Evaluation of the relationship between appearances of the lingual foramen on panoramic radiography and cone-beam computed tomography.

Aim: The aim of this retrospective study is to determine the level of visibility of the lingual foramen in panoramic radiography using cone-beam computed tomography (CBCT) as a reference tool.

Method: A total of 200 patients (111 females and 89 males) were included in the study. Cross-sectional CBCT images of the mandible in the midline were used to locate and define the orifice and diameter of each lingual canal that was detected. The appearance of the lingual foramen in the anterior mandible in panoramic radiography was assessed using a five-point ordinal scale. Descriptive statistics including tables and graphs were used. The correlation between CBCT and panoramic radiography findings were analyzed using Chi-square tests.

Results: The lingual foramen was found to be located most frequently in the mandibular midline, above the genial tubercle (78.5%). A narrow-diameter type was found to occur most frequently (56.5%). A prominent genial tubercle was the most commonly found type (57.5%). The lingual foramen could be definitively identified in panoramic radiographs in only 8 cases (4%), while a high degree of probability was found in 25 cases (12.5%). The lingual foramen appears wider and therefore more distinctive in panoramic radiographs when the angulation of the lingual canal is less than 20° to the ground plane.

Conclusions: Radiological evaluation with panoramic radiographs alone may lead to inadequate assessments prior to surgical procedures involving the anterior mandible. Clinicians may consider using three-dimensional imaging for procedures with a risk of hemorrhagic and neurosensory complications such as dental implant placement in the anterior mandible.