Radicular Groove Accessory Canal Morphology in Mandibular First Premolars: Micro-computed Tomographic Study

Area of Science:

• Endodontics
• Dental Anatomy
• Micro-CT Imaging

Background:

• Radicular grooves are common in mandibular first premolars.
• Accessory canals within these grooves (RGACs) can impact endodontic treatment outcomes.
• Understanding RGAC morphology is crucial for effective root canal therapy.

Purpose of the Study:

• To investigate the morphological characteristics of RGACs in mandibular first premolars.
• To analyze the relationship between RGACs and root canal anatomy using micro-CT.
• To correlate RGAC presence with groove severity and root anatomy classifications.

Main Methods:

• Micro-computed tomographic (micro-CT) imaging of 154 mandibular first premolars with radicular grooves.
• Assessment of RGAC presence, origin, foramen position and diameter.
• Classification of grooves (ASUDAS) and root anatomy (Vertucci).
• Statistical analysis using the chi-square test (P < .05).

Main Results:

• The incidence of RGACs was 49.9%.
• RGAC foramina were predominantly in the middle third of the root, averaging 8.83 ± 2.53 mm from the CEJ.
• RGAC presence was significantly higher in more severe groove classifications (ASUDAS 3 & 4) and complex root anatomies (Vertucci type V).

Conclusions:

• Mandibular first premolars with radicular grooves frequently exhibit RGACs.
• A significant association exists between internal root anatomy, external groove morphology, and the presence of RGACs.
• These findings highlight the importance of considering RGACs in endodontic treatment planning for these teeth.