Juxta-apical radiolucency: relation to the mandibular canal and cortical plates based on cone beam CT imaging.

Objective: To evaluate the relation of juxta-apical radiolucency (JAR) to the mandibular canal and cortical plates on cone beam computed tomography images, as well as to assess whether the presence of JAR is related to the position of the mandibular canal.

Study Design: Forty-seven JAR cases were evaluated by cone beam computed tomography. JAR position and its relationship to the mandibular canal and cortical plates were investigated. The position of the mandibular canal was recorded and compared with a control group. Descriptive analyses and χ tests were performed.

Results: A significant association was established between JAR and the position of the mandibular canal (P = .0193), which was positioned lingually in 59.6% of JAR cases. In most cases, JAR was located distal to the tooth (66%) and in contact with the mandibular canal, either with (53.2%) or without (40.4%) preservation of the cortical border of the canal. In 22 cases (46.8%), thinning of cortical plates was observed, but no statistical differences were found between buccal and lingual sides (P = .5728).

Conclusions: The mandibular canal is located lingually in the third molar region in most JAR cases. JAR is located distal to the tooth and is generally in contact with the mandibular canal. These relations may increase the risk of nerve injury during surgical removal of third molars.