Beyond Canal Number: Anatomical and Clinical Challenges in Maxillary Premolars – A Case Series

Fig. 1

Expected Anatomy with Narrow Canals

A maxillary premolar presented with the expected two-canal configuration. Despite the conventional anatomy, both canals were markedly narrow, making negotiation and instrumentation more challenging.

Careful exploration using small hand files under magnification allowed progressive negotiation while maintaining a conservative approach.

Fig. 2

(A) Clinical view during irrigant activation. (B) Master cone radiograph confirming the fit and position of both gutta-percha cones.

Fig. 3

A) Postoperative periapical radiograph demonstrating the final obturation of both canals. (B) Clinical view of the pulp chamber following obturation.

Fig. 4

Single Canal with a Deep Split

The premolar initially presented as a single canal extending through a considerable portion of the root. Deeper exploration revealed bifurcation into two separate canal pathways.

Deep canal divisions may be particularly difficult to detect because the coronal anatomy initially suggests a simple single-canal configuration [2,5].  (A) Preoperative periapical radiograph showing an apparently single canal in the coronal portion of the root. (B) Initial clinical view of the access cavity showing a single canal orifice.

Fig. 5

Figure 5. (A) Clinical view following access refinement. (B, C) Master cone radiographs demonstrating the deep bifurcation of the initially single canal into two separate canal pathways.

Fig. 6

Figure 6. (A) Postoperative clinical view. (B) Final periapical radiograph demonstrating the initially single canal dividing deeply into two separate, obturated canal pathways.

Fig. 7

Molarized Premolar

Clinical and radiographic examination revealed an unusual maxillary premolar with three separate roots and three canals arranged in a molar-like configuration. Three-rooted maxillary premolars are uncommon [1,2]. When arranged as two buccal roots and one palatal root, the morphology resembles that of a miniature maxillary molar and has been described as a “small molar” or “radiculous molar” [4,6]. Identification of all three canals required careful assessment of the preoperative anatomy and exploration of the pulp chamber floor.

(A) Preoperative clinical view of the maxillary premolar. (B) Preoperative periapical radiograph revealing an unusual root outline suggestive of complex root anatomy.

Fig. 8

CBCT evaluation confirming three separate roots and three canals: mesiobuccal, distobuccal, and palatal.

Fig. 9

Clinical view of the access cavity demonstrating the two buccal canal orifices: mesiobuccal and distobuccal.

Fig. 10

Clinical view demonstrating the palatal canal orifice.

Fig. 11

Schematic illustration of the negotiation, glide-path establishment, and instrumentation of the three-canal system in the molarized maxillary premolar

Fig. 12

. (A) Clinical view of the three master gutta-percha cones positioned in the mesiobuccal, distobuccal, and palatal canals. (B) Master cone radiograph confirming their position within the three separate canal pathways.

Fig. 13

(A) Clinical view following obturation. (B, C) Postoperative periapical radiographs at different horizontal angulations demonstrating final obturation of the three separate canals.