The retromolar canals and foramina: radiographic observation and application to oral surgery.
PURPOSE
The retromolar canal (RMC) and foramen (RMF) are anatomic variants in the retromolar area of the mandible. The purpose of this study was to clarify the relationship between the RMC and RMF and related complications, and to reveal how the RMC could impact the mandibular anatomy using cone-beam computed tomography (CBCT) and panoramic images (PAN).


MATERIALS AND METHODS
CBCT and PAN images of 50 patients were retrospectively analyzed to investigate the morphology of the RMC and RMF, and their impact on impacted third molar surgery and orthognathic surgery.


RESULTS
In PAN images, neither the RMC nor RMF was detected. In CBCT images, the RMCs were detected in 26% (13/50) of the patients. A double RMC was detected on one side of one patient. The diameter of the RMC ranged from 0.8 to 2.9 mm (mean; 1.5 ± 0.6 mm), and the RMF ranged from 0.6 to 2.3 mm (mean; 1.1 ± 0.5 mm). No patients experienced unexpected bleeding. Unilateral postoperative hypoesthesia of the buccal gingiva in the molar region was reported in 6.7% of patients with the RMC.


CONCLUSIONS
Hypoesthesia of the buccal gingiva in the lower molar region may be the main complication when the RMC is damaged.
['Kikuta|Shogo|S|http://orcid.org/0000-0002-2236-2884', 'Iwanaga|Joe|J|', 'Nakamura|Ken|K|', 'Hino|Kiyosato|K|', 'Nakamura|Moriyoshi|M|', 'Kusukawa|Jingo|J|']
D000293:Adolescent D000328:Adult D000368:Aged D063405:Anatomic Variation D054893:Cone-Beam Computed Tomography D005260:Female D006801:Humans D008297:Male D008334:Mandible D008340:Mandibular Nerve D008875:Middle Aged D008964:Molar, Third D019647:Oral Surgical Procedures D011183:Postoperative Complications D011862:Radiography, Panoramic D012189:Retrospective Studies D055815:Young Adult
Retromolar canal Oral surgery Mandible Cone-beam computed tomography Anatomic variation Retromolar foramen