3-Rooted Maxillary First Premolars: An Ex Vivo Study of External and Internal Morphologies

Area of Science:

• Endodontics
• Dental Anatomy
• Radiology

Background:

• Maxillary first premolars with three roots are anatomically complex.
• Understanding their external and internal morphology is crucial for successful endodontic treatment.
• Cone-beam computed tomographic (CBCT) imaging offers detailed insights into dental anatomy.

Purpose of the Study:

• To analyze the external and internal root morphologies of three-rooted maxillary first premolars.
• To classify these teeth based on external root variations.
• To measure internal morphologic features, including root canal bifurcation distances.

Main Methods:

• Fifty-six three-rooted maxillary first premolars were imaged using CBCT.
• Teeth were classified into four groups based on external root morphology.
• Internal features, such as orifice shape and root canal bifurcation distances from the cementoenamel junction (CEJ), were measured.

Main Results:

• Four external morphology groups were identified, involving varying degrees of root fusion.
• The buccal orifice shape was predominantly triangular/heart-shaped.
• Significant differences in root canal bifurcation distances were observed between different external morphology groups.
• Four teeth displayed C-shaped root canal systems.

Conclusions:

• Three-rooted maxillary first premolars demonstrate considerable variability in both external and internal root morphology.
• These anatomical variations, particularly in root canal anatomy, necessitate careful consideration during endodontic procedures.
• CBCT imaging is an effective tool for evaluating these complex dental structures.