Descriptive study of the bifid mandibular canals and retromolar foramina: cone beam CT vs panoramic radiography.
OBJECTIVE
To examine the presence and morphologic characteristics of bifid mandibular canals (BMCs) and retromolar foramens (RFs) using cone beam CT (CBCT) and to determine their visualization on panoramic radiographs (PANs).


METHODS
A sample of 225 CBCT examinations was analysed for the presence of BMCs, as well as length, height, diameter and angle. The diameter of the RF was also determined. Subsequently, corresponding PANs were analysed to determine whether the BMCs and RFs were visible or not.


RESULTS
The BMCs were observed on CBCT in 83 out of the 225 patients (36.8%). With respect to gender, statistically significant differences were found in the number of BMCs. There were also significant differences in anatomical characteristics of the types of BMCs. Only 37.8% of the BMCs and 32.5% of the RFs identified on CBCT were also visible on PANs. The diameter had a significant effect on the capability of PANs to visualize BMCs and RFs (B = 0.791, p = 0.035; B = 1.900, p = 0.017, respectively).


CONCLUSIONS
PANs are unable to sufficiently identify BMCs and RFs. The diameter of these anatomical landmarks represents a relevant factor for visualization on PANs. Pre-operative images using only PANs may lead to underestimation of the presence of BMCs and to surgical complications and anaesthetic failures, which could have been avoided. For true determination of BMCs, a CBCT device should be considered better than a PAN.
1 Department of Stomatology, Medical and Dentistry School, Santiago de Compostela University, Santiago de Compostela, Spain.
J
J
Muinelo-Lorenzo
J A
JA
Suárez-Quintanilla
A
A
Fernández-Alonso
S
S
Marsillas-Rascado
M M
MM
Suárez-Cunqueiro
D000293:Adolescent; D000328:Adult; D000368:Aged; D059925:Anatomic Landmarks / Q000002:abnormalities / Q000000981:diagnostic imaging; D063405:Anatomic Variation; D054893:Cone-Beam Computed Tomography / Q000379:methods*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008297:Male; D008334:Mandible / Q000002:abnormalities / Q000000981:diagnostic imaging*; D008875:Middle Aged; D011862:Radiography, Panoramic / Q000379:methods*; D012737:Sex Factors; D055815:Young Adult
accessory nerve; cone beam computed tomography; endosseous dental implantation; inferior alveolar nerve; panoramic radiography