Root Canal Anatomy

  1. Canal Configuration

    Krasner and Rankow.
    Bjorndal et al.
    Krasner and Rankow -  The cementoenamel junction (CEJ) is a consistent landmark for the location and shape of the pulp chamber.

    Bjorndal et al. - Root shape predicts the number, location, and morphology of canals within the root.
  2. Vertucci's Canal Classification
    Vertucci's Canal Classification

    • Type I represents a single canal.
    • Type II indicates two canals that join at the apex.
    • Type III begins as a single canal that splits into two canals and joins at the apex.
    • Type IV is a root containing two canals.
    • Type V is a single canal that bifurcates at the apex.
    • Type VI begins as two canals, joins in the midroot area, and bifurcates at the apex.
    • Type VII begins as a single canal, bifurcates in the midroot area, joins in the apical third, and again bifurcates.
    • Type VIII indicates three separate canals.
  3. Apical Anatomy

    Location of apical foramen?

    Burch and Hulen.
    Kuttler et al.
    El Ayouti et al.
    Burch and Hulen - 92.4% of the major foramina of all classes of teeth open short of the anatomical apex.  Furthermore, the average distance between the foramen and the anatomical root apex is 0.59 mm.

    Kuttler et al. - Demonstrated that the apical foramen is often not coincident with the root apex. He found that the average distance between the center of  the foramen and the apical center was 495 μm.

    El Ayouti et al. - Found that the distance between the apical foramen and the apex was, on average, 0.9 mm when evaluated by cone beam computed tomography (CBCT).
  4. Apical Anatomy

    Distance from minor foramen to major foramen?

    Stern and Corcoran.
    El Ayouti et al.
    Meder-Cowherd et al.
    Stein and Corcoran - Found that the average distance between the major and minor foramina was 0.724 mm, and the width of the CDJ remained constant with age at 0.189 mm.

    El Ayouti et al. - Measured the mean distance between the apical constriction and apical foramen on CBCT scans at 0.2 mm.

    Meder-Cowherd et al. - Unable to locate a defined apical constriction in 65% of the palatal roots of maxillary first molars evaluated by CBCT scans. This demonstrated that not all roots necessarily exhibit the traditionally defined apical constriction.
  5. Accessory Canals

    Formation

    Gutmann
    Gutmann - Theorized that these structures form via localized breaks in HERS around blood vessel communications.
  6. Accessory Canals

    Definition

    De Deus et al.
    De Deus et al.

    • Lateral canal as one extending from the main canal to the periodontal ligament (PDL) in the body of the root
    • Secondary canal as one extending from the main canal to the PDL in the apical region
    • Accessory canal as one derived from the secondary canal branching toward the PDL in the apical region.
  7. Accessory Canals

    Location
    Research confirms the most common location for lateral anatomy is in the apical third (De Deus, Vertucci).
  8. Accessory Canals

    Prevalence

    Rubach and Mitchell
    De Deus
    Gutmann
    Vertucci and Williams
    • 45%
    • Rubach and Mitchell

    • 27.4% (17% in apical third)
    • De Deus

    • 28%
    • Gutmann

    • 46%
    • Vertucci and Williams
  9. Unique Anatomical Variants

    Dens Invaginatus - Formation
    The DI forms via infolding of enamel and dentin into the root canal space.

    Narayana et al proposed several potential etiologic factors including trauma, infection, growth retardation of specific cells, disruption in the regulation of the enamel organ, and genetic predisposition.
  10. Unique Anatomical Variants

    Dens Invaginatus - Incidence

    Holland and Block
    Rotstein et al. (Location)
    Hulsmann (Bilateralism)
    Hovland and Block - Reported an incidence of between 0.4% and 10% in the general population.

    Rotstein et al - Found that 42% of DI cases occurred in lateral incisors.

    Hulsmann - Found bilateral presentation 43% of the time.
  11. Unique Anatomical Variants

    Dens Invaginatus - Classification

    Oehlers
    Oehlers

    • Type I represents a minor extension into the root canal space.
    • Type II extends into the root and may perforate the pulp tissue.
    • Type III penetrates to the apex and may have its own apical foramen.
  12. Unique Anatomical Variants

    Dens Evaginatus - Formation
    DE forms from an out-pouching of enamel and dentin onto the occlusal or lingual surfaces of the dentition. The remaining portion of the clinical crown of teeth affected by DE is often normal in appearance.
  13. Unique Anatomical Variants

    Dens Evaginatus - Incidence

    Levitan and Himel (Location)
    Levitan and Himel - The variant can be found on any tooth but is most commonly observed on premolars and often presents bilaterally. If found on anterior teeth, it is frequently seen on the lingual surface and has been described as a talon cusp.
  14. Unique Anatomical Variants

    C-shaped canals - Location and Presentation
    C-shaped canals have been described in mandibular and maxillary molars and mandibular premolars.

    They present with large, interconnected tissue spaces and are often difficult to diagnose by two-dimensional radiographs alone.

    Although the majority of these teeth exhibit fused roots, C-shaped canals have also been noted in nonfused roots (Lu et al).
  15. Unique Anatomical Variants

    C-shaped canals - Incidence

    Cooke and Cox
    Lu et al.
    Newton and McDonald
    Cooke and Cox - They have been observed in as many as 8% of mandibular second molars when examined clinically.

    Lu et al. - Located the anomaly in 18% of mandibular premolars in a Chinese population.
  16. Unique Anatomical Variants

    C-shaped canals - Possible pulp chamber appearance in C-shaped mandibular molars.

    Min et al.
    Possible pulp chamber appearance in C-shaped mandibular molars:

    • Continuous C-shaped orifice
    • C-shaped medial orifice with a separate distal canal
    • Continuous MB-D orifice and separate ML orifice
    • Non-C-shaped pulpal floor
  17. Unique Anatomical Variants

    C-shaped canals - Treatment Considerations

    Gu et al.
    Caution must be exercised in the endodontic treatment of teeth with a C-shaped canal because of the presence of thin canal walls.
  18. Maxillary Root Canal Anatomy
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  19. Maxillary Root Canal Anatomy
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  20. Mandibular Root Canal Anatomy
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  21. Mandibular Root Canal Anatomy
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Author
ucsfendo
ID
344370
Card Set
Root Canal Anatomy
Description
Root Canal Anatomy
Updated