Let’s have a look at the Carriere Motion III appliance!
In previous posts, we have looked at the Carriere II appliance. You may remember that we concluded that this appliance was just another method of applying Class II forces.
There is also a Carriere Motion III appliance! This recently published paper looked at the effects of this form of treatment. Luis Carriere highlighted the article in social media posts and felt that it was “excellent”. So I thought that I should have a good look at it.
A team from Michigan did the study. The Angle Orthodontist published the paper.
McNamara J et al. Angle Orthodontist, Vol 91, No 2, 2021 DOI: 10.2319/073120-669.1
As you know, I do not usually review retrospective studies unless they are controversial, or I feel that they provide us with helpful information, albeit with a high risk of bias. This paper ticked both of these boxes.
What did they ask?
They did this study to ask the following question:
“What are the treatment effects of the Carriere Motion III appliance on relatively non growing Class III patients”?
What did they do?
They did a retrospective study of patients who had Carrier Motion III treatment as part of a comprehensive course of orthodontic treatment.
The records were selected from patients who had an initial phase of treatment with the Carriere Motion III appliance, followed by fixed appliances.
They got the records from two sources. The first was Luis Carriere’s clinic in Barcelona, and the second was McNamara Orthodontics in Michigan. The records had to include lateral cephalograms taken at the start of treatment after removing the CM3 and after fixed appliances. If the patient did not have these three serial views, they excluded them from the study.
They used the CVM technique to check that the participants had stopped growing.
Their final sample of patients included 35 from Luis Carriere and 14 from the McNamara clinic. They then excluded 11 of the patients for having incomplete records or not satisfying other criteria. This meant that they rejected 25% of the original sample.
They did not use a matched control, but they compared the treated group with the records of 125 untreated Class II subjects.
They then looked closely at 11 skeletal and seven angular measurements from the cephs, using many univariate tests across the groups and stages of treatment.
What did they find?
Most of the data that they presented were concerned with the cephalometric analysis.
- The mean age of the CM3 patients was 18.6 years (SD=6.7). The duration of the CM3 treatment was 6.3 (SD=4.3) months.
- The overall treatment time was 19.2 (SD=6.5) months.
- When they compared the CM3 sample and the Class I untreated groups, there were many differences.
The cephalometric analysis showed:
- There was minimal skeletal change.
- The upper incisors and molars moved forwards by almost 2mm.
- In the lower arch, the lower incisors moved anteriorly by 0.5 mm during phase 1 and a further 1.9mm in phase II. Similarly, the molars moved forwards by 1.8mm, but there was a rebound during phase II, resulting in a total distal movement of 1.4mm.
Their overall conclusions were;
“The Carriere Motion III appliance is an effective and efficient adjunct to fixed appliances. Most of the treatment effects were dento-alveolar. No noteworthy skeletal changes can be anticipated with the CM3 appliance”.
What did I think?
A highly respected team of investigators did this study. They used their “tried and trusted” retrospective methods and have published many papers of this type. When we look at this method, we have to consider a high risk of selection bias. Importantly, other research methods have now superseded it—for example, the prospective cohort or RCT. As a result, I did not agree with Dr Carriere’s opinion that it was excellent. However, this is the only research that we have on this appliance.
Unfortunately, this study suffered from several issues.
- Firstly, there was marked selection bias, with the authors excluding 25% of the initial patient records. Importantly, we do not know the direction of the bias. We simply need better research.
- It was also not clear why they compared the patients with a historical record of Class I subjects. This step did not add to the paper.
- The primary outcome measures were cephalometric values that they analysed with multiple simple statistical tests. This analysis increases the risk of false positives. I also felt that many of the effect sizes were not clinically significant.
I was concerned that they did not declare the apparent conflict of interest of Luis Carriere. He is a major KOL for Henry Schein Orthodontics, and the appliance has his name on it! Notably, he selected most of the patients from his clinic. Again, I will emphasise nothing wrong with a conflict as long as it is declared. I am surprised that the Journal did not include the conflict.
Final thoughts
Finally, I am left with the feeling that the effects were similar to Class III elastics. This brings us to the suggestion that the Carriere Motion III is similar to the Carriere II. At present, we have to wonder if this is just a fancy and expensive way of applying intermaxillary elastics? Perhaps, someone will do a much-needed study comparing elastics with the Carriere appliances? Or do we just believe in the publicity?
Emeritus Professor of Orthodontics, University of Manchester, UK.
I ALSO FEEL THAT THERE IS A FINANCIAL INTEREST
Why do editors slavishly accept articles like this? That is the real scandal.
As a person that deeply respects your thinking process and your contributions to the art and science of orthodontics, I would ask you to enlarge upon your brief comments. Thank you, Ron Jawor
Hi, doctor Kevin O’Brien! I am from Brazil. Thank you for sharing all the researches with us. I like to read what you conclude about many important treatments, but I think it would be better if we could read the comments from the doctors who are reading as well. It would be valuable for enriching our experience in your blog. Please think about it!
Thanks for the comment. I publish comments that I receive. Or do you mean comments from the authors about the papers?
As Ron Roth used to say, “With a lot of people, every time the latest circus comes to town, and they get a whiff of the elephant shit, they’re off and running.”
Dear Kevin,
Thank you for your constant scientific spirit and honesty as well for your tedious research and analytic work.
I had a few words myself with Luis Carriere on his Cl2 miraculous appliance that he heavily advertised on Linkedin . It is our mission as trained orthodontist to moderate this ravaging marketing boasted by reknown colleagues because acceptation by numerous not so trained Orthodontists finally equal to acceptation of a new standard , to a truth which is not a scientific one. And as I told Luis Carriere you cannot repaint the ceiling holding yourself to the brush.
Take this for what it is worth. I occasionally use Carriere for class II and III correction. I only band the opposite arch of the appliance and work up to a 17×25 rectangular wire for anchorage. (not a fan of essex retainer for anchorage) I talk with the patient and parent and say you are absolutely wasting time and money if you do not wear your elastic 24/7 take them out to eat. I seem to get much better compliance with elastics this way.
Unfortunately the team from Michigan keeps repeating a research methodology which is out of date and significantly flawed with selection bias and missing data…. and yet most or all of these papers still seem to get published? I have to wonder about the review process as personally I would have rejected this paper for these and other reasons – it does not help us clinically and just muddies the waters. The applaince is just another option as are Class III elastics, but from a cost/benefit analysis, I know which of these two options I would choose.
Unfortunately the University of Michigan keeps promoting to its students a debunked research methodology. Students that are primed to believe all sorts of specious conclusions.
Disclaimer, I am NOT a KOL for Henry Schein!!!! I know, hard to believe I would like an appliance that I have no financial interest in. It defies the Snake Oil Salesmen that myself and all other KOL’s are. I’ve never even met Dr. Carriere.
I have never been able to treat Class 3 cases as successfully as I have been able to prior to this appliance. The way it ‘anchors’ the lower buccal segment in one piece, allowing a rigid distal pull without the normal sliding mechanics of Class 3 elastics on a wire and brackets just works better. Believe me, I would rather not spend that extra money for the appliance (and especially one I receive no KOL Bribery Money from being the slimy KOL we all know I am), but it just flat out works better.
And when it comes to correcting Class 3’s (or Class 2’s with his other appliance) while using Clear Aligners, there is just no better method. Clear aligners and elastics just don’t work nearly as well, and incorporating these appliances allows us to offer a treatment modality for adults (and even teenagers) that can be completely successful in a non discreet, esthetic method. Most patients in todays world do not want braces. If us orthodontists do not find a better way to provide treatment to these patients, they will find it at their general dentists, or even worse, from direct to consumer companies.
It’s so funny how the academic world clammers for all these ‘non biased’ prospective, double blind studies and such other nonsense. These are nearly impossible to do in orthodontics with appliances that have to be checked by the doctor. Everyone in academics always asks for studies to be done on appliances, on techniques, etc. And then when they are done, they say that are invalid.
Academic World, get off your lazy kiesters and do your own studies or quit crying and complaining about the work all of us wet finger clinicians do everyday successfully for our patients. But of course, the only reason we treat our patients is to make ourselves rich, right?
Dr. Carriere’s appliances work. Are they they the end all, be all in the world of orthodontics and the most innovative product of all time? Of course not, but by golly, they work. That is absolutely all I care about. End of story. Dr. O’Brien, have you ever even placed one of these appliances in the mouth? Any of you other critics in this thread every even tried one of these? Probably not. Same old same old.