What's in a name? The Co-Option of the term Tongue-tie

Since when is it OK to change a centuries-old definition because one has observed an as yet un-comprehendible or un-parsable phenomenon? This is exactly what has happened with the co-option of the term tongue-tie.

Tongue-tie, the vernacular for partial ankyloglossia, has been written about for centuries. A passage written by Aristotle in the 3rd  century BC describes it thus: (In O’Bladen, 2010.)

The human tongue is the freest, the broadest, and the softest of all: this is to enable it to fulfill both its functions…It has, also, to articulate the various sounds and to produce speech, and for this a tongue which is soft and broad is admirably suited, because it can roll back and dart forward in all directions; and herein too its freedom and looseness assists it. This is shown by the case of those whose tongues are slightly tied: their speech is indistinct and lisping, which is due to the fact that they cannot produce all the sounds.

As the centuries unfold other prominent healers and scientists also described the phenomenon in similar terms. Celsus in the 1st century AD, Galen in the 2nd  century AD and Paul of Aegina in the 7th century AD. Paul even describes the surgical technique used to resolve the tie. (In O’Bladen, 2010.)

Complete ankyloglossia, a term originating from the Greek combined form of ankylo, meaning crooked or bent, and glossia, meaning tongue, is a complete failure of embryonic apoptosis that carves the tongue body and blade out from the block of primordial tongue tissue, thereby delineating it from the mouth floor. Complete ankyloglossia is extremely rare.

Partial ankyloglossia appears in several forms. Its appearance ranges from the swiss-cheese-like look of partial apoptosis failure to the midline defect that leaves behind a more prominent, short and/or tight lingual frenulum we refer to as tongue-tie. The midline form of partial ankyloglossia is far more common than any of the other more bizarre forms.

We do not know at what point the term partial ankyloglossia became tongue-tie or if the term tongue-tie precedes the more scientific and formal term. Perhaps its observed impact on speech and feeding led to the adoption of this common-language moniker. Tongue-tie certainly best describes the hypothesized problems that can occur when partial midline ankyloglossia is present.

The long-lived definition of tongue-tie is a functional one cum appearance characteristics. In every writing about tongue-tie, until lately, the condition is a congenital anomaly coded by one or more genes (Tbx22 is implicated.) The shortness, tightness or prominence of this midline structure likely causes tongue-motion deficits that interfere with activities of daily living like eating and talking. In Science time, we are at the very beginning of our understanding of this phenomenon. We actually know relatively little about the condition or its impact.

Here’s my most important point: the condition known as tongue-tie occurs as a result of coding errors at the gene level. Expression of one (or more) genes causes the apoptosis failure during the embryological period of development. Co-opting the term tongue-tie to refer to acquired conditions, as has been done in the last decade and a half, undermines the entire concept and definition of tongue-tie, leading professionals and parents astray.

These days, tongue-tie refers to any visible frenum making the normal phenotype pathological. Any cause of tongue motion deficits is dubbed tongue-tie leading many babies to unneeded surgery (like cattle to slaughter.) The use of the term tongue-tie to refer to torticollis, hyoid strain patterns and cranial nerve-mediated sucking dysfunction is at the very least a spectacular show of ignorance and at worst, highly unethical. We made rules about the protection of vulnerable humans for good reason.

To complicate matters, the term Tethered Oral Tissues (TOTs) entered the picture about five years ago and has spawned an industry. (What color of ribbon should we wear for this vague and confusing disease?) Does the bandying about of this term clarify or muddy the waters? I vote for the latter. These days, any sucking, feeding, eating, and talking dysfunction is attributed to TOTs. The leaders of this new industry abuse the truth to justify their opinions and so the “alternate facts” become ever-more deeply rooted.

The truth is that there is no scientific evidence that proves that prominent labial frena, “buccal ties” or any other form of (fabricated) tongue tethering causes any of the dysfunctions claimed to occur by the participants in this burgeoning industry.

The institutionalization of the TOTs rubric gives permission for anyone to park their observations under the everything-is-tied roof without data to back them up. We now find ourselves on the proverbial slippery slope.

For example, Coryllos and Watson Genna have never provided any incontrovertible data to back up their claims about “posterior tie.” At the time they proposed their hypothesis, torticollis of all types, of which there are several, was increasing and creating tongue function deficits akin to tongue-tie. The mouth floor tightness that typically accompanies torticollis can even make the lingual frenulum appear tighter than it actually is. Coryllos and Watson Genna were most likely observing the impact of torticollis when they dubbed what they were seeing “posterior tie.” If you look at Watson Genna’s website today, the pictures of “posterior ties” are pictures of babies who actually have torticollis.

Torticollis is a robust competitor diagnosis to tongue-tie because 25% of babies are afflicted, but unlike tongue-tie, torticollis is always secondary to some other cause, whether it be ischemic events during pregnancy causing scar tissue on the sternocleidomastoid (SCM) muscle or the more common soft-tissue form acquired from structural-insult events during pregnancy and/or delivery. Tongue-tie, on the other hand, is simply and ALWAYS a genetic coding event, whether it be hereditary or epigenetic in origin.

Words have meanings. Names are powerful.

Good Science shows us that only 3-5% of babies are truly tongue-tied. The co-option of the term has led us down the pathway of mis- and over-diagnosis to the tune of 50% of all babies in some corners of the world.

Its best we get back to clarity and precision in our language. Only then will we be able to continue the grounding scientific work of determining the role tongue-tie plays in feeding and development. Cleaning up the muck and mire of TOTs-informed opinion and once again relying on the science will strengthen the argument for routine tongue-tie screening and timely treatment thereof when absolutely needed.

O’Bladen, M. (2010). Much ado about nothing: two millennia of controversy on tongue-tie. Neonatology; 97:83-89.