The
lingual (or
inferior)
frenulum is a folded piece of
mucous membrane that anchors the anterior
tongue to the floor of the
mouth.
The
etymology of the word frenulum is from
Latin and means “small
bridle” or “
curb”. Frenulums occur when there was originally an embryonic fusion of 2 surfaces, which later are separated with normal growth, such as the frenulum of the penis (the glans and the inner foreskin are originally fused) or the
lingual frenulum (the
tongue and the floor of the mouth are originally fused).
The “
bridle” origin of the word is particularly appropriate as a bridle is used to guide as well as to control. Embroyonically, in early gestation (as early as 4 weeks) the lingual frenulum serves as a guide for the forward growth of the tongue. After birth the tip of the tongue continues to elongate, giving the impression of the frenulum retracting. In reality this has been going on for some time before birth. This is what gives the impression that the frenulums of some previously tongue-tied infants will “stretch” with age and growth. In reality the tongue often just grows beyond the frenulum, although some do also stretch and/or rupture after mild accidents. Many others continue to cause problems throughout life, unless corrected.
The control or curb aspect of the bridle analogy is more pathological. The frenulum, if too short or endings too close to the tip of the tongue OVER controls the tongue, curbing movement and function. This is often referred to as
tethered, another
equestrian term. It is also called
Ankyloglossia.
The linqual frenulum is most important during embryonic development, after that it is sometimes a source of trouble and in most adults (unless tongue tied) pretty much vestigial, although is can still be seen, it does little to curb or guide the tongue once growth is complete.
If you lift your tongue to the roof of your mouth and look in a mirror you can see what is left of your linqual frenulum.
SOURCES
http://www.bartleby.com/61/1/F0320100.html
http://www.anatomy.usyd.edu.au/glossary/glossary
http://www.brianpalmerdds.com/frenum_pdf.pdf