PMC9375130_01
Oehlers' classification of dens invaginatus
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F1
Considering the unique configuration of the current dens invaginatus, it cannot be placed into any of the current classifications as previously described by Oehlers (Fig. 1).
Periapical radiograph showing lateral and periapical radiolucencies, two root canals, and indistinct canal anatomy
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F2
A periapical radiograph was taken, which showed periapical and lateral radiolucencies and two root canals with indistinct morphology (Fig. 2).
(A) Cone-beam computed tomography (CBCT; axial view of the coronal third); the main root canal is pushed laterally by the invagination. (B) CBCT (axial view of the middle third); the main root canal and the invagination. (C) CBCT (axial view of the apical third); two apical openings, one is the pseudoforamen of the invagination and the other is the apical foramen of the main root canal
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F3
It was demonstrated that the main canal was pushed laterally by an invagination in the coronal third, which continued to the apex with apical and lateral communications through pseudo foramina (Fig. 3 and 4).
Type IV dens invaginatus. (A) Preoperative radiograph and (B) pictorial diagram showing that the main root canal is pushed laterally by the invagination with a lateral canal arising from the main root canal plus the lateral communication of the invagination on the distal aspect of the maxillary right lateral incisor. (C) Cone-beam computed tomography (CBCT; axial view) and (D) pictorial axial view showing the lateral communication of the invagination with the periodontium and a lateral canal arising from the main root canal
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F4
It was demonstrated that the main canal was pushed laterally by an invagination in the coronal third, which continued to the apex with apical and lateral communications through pseudo foramina (Fig. 3 and 4). There was also a lateral canal arising from the main root canal and communicating laterally with the periodontium along the same plane as the lateral communication of the dens invaginatus (Fig. 4). Therefore, we propose to classify it as type IV dens invaginatus (Fig. 4).