00000-00000