Is Tongue Tie Becoming More Common?

In October 2016, I listened to an interesting lecture by Dr. Ghaheri (ENT in Portland, OR) who at one point attempted to explain through genetics why clinically significant tongue tie may be increasing in frequency.

After all, it seems that every year, more and more moms are reporting breastfeeding difficulty/pain as well as more infants are being diagnosed with tongue tie now than in the past.

One explanation may be due to genetics. He specifically mentioned three research papers that suggest tongue tie is inherited in an autosomal dominant fashion.

• Acevedo in 2010 identified a Brazilian family that had both ankyloglossia and dental abnormalities. The study demonstrated an autosomal dominant pattern of inheritance.
• Han in 2012 identified potential X-linked pattern of inheritance.
• Klockars in 2007 also suggested that tongue tie is passed in an autosomal dominant fashion and that the prevalence of ankyloglossia in the population is approximately 4-5%.

Autosomal dominant means that for a given trait, if this gene is present, it WILL appear in the next generation, even if only one copy is present (whether from mom or dad).

Autosomal dominant trait also means that over time, it will appear in greater frequency in the population over time.

But this is probably only part of the story because...

Why NOW does it seem to be SO much more common than in the past? After all, tongue tie has been recognized since even ancient times. Aristotle (3rd century BC), Paul of Aegina (7th century AD), Celus (1st century AD), and Galen (2nd century AD) have all described tongue tie in their writings.

The other keys to the puzzle beyond genetics (pure speculation) may be the development of the baby bottle and formula.

Hypothetically, these two "inventions" along with the tongue tie release procedure may have allowed infants with significant tongue tie to better survive infancy allowing their autosomal dominant genes to be passed to future progeny with increased frequency.

Check out the graph below showing infant mortality from 1915-1997 published by the CDC [link].

In the 1850s, infant mortality was about 300 per 1000 births.  In the early 20th century, infant mortality improved to around 100 per 1000 live births. Thereafter, there has been a profound decrease in infant mortality to where it is currently holding steady at around 6 per 1000 births.  [link]

The significant decrease in infant mortality is attributed to a variety of reasons including improved medical care, improved nutrition, improved sanitation (environment), etc.

However, hypothetically, it just may be that under the improved nutrition category, tongue tie may have been a contributing factor to infant mortality.

Infants with clinically significant tongue tie may not have survived infancy back in the pre-20th century due to malnutrition and dehydration from being unable to breastfeed effectively, whether from maternal factors (decreased milk supply due to poor demand of tongue-tied infants) or infant factors of just not being able to feed that well from an oral mechanical perspective. (This is assuming tongue tie was not recognized and corrected... Read more about the historical debate over tongue tie release here.)

As such, only a small fraction of such infants may have survived to adulthood to pass along the tongue tie autosomal dominant gene.

But along with improved medical care and sanitation, a number of inventions allowed for such tongue-tied infants who otherwise may not have survived to obtain nutrition regardless of breastfeeding difficulties... the baby bottle and formula.

For the baby bottle history,

• In 1841, the glass baby bottle was patented.
• In 1845, the rubber nipple was patented.
• In early 1900s, both were able to be mass-produced cheaply.
• By the 1940s, numerous different baby bottle designs were available.

For the baby formula history,

• In 1867, the first cow's milk formula was developed
• In 1890s, many different raw milk formulas were developed and gained widespread use by 1907 as baby bottles become more readily available
• In 1915, powdered milk was developed
• In the 1920s, such evaporated milk became widely commercially available
• In the 1920s, commercial formula was developed to mimic as close as possible human breastmilk

Even in 2017 in the USA, there is one report of an infant who died from exclusive breastfeeding... the title says it all, "If I had given him just one bottle, he would still be alive."

Concurrent with the development and mass production of baby formula and the baby bottle, breastfeeding decreased substantially from the late 1800s to the 1960s. By the late 1960s, it is estimated that over 75% of all babies were fed exclusively on commercially produced baby formula.

As such, large numbers of tongue-tied infants would have been the beneficiary of not only a substantially lower infant mortality rate but also the bottle and formula by the 1960s of moms who may have had trouble breastfeeding (if breastfeeding was even tried). These infants would have gone on to have children of their own passing along their tongue tie genes into the next generation in the late 1990s and early 21st century.

By this point, we have the perfect storm of:

Increasing prevalence of the tongue tie gene in the human population

AND

Resurgence of breastfeeding interest, especially by the 1990s

As such, one would expect there to be a seeming epidemic of moms reporting breastfeeding difficulty due to the steadily increasing numbers of tongue-tied babies being born.

But is this true???

The easiest way would be to see how often "breastfeeding pain" is searched for on google via google trends. Here is the graph showing a steady upswing over time:

How about tongue tie? [link]

The delay in upswing for "tongue tie" keyword searches compared to breastfeeding pain is probably due to the fact that one would need to first recognize that tongue tie may be a cause for breastfeeding difficulty before one can know to search for this keyword phrase.

Though skeptics may consider the increase in tongue tie diagnoses to be one of increased awareness or recognition and not necessarily due to an actual increase in population frequency, it is harder to explain away the increase in reported (or rather searched for) symptom of "breastfeeding pain" over time. Indeed, one would expect the graph of "breastfeeding pain" to remain constant over time if tongue tie frequency truly remained constant.

Just for comparison with a more neutral search phrase that one would not expect to change over time, here is a graph comparing a google keyword search frequency for "breastfeeding pain" (blue) and a more neutral related search term "pregnant swollen breasts" (red).

Just for fun, click here to view a graph for search term frequencies for "breastfeeding pain," "tongue tie," and "pregnant swollen breasts" all displayed on one graph.

If the frequency of google keyword searches is any indication for how frequently a problem exists, than these graphs certainly seem to suggest that tongue tie and the pain it causes with breastfeeding is increasing in frequency over time and will continue to increase in frequency into the future.

Is there a tongue-tie epidemic? I would argue yes based on all the above information, albeit circumstantial evidence.

So, THAT's why it seems tongue tie is so common.

References:

Autosomal-dominant ankyloglossia and tooth number anomalies. J Dent Res. 2010 Feb;89(2):128-32. doi: 10.1177/0022034509356401. Epub 2009 Dec 30.

A study on the genetic inheritance of ankyloglossia based on pedigree analysis. Arch Plast Surg. 2012 Jul;39(4):329-32. doi: 10.5999/aps.2012.39.4.329. Epub 2012 Jul 13.

Inheritance of ankyloglossia (tongue-tie). Clin Genet. 2009 Jan;75(1):98-9. doi: 10.1111/j.1399-0004.2008.01096.x. Epub 2008 Oct 24.

Familial ankyloglossia (tongue-tie). Int J Pediatr Otorhinolaryngol. 2007 Aug;71(8):1321-4. Epub 2007 Jun 22.

History and culture of breastfeeding. Wikipedia. Accessed 11/4/16

If I had given him just one bottle, he would still be alive. Fed is Best. Feb 2017.

Mom who exclusively breast-fed son shares heartbreaking post to help others. Fox News 3/2/17.

Baby bottle. Wikipedia. Accessed 11/4/16

Infant formula. Wikipedia. Accessed 11/4/16

Achievements in Public Health, 1900-1999: Healthier Mothers and Babies. CDC. Accessed 11/4/16.