The most meaningful things in orthodontics I am aware of

I have recently returned from Italy where I have been taking a course in orthodontic mechanics specific to treating adult patients. It was held in the city of La Spezia by a famous Italian orthodontist, Giovanni Biondi, who, among many other titles, is a secretary general of the Italian Association of Specialists in Orthodontics and an ambassador of Italy in the American Association of Orthodontists. I have learnt several useful tips and tricks and am sure this will help me a great deal since during this year I am experiencing a surge in the number of adult patients.

I also had a chance to visit Florence where I clearly have been through a condition called Stendhal syndrome. Our host in the city was an Italian psychoanalyst and a specialist in Carl Jung. The apartment was packed with books and journals on the subject. Most of them were in Italian, so I did not have a chance to expand my knowledge in psychoanalysis. However, even my superficial acquittance with Jung and perhaps the atmosphere of this beautiful psychoanalytic studio turned apartment made me come back home in a “Jungian” mood. It is known that the pivotal topic of the Swiss psychoanalyst was the quest for meaning in a life of an individual. So, for this blog post I decided to dig for the most meaningful things in orthodontics I am aware of. Surprisingly, it was an easy task…

Moses Beholds All the Work, 1966 by Marc Chagall, a world-famous Russian-French artist

I can’t stop feeling that the most eloquent form for wrapping up all the common orthodontic sense was found long ago by Charles Tweed. For this blog post I decided to look at his classic “Ten Commandments” from the modern-day perspective of evidence-based care and to find out if these are still the most powerful concepts of our specialty?

Ten Orthodontic Commandments

1. Thou shalt not expand.

In other words, we have to keep initial arch form to avoid relapse. This is as true today as it was decades ago. Every now and then we see some orthodontists advocating for expansion, but there is still nothing in the literature to support such claims. Looking closely, all the pro-expansionists have conflicts of interests. I even wonder if they do provide expansion on a regular basis themselves or just use it as a marketing tool to attract patients and excited freshly graduated orthodontists. Once you violate this commandment, you’ll lose all your excitement.

2. Honor the patient and strive for perfection and pleasing profile.

Profile is still the cornerstone of orthodontic treatment. Lay people believe we are about straight teeth. We know that faces go first. We have to consider this during the stage of treatment planning.

3. Remember that the master has said that the lower incisors must be 90 degrees to the mandibular plane, or 65 degrees to the Frankfort horizontal. Do not deviate.

IMPA = 90. FMIA = 65.

I wonder, if we have studies to prove evidentially that 90 degrees IMPA results in greater stability? I am not aware of such. However, my subjective experience suggests that everything more than 95 relapses very easily.

4. Do not hesitate to extract premolars. Only in this way can you achieve the objectives requires by our master.

Now I have to notice that I am strictly against the cult of personality, whether in orthodontics or anywhere else. I agree with everything apart from “our master”. Premolars extraction is a useful procedure that according to the literature doesn’t harm anyone.

5. Band as many teeth as possible; to do less indicates sloth, indecision and lack of comprehension of the only road to orthodontic salvation.

This also doesn’t lose any meaning. Bonding the second molars is important in anchorage preparation as well as for levelling the curve of Spee. Most of the time I wait for the second molars to be fully erupted prior to start the treatment.

6. Ignore muscles, particularly those of the tongue, as you strive for the mathematical formula.

It is astounding how much polemics on tongue and its posture we have had after this was written. Still nothing of meaning.

7. Ignore morphogenetic factors, pattern of growth gradients. Occlusion is the be-all and end-all of our existence.

Now we have high-quality studies that unambiguously show that it is impossible to influence the facial growth. No Santa Claus.

8. Ignore root resorption. Do not show the roentgenograms to your confreres because they might interpret this as a sign of weakness.

We have some recent studies telling us that root resorption has no clinical significance. Still true.

9. Take your finished records as soon as you remove appliances. If you have not achieved the objectives as outlined by the master, the case is not to be considered ‘finished’.

I take records at the appointment after debonding letting the gingiva to heal up a bit. I think the perception of time was somewhat different in the pre-Internet era, therefore my approach might be considered equal to Tweed’s “as soon as you remove appliances”. Taking good records is still one of the key elements to avoid pitfalls.

10. Retain the case indefinitely; never discuss failures with non-believers, for you may sow the seeds of ugly suspicion and mistrust.

Retention is a topic of great debate, but it is unquestionable that every patient requires some form of it. Discussing failures is still something you shall do only with the closest allies. We all have relapses. And this elegantly takes us back to the commandment number one.

That was “Ten Commandments” by Charles Tweed. It is interesting that more than a half century and hundreds of research papers after these brief and elegantly put instructions are still of value. They are still the most meaningful things in orthodontics I am aware of. I didn’t follow them 100 %, but I am trying to always keep them in mind while treating my patients. Those of you who have read them for the first time might feel a little uncomfortable with some vivid orthodoxy. I also felt suspicious by a rather dogmatic tone when I first read them five years ago. Now I think that in clinical work orthodoxy is much better than uncertainty. Try them and perhaps you’ll form the same opinion later on…


  1. Love the 10 commandments!
    Another great read from the early 60’s is Fred Schudy’s work on class ll problems often are vertical.


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