An important message by Jeffrey Okeson at our recent meeting.

“TMD is reported; it is not discovered.”
Charles S. Greene

The image above is from the 8th edition of “Management of Temporomandibular Disorders and Occlusion” by Jeffrey P. Okeson.

https://pubmed.ncbi.nlm.nih.gov/20805344/

https://www.tandfonline.com/doi/full/10.1080/14653125.2016.1201302

https://journals.sagepub.com/doi/10.1177/14653125241255139

Let’s talk about Nicky Mandall’s studies. Personally, I see no justification for maxillary protraction therapy regardless of the appliance used. Do you protract maxillas in children? If yes, how do you justify this?

Late-night Tuesday pearl:

Take as many final smile photos as the time allows. A good smile is hard to catch. Here I took over 20 shots to get one decent photograph.

Gnathology is like communism. Created in the West, adopted by the Russians. Many people suffered. But to this day no one knows what the hell it actually supposed to be.

Here is a classic study of mock occlusal equilibration. No, occlusion is NOT a significant risk factor in most TMDs.

@Everyone, do you find something wrong about this surgical outcome?

Tuesday clinical pearl here

Conflict of interest to declare: I have a financial interest in selling the heat-treating unit shown in the video. We started manufacturing those with my classmate about a year ago. Simply because there were no options to buy such devices in Russia.

Today is the birthday of a legendary academic orthodontist, Dr. Lysle E. Johnston, who is regarded by many as “the conscience of the specialty”.

The attached article is my favourite of him. And what’s your favourite quote of Dr. Johnston?

One more good quote from LJ:

“It is the "clear-cut" extraction patient who is now most in danger of clinical misadventure at the hands of those who would avoid extraction at any cost.”

https://meridian.allenpress.com/angle-orthodontist/article/63/4/257/57240/The-effects-of-premolar-extraction-A-long-term?searchresult=1

We just got the sad news that Lawrence Andrews passed away. Here is a footage with younger me filming him in San Diego: https://m.youtube.com/watch?v=MhQXFuOlY1c&t=165s&pp=ygUQTGF3cmVuY2UgYW5kcmV3cw%3D%3D

Quantity vs quality

Hello @everyone! Let’s start the week with this concise and thought-provoking article by late Vincent G. Kokich.

In North America, there is an increase in popularity of so-called "monster practices" with over 1000 ongoing patients. However, there are also clinicians like Sylvain Chaberland who has only 150 active patients.

In Russia, we often see freshly graduated folks who are trying to collect over 100 patients in just their first two years of practice. This inevitably leads to catastrophic results and an increase in nonsensical Instagram posts.

So, does your practice flow resemble a funnel or a cylinder? Write in the comments.

Should we take Roth's ideas seriously in the 21st centrury? As clinicians who practice evidence-based orthodontics, we should not waste our time on that.

Here is a great paper on articulators in orthodontics from an evidence-based perspective.

● The articulator can never simulate human mandibular movement and is based on the faulty theory of the terminal hinge-axis.

● There is no evidence that orthodontic treatment results (outcomes) are better when articulators are used in terms of improved patient TMD status and stomatognathic health.

● No scientific evidence suggests that the use of articulators will influence orthodontic diagnoses in any meaningful way.

● Although the polycentric hinge articulator is possibly better than the hinge axis arcon articulator, it is by no means ideal.

● CR records have only been demonstrated to be reliable under controlled laboratory conditions.

● The errors involved in taking the bite registrations and the mounting procedures reduce the significance of the gnathologic findings.

● Bite registrations used in the mounting process are static records and do not encompass any meaningful movement of the human mandible.

● The internal validity of the Roth power centric bite registration has not been established. Roth did not demonstrate where patients’ condyles are positioned as a result of the power centric bite registration; he assumed they are in an anterior-superior seated position, but he gave no documentation.

An excerpt from our last study club meeting: 24/7 splints — a sure way to leave a patient without occlusion and …a big business!

Last year, I spent an entire month of November on writing this blog post. It encapsulates all my knowledge on aligners. And I think it has been one of the best texts on my blog. https://orthodonticgrammar.com/2023/12/07/orthodontic-russian-roulette-what-do-i-know-about-clear-aligners/

I’ve recently asked J Okeson to mention studies supporting that iatrogenic effects of 24/7 full-coverage splints are caused by muscular adaptation. Here is the list he sent me:

Herring SW, Grimm AF, Grimm BR. Regulation of sarcomere
number in skeletal muscle: a comparison of hypotheses.
Muscle Nerve. 1984;7:161–173.

Williams PE, Goldspink G. Changes in sarcomere length and
physiological properties in immobilized muscle. J Anat.
1978;127(Pt 3):459–468.

Goldspink G. Cellular and molecular aspects of muscle growth,
adaptation and ageing. Gerodontology. 1998;15:35–43.

Hayatsu K, De Deyne PG. Muscle adaptation during distraction
osteogenesis in skeletally immature and mature rabbits.
J Orthop Res. 2001;19:897–905.

Zumstein MA, Frey E, von Rechenberg B, Frigg R, Gerber
C, Meyer DC. Device for lengthening of a musculotendinous
unit by direct continuous traction in the sheep. BMC Vet
Res. 2012;8:50.

Caiozzo VJ, Utkan A, Chou R, Khalafi A, Chandra H, Baker
M et al. Effects of distraction on muscle length: mechanisms
involved in sarcomerogenesis. Clin Orthop Relat Res. 2002;
October(403 Suppl):S133–S145.

Green SA, Horton E, Baker M, Utkan A, Caiozzo V. Distraction
of skeletal muscle: evolution of a rat model. Clin Orthop
Relat Res. 2002;October(403 Suppl):S126–S132.

Williams P, Simpson H, Kyberd P, Kenwright J, Goldspink
G. Effect of rate of distraction on loss of range of joint
movement, muscle stiffness, and intramuscular connective
tissue content during surgical limb-lengthening: a study in
the rabbit. Anat Rec. 1999;255:78–83.