Gosh, I feel like it's been so long that I posted about my braces, dental work or surgery. I apologize! I know what it's like to look forward to updates about progress and I've been slacking.
To bring you up to speed, I'm at the last few wire stages with my braces before surgery. I was booked to have my CT scan for surgery at the end of April, but that, too has changed. When my surgeon booked me for the scan, we had thought it would mean (calculating forward 3-4 months from scan date to implant delivery) that put me in August for surgery. But because the hospital only gives him 1 day/month in July and August, and the # of patients ahead of me who already have had their scans done, I'm really looking at the fall to have the surgery. This means that if I have the scans done now, the implants will be ready and sitting waiting for me for a couple of months - months during which nobody can touch me because my bite can't shift one bit before surgery. So the new plan is to get a bit more work done before I schedule the scans in May or June. This should not slow down my surgery timeline, but will allow me 1-2 more months to get some work done before surgery, rather than after.
I have to tell you, when I got the date for the CT scan, I completely lost my mind. Like, LOCO crazy, for real. I had no idea it was going to affect me that way, but this journey has been so incredibly long and hard, that even the thought of another root canal is enough to send me over the edge. I'm not kidding - for someone who truly loves her dentist (and I mean real, deep love - she is one of the best people to come into my life) I get extreme anxiety going to get any work done. So - jaw replacement? I just couldn't even handle the thought. I wanted to jump off a bridge, cancel the surgery, scream out loud...howl at the moon...whatever made the anxiety go away. I'm not sure how I'll cope when the next scan is planned, but hopefully a lot better when I've got some new teeth in my head! (How I'm preparing mentally is the subject for another post.)
The work that is planned to be done is some more teeth straightening (I had another wire change on the top that wasn't supposed to happen) and my teeth are looking even better as time goes on! I can't tell you how great that feels. I also can say that, generally speaking, the wire changes are becoming a little less painful as I get further into treatment. Of course, I'm several weeks out from the last one so it's easy to say that - I do remember there being a lot pain after the last one that really stressed me out because it was in the top front 2 teeth. I'm deathly afraid of (and too close for comfort to) losing these teeth, so any pain there puts me at a constant DEFCON 3 level.
Another thing that my dentist (Dr.T) and orthodontist (Dr.O) came up with is to do the top front 8 crowns before surgery. There are a couple of reasons for this - to get them in before I potentially lose my accident insurance coverage, and to get them done now instead of after surgery when I'll be recovering. They also thought (how incredibly sweet of them) that if I could get these nice, perfectly shaped, white permanent teeth on, I'd feel a lot better about myself psychologically before going into such a hard surgery and recovery. And I have to say that I agree.
So that's the new plan for now! If you have any questions, feel free to ask.
Wednesday, April 6, 2016
Friday, March 18, 2016
Hey there Chronic Pain:
You suck. A lot.
At this point, I feel like that could be my entire post on this subject. But if you know me, you know I can't shut up, so it won't.
So let me just tell you (chronic pain) what else I have to say.
Thank you for being there every minute of every day. If you're one thing, it's dependable. Thanks for being there when I wake up in the morning, and for feeling like a hangover that I didn't earn. On second thought, maybe it was that can of ginger ale I had last night.... or not. Thanks for getting worse when I get tired. Thanks for making me tired. It's really fun to run out of energy at 3pm and have to pretend that you're fine for the rest of the day, because nobody wants to hear about you. And even if they did, I don't like talking about you! You're depressing!
Thanks for getting worse over time and building up a tolerance to pain medications. It's really fun to have to justify to your doctor, your friends, yourSELF why you're asking for a stronger medication. It isn't embarrassing, and it doesn't make me feel like a pill-seeker. Thanks for the mood-swings that one day make me feel like "fuck yeah, it's my pain, I'll take this if I need it! I don't need to feel bad!" and the next day make me feel like "no way, I'm not taking this pill, what if I get addicted?" even though I actually hate all of the side effects of pain medication, EXCEPT for the one that makes my pain go away.
Thanks for making me feel like an old lady. When my friends and coworkers talk about the crazy things they do like go to the gym, run a race, or go out at night, I smile and nod and pretend like I do those things too. Nope, I don't go to bed at the same time as my 4 year old son! My husband thinks it's sexy that I put my jammies on at 8 pm and pass out! What could be more 34-year old like behaviour?? I tried doing some 3 km runs a few days a week, and guess who not so subtly told me that I can't do that??? YOU did! Thanks for the reminder.
Thanks for turning some days at work into complete wastelands of productivity. I really love sitting and staring at a screen, wishing you'd go away so that I could focus. I sit there anyways, so nobody thinks I'm a slacker who goes home sick all the time. Because if there's one thing I've learned is more important than your health, it's what other people think of you.
And finally, thanks for getting a whole lot worse when supplemented by hormones. Because going through uterine surgery and IVF is a whole lot of fun on its own....I need you to be there too.
Come to think of it, it kinda seems like you have a little bit of FOMO. Or you would, if you ever just pissed off for a while.
At this point, I feel like that could be my entire post on this subject. But if you know me, you know I can't shut up, so it won't.
So let me just tell you (chronic pain) what else I have to say.
Thank you for being there every minute of every day. If you're one thing, it's dependable. Thanks for being there when I wake up in the morning, and for feeling like a hangover that I didn't earn. On second thought, maybe it was that can of ginger ale I had last night.... or not. Thanks for getting worse when I get tired. Thanks for making me tired. It's really fun to run out of energy at 3pm and have to pretend that you're fine for the rest of the day, because nobody wants to hear about you. And even if they did, I don't like talking about you! You're depressing!
Thanks for getting worse over time and building up a tolerance to pain medications. It's really fun to have to justify to your doctor, your friends, yourSELF why you're asking for a stronger medication. It isn't embarrassing, and it doesn't make me feel like a pill-seeker. Thanks for the mood-swings that one day make me feel like "fuck yeah, it's my pain, I'll take this if I need it! I don't need to feel bad!" and the next day make me feel like "no way, I'm not taking this pill, what if I get addicted?" even though I actually hate all of the side effects of pain medication, EXCEPT for the one that makes my pain go away.
Thanks for making me feel like an old lady. When my friends and coworkers talk about the crazy things they do like go to the gym, run a race, or go out at night, I smile and nod and pretend like I do those things too. Nope, I don't go to bed at the same time as my 4 year old son! My husband thinks it's sexy that I put my jammies on at 8 pm and pass out! What could be more 34-year old like behaviour?? I tried doing some 3 km runs a few days a week, and guess who not so subtly told me that I can't do that??? YOU did! Thanks for the reminder.
Thanks for turning some days at work into complete wastelands of productivity. I really love sitting and staring at a screen, wishing you'd go away so that I could focus. I sit there anyways, so nobody thinks I'm a slacker who goes home sick all the time. Because if there's one thing I've learned is more important than your health, it's what other people think of you.
And finally, thanks for getting a whole lot worse when supplemented by hormones. Because going through uterine surgery and IVF is a whole lot of fun on its own....I need you to be there too.
Come to think of it, it kinda seems like you have a little bit of FOMO. Or you would, if you ever just pissed off for a while.
Monday, February 22, 2016
Hello 2016!!
Hello everyone!
I'm back! I'm here! Did you miss me?
Sorry for the hiatus, or maybe you're welcome for the break :) It's been a really busy few months for me, particularly with work as I transitioned to a new location of our company (new building, new environment, team, boss, etc) and it has been busy. So good, but busy. I have been so exhausted at night that I just haven't felt like writing. If I'm honest, it has been kinda tough for me personally to cope with the lack of energy. Great at work, but really tiring.
Where am I with my jaw and teeth? I am scheduled to have my next, and final, wire change on my lower braces only on March 7!! I am so excited!! No more wire changes. It hardly seems real. My teeth are pretty straight now, but the bottom ones have only just started to look that way, so it does seem surreal. Since I had a lower canine removed, my front middle lower teeth are all shifted, and they don't really line up properly with the top ones, but it is something I'll just have to get used to.
That means I'm one (big!) step closer to my Jaw Replacement Surgery. Once this wire change is done, and the teeth settle in about 6 weeks, I can have the big scan done. This scan is crucial - it will be sent to the implant manufacturer and it's what they will use (along with some impressions and a lot of my surgeon's input) to design and build my custom joint implants. Once they receive the scan there's lots of work to be done, consulting with my surgeon and getting these babies just right. It will take about 3 months to make them, and only when they are about 1 month out from completion will the implant company give my doctor the ok to schedule the surgery. So if you add up all that time, I'm looking at roughly August for the whole big deal. Implants. In my face.
So it's basically starting to feel super real to me now. I'm thinking about when I should let my work know, how long I think I might be off for, what I'll need for surgery, how to prepare, all that stuff. Should I take a vacation before I go off? (I'm thinking yes). What will I need to buy? How am I going to feel?
Of course, there's a massively terrifying part of this too. What is the pain going to be like? How long will it take me to feel relatively normal again? I remember how long and how hard healing was when I just broke my face..this has to be just as hard. Most certainly, my face is going to change after this. What is it going to look like? Will I be ok with it? How will my massive scars heal? Will my son be afraid of me? Will I have facial paralysis? Will I be able close my eyes?
On the plus side, I get to get a rad new hairdo for it all. They're going to shave my hair above my ears, and I'm not just going to let the nurses do it. I'm planning to prep...embrace my inner rocker chick...let my freak flag fly! What do you think of this look??
I'm back! I'm here! Did you miss me?
Sorry for the hiatus, or maybe you're welcome for the break :) It's been a really busy few months for me, particularly with work as I transitioned to a new location of our company (new building, new environment, team, boss, etc) and it has been busy. So good, but busy. I have been so exhausted at night that I just haven't felt like writing. If I'm honest, it has been kinda tough for me personally to cope with the lack of energy. Great at work, but really tiring.
Where am I with my jaw and teeth? I am scheduled to have my next, and final, wire change on my lower braces only on March 7!! I am so excited!! No more wire changes. It hardly seems real. My teeth are pretty straight now, but the bottom ones have only just started to look that way, so it does seem surreal. Since I had a lower canine removed, my front middle lower teeth are all shifted, and they don't really line up properly with the top ones, but it is something I'll just have to get used to.
That means I'm one (big!) step closer to my Jaw Replacement Surgery. Once this wire change is done, and the teeth settle in about 6 weeks, I can have the big scan done. This scan is crucial - it will be sent to the implant manufacturer and it's what they will use (along with some impressions and a lot of my surgeon's input) to design and build my custom joint implants. Once they receive the scan there's lots of work to be done, consulting with my surgeon and getting these babies just right. It will take about 3 months to make them, and only when they are about 1 month out from completion will the implant company give my doctor the ok to schedule the surgery. So if you add up all that time, I'm looking at roughly August for the whole big deal. Implants. In my face.
So it's basically starting to feel super real to me now. I'm thinking about when I should let my work know, how long I think I might be off for, what I'll need for surgery, how to prepare, all that stuff. Should I take a vacation before I go off? (I'm thinking yes). What will I need to buy? How am I going to feel?
Of course, there's a massively terrifying part of this too. What is the pain going to be like? How long will it take me to feel relatively normal again? I remember how long and how hard healing was when I just broke my face..this has to be just as hard. Most certainly, my face is going to change after this. What is it going to look like? Will I be ok with it? How will my massive scars heal? Will my son be afraid of me? Will I have facial paralysis? Will I be able close my eyes?
On the plus side, I get to get a rad new hairdo for it all. They're going to shave my hair above my ears, and I'm not just going to let the nurses do it. I'm planning to prep...embrace my inner rocker chick...let my freak flag fly! What do you think of this look??
Monday, November 2, 2015
Pain Science on Bruxism, Jaw Clenching amd TMJS
I know that I have talked before about how I get my head massaged (and shrunk, but that's a different topic) every week or two on the reg, but I have yet to post any of the science behind it. My chiropractor focuses on my temporalis, masseter and suboccipitals during treatment. Speak English Tiffany! What do those sciency words mean?? Why do you give your chiropractor so much money to massage them?
Ah. Relax my friends. I don't have to explain all of this, because blogger Paul Ingraham (a self-described over-qualified massage therapist) at PainScience.com has published the most helpful article on Massage Therapy for Bruxism, Jaw Clenching and TMJ Syndrome. In this article, he describes the Trigger Points, or muscle knots, that can be self-massaged for TMJ pain relief. Am I just wasting my money? (Just kidding...I couldn't do all that Dr. Nino does for me).
Not only does he talk about where to push, but the article describes, in easy to read style, your masseter muscle anatomy, physiology, the areas that it can affect, symptoms and tips to help you relax your jaw muscles and how to care for them by lifestyle adjustments. In fact, there are so many links in there that are incredibly useful and relevant, I can't even describe them all.
Anyways, if you are still reading here, stop. Go to the article. It's long, but it's so incredibly useful and educating. And if you are reading this blog in support of me, but not because you're dealing with TMJ pain...check out the Pain Science blog. He has tips for all kinds of aches, pains and injuries. I highly recommend checking it out, even just to better understand what's going on inside all of us.
P.S. There's also an article linked in there called Pain Changes How Pain Works. It's a discussion about how pain itself results in more pain with less provocation, and he describes it as "Owner's Manual Stuff".
Ah. Relax my friends. I don't have to explain all of this, because blogger Paul Ingraham (a self-described over-qualified massage therapist) at PainScience.com has published the most helpful article on Massage Therapy for Bruxism, Jaw Clenching and TMJ Syndrome. In this article, he describes the Trigger Points, or muscle knots, that can be self-massaged for TMJ pain relief. Am I just wasting my money? (Just kidding...I couldn't do all that Dr. Nino does for me).
Not only does he talk about where to push, but the article describes, in easy to read style, your masseter muscle anatomy, physiology, the areas that it can affect, symptoms and tips to help you relax your jaw muscles and how to care for them by lifestyle adjustments. In fact, there are so many links in there that are incredibly useful and relevant, I can't even describe them all.
Anyways, if you are still reading here, stop. Go to the article. It's long, but it's so incredibly useful and educating. And if you are reading this blog in support of me, but not because you're dealing with TMJ pain...check out the Pain Science blog. He has tips for all kinds of aches, pains and injuries. I highly recommend checking it out, even just to better understand what's going on inside all of us.
P.S. There's also an article linked in there called Pain Changes How Pain Works. It's a discussion about how pain itself results in more pain with less provocation, and he describes it as "Owner's Manual Stuff".
Tuesday, October 20, 2015
Are your limitations really limiting you?
One thing I certainly didn't expect from this injury is the limitations that have been placed on me physically. It makes me uncomfortable to say it, but I don't feel like I'm one to accept limitations without pushing them a little bit first. I wouldn't say that I'm someone who pushes through anything super human to achieve a goal, but I'm not one to say "I can't do that" without trying it first. Maybe I'll try it secretly...without announcing the results...but I'll give it a go.
This injury has been a source of almost constant discomfort. I say almost because there are good drugs and bottles of wine (not to be combined!) that can take it away but neither of these are perfect. Hangovers and side effects need to be managed! Whether it's neck, shoulder, head, jaw or tooth pain, it always seems to be something. I find that often times I'm taken aback by how unrelenting it is, and how places that I thought could never hurt, do. Like your head muscles. How many of you have asked to have your head muscles massaged? Did you even know you HAD head muscles? The ones that cover your skull and barely move? I get them massaged every other week....and it never makes the pain go away completely. (Actually, if you're reading this you probably have TMJ and totally get it. Sorry.)
Anyways, I'm not writing this to whine about my aches (ok, maybe a little bit), but to talk about accepting, and sometimes pushing, your limitations.
There are a lot of things that I want to be able to do without ending up in a pain crisis, or fully exhausted for a week, or without crying because I've over done it. Like go out for a night on the town. Or train for a competition. Or stay up past 10 pm on a weeknight. Or deal with a cold. Or go out in the cold for a day. Or make multiple plans on a weekend (with associated eating/drinking) and function like normal the following week.
You get it.
I'm whiny.
But really, all of these things end up sort of crushing me at some point. And I don't mean like "oh boy, I'm extra tired on Monday." This past weekend I went out to a late dinner Friday night, cleaned my house on Saturday, went to a friends house in the afternoon and then walked around Toronto watching my sister run a marathon on Sunday. By Monday I was exhausted, had a splitting headache and a nasty sore throat, which I really felt was set off by my lack of energy and ability to bounce back after some busy times. My jaw muscles were aching and I felt the vice-like grip around my temples that comes after a lot of talking, eating socially and maneuvering my jaw around trying to make my braces presentable after just taking a bite. Maybe it's just cold/flu season, but I'm really tired of this!
I used to just push through busy things, over-schedule myself and rebound alright....now I'm like a ticking time bomb. I have another late night, busy weekend coming up and I'm already dreading the "recovery time" from that. My sister went to work the day after the marathon, damn it!! Why can't I??
If this whole situation has taught me anything, it's got to be patience. The funny thing is, there's patience with life and then patience with yourself. Having patience with yourself (and self-care) is the hardest thing to practice. I would rather just push through my plans and obligations and deal with the tiredness later. It's just that now, it's not just being tired. It's pain, it's exhaustion, and it's the "me" that I put forth and give to my family that I have to be concerned with. Sigh.
Or here is this question to ponder....
How bad is this situation? You know when you hear about people doing incredible things, like, oh...say EVERY paralympian, EVER? Who am I to whine?
Time to feed that courage wolf...
This injury has been a source of almost constant discomfort. I say almost because there are good drugs and bottles of wine (not to be combined!) that can take it away but neither of these are perfect. Hangovers and side effects need to be managed! Whether it's neck, shoulder, head, jaw or tooth pain, it always seems to be something. I find that often times I'm taken aback by how unrelenting it is, and how places that I thought could never hurt, do. Like your head muscles. How many of you have asked to have your head muscles massaged? Did you even know you HAD head muscles? The ones that cover your skull and barely move? I get them massaged every other week....and it never makes the pain go away completely. (Actually, if you're reading this you probably have TMJ and totally get it. Sorry.)
Anyways, I'm not writing this to whine about my aches (ok, maybe a little bit), but to talk about accepting, and sometimes pushing, your limitations.
There are a lot of things that I want to be able to do without ending up in a pain crisis, or fully exhausted for a week, or without crying because I've over done it. Like go out for a night on the town. Or train for a competition. Or stay up past 10 pm on a weeknight. Or deal with a cold. Or go out in the cold for a day. Or make multiple plans on a weekend (with associated eating/drinking) and function like normal the following week.
You get it.
I'm whiny.
But really, all of these things end up sort of crushing me at some point. And I don't mean like "oh boy, I'm extra tired on Monday." This past weekend I went out to a late dinner Friday night, cleaned my house on Saturday, went to a friends house in the afternoon and then walked around Toronto watching my sister run a marathon on Sunday. By Monday I was exhausted, had a splitting headache and a nasty sore throat, which I really felt was set off by my lack of energy and ability to bounce back after some busy times. My jaw muscles were aching and I felt the vice-like grip around my temples that comes after a lot of talking, eating socially and maneuvering my jaw around trying to make my braces presentable after just taking a bite. Maybe it's just cold/flu season, but I'm really tired of this!
I used to just push through busy things, over-schedule myself and rebound alright....now I'm like a ticking time bomb. I have another late night, busy weekend coming up and I'm already dreading the "recovery time" from that. My sister went to work the day after the marathon, damn it!! Why can't I??
If this whole situation has taught me anything, it's got to be patience. The funny thing is, there's patience with life and then patience with yourself. Having patience with yourself (and self-care) is the hardest thing to practice. I would rather just push through my plans and obligations and deal with the tiredness later. It's just that now, it's not just being tired. It's pain, it's exhaustion, and it's the "me" that I put forth and give to my family that I have to be concerned with. Sigh.
Or here is this question to ponder....
How bad is this situation? You know when you hear about people doing incredible things, like, oh...say EVERY paralympian, EVER? Who am I to whine?
Time to feed that courage wolf...
Current TMJ Implant Options
The world of alloplastic implant options is small you might say. There are three options on the market for your surgeon to choose from:
1. TMJ Implants
2. TMJ Concepts
3. Biomet/Lorenz
To start, there are several criteria that are considered when designing an implant for use in the TMJ. This is done to ensure that a situation like the Vitek implant disaster does not happen again, and takes into account what was learned with that experience, as well as what can be applied from hip and knee replacement implants that have been around for decades. I found an excellent review article in the McGill Journal of Medicine that explains implant design in detail.
(Sinno H, Youssef T, Giladino M, Bobyn D. Engineering Alloplastic Temporomandibular Joint Replacements. MJM 2010 13(1): 63-72.
The following is a summary of the key factors in implant design.
1. Biocompatibility.
The implant has to affix well to the bone to which it is attached, while causing the least amount of damage to the surrounding tissues as possible.
2. Modulus, or stiffness of the material.
The more flexible the implant material, the more it can share the load with the bone it is affixed to. When bone is stressed with a load, the more bone density and strength are preserved in the long run.
3. Stiffness.
This depends on both the flexibility of the material and the shape and thickness of the implant. The thicker the implant, even if it is made of a flexible material, the stiffer it will be. This is the reason why, when you look at pictures of the implants, they show little notches in the metal parts. Putting these notches in, or making it hollow, or very porous, helps to reduce the stiffness of the implant.
4. Stress Shielding.
Similar to, and perhaps a summary of modulus and stiffness, when 2 materials have a uniform load applied to both, the stiffer material will absorb most of that load. So when an implant is attached to bone, it will absorb the loading and shield bone from the stress. As mentioned above, this will cause the bone to lose density and strength in the long term.
5. Notch Sensitivity.
This was the hardest for to me to understand, but when an implant is made with notches in it to reduce it's stiffness, or perhaps to encourage the bone to grow into the notches and rigidly fix the implant, those notches are a point of weakness. So notch sensitivity is is how sensitive the material is to fracture due to the presence of the notches.
6. Modularity.
This enables the use of different materials for different parts of the implant. Materials that are best for wear resistance can be used for bearing components. Materials that are less stiff can be used for load carrying and fixation to reduce the stress shielding and bone resorption that results.
7. Materials.
The same materials that are used in hip/knee replacements are what are used in TMJ implants. Cobalt-Chromium (Co-Cr) and titanium alloys are useful in the stems and bodies of the implants. There are also a variety of options for porous fixation surfaces. A new development is the use of highly cross-linked polyethylene, which is a very wear resistant plastic - ultra high molecular weight polyethylene (UHMWPE) that is also being used widely in hip and knee replacements.
Stainless steel is not used, because it can corrode - so it's not biocompatible for the TMJ.
A few notes on Co-Cr, titanium alloys and UHMWPE:
Co-Cr is very hard and abrasion resistant, but can cause significant stress sheilding.
Titanium alloys are more flexible than Co-Cr, but does not have good wear properties. It is also notch sensitive, so it can't be impregnated with beads or wire to promote bony ingrowth. It can, however, be roughened at the surface, or coated.
UHMWPE has had long term success in orthopaedic surgery, but is subject to wear after repeated loading.
Comparison of current implants:
The condylar portion of all implants is made with Co-Cr alloy. The Biomet/Lorenz implants have a plasma spray titanium coating on the bone-contacting surface to help bone fixation. The Co-Cr bearing has high hardness and strength.
Attached to the condyle is the ramus (below the condyle on the jaw). In TMJ Implant and Biomet, the ramus is made of Co-Cr alloy. TMJ concepts uses titanium alloy. The authors of the study thought that since the ramus is a thinner bone, using a titanium alloy would distribute the load better, and reduce stress sheilding.
The ball and socket portion of the implant is the fossa. The TMJ implants uses metal-on-metal bearings made of Co-Cr. Both TMJ Concepts and Biomet use UHMWPE.
Overall, the study suggests that Alloplastic TMJ reconstruction devices have shown a lot of predictability and reliability. Choosing Alloplastic over Autogenous reconstruction provides a few benefits, including custom made implants that allow for immediate jaw function (in most cases, no wiring shut) after surgery.
Of course, everyone in this "business" knows that these implants are not meant to last forever, and will need replacement at some point in time. The current suggestion is about 20 years of life, since they are relatively new and every year that goes by, another one lasts another year longer.
It's sure no picnic to sift through all of this information...so I hope it's somewhat helpful in learning more about TMJ implants!
1. TMJ Implants
2. TMJ Concepts
3. Biomet/Lorenz
To start, there are several criteria that are considered when designing an implant for use in the TMJ. This is done to ensure that a situation like the Vitek implant disaster does not happen again, and takes into account what was learned with that experience, as well as what can be applied from hip and knee replacement implants that have been around for decades. I found an excellent review article in the McGill Journal of Medicine that explains implant design in detail.
(Sinno H, Youssef T, Giladino M, Bobyn D. Engineering Alloplastic Temporomandibular Joint Replacements. MJM 2010 13(1): 63-72.
The following is a summary of the key factors in implant design.
1. Biocompatibility.
The implant has to affix well to the bone to which it is attached, while causing the least amount of damage to the surrounding tissues as possible.
2. Modulus, or stiffness of the material.
The more flexible the implant material, the more it can share the load with the bone it is affixed to. When bone is stressed with a load, the more bone density and strength are preserved in the long run.
3. Stiffness.
This depends on both the flexibility of the material and the shape and thickness of the implant. The thicker the implant, even if it is made of a flexible material, the stiffer it will be. This is the reason why, when you look at pictures of the implants, they show little notches in the metal parts. Putting these notches in, or making it hollow, or very porous, helps to reduce the stiffness of the implant.
4. Stress Shielding.
Similar to, and perhaps a summary of modulus and stiffness, when 2 materials have a uniform load applied to both, the stiffer material will absorb most of that load. So when an implant is attached to bone, it will absorb the loading and shield bone from the stress. As mentioned above, this will cause the bone to lose density and strength in the long term.
5. Notch Sensitivity.
This was the hardest for to me to understand, but when an implant is made with notches in it to reduce it's stiffness, or perhaps to encourage the bone to grow into the notches and rigidly fix the implant, those notches are a point of weakness. So notch sensitivity is is how sensitive the material is to fracture due to the presence of the notches.
6. Modularity.
This enables the use of different materials for different parts of the implant. Materials that are best for wear resistance can be used for bearing components. Materials that are less stiff can be used for load carrying and fixation to reduce the stress shielding and bone resorption that results.
7. Materials.
The same materials that are used in hip/knee replacements are what are used in TMJ implants. Cobalt-Chromium (Co-Cr) and titanium alloys are useful in the stems and bodies of the implants. There are also a variety of options for porous fixation surfaces. A new development is the use of highly cross-linked polyethylene, which is a very wear resistant plastic - ultra high molecular weight polyethylene (UHMWPE) that is also being used widely in hip and knee replacements.
Stainless steel is not used, because it can corrode - so it's not biocompatible for the TMJ.
A few notes on Co-Cr, titanium alloys and UHMWPE:
Co-Cr is very hard and abrasion resistant, but can cause significant stress sheilding.
Titanium alloys are more flexible than Co-Cr, but does not have good wear properties. It is also notch sensitive, so it can't be impregnated with beads or wire to promote bony ingrowth. It can, however, be roughened at the surface, or coated.
UHMWPE has had long term success in orthopaedic surgery, but is subject to wear after repeated loading.
Comparison of current implants:
The condylar portion of all implants is made with Co-Cr alloy. The Biomet/Lorenz implants have a plasma spray titanium coating on the bone-contacting surface to help bone fixation. The Co-Cr bearing has high hardness and strength.
Attached to the condyle is the ramus (below the condyle on the jaw). In TMJ Implant and Biomet, the ramus is made of Co-Cr alloy. TMJ concepts uses titanium alloy. The authors of the study thought that since the ramus is a thinner bone, using a titanium alloy would distribute the load better, and reduce stress sheilding.
The ball and socket portion of the implant is the fossa. The TMJ implants uses metal-on-metal bearings made of Co-Cr. Both TMJ Concepts and Biomet use UHMWPE.
Overall, the study suggests that Alloplastic TMJ reconstruction devices have shown a lot of predictability and reliability. Choosing Alloplastic over Autogenous reconstruction provides a few benefits, including custom made implants that allow for immediate jaw function (in most cases, no wiring shut) after surgery.
Of course, everyone in this "business" knows that these implants are not meant to last forever, and will need replacement at some point in time. The current suggestion is about 20 years of life, since they are relatively new and every year that goes by, another one lasts another year longer.
It's sure no picnic to sift through all of this information...so I hope it's somewhat helpful in learning more about TMJ implants!
Saturday, October 10, 2015
TMJ Replacement Options
I was recently asked the question: are you getting TMJ Concepts custom made implant or Biomet custom implant? Do you know by any chance what is the difference and which one may be a better one?
This is a question that I've thought a lot about myself, but just sort of trusted my surgeon to recommend what's best. And I still feel that way - whatever he is most comfortable "installing" in my face has got to give the best outcome. Some might feel differently, but allow me to explain myself. This is a very uncommon and relatively new surgery. There are fewer surgeons who actually perform the TMJ replacements, so they are on the leading edge of what is being developed and seeing the results of themselves with their patients. However, having a solid Biology background (as in, an undergrad degree), I am keenly interested in the implants that I'm getting and why.
Without disrespecting anyone who has dealt with this longer than I have, and certainly that's almost anyone who is facing this as a result of a systemic issue rather than a recent trauma (like me), I'm writing this from the perspective that your surgeon has recommended a TJR (total jaw replacement) and a certain type of implant and you're wondering why they might be recommending that type and the history behind it. In my particular case, I know that this is my only option going forward - foregoing TJR of any type is not an option. I know that there are some folks out there who believe surgery should be avoided at all costs, and certainly there are cases where this should not be jumped into. However, I've done enough research and know my own situation well enough to know that this is something that I need and there is no other option.
That being said, here are the options for complete TMJ reconstruction surgery:
Pros:
Alloplastic Replacement is the replacement of the whole joint (fossa/"socket", condyle/"ball" and ramus - what you think of as the jaw bone) with a manufactured joint. These implants can be conceptualized as the same as a hip or a knee replacement implant.
The reasons you might get an alloplastic implant are:
Some of the benefits of alloplastic joints over autogenous grafting are:
This is a question that I've thought a lot about myself, but just sort of trusted my surgeon to recommend what's best. And I still feel that way - whatever he is most comfortable "installing" in my face has got to give the best outcome. Some might feel differently, but allow me to explain myself. This is a very uncommon and relatively new surgery. There are fewer surgeons who actually perform the TMJ replacements, so they are on the leading edge of what is being developed and seeing the results of themselves with their patients. However, having a solid Biology background (as in, an undergrad degree), I am keenly interested in the implants that I'm getting and why.
Without disrespecting anyone who has dealt with this longer than I have, and certainly that's almost anyone who is facing this as a result of a systemic issue rather than a recent trauma (like me), I'm writing this from the perspective that your surgeon has recommended a TJR (total jaw replacement) and a certain type of implant and you're wondering why they might be recommending that type and the history behind it. In my particular case, I know that this is my only option going forward - foregoing TJR of any type is not an option. I know that there are some folks out there who believe surgery should be avoided at all costs, and certainly there are cases where this should not be jumped into. However, I've done enough research and know my own situation well enough to know that this is something that I need and there is no other option.
That being said, here are the options for complete TMJ reconstruction surgery:
- Autogenous Replacement (rib graft most often)
- Alloplastic Replacement (manufactured implant)
- TMJ Implant
- TMJ Concepts
- Biomet/Lorenz
Pros:
- Cost - since no manufactured parts are required, the cost is lower for this surgery. However, since there is another surgical site and associated pain, the hospital stay is longer, and the recovery may be longer. This may offset the cost savings to the patient.
- Growth potential - in children, this is the only option for reconstruction, since they will continue growing and a manufactured implant will not.
- Recovery time is long
- Only reconstructs the "ball" and not the "socket" part of the joint
- Often requires re-operation, which may ultimately include a manufactured implant
Alloplastic Replacement is the replacement of the whole joint (fossa/"socket", condyle/"ball" and ramus - what you think of as the jaw bone) with a manufactured joint. These implants can be conceptualized as the same as a hip or a knee replacement implant.
The reasons you might get an alloplastic implant are:
- Ankylosis of the TMJ with severe anatomic abnormalities
- Failure of autogenous grafts
- Failure of Proplast-Teflon or Vitek-Kent or partial joint implants
- Severe inflammatory joint disease resulting in joint mutilation and functional disability
Some of the benefits of alloplastic joints over autogenous grafting are:
- Immediate jaw function, allowing for physiotherapy to begin on Day 1 of recovery
- No need for a secondary donor site (rib sectioning, etc)
- Custom implant availability
Surgeons seem to see that immediate movement of the joints contributes to a much shorter healing time, and better outcomes. Of course, one of the deciding factors in the relative success of the surgery is dependant on how many prior surgeries a patient has had. The more surgeries, the lesser the degree of success.
I hope that this helps to understand the differences between grafting-type TMJ reconstruction and manufactured implants. In my next post, I will share what I've learned are the subtle differences between TMJ Concepts and Biomet/Lorenz manufactured implants.
Keep feeding the courage wolf!!
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