Martyn Cobourne & David Rice - Developmental biology meets Orthodontics

[Music] Welcome to another episode of the European Orthodontic podcast where we dive into the latest innovations, evidence-based practices and inspiring stories from leading orthodontists across the world. I'm Thin Gagan, I'm an orthodontist from Dublin and I'm an EOS member and we are preparing for the 101st EOS Congress in Dublin in June, 2026. So this podcast is brought to you by the European Orthodontic Society. Today we're exploring developmental biology and orthodontics with two of the fields leading figures. We have Professor Mark and Coburn who graduated from Kings College London in 1990 and trained as an orthodontist in Kings College London. He went on to complete PhD in Paul Sharps lab in Guy's Dental Hospital where he studied molecular pathway shaping very early cranial facial development. Now, Professor at Orthodontics at Kings, Martin has produced over 130 peer-reviewed papers, authored several orthodontic textbooks and led landmark trials. Joining him is a friend and colleague of Martin's Professor David Rice is the Professor and Head of Orthodontics at the University of Helsinki and Helsinki University of Hospital as well as Director of the Finnish National Doctoral Program and oral science. David trained an orthodontics in the UK before completing his PhD in Finland. His research focuses on the etiology of craniofacial anomalies such as craniosynostosis and clef lip and palate. A previous work has been supported by fellowships from the Welcome Trust and the UK Medical Research Council. He is an honorary fellow of the RCS Edinburgh and recipient of the EOS Houston Research Award. And as of yesterday was the editor of the E.J.O. and Martin, which I didn't include. You are currently this year's distinguished teacher from the EOS, am I correct? That is correct, yeah. So thank you very much for doing this. Martin, are you sitting in your lofty on the 27th floor of the of Geistair overlooking Greater London? I am, yes. I'm just looking out over a fairly, it's not too bad a day today actually. Yes, quite a nice view. And David, do you have a similar, I've never, do you have a similarly impressive view from your office? Absolutely. Yeah, we have a typically Nordic landscape around me. Nice modern building with good facilities. Oh fantastic, I'm looking into my back garden. So thanks very much for doing this. And I wanted to like with other guests just have a chat about what you do and your work at the moment. But firstly, perhaps Martin, if I might draw you in, you ended up an honest honest, why was that? I always quite enjoyed pediatric dentistry when I was training, but I kind of realised that orthodontics was probably a better area to go into. I mean, I enjoyed treating a younger population. And so I did ultimately decide to do orthodontics and that was, I guess, was the primary reason. But I'd always enjoyed treating children. I did a children's SHO job during my early training. But orthodontics was probably the natural choice. But you also, you grew up in a village that produces professors of orthodontics, so there's a history of, is that correct or a talent area? Well, bizarrely yes, Kevin O'Brien was born locally and brought up in the village of Hangeley, which is where I came from and where my mother still lives. He was older than me, I would like to point out. And our past never crossed in Hangeley, but it did transpire in later years that we were both in the same came from the same village. He went to a different school. And is your background? Did you have parents in medicine or in academia or where their teachers or was it completely different? No, not at all. My father was a sales director for a garden tool manufacturer. And David, how about you? What drew you into orthodontics? I think because it's creative. And when I graduated in dentistry and I did a couple of years working in general practice and then as a junior hospital surgeon, I realized that you're sort of patching things up and I saw orthodontics as being much more positive and 3D in its conception. And I like the idea of that and and that you have a slightly more long term sort of perspective on patients. You know, you see them for longer periods and you build up a better relationship with them rather than just seeing a patient for once or twice and doing a procedure and then that's the end of it. So maybe that's the region. And David, you grew up in the UK, but you sort of have a more European story than myself from Martin, is that right? Yes. So I trained in England, as you said, and in in in my orthodontics in the UK and in precisely where Martin is sitting now in Guy's Tower and at in Rohampton Hospital in London. And then I thought I would go on an excursion and I'm really still on that excursion. Actually, I thought I was interested in research at that point. I knew that and I thought that maybe some travel would be good. So I thought I'd go off for a six or nine months and it I knew at the time that the Nordic countries were really at and still are to some extent at the forefront of orthodontic and craniofacial research. And I was lucky enough to meet up with with my mentor at that time, Irma Testlev. And it's turned out in Finland and it turned out that the environment was super good. And I then went on to do a maintaining clinical practice but also went on to do a PhD in in craniofacial developmental biology. Actually, I have to say at that time I got initially a small sort of traveling grant but then I got a mobility grant from the EOS and that was really instrumental in in sort of setting me on my path without that I wouldn't have been out to to stay or I'd really have struggled. Yeah. If I'm correct at that point you had Irma in Finland perhaps Bjorn Olsen maybe in the East Coast but then Martin you had on your doorstep there Paul Sharp. And Paul Sharp, he came into the dental school, he wasn't a dentist, he came down from Manchester and what was if I'm correct because well to be known I was also in that lab for a few years as you were my supervising PhD, you supervised my PhD. That was quite a unique lab within a dental facility would that be correct to say? Yes, I mean I think the Dean of Guides at the time was a guy called Frank Ashley who wanted to bring some basic science into this is before my time but into the tower really and he brought Paul Sharp down from Manchester. Paul was working in a group up in Manchester and had I mean he'd cloned what was to become known as MS61 and was work so he'd sort of got drawn into into to development he was a developed he was a barlegist by training and came down and basically I was given free reign really to to set up a department which is what he did and by recruiting individuals and I was I was Dan at King's College Hospital at the time just finished my orthodontic specialty training and was keen to do research had always been quite keen to do research, ideally biological research and was introduced to Paul via Murray Meekle who was the head of orthodontics at guys and Meekle himself had an unusual background he was a key we wasn't he and he trained in I think was at Seattle will come back to the UK and worked in strange ways lab, whilst working in practice and then came down to London was that correct? Yes so he there's lots of connections I mean he he had done a PhD as you said and and was at the Eastman and then Bill Houston died prematurely he was the professor at guys and so Murray came over as the new professor I'd worked in Bristol with a guy called Jonathan Sandey who had worked with Murray and Jonathan had sort of really inspired me early on in my career before I did my orthodontic training to want to become an academic orthodontist and really via Murray and Jonathan I got introduced to Paul and literally came up one day to see Paul and he was incredibly warm and more than happy to take someone on who had no experience at all and we set about getting some funding to do the research. And that's really where it started. I was lucky enough to get 12 months funding from the welcome trust. And then so came up here with a years funding and was lucky enough to get a medical research council fellowship about six months in for three years. So I ultimately managed to get four years funding which gave me the funding to do the PhD. So there's a question addressed to Boatian, whoever would like to take it, let me know. But if we set the stage for people who aren't that familiar with craniofacial or developmental biology, how would you define it in simple terms? What is it we're talking about when we talk about developmental biology or craniofacial biology in terms of how it intersects with orthodontics? So if you take a step back and think about dentistry, I think that basically all dentists should know. And it's not just, I mean at the heart of developmental biology is genetics and epigenetics. But for all dentistry, all dentists should know, I've rather actually good understanding of how the teeth and jaws developed. I think it's fundamental. And that then goes a little bit beyond that in that they should understand a little bit about how the face develops and about of course then when things go wrong. Not just because if patients ask, well why haven't I got a tooth that's formed in this location or why is it a funny shape or why have I got a cleft of this kind of thing. But also so that they can keep at least have some concept of future developments. It's not just about being able to give patients a sort of reasoned and good response as a biomedical professional. But I think to that extent we have an obligation and orthodontics has been very much part of treatment of patients with craniofacial anomalies whether they're craniosynostosis or cleft patients or a variety of patients. And they've been at the heart of orthodontic research and cleft research and craniofacial research from clinical aspect and it's only natural that there's a sort of progression into basic biology and understanding as well. I think it's I think that they go hand in hand. I mean I would agree with that. Biology is the sort of foundation of orthodontics really, not only developmental biology but also the biological systems, host and adult development, biology and the biological systems that underlie how you move teeth through the jaws. It's absolutely completely integrated with the practice of orthodontics. And then when I was in Kings I was I think my first initial thoughts were how very different the ethos in a basic science lab was compared to the orthodontic department I had been before. So for example when we did our seminars or somebody a student would stand up and present the sort of feeling I got was the level of questioning, the rigor, the involvement in the students was much higher. And I think when I go back to presentations by post grads or even doctoral orthodontic students I find sometimes there can be a tendency for someone to stand up, present their topic. They may get a question, a sort of fake complete, they sit down and we move on to the next speaker. Does that resonate, that experience resonate with you guys with your training? Did you feel that that was there's something in there? Yeah, definitely. I mean it's not just the scientific rigor that you mentioned but there's also a scientific sort of how can I put this, that people are not afraid to ask questions. There's a sort of a level that they don't mind, they're inquisitive, of course most people are inquisitive but also that they don't mind asking a question of some respected individual who may be presenting or a fellow colleague. So I think that's important but there is a definite difference. I think the other thing that you notice sort of as there is in lots of parts of orthodontics but often it doesn't come quite out. You mentioned being in a sort of a basic science sort of symposium or a general club or a conference or whatever it is. There is a slight difference there in that there is a level of excitement and interest that you really are discovering something and that it's great fun and then this kind of thing. It exists in orthodontic conferences but they have a different emphasis and basically from my perspective learning how the face develops and how cells and tissues interact and in the sort of intricate processes is fantastic. I mean it's something that is fun and I think Martin and I have been actually quite lucky in that we've been sort of transitioned from a time where the basic anatomy and embryology and traditional sciences were fairly well understood. And then we've come into this era in the 1990s of a molecular era where we actually can actually see where and when particular regulators are switched on and off and what effects they might have. But to put it even a step further I think it's very important that there is a clinical and input and aspect and questioning of the basic science because otherwise it's just basic science for basic science sake. There's no relevance and the importance of it are the key questions must come from a general public or a clinician perspective and I think that key link is very very important. Martin you had a student and I found it I talk about it a lot it was a student you co-supervised with Jeremy Green and Andrew Iconomal and I remember knowing Andrew he'd sit in this postgraduate room he was in early because I think he just started having a family and he was teaching himself to code and he would teach himself and he was just kept himself to himself and then one presentation I think was a nature genetics paper that you guys had done together where he had looked at periodic striped formation by a touring mechanism at growth zones in the palette and I just couldn't believe this was the same guy it was mind blowing what he'd done and I just felt that it had that been orthodontics alone that surely would have been the paper of the year it was incredible but we out within that biology basis it was received well obviously but it wasn't it was kind of mind blowing it was like two different worlds in a way you know because of me a very major because it wasn't in the EOS or the A.J.O.D.O. it didn't really feature. Well I mean Andrew yes Andrew Iconomal was his name he was a he was a very very capable postdoc yes and I mean in collaboration with Jeremy Green who's a very very capable developmental biologist you know I was lucky enough to be involved in a project that sort of came from nowhere really it wasn't part of the grant so it was it was a spin off from things that we noticed I mean when we first started when we first started I mean Jeremy and Andrew didn't really know what Rougie were so it's a good kind of went from there really applying their developmental biology core skills and I mean I think it's you have to remember that in an environment I mean David and I were very lucky because we ended up in environments that were world leading I mean Irma Thessaleth Paul Sharp were absolutely the leaders in their field and you get parachuted into an environment of professional research essentially you know I mean there's a lot of orthodontic research clinical research he's done some is good some is not so good but often it's done as a sort of a side show the individuals maybe are more involved in the clinic they do some research as part of their portfolio but you know in a research lab it really is everything is focused on on the research everything is focused on getting the funding to carry out that research and so it's high level you know and David and I've been lucky enough to sort of witness the progression of knowledge in in some of these areas. There are some very, very high performing laboratories around the world. And you really do see advances in knowledge and it's something that David and I both very much enjoyed as part of our careers. But before I ask you a little bit about what you do specifically that is different in the area of development biology, can I ask about this? I don't want to use a loaded phrase but translational. So if I take my SPR, my resident orthodonticins and send them into a lab, if I'm a departmental head to be immersed in that type of science or we talked earlier that we spoke to Professor Eliadis Mzeurik to talk about material science, which is a pure more specific basic kind of science. What do you think is possible with your background and having had that experience yourselves? What are you bringing back? And what would you hope to do to bring back to your department? How do you enrich? You take that knowledge via that student and enrich your own department and how do you make it kind of beneficial or how do you even measure that? What's your approach or what are your thoughts on that? How did the department change because of what you had experienced Martin in Sharp's lab for example? I know I've asked six questions there in consecutive order but you'll get the gist of it. I don't think you changed much. I don't think I changed much. I mean I came in as a completely untrained PhD student to a bit of a liability in the lab I would say for at least the first 12 months. Did I ever tell you the story where I asked your postgraduate a question about base pairs in front of everybody in the lab in my first week and he looked around like from a sketch and lent over to me and whispered thin. If you need to ask questions at such a low level like this remember this is a real lab we can go down for a cup of coffee and I think it was the moment of which I realised oh dear I have a bit to learn here. Well you know I mean I'm the man that put some restriction enzymes in the hot block you know which is an absolute no no as any molecular barless will know so they're completely ruined within two seconds but I mean I'd think the translational thing is more is more tricky. I think David and I both done primarily discovery biology I guess and but we've done some stuff that has translational you know I mean David we both we both have papers in the Journal of Clinical Investigation which certainly for me was probably one of the best papers I had and we both used mouse models to demonstrate things that would be that are of relevance to human cranifacial disorders so I think that's probably as close as I've come to sort of translational stuff if you like I'm David may have made more recently have done some other other things but I think also that those if you talk about translation it has to be in in view of a bigger picture so they're all parts of not a puzzle but a picture that that is made up and the the basic science discoveries or if you like the fundamental discoveries are often just a seed of of of further understanding and research so I don't think we should be so I wouldn't say wound up but so disappointed if if something doesn't immediately lead to an obvious discovery but there are clear directions in which in which we go and as I said just previously the you know patients who have conditions that are developmental whether it's a missing tooth or a cleft or whatever they want to know what's caused it and when it occurred and can you treat it and will it happen again or and this sort of patient information is translational and they want to know and otherwise the great in the cranifacial field the great sort of translation has been targeted towards targeted drug therapy and of course the problem is with developmental conditions is that the conditions already occur by the time you found discovered them so the idea in a cleft that you may have scarring which then inhibits mid-facial growth so that if maybe you could do something at the time of surgery to improve that so that you would have less scarring therefore better grow that's still valid but really very little progress has been made in those sorts of directions I think probably as if you talk talk about targeted therapy which is not just simple public health advice about you know we now know that there's a gene connection between so if you have a gene mutation you're more susceptible if you also smoke to have a cleft for example even passive smoking so these sort of public health advice is also targeted knowledge if you like but I think that the where things have advanced actually quite dramatically is not only in our genetic understanding of development if you like but in something called deep phenotyping and by that I mean that clean at deep clinical understanding deep clinical knowledge that is then translated into the lab so that we would then for example know it a certain patients have a certain eruption pathway or what time those teeth erupt or why certain patients get a canine impactional this kind of thing and and if those can be tied to more genetic understanding then that is the way that the future lies and that is kind of the bigger picture of translational treatments that basically clearly would improve the efficiency of treatment so you could target certain treatments whether it's a classary malocclusion that you know is going to get because of certain characteristics or they have a particular genetic variant that would almost definitely need orthognathic surgery then you can target specific treatment towards them or if you know that a particular population would have have have more canine impactions or whatever it might be so I think looking in in the more distant future that's the direction it is and I think people get too hung up on on making if you like saying that this how why is this relevant why is it translational so the bigger picture is much more translational and for the individuals every day orthodontics it's it's not so effective on you know on both Martin and I clinical orthodontists so in fact I'm going to see patients this afternoon so it's not going to affect what I do this afternoon what I've done in the lab this morning but but it's also obvious that genetics controls tooth development, tooth position, tooth size, jaw size and malocclusion so any parent or patient will tell you that they say well yeah my father had a similar treatment or a similar facial characteristic so those are the sort of it's so obvious that I don't think we should be sort of discouraged or lost in the in the bigger picture just because we we don't have a new bracket system that is designed from basic science or whatever it might be I don't know Martin thinks about that I think I think we get a little bit too hung up on it well what one of the things one of the things that comes to mind is and I see it in clinic and perhaps as you are both practicing orthodontists as well you see is an increasing numbers of parents of younger children coming to see us talking about breathing and expanded airways and breathing through their mouth and and I find in a lot of cases your clinical background is healthy but also an understanding of how the maxilla develops between eight and ten or eleven or how the upper airway develops can be a great help in explaining to parents what's going on and to decide that perhaps an intervention isn't needed here this is part of the normal growth sequence at the juvenile period I don't know what your if you've had experience of this or what your thoughts are about things like this that occur clinically are perhaps in the greater sort of what's the word where something becomes thematic like airway I mean you've veered into a slightly more controversial area I think but I mean there is more interesting airway it seems to be the I find particularly amongst dentists in primary care there's a lot of interest in expansion and improving breathing and then nasal function I mean the evidence base is not great and I think probably there's not much more you can add to that I mean I think what David was talking about in terms of translation is I mean really it's been driven by you know next generation sequencing essentially you know you can now you know borrow into the genome of individuals with with incredible rapidity and these data will inevitably to be informed how we treat our patients in the future. I mean, I was in the lab, I did some sangose sequencing. I spent a whole day sequencing about 200 base pairs. Now you can sequence the entire genome using the most advanced methods in a day. The data that that generates informs how patients and individual is going to respond to therapies and it will inform why an individual has a particular phenotype. And I mean, orthodontics and dentistry is probably a little bit further down the line, but certainly in other aspects of medicine, adverse drug reactions, how people respond to drugs. I'm sure in the next decade or so, we'll see some fairly monumental changes or advances in how some of those things are managed. But I mean, in terms of breathing an airway, I mean, I think that's a fairly controversial area and there's no significant evidence that orthodontic interventions can really improve outcomes in young children. Certainly, not to say that they potentially can't, but I would say that the evidence isn't there and it's probably a very good platform for some interesting research over the next few years, particularly looking at children having tonsils and adenoy is removed, maybe with them without some form of orthodontic expansion and really trying to investigate carefully and robustly the relative outcomes. I also was just mentioning because I just found it was having that applied knowledge was enabled me to, sorry, you know, to communicate to the parent about concerns that they may have had, which may not have been substantiated or brought to their attention by a dentist or a oral health professional, but may have been something that they'd read about or they'd seen on a channel or something. So I found it helped me rebut and sort of back up what I was going to do clinically. So in that respect, in that respect, could I ask you both, if I could just comment on the airway just for a moment, is that that's why exactly why of well-balanced, reasonable opinion is so important that the clinician can get to hold of this and the two people that come to mind there are the lectures by Timopelter Mackey, but also the blog from Kevin O'Brien, where they consider these issues and try and give us as professionals some, you know, a well-balanced view, if you like. Could I ask you both about your current research work? And the first thing just for people listening, is how does your research differentiate from each other? What is your, I sort of mentioned it at the beginning, what is it David that you are primarily focused on in the lab and have been since you've set up in Finland? So my focus has primarily been on craniosynostosis and the biological understanding of what causes craniosynostosis. I mean, that's a rather fundamental picture, if you like. However, I've strayed into other fields as well, particularly looking at the control of how pallet and lips form and cleft palate etiology. But actually in the last four or five years, I've been much more involved in large scale population genetics with a look at clefting and also now a little bit more in a direction of malaclusion. So that demands that, so the large scale population genetics is basically the Fingen project where in Finland we're lucky enough to have a private and public initiative where half a million people have been had samples taken and that is combined with their clinical records so that we can do large scale G-West studies, genome-wide analyses. And the op, so not to draw this out too long, but the thing that drew me into that was basically that Finland has a very high prevalence of cleft palate only, so without the cleft lip. And in a paper last year we basically discovered why that was exactly from this material. But now we've been drawn into much more into trying to understand skeletal malaclusion, as you all malaclusion. And the problem that we find is that you rely not necessarily on the genetics, but you rely on deep clinical input. So that the clinicians have entered, for example, ICD codes into their diagnostic evaluations and that those are nationally available. And it's coming out of fruition. This is the way forward. So this is basically what I've been working on and I can see this is where I will be working on for the next year or two at least. Thanks David. And Marjan, it's been a few years since I was in the lab. What is it that's occupying your time at the moment or what areas are you working because I know you have two hats, don't you? You're looking a lot of clinical research as well as so you move between the 18th floor or is it the 21st floor and the 27th between both your offices. Yes. Well, I mean, I for a long time kind of worked on a gene called sonic Hedgehog, which despite the name is a very, very important signaling molecule in development. We used mouse models of a condition called holoprosincephaly, which is very much associated with disrupted Hedgehog signaling. It's a defect to full brain development that affects the face. You get pallet, single incisor. So did quite a lot of work on that. More recently in the lab, we've worked on the pallet. So I work with Jeremy Green, who's a developmental biologist, and we currently have a very talented orthodontist, researcher Daniel Stonehouse Smith, who's working on really looking in great detail at the cellular mechanisms of of palletogenesis using normal and mutant mice. But yeah, we have also done some clinical research over the years. We've done a few randomized trials. We did the first trial on Damon brackets, self-legating brackets. We've done trials on the vibrational device, the accelerated device. We've looked at outcomes in patients with increased body mass index versus normal weight. And then sort of recently, we've got another academic fellow called Rory, Rory Okane, very, again, very talented. And he's been doing some work on automated speech recognition using large language models and looking at the accuracy of these things within an orthodontic context. So yeah, we've got quite a spread of things. And we've done quite a few small-scale studies looking at various aspects of clinical orthodontics. With blood at the talk both clinically and I suppose in sort of popular science of technologies and all the talk about AI and computer modeling and what are your thoughts about where things are going in terms of future technologies? There is, you mentioned Martin earlier about the speed of which you can analyze data or process, and genomic information. Are you seeing any tangible changes in your day to day work in that field of the month? Well, yeah, yes. I mean, it's the simplifying sum. There are all sorts of digital-based developments that massively impact on our day-to-day work. And I mean, for old people like me and David, I find it's increasingly difficult to keep up with it, to be honest. I mean, I really have noticed in the last few years the difference between young people and old people in terms of adapting to tech. And younger people now, we'll come into our environment now, have lived with digital tech, all their lives, whereas obviously people like me and David, and you think, to be honest, we've got to adapt to digital tech. So I think you have that innate advantage if you've used it since really, since you can walk around. So that's something I've noticed. And you see, it is difficult. I mean, a good example is, the bread and butter of my PhD was in situ hybridization. So you generate molecular ribo probes. You would prepare your tissue, and then you would do a three or four day experiment using some kind of labeled probe to see where the gene was being expressed. Well, I mean, now, you know, via next generation sequencing technology, you can do, you know, RNA-Seq, which is a technique that will give you a kind of snapshot of the transcription of your particular tissue, the entire transcriptional profile of your particular tissue. So what took a week to generate data for one gene now? You can very quickly get data for the entire transcriptional profile of the tissue that you're interested in. So I mean, that's the difference in scale. Just that's just one example. Well, that was a great conversation point to end on. I thank you so much for taking your time out of a busy day and a busy schedule to share with the podcast subscribers, the role and the importance of developmental biology and craniofacial biology in what we do from clinical practice to managing malocclusion to thinking carefully about some of the things that come up from time to time with our patients. Before we sign off, I just like to give a quick reminder to our listeners to ask them to subscribe to the podcast on Spotify. So you get notified when our next episode goes live. In our next episode, we'll be talking to Professor Poric Fleming and to Simon Littlewood about retention in orthodontics. While you're at it, please explore the brand new EOS Resource Library, which is a growing collection of webinars, Congress recordings, abstracts and more, create it to support EOS members at every stage of their careers. You can find that in the link below. It's also at www.eosEurope.org. And finally, mark your calendars from the 7th to the 11th of June, 2026 in Dublin, where it'll be the 101st annual Congress of the European Orthodontics Society, which we hope to have over 2,000 orthodontists with an outstanding program on the theme innovation meets clinical excellence curated by scientific chair Professor Poric Fleming, of Trinity College Dublin. And we hope to see Martin and his students and his co-oritor colleagues and David with his team from Finland. It'll also be there. We'd be delighted if you're able to attend. So thank you very much again, guys, and have a nice day. This podcast was brought to you by the European Orthodontics Society and is sponsored by DWLingual Systems, Improving Orthodontics. Visit www.lingualsystems.co.uk for further information. The EOS is a membership organisation with over 3,000 members from all branches of the orthodontic profession, working in private practice, hospitals and universities throughout Europe. To find out more, visit www.eosEurope.org and follow the EOS on Instagram, LinkedIn, Facebook and X. All views expressed on this podcast are solely those of the hosting guest speakers and do not reflect the opinions and beliefs of the European Orthodontics Society. Sponsors have no input into the selection of speakers and topics.