linguogingival fissure

lin·guo·gin·gi·val fis·sure

a fissure sometimes occurring on the lingual surface of one of the upper incisors and extending into the cementum.

lin·guo·gin·gi·val fis·sure

(linggwō-jinji-văl fishŭr)
Fissure of lingual surface of upper incisors extending into cementum.