Dr Nikki Mills is a New Zealand based paediatric ENT surgeon, who has a special clinical and research interest in breastfeeding and is also an International Board Certified Lactation Consultant. Nikki worked for many years at the Starship Children’s Hospital in Auckland, moving in 2020 to Nelson Hospital in Nelson, New Zealand.

In this first episode of an in-depth 3-part conversation, Pam and Nikki take a deep dive into Nikki’s groundbreaking anatomical dissection studies of the floor of mouth fascia, which reveal the true nature of the infant lingual frenulum. They discuss the implications of her studies for the biomechanical model of infant suck during breastfeeding, the diagnosis of ‘posterior tongue-tie’, the decision whether or not to proceed with frenotomy, and the risks associated with frenotomy.

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Pam

Welcome to the 2020 Baby podcast with me, Pamela Douglas and my friend and colleague down the line from New Zealand, Dr. Nikki Mills, to talk with me today to have a good old chat, really, which I've been very much looking forward to on the functional anatomy of sucking and swallowing in breastfed babies. So welcome, Nikki.

Nikki

Thank you, Pamela.

Pam

It's just great to have you available to talk about this topic that both of us find so fascinating. So, I wonder if you could start by telling us just a little bit about yourself if that's okay.

Nikki

Of course. So I'm a paediatric ENT surgeon. I did my fellowship training at Great Ormond Street in London, and then came back to New Zealand to work at Starship Children's Hospital, which is a tertiary referral children's hospital for the whole of New Zealand about 11 years ago. I have a special interest in airway problems and it became apparent to me very early in my consultant experiences that a lot of babies who had problems with breathing also had problems with feeding, so feeding and airway for me go hand in hand. But I also realized really early on that a lot of babies, if they have difficulty feeding, the first thing that kind of becomes problematic is breastfeeding. And often those babies are transitioned to bottle feeding because of difficulties and that became something really important for me to try and understand what was happening with those babies and how we could support them if at all possible to establish or continue successful breastfeeding. So it did become a passion of mine very early on in my career and it's something that I've just, I guess, followed and made something off.

Pam

Well, very definitely made something off because I have here on my desk, and I know these aren't the only papers that you have published, but certainly last year and this year, five papers, not all out yet, but a very substantial body of groundbreaking work in this area. So we've had some really terrific conversations on a number of occasions in the past, but I'm really looking forward to opening up some of this now. I wonder if a place to start isn't with the ... you might say the epidemic of diagnoses of ankyloglossia in high-income countries over the last, let's say 15 years. In 2018, a pediatrician and PhD student and my team published some Australian data on this showing that between 2006 and 2016, the numbers of Medicare-funded frenotomies had increased by 420% and that Medicare data didn't capture frenotomies done for instance, by dentists who anecdotally are doing a lot, maybe even most of the frenotomies and actually in the Australian capital territory in that period, there was no dentist, there was no access to laser frenotomy and the incidence of, frenotomy that was Medicare-funded increased by 3710%.

Pam

So, there's some thought that that may better reflect the increased incidents of frenotomy in that time. And then there's other data that's come out from North America, Canada and just this year [Wei 00:04:40] and his team, including Jonathan Walsh, have published an update of the US data showing that between 2010, 2016, the rate of frenotomy had doubled. And that was just mirroring trends of exponential growth in the incidents of frenotomy prior to 2012. So I was wondering Nikki, if you're seeing anecdotally in your experience, any decrease in the incidents of frenotomy there in New Zealand. Do you have a feel of where things are at where you are in terms of rates of frenotomy?

Nikki

Well, I think it's really hard to know. And the reason for that you pointed out is that I think a lot of them are being done by dentists and there is no way of easily capturing those numbers. So I I think it's really hard to know how many are actually being done. I certainly am hoping that the trend is coming towards people being a little bit more cautious and thoughtful rather than rushing to blaming the lingual frenulum as being the cause of all breastfeeding problems. And certainly that's been, I guess, one of my motivators for doing my research is really just trying to understand better what the lingual frenulum is, what are we cutting and kind of moving towards trying to think about and understand biomechanically when that's potentially causing problems, so that we get better at understanding which babies are most likely to benefit from a frenotomy.

And we're not doing procedures on babies that aren't going to get benefit. And I guess that's the two primary concerns for me are relating to the potential for harm. So, I think although it's perceived as being a very safe procedure and I'm sure on the great majority of babies, there are no significant complications, but I think it is a surgical procedure. And I think we need to be really careful about being better at knowing when it's going to have enough benefit that those complications or risks are warranted to put a baby through a procedure. And yes I think-

Pam

Yeah, yeah, absolutely. And actually you were involved in the team that quite recently published some New Zealand data around potential side effects. Could you just speak briefly to that, Nikki, what that study showed?

Nikki

Yeah. So, it was really, I guess it's more case reports on infants that had been admitted to hospital specifically relating to complications from, frenotomy, so it is a weakness of the study. We have no denominator and really, we were just packing up and reporting to increase the awareness of complications relating to frenotomy. And some of them were direct complications relating to pain and poor oral intake and failure to thrive, bleeding, things that are well known, but also thinking a little bit about misdiagnosis. So babies that had problems breastfeeding because of congenital cardiac anomalies that hadn't been diagnosed. And I think it was important to publish it because really no one had looked at those kinds of complications other than just a few case reports or small case series on quite catastrophic complications. So it was really just saying we need to be thinking about this a little bit more carefully.

Pam

Yes. Thanks. Well, it was important I thought to see it come out. So well, Nikki, just lately, I've been listening into some conferences for lactation consultants, conferences and workshops on ankyloglossia, on tongue-tie, and many of these talks actually start by showing what has been a groundbreaking diagram actually or a diagram that arises out of your groundbreaking work around infant floor of mouth fascia. I wondered ... I'm showing them the diagram I mean, I wondered whether you could talk to those findings, what that diagram is saying, for a moment, if you would.

Nikki

Sure. So, there's a concept that I was trying to do visually with a picture -

Pam

Which you did so well, actually.

Nikki

because I'm a very visual person. So, it was based on both my anatomy and my histology research, so it's based on real anatomy that exists. And I guess, it's really the key relating to that component of my PhD research was that I believe that the popular construct or understanding of the lingual frenulum is that it's a midline structure and it's often referred to as a cord or a band or a string. And when the tongue is elevated and the lingual frenulum is raised and put under tension, forms a structure that is visible in the midline and a lot of people, and this is universal, it includes Grey's Anatomy and the Bible. And it's widespread, that concept.

Nikki

And I think what I tried to show is what I think the understanding was, if you imagine a clothes line with something draped over it, that string that forms the clothes line is what people thought the lingual frenulum was. And so, from a surgical point of view, if that's what you're cutting and that's the concept of it's a string or a band, then that's a very specific procedure if you like from a surgical point of view of what you're cutting, but that certainly wasn't my experience clinically. And when I first got asked to divide a tongue-tie on a baby, I was uncomfortable doing it before I really understood what I was cutting and when I should be doing it and how I should be doing it. And I searched really hard for that information.

Nikki

And just for my own personal level of comfort, I couldn't find the information that I wanted to be happy to do that procedure. So that was, I guess, the motivation, that doing my research, I couldn't find the answers that I felt I needed as permission to do that procedure. So interestingly with my research, I found that actually it's not a true midline strike through at all. And hopefully from those diagrams, you can see that it actually is a layer of fascia that spans across the whole floor of mouth. And that it's actually the tongue elevating and creating tension in that layer of fascia that draws it up into a fold that we can see visibly in the midline. And there's lots of variations between different individuals that I think now you can explain when we see a very thin, transparent frenulum or when we see a less well-defined chunky one, we can actually understand from an anatomy point of view and thinking about the layers of the mucosa, the fascia underneath that, and then the genioglossus muscle fibers below that, that what we actually see, we can explain that and explain why different individuals, the appearance is different and understand that. So I think there's lots of things that my research hasn't answered like when should we be dividing it and what's the impact and how do we decide which individuals it's going to benefit. But I think at the very least, we hit the foundation of understanding what it is and when we look at it, what we're seeing. And I think from certainly from a surgical perspective, I think that it's the building blocks of surgery for sure.

Pam

Hmm. Hmm. Well, I was really interested then listening in to these conferences to find that even though the presenters were able to state clearly out of your work that the frenulum is not a midline band or indeed midline structure, they would nevertheless move on to conceptualizing breastfeeding problems in terms of restricted tongue mobility due to tight oral connective tissues and indeed tight floor of mouth fascia.

Pam

And, so, there's been an increasing integration of bodywork into the teams that are working with babies who've been diagnosed with tongue-tie, the concept that conservative treatment might involve a whole range of techniques for working with tight fascia, with restricted oral connective tissues, particularly intraorally, but a concept of these connective tissue and fascial tightnesses having implications right throughout the body actually.

Pam

So, body workers, whether it's craniosacral therapists, myofunctional therapists, chiropractic osteopaths have become I think increasingly engaged in working with these bubs, who've been diagnosed with restricted oral connective tissues, but also in the event that the body work or the work with latch and positioning doesn't get the desired results than frenotomy for diagnoses of anterior tongue-tie, for diagnoses of posterior tongue-tie, upper lip tie, and indeed in some cases buccal ties, are still being recommended. And this would be reflected in my clinical work where I find it hard at the minute to see any real decrease in the dominance of the diagnosis of tongue-tie in babies with breastfeeding problems, in women with nipple pain as they're breastfeeding, in those bubs who are very unsettled at the breast. So I wondered whether we're understanding the implications of your work properly.

Nikki

That said, it's a tricky question in a way because I think there needs to be more research building on what I've done looking at biomechanical impact of different variations of lingual frenulum morphologies like the appearance of the frenulum and understanding when particular, I guess, appearance and function of a lingual fringe is impacting on how the tongue goes. And I think both of you and I understand that it's far more complicated than just that and that a tongue that looks the same in one baby will behave and function very definitely than that with another baby because we also have the anatomy of the mother and their nipple, breast tissue, elasticity and soft. But also as we've talked about the huge impact of positioning and how much maternal breast tissue is in the infant's mouth and therefore impacting how much the baby's tongue needs to lift to create a vacuum.

Nikki

So all of those factors are things that are, to me, seem far more important to try and recognize and optimize before you start cutting a baby's lingual frenulum. And it would be a kind of last resort thing rather than something that you do. It's the first thing on the list, given that there are so many factors that can be improved by understanding how you can manipulate positioning and ... The myofunctional therapy stuff, I think if it has put a little bit of a handbrake on jumping straight to surgery and thinking about other things that can be done to improve what's happening during feeding and that some babies are not going to jump straight to surgery, I think that's a good thing rather than all of them going straight to surgery without even thinking or looking at anything else.

Nikki

But I think also that this is what I consider a vulnerable population and that this is a very emotionally charged thing, so important to so many mothers to be able to breastfeed their babies. And when things aren't going well, I think they're easily exploited by people telling them things and charging them lots of money and promising them something. So I think I worry about exploitation of mothers and young babies when things aren't going well.

Pam

Yeah. Yeah. And, in the way I conceptualize it, if we're thinking conservative interventions, and yet we know that term, if you work around latch and positioning, which as you know, I will refer to as fit and hold in our Gestalt breastfeeding work, that remains a research frontier. So to my mind, this is the big blind spot isn't it? How can we avoid inappropriate medicalization when we really don't have much evidence at all to show that the approaches that we're using to support that fit and hold to optimize that latch and positioning are at all effective? And in fact, there's even that one Victorian study that showed very well conducted large numbers, and it showed that one of the most popularly used approaches to fit and hold actually worsens nipple pain fourfold, that's the sort of shaping of the breast and the cross cradle bringing on of the bub. So, yeah. So anyway, as you know, that's been a real passion of mine to look at how we can support that fit and hold to optimize pain-free efficient milk trends.

Nikki

And I think from a biomechanical perspective, I can understand how the fit and hold is important and can change the biomechanics intraorally with the infant significantly. I think it's not that hard to understand or conceptualize how a deeper latch and more intraoral breast tissue is going to improve how the infant's tongue needs to move. And I think from a clinical perspective, there are so many things to me that makes sense about the work that you're doing and the positioning and how important that is both for the mother and for the baby and how thinking about your concept of the dialing up and dialing down, that if the baby feels more supported and secure, which they certainly do when you position them and the Gestalt approach, that it changes completely how they're able to function, if they're having difficulties, if they are not stressed.

Pam

Yeah. That's right. That's it.

Nikki

Going back to ... Sorry, just going back to what you said about the medicalization around the lingual frenulum, I think that's certainly been one of the really big things that I've been pushing with the education that I do around the research that I've done is that really trying to push the concept that having a lingual frenulum is a normal part of anatomy.

Nikki

And that the problem around the grading that's used is that they grade the appearance at the lingual frenulum is grades of ankyloglossia. And so, in fact, if you think of grade one through grade four, that encompasses all possible appearances of lingual frenulum. So, if you use the grading based on their visual appearance for ankyloglossia you're in fact labeling every lingual frenulum as being abnormal and potentially being the cause of problems. So my approach is really pushing for people to call it a grade one frenulum or a grade two frenulum and to use it as a way of describing what you see, but not labeling it as abnormal, so not labeling it as grade one ankyloglossia, they're labeling it as a grade one frenulum, and saying specifically that you're just looking at one aspect of morphology when you're doing that.

Pam

Absolutely. And in fact, it might be useful if we're doing this sort of translation of this tool. And I think is this you're thinking here of the Corilis tool in particular, I have it in my mind, what you're meaning by grade one to four, but maybe you could just tell me what you have in mind there.

Nikki

So both Kotlow and Coryllos looked at the attachment and the midline to the ventral tongue or the undersurface of the tongue, and when you place the lingual frenulum under tension, so that's either elevating or retracting with the tongue, you create a fold that's visible. And they have allocated if you like the frenulum that attaches towards the tip of the tongue as being a grade one. And if it doesn't extend very far along the ventral surface, and therefore it's not a very visible or defined fold that that's a great four or what people call a posterior ankyloglossia. But I think what I've tried to, I guess, get people to appreciate is that that's one factor of morphology or appearance that came be reasonably easily assessed and visualized, but I think there are lots of other things that potentially are impacting our tongue function that includes the length of the frenulum between the tongue and the insertion onto the mandible.

Nikki

And also the histology research that I did showed that there's variable amount of elasticity or less than type three collagen in the floor of math fascia. And I think some individuals have more distensibility or elasticity of the frenulum than others, so that's another variable, but I think the other thing that again is really underappreciated when everyone's focusing just on the frenulum, is the position of the mandible, so the lower jaw and it's position relative to the upper jaw alters where the tongue sits in the oral cavity. And the other thing is that from a developmental point of view, the position of the mandible affects the possession of the tongue, as the fetus is developing and alters the shape and contour of the hard palate. And if the hard palate is very high then to create a vacuum with the nipple and areola and the mouth.

Nikki

It's a different space that the tongue's working in and the biomechanics of that is a little different and also the position and shape of the mandible affects the length of the tongue. So the free length of the tongue from where it attaches to the floor of mouth to the tip of the tongue can be quite short, particularly in infants that have a setback mandible or what we call retrognathia or micrognathia. And from a biomechanical point of view, I think that changes how their tongue works. And I think those babies definitely as a subgroup, anecdotally, seem to have more difficulties breastfeeding. And I think positioning at the breast becomes really important and perhaps needs to be adapted in different ways than a infant that has a longer tongue and a more kind of neutral mandible position.

Nikki

So I guess what I'm trying to say is that I think the frenulum is just one component. And yes, if it is really limiting how the tongue is moving and that individual and with that mother is causing difficulties, I think there are definitely some cases where diversion can make a difference to how the tongue moves and how it works. But I think there are many factors, not just the frenulum that impacts on biomechanics. And I think appreciating all of those factors is really important.

Pam

Mm-hmm (affirmative). So we're really talking about a complex adaptive system, a dynamic system, whether we're looking at the infant or we're looking at the mother- baby pair, we're talking about complexity and multiple factors interacting together. And out of that..

Pam

Yeah, out of that complex system, there may be the emergent issues of breastfeeding difficulties, but there's multiple compensations that come into play which can stabilize the system and prevent or if we work well with it, actually repair emergent difficulties without needing to resort to that if you like that term, cause effect paradigm, that coming in with a surgical intervention. And we could say the same for instance, about diagnoses of gastroesophageal reflux disease, for instance, in breastfed babies.

Nikki

And I think the language that people use is really important. And that's why I've really tried to push people towards describing a frenulum rather than labeling the frenulum as ankyloglossia because I think if we do ... Parents really ... When problems are occurring, if someone has labeled a frenulum as ankyloglossia, if you're not addressing that surgically and they're having difficulties, they think either you're withholding that from them or that you're not the person that's going to be able to help them. If they have in their mind that their child has something wrong with them, that when they read on the social media that it needs to be divided. So I think trying to get people to use language that doesn't label infants as having something wrong with them that needs a surgical intervention as a really, really important step.

Pam

I can only agree. There was a study done around parents with an unsettled baby. And if a practitioner used the term reflux, even if that practitioner followed up use of that term with explanation that it's physiological, it's not causing the baby pain, we don't need to be treating it, nevertheless, parents quite understandably in their exhaustion and desperation, usually with these unsettled babies, would press the practitioner for a proton pump inhibitor for pharmaceutical intervention, just in the hope that it might make a difference. So yes, the power of those medical labels, it affects our neurobiology actually in the same way that placebo has a measurable neuro-biological impact, so-

Pam

Placebo has a measurable neuro-biological impact. So use of medical labels or labels, I think just is you're saying, can have and unintended impact.

Nikki

And it's very hard if someone comes to you with that label, and you are dealing with already someone having the concept that there's something wrong with their baby, and that there's a magic wand to fix that.

Pam

Yeah, yeah. Well, I wondered if I could share with you what I thought, because as you know, Nikki, I have the view, and I'm not alone in having this view, that your work on the functional anatomy of sucking and swallowing in breastfed babies is groundbreaking, internationally. And can I share with you what I have taken out as the important contributions, or key contributions in your work, in your painstaking dissections? And I have some feel for the enormity of these dissection projects. Firstly, with the adult cadavers, and then following up with the neonates. And so I suppose the key things that I'd like to highlight, I guess, for those listening in on our chat, that you stated really clearly in both papers, actually, both of the anatomy papers that there's no anatomical basis for a diagnosis of posterior tongue tie. So that's one thing. Actually, I might even get you to speak to that for a little bit.

Nikki

Yeah, sure. I think, like you, I think it's a really bad term for lots of reasons. The first being it's anatomically incorrect. The posterior tongue or tongue base is really nothing to do with the lingual frenulum. And I think it's misleading to use that terminology, from an anatomy perspective. So I think to begin with, the initial choice of words to describe that, I think it's really, yeah, bad. Sorry.

Pam

Yeah, yep.

Nikki

But I think it's more than just being pedantic about that. I think it's the concept of a posterior tongue tie relies on the construct of the lingual frenulum being a mid line band, or a mid line structure. And I think if we think of it as a layer of fascia, then the posterior tongue tie and the concept of that people have built around that is just incorrect.

Nikki

So it's not to say that infants who have a frenulum that doesn't extend significantly along the ventral surface of the tongue. So what would be called at a grade three or four ankyloglossia. So if we think about that morphology, I think it is possible that the fascia or the frenulum in those individuals is restricting how the tongue moves, but in my experience clinically, I think that configuration is really commonly associated with other anatomical variables or variants that make biomechanically breastfeeding more difficult. And it's not just that part of their anatomy that's the problem. And I don't believe that the frenulum caused those other things. I think it's much more related to mendable growth and size, that all of those things kind of go together, rather than that, people talk about the tongue tie causing other things. I think it's an association that that configuration kind of comes together often. But as a concept of what people understand as posterior tongue tie, I think it's really incorrect and unhelpful in understanding overall, biomechanically and anatomically, what's going on for the individual. And I would encourage people not to use it as a term.

Pam

Thank you. And so you've already touched on this, that your work showed there's no continuation between what we call the frenulum, which isn't a mid line band or structure, but something that becomes apparent when the tongue is lifted to place the floor of the mouth under tension. So there's no continuation between the frenulum into the median septum of the tongue, of the tongue muscle, and also as you said, not into the base of the tongue.

Nikki

Yeah. And I think that was a really important part of my research, was to really understand how it related to the median septum. And the reason for that is I actually spoke at a conference in Australia, it would have been five or six years ago now. And at that conference, there was someone who gave a talk that discussed the need for cutting deeply into the median septum of the tongue to release the frenulum. And I watched in horror, the pictures that they showed me of infants that they had operated on, and felt physically unwell watching it. And then I thought, actually, I had nothing to back me up, to support why I didn't think that was correct. So that was actually a really big turning point for me and my motivation, because I thought that was really bad, and that I thought it seemed like really the wrong thing to do to cut deeply into a baby's tongue. And I think my research has 100% supported my instinct at that time, but now I have the evidence for it.

Pam

I have to say that early on, I was prompted into activism around the over-diagnosis of tongue tie by the sight of a little one's ventral surface of the tongue almost splayed in two, from a very deep incision up into the median septum. That actually, Nikki, and the site of little ones with suture knots hanging out of their upper gum. And I think this was from labial frenectomies, that it had a bleed, so that the dentist threw in some sutures. But then you can imagine that little one presenting with a condition dialing up at the breast, what you might call breast refusal or oral aversion because they're trying to breastfeed with this knot in the upper gum. So they're two early cases, actually, that really prompted me to start looking quite closely at this phenomenon, and take some kind of stand, really, around what was happening.

Nikki

Yes and I mean, I've seen a large number of infants who have developed oral aversion relating to pain and stress around, not only the procedure, but the post-procedure exercises where people poke the wound six times a day to try and stop it adhering. And babies are smart little individuals, I think. They're born really taking everything as learning about the world, and if breastfeeding becomes painful for them when they do it, of course they're not going to want to do it. So I think we need to really understand that everything we do to babies has an impact on them.

Nikki

And although I'm sure those parents aren't intentionally doing something horrendous to their babies, they're doing it for what they're being led to believe is a longer term gain. But in the short term, if the baby's already having problems breastfeeding, and then you add on to that pain and recurrent discomfort of having discomfort every time they feed, I think there are a significant number of babies that have frenectomy, that not only does it not improve their breastfeeding, but it actually can make it worse because of these really under reported complications from frenectomy.

Pam

Yes, absolutely. And that would accord with my clinical experience, and either the ongoing breastfeeding issues post frenectomy, or in fact, the worsened dialing up at the breast, which brings me to the other point, really, that I think has been very important about your work on the anatomy of the neonatal lingual frenulum. Because that is your work demonstrating the location of the lingual nerve and its sensitivity to damage. Could you elaborate on that a bit, Nikki? And I might just jump in there because, although it's gone back to normal, for a little while, I don't know whether you moved or something happened, but the sound deteriorated. So just to mention it might've been you moved away or something, but it's come back to normal. I'll let you check.

Nikki

No, I haven't moved anything, so I'm not sure.

Pam

Oh, okay. That's all right. It's all right, we'll just keep on going. I was playing with knobs and things here, but anyway, it's all good now.

Nikki

Oh, good. So interestingly, that was really the main difference that I found between the adult and the neonates when I did the dissections, was that in the neonates, the lingual frenulum, the lingual nerve was huge, relative to the tongue, massive. So location wise, it's very superficial that the lingual nerve branches that supply the interior tongue and come across the ventral surface of the tongue from lateral to medial as they come towards the tip of the tongue with branches that come across onto the frenulum. So they are immediately underneath the fascia, so from a risk point of view, the deeper the frenectomy bone, and also the broader, if you go laterally, you're more likely to get into the bigger branches. But also, any surgical technique that involves any thermal injury that's absorbed into the tissues, deep to where you're cutting is more likely to cause damage to the underlying nerves, or nerve branches.

Nikki

And the neonatal dissection paper, I've put pictures of it just to show how big those nerves are, and how superficial they are. So really, how they're just exposed once you take the facial layer away. So from a frenectomy point of view, I think that's really important to understand. And I guess the thing around that is that, what would happen if you injured those branches is that you would have some impact on sensation of the interior tongue, and from a breastfeeding point of view, it's really interesting. It's actually been shown that there are direct neuro connections between the lingual nerve and the hypoglossal nerve branches that supply the intrinsic muscles of the tongue. So what that means is that the sensation of the front of the tongue, and if you think about this in the context of breastfeeding, that the tongue and sensation of the tongue, one, we've shown has huge nerves, so if we knock out the homunculus and the representation of different body parts in the brain in an infant, the tongue is massive, right? Because everything around a baby and a baby's survival is around feeding and the tongue.

Pam

Yeah.

Nikki

The sensation of the tongue as it touches the nipple and shapes around the nipple, the neural connections that go directly to the intrinsic muscles then can shape and cup around the nipple to create the vacuum inside the oral cavity. And that is even more basic than a reflex, because the reflex is a pathway that has to go to the spinal cord and then come back again to innovate muscle action. So this, I think it's huge that they've shown that this is even more primitive and direct than a reflex. So we talk about rooting reflexes and sucking reflexes in infants, but this reflex, this neural pathway is about shaping the tongue and responding to touch and sensation of the tongue.

Nikki

So if you think with a frenectomy that you may damage the sensation to the anterior tongue, the impact of an infant who's struggling to breastfeed, you can imagine that that's going to make all of those neural pathways impaired. And a baby can't tell you that their tongue is numb or doesn't feel so well, or that they're having trouble coordinating and shaping the tone around the nipple, that there is no way of measuring that, that we know. So I've talked to lots of laser frenectomy surgeons, and they've said, "Oh no, my babies don't get any sensory impairment." And I'm like, "How can you be sure?" You don't measure it and you're using a tool that definitely, the risk of that is increased. So I think, I hope that people will read and understand that, and understand the potential for risk. I suspect that not many people really understand the implications of harm if that sensory awareness is impacted. But anyway-

Pam

Yeah, so this is a particular risk you'd propose with laser frenectomy, versus scissors, deep scissors frenectomy?

Nikki

I think again, from my own clinical experience, and sometimes I have divided lingual frenulums under general anesthetic. So obviously, I take babies to the operating theater for general anesthetics for airway endoscopies and airway procedures, and there has been occasion for me to sometimes divide a lingual frenulum in the operating theater, and using a scissor technique and looking with magnification and very carefully, I can see that the fascia glides over those nerves. And if you cut very carefully with scissors, not going into the genioglossus muscle fibers at all, and just stay on the facial layer, you don't harm those nerves. I think if you do anything to stop bleeding, which would involve either a heat source such as diathermy, or I have seen people with silver nitrates braided under the tongue. Yes, I have.

Pam

That's a terrible thought, I've got to say.

Nikki

Don't even go there.

Pam

Won't think about that too much.

Nikki

Obviously, that causes injury to the tissues. That's how it stops the bleeding, is it's thermally coagulating, so it's creating damage to those tissues underneath. So certainly, anything such as a laser or diathermy, and particularly in the context of not necessarily being able to see really carefully what you're doing in an alive, awake baby who wriggles and cries and there's blood and things there. It's very hard to see-

Pam

Exactly.

Nikki

Obviously under general anesthetic, you can do that in a very controlled way that you can't when they're awake and breathing and crying. And yes, so I think from a technique point of view, I would say that I would favor a scissor technique over laser because of reducing the risk of damage to those nerves. I think it's perhaps not as simple as that regarding, I think, with a laser, obviously how it's done from a technique point of view and what kind of laser you use, and how long you deliver laser energy in one particular location is going to have a huge impact on that. So it's not that all lasers are the devil and no one can possibly do a good technique using a laser.

Pam

Yeah.

Nikki

But I think the potential for risk or harm, particularly if someone's a little bit more heavy handed and holding the laser longer, and delivering more energy to that area, the risk is higher.

Pam

And then we have human factor science, really, that tells us the more often we do a particular thing or a particular procedure, then naturally, the greater the risk of unintended outcome, even for someone who, in most instances, is using that laser in a way that's very conservative. Just by sheer volume of procedures, we increase the risk of the unintended side effect, or the damaged lingual nerve, don't we, really?

Nikki

Yeah, I think that it's complicated. There are lots of factors, aren't there?

Pam

Well, that's right.