Microcomputed tomography analysis of mesiobuccal orifices and major apical foramen in first maxillary molars

Abstract

Objective: Aim of the study was to determined by microcomputed tomography (µCT) the horizontal distance between the main (MB1) and the second mesiobuccal canal (MB2) orifices, the vertical distance between the MB1 and MB2 orifices planes, and the distance between the anatomic apex and major apical foramen (AF). Furthermore, we characterized the entire internal and external anatomy of the MB, distalbuccal (DB) and palatal (P) maxillary first molars roots.

Materials and methods: Twenty-two intact extracted first maxillary molars were scanned by X-ray computed transaxial µCT and then 2D and 3D images were processed and analyzed.

Results: The results showed that 77.27% of the mesiobuccal (MB) roots presented a second MB canal, and 29.41% of the MB2 were independent from the MB1 canals. In 15 teeth, there were three root canal orifices on the chamber floor, and 10 of these teeth presented MB2 canals. The mean vertical distance between the MB1 and MB2 planes was 1.68 ± 0.83 mm. Seven teeth had four orifices. The mean horizontal interorificial distance between the MB1 and MB2 orifices was 1.21 ± 0.5 mm. Accessory canals were observed in 33.33% of the roots, loops in 6.06%, while isthmuses were found in 15 of the 22 MB roots. Of the total roots, 74.24% presented one foramen, while all of the roots showed a major apical foramen that was not coincident with the anatomic apex.

Conclusions: Our µCT analysis provided interesting features on the horizontal and vertical distance between the MB1 and MB2 orifices and on the distance of AF and anatomic apex.

Clinical relevance: These results have an important clinical value because might support the endodontist in the recruitment, negotiation and obturation of maxillary first molar canal system.

Keywords: First maxillary molar; MB2; anatomy; µCT..

Fig. (1)

Representative 3D image of an MB root and 2D images of canal orifices. Three canal orifices at the pulp chamber floor (a) turn into four canals apically in the root (b). Anatomic distances (c) were measured as reported in the materials and methods section.

Fig. (2)

Representative 2Dand 3D images of an apical third. Anatomic apex (a), major apical foramen (b-c).

Fig. (3)

Representative image of a Type VI canal, classified according to Vertucci (1984).

Fig. (4)

Representative images of an apical delta. 2D image (a) and 3D image (b).

Fig. (5)

Representative image of a lateral canal in a MB root (a). Particular of root (b). Magnification (c).

Fig. (6)

Representative images of a loop in a DV root. 3D images (a) and magnification (b). 2D images, before the loop (c), of the loop (d), and after the loop (e).