Twin Block, with or without upper labial bow? Angle Orthod, ahead of print.

One of the most read posts of this blog, is the recent W.Clark article at the JO. The Twin Block is a widely used functional appliance, and its creator advocates that his 30 years experience has taught him, that there is no need for a facial bow at the upper plate of the appliance.


A group of scientists from King's College university, have performed a RCT, to test the above hypothesis. What they find is that indeed the use or not of a facial bow at the upper plate of the twin block, does not seem to influence significantly the treatment results.

Construction of the Twin Block with and without a facial bow.

For further information please refer to the ahead of print of The Angle Orthodontist, at this link

D.G.

Anterior open bite and tongue positions, DPJO

A very interesting article can be found at the current issue of the Brazilian journal. The anterior open bite patients are among the hardest ones to treat, and the most common complication is the relapse of the treatment result even after complete closure of the open bite.

By looking a little more into the reason that created the malocclusion we can try to enhance our treatment results. The equilibrium theory is know from Proffit, and from studies of researchers like Thüer in the 80ies. It is according to those beliefs that the equilibrium between the tongue function and position, and the lips assures a perfect inter-incisal angle and stability at the front region.

Take a look at this scheme of different tongue positions, taken from the article:

The first one is the normal position of the tongue, showing the forces exerted upon swallowing.

Birte Melsen: How has the spectrum of orthodontics changed over the past decades?

The Journal of Orthodontics of this month has invited Prof. DrOdont, B.Melsen from the university of Aarhus Denmark, to write an article about orthodontics today.


This article is in a form of a lecture. Dr. Melsen talks about almost every aspect of orthodontics today.


From "fast food orthodontics", self-ligating, "intelligent wires and brackets", "no bending orthodontics" to individualized treatments for adults with periodontal and degenerative diseases. TADs and digital orthodontics (digital casts, computerized treatment planing) are a field of interest for the future, and push the limits of orthodontics according to Prof Melsen.


Along the caustic comments about the industry, the marketing of new wires and brackets, it is reminded to everyone, that orthodontics is all about treatment planning and goals orientation. There is no cook book in orthodontics, and this article is certainly worth of your time.

Gnathology

For those of you interested in Gnathology here is an opportunity to assist a fantastic scientific program organized by the International Academy of Gnathology – American Section in an outstanding location (San Antonio, Texas).

Some of the most relevant presentations for orthodontists are presented bellow:

Dr. Barry Glassman – Allentown, Pennsylvania

Functional diagnosis of the TMJs using joint vibration analysis

Dr. Mariano Rocabado – Santiago, Chile

The craniovertebral centric relation concept, synovial TMJs, and occlusal prevention

Dr. Larry Wolford – Dallas, Texas

Examination, diagnosis and treatment of retrognathic mandibles with TMJ derangements

Dr. Ron Verrett – San Antonio, Texas

An update on oral appliances in the treatment of sleep apnea

Dr. Markus V. Troeltzsch – Ansbach, Germany

Stomatognathic Etiologies of Headache and their Treatment

For more information please visit the website

http://www.gnathologyusa.org/

N.S.D.

Re-evaluation of cervical vertebral maturation and its relation to mandibular growth, AJO-DO

The cervical vertebral maturation stages were introduced by Dr. Baccetti as 5 stages initially, and 6 stages in 2005.


This relates the mandibular growth velocity with  6 distinguished stages of cervical vertebral maturation.


These are the stages from the article of Baccetti Sept 2005, Sem Orth:

 CS1:Mandibular peak will start in 2 years

CS2:Mandibular peak will start in 1 year

CS3:Mandibular peak will happen during that year

CS4:Mandibular peak has started 1-2 years ago

CS5:Mandibular peak has finished 1 year ago

CS6:Mandibular peak has finished 2 years ago

DIOSPORT

Diosport is an intraoral device that serves to restore the muscle balance of the body and thus allow the athlete to develop their true high performance.

This device works by decompression and reposition of the mandible by means of high-tech electronic mandibular deprogramming, objective measurement of masticatory muscles using surface electromyography and mandibular kinetography.

In conclusion, the stability is achieved by repositioning the jaw, allowing the muscle chains to operate in perfect harmony and increasing the airway providing better oxygenation.

For those interested in this subject I recommend to search for publications in the website of Diosport

http://diosport.com.br

N.S.D.

Bone Anchored Maxillary Protraction of Growing Class III Patients, EuJO

The traditional protocol for maxillary protraction of growing class III pre-pubertal patients would be expansion and loosening of the mid-palatal suture with the means of a Hyrax appliance. That will be followed with 5-7months (more depending on the severity and patient compliance) of protraction with a facemask, with a force of 300-400gr elastics (8-14oz). The optimal use of the facemask would be 14-16h/day.

AAOF Craniofacial Growth Legacy Collection.

A very interesting work is taking place online. With the support of the AAO Foundation, USA and Canada are joining forces. 


Nine out of eleven longitudinal craniofacial growth studies are joined together. There's more than enough knowledge to be had and it is right at your finger tips.


Just log in to the website and check / download a series of pictures and superimpositions of those key growth studies.
http://www.cril.org/aaof/aaof_home.asp

D.G.

A re-investigation of the relationship of head posture and craniofacial growth

In the start of the previous century Schwartz (1926) and later Bjork (1955, 1960) investigated the relationship of head posture and craniofacial growth. When A. Bjork retired from the professorship of Copenhagen orthodontic department, Beni Sollow with his interest in cephalometrics continued the research on the field. Prof B.Sollow conducted a series of observational studies concerning head posture and growth (1976, 1986, 1992)

S.D.Springate of the Eastman Dental Institute, has published at the current issue of the European Journal of Orthodontics, a study that tries to put all those key articles under a critical eye and re-investigate the exact relationship of head posture and craniofacial growth. Here is the link to the abstract of the study.

The main weakness of B.Sollow's studies as pointed by the author of the above study, is the fact that posture is assessed only prior growth and not afterwards. The reasoning B.Sollow used was that since he had two variables with a relation with each-other, the one that occurs earlier is the one responsible for the outcome of the later. With that argumentation the posture, that is there earlier in time, is the one effecting the craniofacial growth that follows.

Pediatric Reuhmatology International Trial Organization, PRINTO

PRINTO organization started in 1996 by Alberto Martini, and Nicollino Ruperto. Initially it consisted of rheumatoid arthritis centers in 14 countries. Today it numbers 50 countries and more than 350 centers. 

It is a non profit, non governmental, International organization. Its' aim is the collaboration of different centers around the world to the better understanding, treatment and of-course research in the field of  pediatric rheumatoid diseases. More information can be found here. 

Two of the ongoing projects of the organization:

• Juvenile Dermatomyositis Trial
• Autoinflamatory Diseases Working Group

A list of prior trials and projects of the organization can be found here.

There is a large database of all basic information related to Juvenile Idiopathic Arthritis (poly-, oligo-arthritis, extended or not, and systemic arthritis), Skleroderma, Bechet, Lupus, and other relevant pediatric rheumatoid diseases. This is the link and it is a database translated in more than 15 languages.

Design and Management of Twin Blocks

William Clark published recently an article at the British Journal of Orthodontics.


Design and Management of Twin Blocks: Reflections After 30 Years of Clinical Use


As the abstract reads:
There is an amount of misconceptions concerning the design of the Twin Block appliance. Those misconceptions might lead to poor compliance and poor treatment results and discourage some clinicians from the use of the appliance.


Small note: This post will not go into the principle and the basics of the Twin Block therapy as it's aim is to discuss the common mistakes when constructing the appliance. As such it is mend for readers with prior clinical experience using the appliance. 




Height of Occlusal Blocks


The height of the occlusal blocks should be enough to overcome the freeway space and not allow the patient to retrude the mandible when at rest. However constructing very high blocks would give other undesired complications.


Patient has to be able to close the lips without major strain, to be able to incise and chew posteriorly without difficulty, not to affect his/her speech, and not compromise the aesthetics when worn. These will ensure compliance and full time wear of the appliance which is the goal for the Twin Block therapy.


What is commonly used among clinicians is the rule of 2mm inter-incisal clearance, that will give a 5-6mm opening at the first premolar region. However this is not the case for all starting malocclusions, and that is one of the most common mistakes.