Mandibular incisive canal and lingual foramina characterization by cone-beam computed tomography

Many patients have haemorrhagic and neurologic complications after surgery at the symphysis region, while this area between the mental foramina is commonly considered to be risk-free because the presence of vasculo-nervous anastomoses found in the mandibular incisive canal (MIC) and lingual foramina (LF). The purpose of our study was to better analyse these anatomical structures to better identify and preserve them during surgery.

This prospective radio-anatomical study evaluated the presence, morphology and topography of MIC and median LF (MLF) and paramedian LF (PLF) by cone-beam computed tomography according to age, gender and dentition of 50 consecutive patients.

Among the MIC, 99% were visualized at their origin. Their visibility decreased gradually towards the symphysis. The MIC had a larger diameter and followed a significantly more superficial and more vestibular way in older patients. At least, one MLF by hemimandible was found whereas PLF were found only in 68% of the cases. The mean distance from the basal border was 7.11mm for the lower MLF, 16.33mm for the upper MLF and varied from 11.15 to 10.85mm for the left and right PLF.

Our study suggests that MIC and LF are constant structures with anatomical variations and that three-dimensional topographic study of the interforaminal region would be beneficial in patients requiring surgery in this area to reduce the risk of haemorrhage and neurologic complications.