S5 E6: Migraine and facial pain: should I see the dentist?

Migraine and facial pain: should I see the dentist?

Series 5, episode 6

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Transcript

00:00:00 Welcome to the Heads Up podcast, brought to you by the National Migraine Centre, the only UK charity treating headache and migraine. Visit our website to book your appointment with a world-class headache doctor, wherever you are in the UK. There is no need for a referral. You can refer yourself. Our headache specialist doctors are looking forward to helping you soon.
00:00:35 Dr Katy Munro
Welcome to this episode of Heads Up podcast and thank you for joining us. I’m very excited to be having as my guest this week Professor Tara Renton, who is the professor of oral surgery at King’s College Hospital in London. I heard Tara speaking about this topic last year at the British Pain Society meeting and about the link between migraine and dental pain, and how sometimes the two can be confused. And it’s not a topic that we’ve covered at all, so I’m delighted that Tara can join us today. And so Tara, would you like to say a bit about yourself and the work that you do?
00:01:12 Prof Tara Renton
So thank you, Katy, for the introduction. It’s great to be speaking to this fantastic podcast series. And yes, essentially, I’m a dentist by an original qualification, did some maxfac training internationally and in the UK, came back and wanted to be a mother to my three children and work part-time and essentially ended up doing a PhD in neuroscience and that was around nerve injuries in relation to dental procedures. So I’ve become a perceived expert in orofacial pain. I’ve obviously been very fortunate to work with some amazing people, and I’ve set up a great team at King’s College London and that’s essentially where I’ve ended up where I am now by mistake really, not by default. So I work with a very fantastic multidisciplinary team. It’s one of the largest orofacial clinics outside the US. We work with neurologists, neurosurgeons, ENT, clinical psychology and psychiatrists. So we see a very large cohort of orofacial pain patients coming through at King’s College Hospital, which is where I’m based clinically. And that’s sort of how I’ve ended up here now.
00:02:21 Dr Katy Munro
OK. That’s brilliant. And I think I was a witness to the fact that you were working in a team, a multidisciplinary team, because I know you work with Giorgio Lambru and some of the other people. Giorgio’s been a guest on the podcast previously. So that’s brilliant. When I became a headache specialist, I was thinking all about the head and all about headaches and where they can affect people, but I’ve never really thought about the dental aspects of things and I think a lot of doctors are probably not very aware about dental issues, but many patients may either think that they’ve got a headache pain when actually it’s something to do with their teeth. Or the other way round. So do you want to just talk a bit about the basic things that we need to know about teeth and maybe the classification of aura, facial pain and the trigeminal nerve, which we know is a very significant factor in pain in the face.
00:03:24 Prof Tara Renton
Of course, the orofacial pain is very difficult when it comes to differential diagnosis because we have ENT surgeons looking at sinusitis, for example, we have headache neurologists and GPs looking at headaches. We have dentists looking at teeth, we have otolaryngologists doing ear, nose and throat. And you know, generalists doing all sorts of things. So we have all these different structures very close together, all primarily sensorially. So sensation provided by the trigeminal nerve, which is the largest sensory nerve in the body. It’s different from other sensory nerves as in spinal nerves because it connects directly into the central nervous system. So the trigeminal ganglion is actually within, just below the brain, and it has a very complex structure. It’s linked with cervical branches C2 and C3, which is why you can often get referred pain from the neck, for example. It’s linked in very closely with the vagus nerve and para-sympathetic, so the autonomic nervous system. We often get symptoms which you wouldn’t necessarily get in other spinal nerves. We see that in migraine, of course. And then there’s the trigeminal cervical complex, the trigeminal parasympathetic complex, and the trigeminal nerve does actually supply sensorially part of the meninges as well. So the 2nd and the 3rd divisions of the trigeminal nerve do supply a large chunk of the meninges, which obviously can get irritated during migraine and probably explains what we’ll talk about later. Why so many migraine patients can actually have symptoms presenting in the lower-mid face and lower face.
00:04:59 Dr Katy Munro
For people who are not aware what the meninges are, those are the linings covering the brain.
00:05:05 Prof Tara Renton
The brain. Indeed. Exactly. And that’s what we have slight changes in when you get your migraine, or the hypothesis as where you get to see the changes. So that’s partly why the trigeminal nerve is such an important nerve because it protects seeing, smelling, eating, chewing and all those social interactions that we so value and underpins our personalities and our identity. So when you have chronic pain or intermittent pain that goes on for a long time that is not explained it’s obviously almost more alarming. We know it’s actually the burden, the physiological burden of trigeminal pain is worse than actually having intermittent chronic pain in the back or the leg or somewhere else. So that’s a very important thing to recognise around the trigeminal nerve and trigeminal pain.
00:05:57 Dr Katy Munro
That’s really interesting. I haven’t really thought about that, but of course all the muscles as well as the sensation innovated.
00:06:04 Prof Tara Renton
Yes. So you just can’t escape it. It’s in your face and in your head. And it’s just with you.
00:06:11 Dr Katy Munro
Yeah. And there we think about the three main branches on the face, don’t we? We call them V1, V2 and V3.
00:06:17 Prof Tara Renton
We do. Yes, you’ve got your forehead and you’ve got your mid-face and you’ve got your lower face, which is your chin and your lower jaw. So 1,2 and 3. And everyone thinks migraine is just the top of your head. Everyone thinks of headache being in the top of your head and then the head pain includes your face and mouth. So it’s just this concept we’ve developed and we don’t often question it, but obviously it’s something that as a clinician, a pain clinician now, and making sure I’m trying to get the right diagnosis, it’s something that we’re beginning to realise that that’s a mistake that we actually think that headaches are just here, particularly migraine.
00:06:56 Dr Katy Munro
We need to think about the head as being the whole head, don’t we? And even migraine pain that can be referred down to the neck and shoulders, but certainly realising that pain can be felt in the face if you’re having migraine.
00:07:06 Prof Tara Renton
Indeed.
00:07:11 Dr Katy Munro
I mean, I’ve experienced that sort of needle-like pain right next to my nose and it took me a while to realise that that was a different expression of my own migraine attacks.
00:07:22 Prof Tara Renton
It does take people a long time, and that’s often what we see in our clinic. I think the average number of consultations that patients have is around thirty and thirty-seven consultations they’ve had before they get to see us. We actually then work as a multidisciplinary team to try and actually bottom out exactly what’s happening with our patients, so going back to your second question around teeth, obviously teeth are remarkable organs and I’m obviously passionate about this, being my field, but they are actually innervated. The bones are innervated as well, but obviously teeth are externalised. They’re in your mouth and you have a solid cap of enamel around the top of your teeth that you can see. And then inside that you have dentine, which is highly innervated. So dental pain is really interesting. In health, teeth are the only organs in the body that can only feel pain. So if you crunch it to an ice block or you brush your teeth where the dentine is exposed, you’ve got a little bit of gum disease, you get pain. You don’t ever feel hot or cold in a tooth or tickly feelings or itchy feelings. You just feel pain. And that as you know as a clinician is called allodynia, so pain to a non-noxious stimulus, so touching or brushing and that’s what we see in trigeminal neuralgia. We see it in migraine patients. We see a lot of orofacial pain conditions. That’s really, really common and toothache is the most common orofacial or headache pain. It affects something like — there’s a recent survey — 22% of US adults have experienced dental pain, orodental pain in the last year. And it’s really the most because it’s the most common. And actually on the whole, quite easy to manage. That’s what we have to make sure is that the patient is dentally fit. We go on to think about some other diagnostics which we’ll talk about later. We know that that between 10 and 90% of adults will actually experience dental pain through their lifetime and around 40% of children under the age of sixteen. And, you know, we are blessed. I know the NHS dental system gets a lot of flack. But there’s over a million patient clinician episodes a week on the NHS. And we service over 50% of the adult population and around 58% of children. So it’s there, it’s challenged like all health services at the moment. But we do have a phenomenal dental system in the UK, which in England particularly is often overlooked.
00:10:02 Dr Katy Munro
Yeah. I suppose also the thing about dental pain is it’s very, very common, but also migraine is very, very common. So a number of people will have both, won’t they?
00:10:14 Prof Tara Renton
Absolutely, absolutely.
00:10:15 Dr Katy Munro
So it’s really about being aware of both possibilities co-existing and making sure that people are getting both things checked out, I guess.
00:10:26 Prof Tara Renton
Absolutely. The interesting thing around the pain presentation of dental pain is if — obviously we’ve talked about dentine sensitivity which is a short, sharp, neuralgic, we call it, nerve-type pain — but if you get dental trauma or dental damage or tooth rot or caries in the teeth, then the pulp becomes inflamed .And that’s when the diagnostics become interesting, because you can get an intense throbbing pain. It’s often an ache pain. Sometimes it can be continuous, but it usually lasts hours to days. It’s intermittent and episodic, and if it’s in the upper jaw it’s here. It responds also to paracetamol and NSAIDs, like migraine does. Migraine obviously doesn’t respond to antibiotics, which dental pain with an abscess formation will, so all those commonalities in those pain presentations. If you go to a dentist and you’re presenting with episodic higher level intense throbbing pain here, the dentist is going to look to find something wrong in your maxillary teeth. And if you’re middle-aged adult, you’re likely to have a few fillings, you’re likely to have maybe the odd crown, you might have a bit of gum disease. It’s very easy for the dentist with their siloed approach – it’s not just dentists with a siloed approach — to find something wrong with the tooth and drill and fill and drill and fill and carry on to the next tooth and next. And we do see so many migraine patients who have gone to the dentist because they’re getting the pain in their teeth and fair enough, they’re going to the dentist doing the right thing to make sure it’s not dental pain, and they have quite a few interventions before they actually end up having a diagnosis of migraine. And they tend to be patients who have more of the mid-face, what we call neurovascular pain, which is a small group, and we’ll talk a little bit more specifically about those later. That’s the difficulty with the diagnosis is they present so similarly.
And the other thing that’s very interesting is if you do have a toothache or even if you have surgery of any kind or intervention or filling, that can actually ignite or aggravate a migraineur. So you go to the dentist and have some routine treatment that can sometimes precipitate a migraine if you have a low threshold migraineur. So they’re two sides of the evil, and I don’t know which one’s the lesser evil because they’re both horrible, but they do need to be assessed conjointly and trying to get dentists interested in making sure the patient hasn’t got a headache of some form is one of my missions. It’s partly why I have my websites and partly why I lecture a lot to dental groups to try and actually highlight the differential diagnosis of non-respondents. You know, if you do your dental treatment and it doesn’t respond, patient doesn’t respond, think about possible migraines, think about temporomandibular jaw disorders, think about some of the rarer conditions that Giorgio talked about, the TACs, the trigeminal autonomic cephalagias or cluster headache type conditions. You know, it’s really important to think outside the box and just not keep doing the same thing. And the same thing could be said about ENT surgeons with people with bifacial migraines. They all have their septums straightened, they all have the odd sinus wash out. But actually 98% of those are migraine. And I think the ENT surgeons are realising, I’ve lectured to that group as well quite a bit and to their trainees, I think they’re realising now that actually sinusitis is very rarely painful.
00:13:56 Dr Katy Munro
Yeah.
00:13:57 Prof Tara Renton
And it’s usually migraine.
00:13:59 Dr Katy Munro
Yeah, it’s both ways, isn’t it? So researching to speak to you now, I was picking up papers and things and there was a paper about four different types of primary headache disorder presenting as dental pain. One was migraine, one was cluster headache, one was hemicrania continua, and one was paroxysmal hemicrania.
00:14:19 Prof Tara Renton
Absolutely.
00:14:20 Dr Katy Munro
So all of those could have presented as dental pain, but there was also, and I think you talked about this in the lecture I heard you give, somebody who’d been treated for migraine for many years and there was a case study of somebody who’d had thirty-five years of treatment for migraine and then saw a dentist who took out the two rotten teeth, cleared all the abscesses and the headaches resolved, and that was extraordinary. But I guess individual cases highlight how or where we have to be. We have to think migraine, which is my little mantra. But yours is also think teeth.
00:14:43 Prof Tara Renton
Yeah, absolutely.
00:14:58 Dr Katy Munro
So we need to be spreading that message, don’t just think about migraine being just a headache on one side of your head at the back. And because it’s so much more than that and dental pain is obviously something else we need to have on our list of things to consider.
00:15:15 Prof Tara Renton
And dental pain is not just one type of pain. I think I’ve presented that slide at the presentation you saw. You’ve got your short-term elicited pain with dentin sensitivity, which is healthy. You’ve got your cracked tooth where you get that horrible neuralgic pain, which is very random. You can’t consistently elicit that pain. And then you’ve got your coccal inflammation, which initially is sensitive to cold, so you get a neuralgic cold sensation, but it’s intermittent and elicited. Then you go on to have a dead pulp where you have sensitivity to warmth, sensitivity to biting on the tooth and tends to be more spontaneous and throbbing like the migraine-type pain. And then ultimately you get the dental abscess which can be quiescent, can be spontaneous, migraine-type pain, throbbing, intense, episodic, nasty. And obviously that’s the end of the line for the tooth. So that’s where the tooth either has to be extracted or root canal treated. So there’s lots of different presentations of toothache. It’s not just one beast.
00:16:15 Dr Katy Munro
Yeah, that’s really interesting to know as well actually. I think you’ve given such a clear explanation that would be really helpful to people to understand about that. Brilliant. So we were going to talk about a little bit about sinusitis, because I know there was also a study where they looked at people presenting with sinusitis. And I’m interested in what you were saying about sometimes the dental abscess pain will resolve with antibiotics. And of course, a lot of the patients we see with recurrent migraine attacks may have been previously told “Oh, it’s probably sinusitis, have some antibiotics.” And with the episodic nature of migraine, the attack will settle down anyway.
00:16:59 Prof Tara Renton
Exactly. And the same with the TACs, the same with the SUNCTs and the SUNAs. It’s exactly the same scenario, so it’s very easy to say, well, it does or doesn’t respond to antibiotics, but obviously it’s very difficult. I mean, one of the cases I presented in my lecture was this young guy, thirty-six, he’d had a fifteen year history of basically having all his upper left maxillary teeth treated and subsequently extracted. So when I saw him he had no teeth in his upper left maxilla and he’d had 141 courses of antibiotics. And he had been SUNCT.
00:17:33 Dr Katy Munro
Oh gosh, yeah.
00:17:35 Prof Tara Renton
And it’s just one of those things. I think things have changed. I think most dentists now are aware of headaches in patients and they think of asking about the cluster headache-type presentation group, but that’s a classic example. And then with the shoe on the other foot, as you mentioned, we see patients who are heading off on microvascular decompression for trigeminal neuralgia. They’ve had, as you mentioned, years and years, decades of treatment for idiopathic facial pain or headaches, and they do in fact, a chronic dental, carious wisdom tooth that doesn’t show up on the X-rays for whatever reason. So you do have to think about the patient holistically and going back to sinusitis, there’s some really very good studies, large cohort studies put on in the States, and they’ve really highlighted that between 88 and 90% of patients who’ve had a lot of history of intermittent painful sinusitis are proven to be migraineurs and that generally sinusitis is not painful. There is a really interesting link between dental pain and sinusitis, because if you have an abscess or chronic disease in your upper teeth, your upper dentition, that can actually then cause secondary irritation in the sinus and you get thickened lining and you can get some infective sinusitis there. So again with sinusitis, one of the routine things that most ENT surgeons will make sure of is that the patient’s been dentally screened and there isn’t ongoing dental disease driving that. So sort of full circle.
00:19:04 Dr Katy Munro
Yes, as part of our history taking we do ask patients, “Do you have any other medical conditions? Have you been to the optician? Have you had your eyes checked? Have you had an MRI scan?” But we need to be adding in, “Have you been to the dentist? Are you regularly getting checked up?” And I think with the pressure on the dental service and I was hearing a news report the other day about the struggles that people have getting an NHS dentist, particularly in certain areas of the country. It’s quite expensive to go to the private dentist and the cost of living and the pressures on people that may be one of the things that they cut back on.
00:19:46 Prof Tara Renton
Absolutely, I bet. But still realistically, I think the dental fees have just gone up 15%. Still great that we have 3 levels of treatment in dental practice and a consultation is around with the increased prices £28 and then the more complex treatment at grade 3 level is between £60 and £80. So it does cost money and it’s an unfortunate model. The dental model is not free like general medical practice, but we just are where we are since the NHS was first initiated, this is how dentistry was set up, a bit like ophthalmology and pharmacies. It’s just the way the business has been set up in the NHS. It is difficult, but then there’s a huge number of people who have access to free dentistry as well. So those on income support, children. Children have free access to dentistry. But as you say with the work, some of the workforce challenges, there may be difficulty to get access to NHS dentistry.
00:20:34 Dr Katy Munro
Yeah, my experience, I’m sure you find the same, is people who have chronic pain are usually really keen to search and search, trying to find the answer, what can they do themselves? You know, many of my patients with migraine are saying to me, I don’t want just another tablet, what else can I do to find out the cause, what else can I do to help myself and obviously getting a dental appointment and making sure that your oral health is good needs to be on that list.
00:21:18 Prof Tara Renton
It’s really important.
00:21:24 Dr Katy Munro
There is another condition I wanted to ask you about, and this is a thing which I came across called orofacial migraine, where there’s only pain in the face and no headache at all, but it’s classified as migraine. Can you tell us a bit more about that?
00:21:40 Prof Tara Renton
I can. So just going back to the International Classification of orofacial pain, which is a very new thing, it’s a massive achievement endorsed by the IHD, the ICHD, the International Association of Study of Pain, the International Association of Dental Research. So we’ve got all the big chaps together and they all endorse this classification and we have acute and chronic pain in there and it’s all based around the orofacial structure. So we have dentoalveolar pain which is — we’ve talked about toothache, but obviously lots of other things as well. We have two sections on temporomandibular disorders. One is around muscular-based temporomandibular disorders and one’s articular, the joint itself. Then we have neuropathic which is basically nerve injuries or nerve disease. Then we have neurovascular for the first time ever. We actually have a group identified as primary headache disorders presenting in the face. And then lastly, we have idiopathic and I always feel very sad for patients when they get that horrible diagnosis. And I’m trying massively to minimise when we actually diagnose those conditions. So the neurovascular headache or primary headaches can often present in the face, and with migraine specifically — I might be going off course here a bit ’cause you’re asking me about orofacial migraine. So just general migraine actually presents in the lower half of the face in around 9-10% of patients. So as you said, you had it yourself, it’s a relatively common feature. Because it’s like a headache, everyone focuses on it up here, but they forget about the prodrome or the pain. So I had migraine as a teenager, so I absolutely empathise with anyone who gets migraine. You’re so consumed by that pain and so debilitated by it, you’re not really thinking, “oh, I’ve got pain here and I’ve got pain here and I’ve got pain here.” You’re just trying to manage your way out of that abyss. So we know that around 10% and we know that’s patients who have the lower facial pain. And that’s probably because of, as I’ve mentioned, the maxillary and the lower facial branches supply the meninges which beautifully explains why you get these symptoms in migraine. If you do have that facial migraine, which I know the neurologists hate that term, then you actually get much more of those autonomic signs that we talk about. So you get those flushing of the face, drooping of the eyelid, unilateral tearing, running of the nose, or bilateral if you have the bilateral migraine. So that’s a really interesting phenomenon. We tend to see more of those signs in cluster headache-type conditions. And there’s a very good paper recently talking about 2.3% of nearly 2000 patients reported involvement, but what was really interesting is in those eighteen patients 41% of them actually said nearly all their migraine was in the face. They didn’t have the V, the top of the head. So it’s a rarer group and it’s a significant group. Because I think most GPs and dentists would be very challenged to say “Intermittent, episodic, intense pain happening here, oh, it could be a migraine” without having the headache type pain. So that’s where we are. It’s a sort of minimal group, but a significant group. And we see a lot of these patients and it’s very simple to diagnose by asking them., there’s three.
There’s three subsets of these patients. So there’s patients who have classic migraine that affects the top of the head who would then have those other symptoms in the maxillary and mandibular region. Then we have a group of patients who basically used to have classic headache migraine, it’s disappeared for fifteen to twenty years, and then after a significant life event, after dental surgery, after cosmetic surgery, it ignites the migraine, but it doesn’t come back in the top of the head. It comes back in the face. And then the last group are basically no history of migraine, no concurrent migraine, but they just have the facial migraine and that’s around a very small proportion. So, what did we say, 2.3% of those patients in that very large survey have predominantly just facial symptoms of migraine.
00:26:05 Dr Katy Munro
That’s really interesting. And if you do diagnose those, I’m presuming that you just treat them with the same things that we use for migraine generally. The acute medicine and the lifestyle things that we’re always talking about.
00:26:15 Prof Tara Renton
Absolutely. And it works really well.
00:26:21 Dr Katy Munro
Yeah, it’s almost a diagnostic test though I guess. If you give them the treatments for migraine, then suddenly their facial pain goes away. I had a patient yesterday who said, “I get neck and shoulder pain and I get migraine attacks that are more typical. And when I had the correct treatment to prevent my migraine attacks, they all melted away. And so did my neck and shoulder pain.” So it’s a sort of retrospective “Oh, that’s what that was”. But it is quite nice we can diagnose it and give people help.
00:26:50 Prof Tara Renton
Yeah, we see very similarly in our lower face migraine, we see exactly the same. And Giorgio and I published a paper, which you actually highlighted in the notes to mention, published in 2020. And we looked at fifty-eight patients, which I think is one of the largest series published on orofacial migraine which as I say really drives the neurologists mad. And basically we just wanted to look at the history and we also found that they had much higher propensity of the autonomic symptoms. 66% of those patients met absolutely the criteria for episodic migraine. So generally, around forty-nine years of age we had those three subsets, but the most common subsets with the ongoing headaches, migraine, top headaches and then with the past history of headaches, so as I mentioned before, the isolated facial pain migraine was much rarer. And then –what else did we find? – it was strictly unilateral, 80% of patients, which is interesting. That’s a high unilaterality compared to migraineurs. And it was in the maxillary region in 85% of patients. And 80% of our patients responded to triptans.
00:28:05 Dr Katy Munro
That’s really interesting. So I’m interested as well that you were saying that the average age was forty-nine. Was there a gender pattern, the same as we see in migraine?
00:28:17 Prof Tara Renton
Exactly the same, yeah.
00:28:19 Dr Katy Munro
So around forty-nine, of course, is the prime age that we are seeing a lot of women in their sort of early to late forties, early fifties with perimenopausal aggravation of their migraine attacks. And I think you know, that’s something that I’m always banging on about now is to get the hormones right as well is such an integral part of our management because if you’ve got fluctuating levels of oestrogen then that’s going to aggravate everything. And I think also it’s very common that we hear, something you just mentioned, that people used to have attacks like this. But now as they enter the perimenopause, the attacks are slightly changed and they say “Now I get more dizziness, or I get more or less aura, or I may have stopped getting the vomiting”, So I think this changing pattern and the way that migraine presents throughout a person’s life is really worth understanding, isn’t it? And part of what you’re describing would go along with that.
00:29:22 Prof Tara Renton
Absolutely and oestrogen depletion pain is something that we obviously explore and we often get the patients to go see their GP if they want their perimenopausal status assessed or if they’re ideal candidates for HRT that’s something that we encourage the patients to do. So it’s part of our practice. But there’s something I’d love to bring up as well because we talked about the different subsets of the International Classification of Orofacial Pain and two of those are temporary mandibular disorders so they’re jaw joint pain. And this is something I think is really worth highlighting. I think I touched on it in my lecture. But about 40 to 70% of the general population at some stage, usually between the ages of twenty to fifty years of age, will get jaw joint pain. And there’s a set criteria for diagnosis of this and generally it’s either muscular: So we call it a myofascial type pain, which is muscular tenderness, tenderness if you press the joint, tenderness if you press your masseter or your temporalis. You may present with pain, ongoing pain, episodic pain, but pain may be exacerbated by opening your mouth and chewing and eating foods. Very disabling condition, and it’s very common. Now what’s really interesting is the link with migraine and TMD. And it’s something I’m exploring with one of my PhD students. So you’re approximately five times more likely to have migraine if you present with a TMD. Much, much, much higher prevalence and it’s something that, again, dentists tend to treat TMD. If you see your patient at your GP, a general medical practitioner, they will send you to a dentist if you’ve got jaw joint pain. So this is very much managed by dentists who don’t have much training or any training in primary headaches. So we’ve done a bit of a study and we’re looking at patients that present just with temporomandibular myofascial disorder then we’re looking at patients with known migraine and TMD, and then we’re looking at patients with TMD, migraine and co-morbid pains like fibromyalgia or widespread pain. And it’s absolutely fascinating because it’s not proven, but there is definitely, definitely evidence for similar biology. Is it the migraine pathophysiology driving the sensitivity, the tenderness of the jaw joint and the muscles? I personally am in that camp. I think that’s what’s going on there. I mean, in the classification, there’s actually — what’s it called? A HATMD, a headache attributed to temporomandibular disorders. And there’s a whole business out there of people who say, get your TMD sorted out and your headaches will go away. And I think it’s probably the cart driving the horse or the tail wagging the dog. And I think there needs to be, there is a lot of research out there and some really quite strong evidence now. But I think we really need to be looking at, are these patients primarily migraineurs and their temporomandibular myofascial pain is maybe symptomatic of underlying migraine pathology and there’s a couple of studies where they’ve treated patients with TMD. Not necessarily diagnosed primary headaches, but treated them with propranolol and other preventatives for migraine. And those patients get better. So that’s a whole other area that you didn’t highlight but I thought was really worth mentioning.
00:33:01 Dr Katy Munro
Yeah, I had it on my list and I thought, oh, maybe we’ll have time for that. But I’m really glad that you’ve mentioned it because I’m now very much aware and I used to have an interest in chronic in chronic pain and fibromyalgia when I was also a GP in the NHS and so many of those patients had TMD, temporomandibular joint disorder.
00:33:14 Prof Tara Renton
Disorders, yeah.
00:33:16 Dr Katy Munro
And the treatment can be very much about intervention. You know, people are saying, oh, I’m being put down for surgery, I’m having injections, I’m having mouth guards and braces and all sorts of things as well as medications, you know, nortriptyline, amitriptyline, we hear people are being put on. So I was going to say to you, is it chicken or egg, you know, which comes first, but from what you’re saying we need to try and make sure that we’re getting the migraine treatment right and in fibromyalgia, we know that there is a sensitization, central sensitisation of the brain that is driving that chronic pain that’s often felt throughout the whole body. The fatigue and the brain is all joined up, isn’t it?
00:33:44 Prof Tara Renton
Absolutely. Surprsingly!
00:33:54 Dr Katy Munro
So that’s really interesting and helpful to say. So are there any procedures that you would say, alarm bells would ring to you? I’ve been looking at your face when I was mentioning some of those things.
00:34:14 Prof Tara Renton
Surgery for temporomandibular jaw joint, for TMDs, I mean… TMDs by definition, exclude neoplasia, exclude trauma, exclude congenital deformities. Surgery may be indicated for those, but it’s not indicated for TMDs. And the whole concept a bit like the orthopaedic knee research. Just because you can see MRI discs not working entirely properly or there may be some bone pathology on a knee joint, that doesn’t correlate with clinical pain and fixing that does not fix the pain. So it’s exactly the same with the jaw joint. And actually there’s a really good prognosis for TMDs, partly because it’s probably migraine and it goes away anyway, some of them. But actually just very simple interventions are required, so reassurance. Patients are worried about cancer. So obviously that’s when they’ve got pain, chronic pain, they’re worried that something is wrong there. So they just need to be reassured, having been examined, that actually, no, it’s not, you know, something sinister, this is a muscular pain that may be attributed to a headache. We need to exclude, that we need to use a soft diet. We can give you any kind of splint. The evidence for splints actually is very poor to alleviate pain. But if you have a concomitant grinding of your teeth, that will protect the teeth, but we know that bruxism or grinding your teeth does not cause pain in your jaw joint. That’s another bit of new newsflash type, that’s a bit like restless leg syndrome, it’s a neuromuscular habit basically. So non-dental interventions, non-surgical interventions, absolutely, exercise maybe, some thermal modalities, time-limited painkillers if it’s really very acute, but obviously you need to make sure that you’re treating the migraine if that’s the cause or not just, you know, empirically the jaw joint. And usually soft diet for maybe less than ten days will help. It’s mainly about reassurance of the patient and just making sure that they understand and you know, asking them. Do you have a migraine history? And they go, Oh yes, I do, actually. And think, well, maybe that needs to be looked at by your GP and better treated. And there’s some new guidelines coming out. Royal College of Surgeons guidelines that Justin — Professor Justin Durham, if you want a really excellent chat about TMDs, he’s your man.
00:36:42 Dr Katy Munro
OK.
00:36:42 Prof Tara Renton
He’s leading the group and that’s coming out of the Royal College of Surgeons very soon, hopefully. So again it’s about non-intervention, it’s about reassurance like I think managing most chronic pain patients, but TMD is quite time-limited generally. It happens around late teens, early 20s, often around exam time, and then happens later on in life. Possibly it’s depletion-related, maybe stress-event related. We don’t really know, but we know stress can drive migraine as well.
00:37:11 Dr Katy Munro
You were mentioning about short-term acute medication if needs be. I’m just going to say the word ‘codeine’.
00:37:19 Prof Tara Renton
No.
00:37:20 Dr Katy Munro
Absolutely not. Always trying to get this into the message from headache specialists is don’t take codeine for migraine. The message from chronic pain specialists is opioids are not great for chronic pain. Try not to use them. And I’m hearing then that the message from dentists would be don’t use codeine for chronic pain.
00:37:41 Prof Tara Renton
Absolutely. There is no role certainly for TMDs, in nearly all the patients I treat. I rarely, rarely might suggest an opioid-based drug and that’s around dissociation from the pain. It’s not actually about managing the pain. And it’s very interesting in the US obviously with their endemic and you know the Vicodin and the Oxycontin. To my horror, I was told by a leading dentist who is phenomenally bright, a pharmacologist and an endodontist, and he was saying that on analysis about the majority of younger patients who started taking those horrible drugs were introduced to them by dentists having their orthodontic extractions and their wisdom teeth taken out. And obviously, patients would often select their surgeon — You might want to edit this out, I don’t know — but you know, they would select the surgeon on the basis that they might get three months’ supply of Vicodin or Oxycontin, having their wisdom teeth taken out, which is absolutely shocking.
00:38:51 Dr Katy Munro
Yeah, yeah, I think we are all very much aware about, not just the addictive nature of the codeine and the opioids, but the rapidity of aggravation of migraine if you take things like Migraleve or combination medications with codeine, and of course, people with a severe pain who may pitch up to casualty very often get given a strong painkiller and come out, you know, clutching their codeine or opioids. So it’s trying to get the message out there. And when I give talks to the public, often the question is, yeah, but why because it works. And I guess in the very short-term, it will take the edge off your pain or may put you to sleep, may make your vomiting worse if you have migraine and you’re feeling very nauseated.
00:39:37 Prof Tara Renton
Exactly.
00:39:44 Dr Katy Munro
Then in the long term it does activate those chronic pain pathways and is the devil to get people off it sometimes.
00:39:46 Prof Tara Renton
Absolutely. And in my earlier life, a lot of research I did was around third molar surgery and I did quite a few pain studies. And the evidence in Oxford Bandelier, if you look at the numbers needed to treat, the optimal way of managing dental pain or perisurgical pain in just about any surgery is a combination of ibuprofen and paracetamol because they’re actually synergistic and if you use the optimum dose of those, I think it’s around between 400 and 600 milligrams of ibuprofen and a gramme of paracetamol in adults. So two 500 milligramme tablets. If you combine those two drugs and take at the same time, if you add in codeine, a good dose of codeine to that, you get less than 1% additional pain relief.
00:40:30 Dr Katy Munro
Well, that’s really interesting, yeah.
00:40:33 Prof Tara Renton
That research has been out there for years. Thank God it was, because otherwise we would have gone the same way as the US. Yeah, it’s really interesting. Fascinating, actually. But yes, I’m always telling patients. I always say to patients, if their handbags rattle, stop it, because the more of those drugs you take, even the NSAIDs and paracetamol, then they’re not benign. Basically, if you take lot of those every day you’re messing up your endogenous pain modulation system. You’re not allowing your natural pain modulation system to work properly, so empty the handbags and don’t fill them up again.
00:41:05 Dr Katy Munro
Yeah, we do normally say to people, keep things like that to ten days in a month and that goes for the triptans as well. Because people do generally say, well, what can I take and how can I take it so that in earlier episodes of the podcast we’ve gone into that in a bit more detail. So Tara, were there any other topics that you think we should talk about today? I think we’ve covered a brilliant amount of ground. I’m definitely going to be looking my patients in the mouth a bit more often now.
00:41:30 Prof Tara Renton
Be warned, be warned.
00:41:39 Dr Katy Munro
On video is a little bit tricky to actually examine their mouths, but I’m going to be recommending and adding a question to my list, and have you been to the dentist recently?
00:41:48 Prof Tara Renton
Just simple questions like, does it hurt when you bite anywhere on your mouth, if you bite on something have you got pain, and do you have high level sensitivity to cold or hot? I mean, very simple questions, but obviously in migraine you have that sensitivity, which again it’s where dental pain and migraine are similar, you can get, you know, hypersensitivity outside and inside the mouth with dental pain and you can get that with migraine. So not a great differentiator.
00:42:16 Dr Katy Munro
If you have dental abscesses and things, do you get sensitive to movement or posture?
00:42:23 Prof Tara Renton
No, unless you have an abscess on an upper molar tooth which is close to the sinus and then you get a sinusitis and you get that postural pain then with sinusitis. Yeah, it’s interesting.
00:42:35 Dr Katy Munro
Because I know when people are having migraine headache attacks, they do tend to try and keep very still, keep their head very still, so that may be interesting to explore with patients as well to try and differentiate between the two.
00:42:48 Prof Tara Renton
Yeah, that would be interesting. That’s a good question.
00:42:51 Dr Katy Munro
So your department at King’s, which runs the multidisciplinary team meeting, how do people get to you? Can people get to you or do they have to go to their local dentist or local neurologist, you know, how do they get referred in?
00:43:07 Prof Tara Renton
They can be referred to us by any dentist and any doctor. I run two pro bono websites as I’ve mentioned, so trigeminalnerve.org.uk and orofacialpain.org.uk . So patients and clinicians often e-mail me asking questions. Basically I can just say to them you need a dentist referral and then I can just forward it on to the referral department or you can just refer direct to King’s College Hospital dental orofacial pain unit and we don’t have a great long waiting list now. I’m embarrassed. I’m mainly retired. So the team have been working very hard. So that the referral time is around six weeks, which is phenomenally good for a chronic pain centre.
00:43:49 Dr Katy Munro
Yeah, that’s amazing. Well, that’s wonderful. And again, thank you so much. This has been really interesting. I’m sure it’s going to have a lot of practice-changing points for my clinician colleagues who listen to it as well as patients who can be heading off to their dentist hopefully. All right.
00:44:08 Prof Tara Renton
It’s my absolute pleasure. My one last plug is one of my PhD students and I are working on a web app which will hopefully help patients get an early differential diagnosis of their orofacial pain. So we’re just in trial period now, so it’s a long way off before it’s that tool, but it’s just such a need for this when poor patients have been years and years and multiple consultations which would just be nice for them to get a much earlier diagnosis and hopefully more successful treatment. But thank you for the invitation, Katy. It’s been an absolute pleasure to talk to you.
00:44:40 Dr Katy Munro
Thank you.