Sublingual damage
From BME Encyclopedia
During tongue splitting and tongue frenectomy ("lengthening") procedures, the sublingual frenum (the webbing under your tongue) is often damaged, either as a byproduct of the procedure or specifically on purpose. The frenum is relatively minor and removal rarely leads to complications, but the sublingual salivatory glands are sensitive and easy to damage. In addition, further back are a number of cranial nerves (inferior maxillary, lingual, hypoglossal, glossopharyngeal and internal laryngeal nerve are all somewhat present).
In unusual cases this could happen from tongue web piercing as well.
