A tongue frenulum vs a tongue-tie

Tongue ties are a hot topic in breastfeeding and there is a lot of confusion and misunderstanding about tongue restrictions both among mums, and among a lot of health professionals. Part of the confusion is caused by the fact that research in this area is new and ongoing and like all research which is pioneering it causes divided opinion. In years gone past the opinions would have been discussed and argued over within journals and professional communities, but now everything is out there on the web, and it creates a lot of murky waters for worried parents to wade through.

A worried breastfeeding mum who is in pain, or hears clicking during feeds, or is concerned about weight gain or windiness (or any other multitude of symptoms) does a quick google or asks on Facebook and up pop dozens of articles on "tongue -tie". Mum takes a quick look at her baby's tongue, sees a frenulum and then worries that their problems are caused by this "tie". I have a personal interest in tongue restrictions and this is part of a series of blogs on tongue tie. In this blog I just want to deal with one common misunderstanding around "ties" and frenula:

A frenulum is not a tongue tie!

A tongue tie can have an enormous impact on breastfeeding and beyond and too often mums and babies do not get the help that they need. The confusion and misunderstanding around frenula and ties unfortunately leads to those babies who need help not getting it, and those who don't have an anatomical restriction getting misdiagnosed. This blog is aimed at simply giving a bit of clarity to what a frenulum is and what is normal and how we know if there is an issue.

Almost all of us have a frenulum. The tongue is one of the earliest structures to form in an embryo. During early development the tongue is fused to the mouth floor. As development continues a process of freeing the tongue from the floor of the mouth begins. Firstly tissue grows downwards under the tongue lifting the tongue off the mouth floor and then a degeneration of the tissue which anchors it to the mouth floor, meaning this tissue becomes thinner and moves back. This becomes the frenulum. How much frenulum is left at birth, where it attaches and how thick it is varies from individual to individual so frenula have traditionally been categorised by where they attach and how they look.

Classification of frenula

The tongue frenulum is most often described by a grading or typing system, where Type 1 means the frenulum attaches to the tip of the tongue and so is visible down the entire length of the tongue; Type 2 attaches a few mm behind the tip of the tongue, Type 3 attaches mid tongue and Type 4 is usually under the mucosa on the floor of the mouth. Type 1 and 2 are known as anterior and Type 3 and 4 are known as posterior.

This classification system describes the appearance of a frenulum only. It is not a severity scale and does not mean that a baby has a degree of "tongue-tie". It is simply a way of describing what can be seen. What matters though is not necessarily how a tongue looks but how it functions. Let's go back to breasts and breastfeeding for a moment. We have a "typing" system for breasts too. We describe them in cup sizes. Just like the frenulum typing system, cup sizes is about appearance. Does cup size actually mean anything when it comes to their function, which is breastfeeding? No! Having a D cup is not better or worse than having a B cup. It is simply a description of appearance. In general all women produce about the same volume of milk over 24 hours. It is function that is important not size and appearance. Frenula are the same - what really matters is how they function.

A recent study from Sweden examined and categorised the frenula of 200 babies and categorised them by type. They found that 199 of the 200 babies had a visible tongue frenulum: 5 were of Type 1, 147 of Type 2 or 3, 47 were Type 4. The fact that all but 1 baby had a visible frenulum should reassure us that the presence of a frenulum is normal in our babies. It does not indicate a problem. They also found no correlation between the typing system and breastfeeding, so nothing which indicated that any particular type was a "tie" or interfered with breastfeeding.

Why does a frenulum exist? Why is it restrictive in some babies?

There have been 2 very recent studies looking at the anatomy of the frenulum to answer this purpose. The first was a study which dissected the mouth tissues of adult cadaavers (Mills et al 2019) and a very new one on infant cadaavers by the same researchers which has been accepted for publication but not yet in print (Mills et al 2019). For many years it was thought that the frenulum was a single band of tissue. If this tissue attached to the tongue in a way which restricted the tongue this was thought to be midline defect in development. These new studies have disproved this idea. There is no single band, and lots of normal variation in where the frenulum attaches. The 2019 anatomical studies found that the frenulum is made of fascia (fibrous and elastic fibres), and that this fascia creates the whole floor of the mouth. When the tongue lifts this fascia lifts the floor of the mouth like a skirt. You can see this if you look into the mirror and lift your tongue. You will see the floor of your mouth shift with your tongue. The researchers describe this skirt structure as both suspending the floor of the mouth from the tongue and also providing stability for the tongue in relation to the floor of the mouth. It is essentially a stabilising device for the tongue. The infant study suggests a kind of see-saw balance of the frenulum between stability and mobility. If the fascia/ mucosa from the mouth floor attaches too far forward on the tongue the frenulum may provide more stability but limit the mobility. Too much stability= not enough mobility. Too much mobility = not enough stability. There is a very wide range of individual variation in this equation, and a large range of normal. Tongue tie is essentially the condition where a baby has too much stability and not enough mobility.

A 2010 study from Brazil also looked at the type of tissue in a frenulum and found a difference between those with a tongue tie and those with normal tongue movement. This study found that babies with a tongue tie where the frenulum attached quite far back on the tongue (posterior attachment) had much more type 1 collagen (does not stretch) as well as muscle fibres in the compared to babies with normal tongue movement. They did not find this in tongue tied babies where there was an attachment to the anterior tongue. The newer 2019 study suggests that in fact when the tongue is lifted the tongue muscle fibres become drawn into the frenulum and that the 2010 study findings may have been due to the muscle having been inadvertently cut.

Another big takeaway from the recent studies is on the terminology. Over the past few years there has been a big proliferation of the term "posterior tongue tie", and I often hear it used as if it is a separate condition to some other kind of tongue tie. What the anatomy studies make clear is that tongue tie (ankyloglossia) does not have separate types of conditions. Where the frenulum attaches is a spectrum, but no matter where it attaches, if the tongue mobility is restricted then it is anklyoglossia (tongue tie). There is no such thing as anterior or posterior tongue tie. The frenulum may attach to the anterior or posterior part of the tongue anatomically, but that doesn't really matter. Mills et al (2019) suggest that the term "posterior tongue tie" is misleading, anatomically incorrect and should not be used.

With a wide range of normal attachment it is impossible for us to know by simply looking at a frenulum whether that baby has normal tongue movement or not. Assessing the mobility is the only way that we can consider an individual baby's balance of stability vs mobility. Assessing for tongue tie requires assessing the function of the tongue, rather than assessing how it looks (classification) and that probably makes sense to most of us. We would find it very odd if we visited a physiotherapist with knee pain for example and the physio looked at our knee and simply described how it looked. He/she may be able to see there is inflammation and swelling for example, but without checking the range of motion of the joint there is no way to know how the knee is affected. The tongue is no different. From ultrasound studies we now know much more about the function needed to breastfeed effectively, and a baby's tongue can be assessed by a trained lactation consultant (IBCLC) or healthcare professional using a gloved finger. The assessment should be gentle and playful and the baby should enjoy it, just as they enjoy sucking on your finger.

This discovery that function and appearance are not necessarily linked is why the Swedish study (Haham 2014) concluded that:

the term "lingual frenulum" should be used for anatomical description and that the term "tongue-tie" be reserved for a lingual frenulum associated with breastfeeding difficulties in newborns.

Many IBCLCs now prefer to refer to 'tongue restrictions' rather than 'tongue tie', because the phrase "tongue tie" has become synonymous for so many people with the presence of a frenulum. The picture becomes increasingly complicated as more recent work in the field suggests that even when a tongue is restricted, it does not necessarily need to have a surgical intervention. Since fascia forms a continuous layer throughout much of the body, the tongue may have impaired function due to other structural issues e.g. muscle tightness/interventions from birth. Releasing the tension can solve the functional problem. This is a complex area covered in more detail in the 2nd Tongue Tie blog but for now what I want to get across is the importance of realising that having a frenulum is normal and does not always mean your baby is tongue tied.

There is so much talk about tongue tie in breatfeeding forums and groups and it is easy to think that perhaps your breastfeeding difficulties are caused by a tongue issue. Knowing that having a frenulum is normal and that most of us have one can maybe help to alleviate those worries. If you are not having a breastfeeding problem then it is likely that your baby's frenulum is just that - a normal frenulum. If you are having difficulties then just because your baby has a frenulum doesn't mean that he has a tongue restriction or that a frenulum is the cause of those problems. There aren't any good definitive statistics on how many people are tongue-tied, but several studies have placed the incidence at 3-4%. One study placed it at 10%.

If you are concerned about your baby's frenulum contact a breatfeeding counsellor or lactation consultant to talk things through. Breastfeeding is a skill that both we and our babies need to learn together and it can take a few weeks to get the hang of things and to start working well together. The first few days can be hard, there can be some temporary pain even when things are going ok (my previous blog on this), and pain can linger on when the latch isn't quite right regardless of a frenulum. In fact one study found that 92% of mums encountered problems or pain in the early days. If tongue-tie incidence is below 10% then most mums must have issues due to other factors. Growth spurts, changes in milk supply and the normal fussy periods can make things more complicated. The symptoms associated with a tongue tie (e.g. clicking, pain, slow weight gain, reflux etc) can also be caused by other issues and in most cases changing positioning, getting a deep latch or working on your breastfeeding management can resolve problems. Snipping a normal frenulum won't resolve any breastfeeding issues and causes an unnecessary procedure to a baby, so checking other steps first makes sense.

With so much on the Internet about ties and division, navigating the whole area can be tricky and scarey. Babies who do have tongue restrictions need support and their mums need good information so they can decide how to move forward. Mums with babies who have normal frenula need good support to overcome their breastfeeding difficulties. Breastfeeding professionals also aren't immune from the confusion around tongue-tie. We all need reassurance about what is normal and we need to ensure we take a wide view of both mum and baby when we encounter breastfeeding problems. Most of us have a frenulum and most of us are not tongue-tied.

Part 2

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A tongue frenulum vs a tongue-tie

A frenulum is not a tongue tie!

Classification of frenula

Why does a frenulum exist? Why is it restrictive in some babies?

Further Reading