Distribution of the hypoglossal nerve at the base of the tongue and its clinical importance in radiofrequency ablation therapy

Aim: To identify the course of the hypoglossal nerve at the base of tongue and to determine a safe area for the placement of radiofrequency ablation therapy (RAT) probes to protect the nerve trunk from any damage. Materials and methods: Anatomical structures located at the base of the tongue were investigated in 10 cadaveric human half-heads. On the base of our landmarks, which are clinically important sign points, measurements were made. Results: The safe area was found to be: in the transverse plane, the 1/2 medial part of the half-tongue between the lateral edge and the foramen caecum of the tongue, and in the vertical plane, a 14.5-mm depth. Despite the presence of minor branches of the hypoglossal nerve in this area, we think that the trunk of the nerve would be preserved. Conclusion: We suggest that the landmarks that we determined to avoid motor deficit of the tongue will be helpful for clinicians during RAT to the tongue base.