Topics of the day:

1. Cementing Stainless steel crown Herbsts
2. En masse versus two-step anterior retraction -- does it make any difference to anchorage loss? No.
3. Late Tooth development
4. SS Crown Herbst Cement correction
5. Marfan's syndrome
6. Digital study models
7. X-ray scanner for Dental Impressions
8. Call for registration - 11th International Symposium on Dentofacial Development and Function
9. ESCO - The Electronic Study Club for Orthodontics

 


Date: Tue, 28 Mar 2006 18:38:58 -0500 (EST)
Subject: Cementing Stainless steel crown Herbsts
From: doctoro@macatawa.com
To: esco@listserv.uic.edu

Roy King asked a question about cementing ss crowned Herbst back about a month ago. I'm sorry I didn't respond in a timely manner. When I looked at the responses I felt that I should chime in too.

I use a lot of cantileverd ss crown Herbsts and we have a technique that works very well. I virtually never have loose crowns and my chair time at removal is 4 minutes. No sweat on my part and no red knuckles for the patient.

One key to bond success with crowns is to not cut down their occlusal-gingival length. You need this length for retention - crown length is nearly as important as the cement.

To cement the crown we use GC Fuji ortho LC mixed on a cold slab. We mix for two crowns per mix since the cement sets rather quickly. After isolating the molar we do a critical step at the cementation for ease of removal: We place a piece of sheet casting wax intimately on the occlusal surface. The wax is: Sybron Kerr casting wax sheets - gauge #26 green. It comes in a box of 32. Wax on the occlusal is light years ahead of Vasoline as a barrier and does not make for loose crowns.

When making the Hebst, we adapt the wax to the occlusal of the molar on the patient's study cast to get the correct size and shape. At cementation I dry off the tooth and push the wax tightly onto the occlusal surface of the tooth. The wax sticks very well when all is dry and provides a total barrier for the cement to not bond to the occlusal surface. Once the wax is in place we push the crown down with finger pressure and the cement oozes out around the crown. We quickly use high volume suction and the air/water syringe to wash off all the extra cement. After most of the cement is rinsed off, we have the patient bite down on the plastic side of a band seating instrument to fully seat the crown. A little more cement oozes out and we proceed to fully rinse off all the extra cement before proceeding to the next crown. My doctor time to do four crowns is 4 minutes - but when I am finished there is no additional clean up.

At removal I use the high speed hand piece with a cross-cut fluted carbide bur and score a cut from the gingival border (almost) of the crown at the mesiobuccal line angle. The cut extends across the occlusal to the distal of the tooth. I cut all four crowns first. Next I use a bond removing plier (Orthopli 098-A) to remove the crown. I warn the patient that I will pull somewhat hard on their tooth so they know what to expect. Usually little tugging is necessary. I use the plier to grab onto the crown at the gingival aspect and at my bur cut and squeeze, twist, and peel to remove the crown. They come off with little effort. If their is resistance it is usually due to the bur cut not extending gingival enough at the mesial buccal line angle.Simply cut the crown a little more with the handpiece.

When the crown is removed there is absolutely no cement on the occlusal surface. I frequently take a scaler and simply flick off the wax if it doesn't come off on its own as the crown is removed. We rinse off the tooth as I am flicking off the wax. There will be some cement on the buccal and lingual which comes off easily with a Rocky Mtn band remover and gentle pressure. A scaler is helpful too. The work in removing a crown is cleaning the occlusal which we never need to do. The buccal, lingual and even the mesial and distal clean up easily and quickly without a handpiece or ultrasonic scaler. This procedure can be delegated in some locales.

I have used this approach for years. It is consistent and reliable. I learned the approach in bits and pieces. I have never seen it presented this way at a meeting.

Their is a steep learning curve to nearly every nuance about the Herbst. However,every little thing makes all the difference.

Greg Oppenhuizen
Holland MI


Subject: En masse versus two-step anterior retraction -- does it make any difference to anchorage loss? No.
From: "Stanley M Sokolow" <overbyte@earthlink.net>
To: "The Electronic Study Club for Orthodontics" <ESCO@LISTSERV.UIC.EDU>
Date: Wed, 29 Mar 2006 10:26:47 -0800

Hi, ESCO members:

In a prior message, I asked whether anyone knew of any research on the question of anchorage loss during retraction in an extraction case, comparing the technique of retracting the canines all the way first, followed by retracting the four incisors, versus the technique of aligning the canine-through-canine segment and retracting all of them at once "en masse". Decades ago I was taught (and I think it's still commonly believed) that when you want maximum anchorage (minimum anchorage loss) you need to retract canines first, and then retract incisors. It was my unresearched clinical hunch that it makes no difference to the ultiimate amount of anchorage loss. While looking online for something else, I just happened to find the following abstract of a paper that will be presented at the upcoming International Association for Dental Research meeting (July 1, 2006) on exactly that question:

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A Randomized Prospective Trial Comparing Two Retraction Techniques on Anchorage T.-M. XU1, W. HU1, X.-Y. ZHANG1, and S. BAUMRIND2, 1Peking University, School of Stomatology, Beijing, China, 2University of the Pacific, Arthur A. Dugoni School of Dentistry, San Francisco, CA, USA

Objective: The purpose of this study was to investigate the relative effectiveness of the en masse and two-step retraction techniques in the conservation of anchorage when extraction strategies were employed for the correction of Angle Class I and Angle Class II malocclusions. Methods: 64 maximum anchorage cases were randomly selected as the study sample from 1999. They were randomly assigned to an en masse group and a two-step group before start of the treatment. The standard MBT appliance was used for all the cases. 63 cases completed treatment by 2005. Computerized cepholomatric measurements (each an average of three independent determinations) focused on molar anchorage and incisor retraction in upper jaw. Treatment time period was also compared. The displacements of the cusp of upper first Molar (UMC) and the edge of upper incisor (UIE) were measured by superimposition on palatal plane using pretreatment anatomic occlusal plane as reference. Results: In the en masse group, UIE retracted 6.23mm ±3.69 while UMC moved forward 2.84mm ±2.39. In the two-step group, UIE retracted 5.31mm±3.79 while UMC displaced forward 3.08mm±2.43. Treatment times were 30.2±9.4 months for en masse group and 31.6±9.4 months for two-step group. Student t-test showed there was no statistical significant difference between these two retraction methods either for anchorage control or for treatment period. Conclusion: Retracting canines first prior to incisor retraction does not necessarily save more molar anchorage in sagittal plane than retraction of 6 anterior teeth together.

Orthodontic Treatment The Preliminary Program for IADR General Session & Exhibition (June 28, July 1, 2006) Top Level Search

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So, the evidence-based best-management-practice is: just retract the canines enough to align the crowded anteriors so they can be engaged on a rectangular archwire, then close the remaining extraction space en masse. I think it's quicker than first retracting canines, tying them back, and then retracting incisors, since all of the teeth are being retracted simultaneously.

I think this evidence also applies in the opposite direction, when trying to protract posterior "anchorage" teeth in a minimal anchorage situation. You can't manipulate the amount of anchorage loss by protracting the posteriors sequentially (bicuspids first, followed by molars) rather than just closing space all at once, en masse. If the appliance is purely tooth-borne (no palatal buttons or mini-screws, for example), each tooth contributes so much anchorage dependent upon its initial position and root form, and the sequence of movement doesn't alter that anchorage-in-the-bank. You just spend the anchorage more slowly with sequential versus simultaneous (en masse) movement.

That's how I see it.

Stan Sokolow

 


From: "Deborah" <dmbarros@btu.flash.tv.br>
To: "ESCO" <ESCO@LISTSERV.UIC.EDU>
Subject: Late Tooth development
Date: Mon, 3 Apr 2006 16:44:57 -0300

Dear Group:

When a patient came to my office for an ortho evaluation,  she was 7 years old and apparent agenesia of upper second bicuspid.  There was nothing to be done at that time except put her on recall.  One year later she came and there was the 26 ( beginning crown formation).  Call her back next year and mom and child wanted her teeh to be straightened.  She was then 9 years old, all permanent teeth in ( except the 26), lots of crowding. I decided to put braces on her, to correct the bite and open space for the 26.  Now she is 10 and a half,  teeth aligned , space openned for 26 but  just 1/3 of root formation.  My question is:  Will the root continue to develop if I surgically expose and force eruption of the tooth?.  When I compare the panoramic x-rays I see very little root development from one year to another.

Dr. Barros

 


Date: Thu, 06 Apr 2006 08:53:10 -0400
From: "GJ/RR Oppenhuizen" <doctoro@macatawa.com>
To: esco@listserv.uic.edu
Subject: Crown Herbst Cement correction

Hi All

Critical error on my Herbst bonding message. I improperly listed Fuji LC as the cement I use for Herbst cementation. Sorry I was looking a bottle we use for occasional bracket placement. I picked up the wrong bottle to get the label information. The Herbst cement we use is: /GC Fuji I Glass Ionomer Luting Cement.

Greg Oppenhuizen


Date: Sat, 8 Apr 2006 19:34:46 +0530
From: "Ganesh Somayaji" <ganeshsomayaji@gmail.com>
To: esco@listserv.uic.edu
Subject: Marfan's syndrome

Dear Group,

We have a patient diagnosed as Marfan's syndrome seeking Orthodontic treatment. The patient demonstrates many features of marfan's syndrome, (Cardiac abnormalities, hyperextension of joints, dispropertionate limbs etc. However, no webbed fingers) Is it a contraindication for orthodontic treatment considering the collagen status of such a person? Any information about managaement (including references)would be greatly appreciated.

Thank you,

Dr Ganesh Somayaji
Virajpet, INDIA

 


To: esco@listserv.uic.edu
From: "Owen Crotty" <owenc@eircom.net>
Subject: Digital study models
Date: Tue, 11 Apr 2006 22:12:28 +0100

Hi Group

Any suggestions regarding digital study models? What are the options out there now, how do they stand up legally and what happens to the models if that company goes belly-up or is bought out at some stage in the future. Is there any option out there to scan models in an industry standard, platform-independent format which can then be read and measured in a standard CAD application, in the same way as a 2-D image can be captured in JPEG, TIFF or .pdf formats and opened in any of many applications. Any help very much appreciated.

Owen Crotty
Ireland

 


From: "John Mamutil" <jrg@bigpond.net.au>  
To: escostudyclub@yahoo.com
Subject: X-ray scanner for Dental Impressions
Date: Tue, 18 Apr 2006 10:12:47 -0500

Does anyone know of a source or pricing of x-ray scanners for dental impressions?  Has anyone on ESCO tried this? A private email is fine if this needs to be kept classified <g>.

John Mamutil
Baulkham Hills
AUSTRALIA

 


From: "Carla A. Evans " <caevans@uic.edu>  
To: escostudyclub@yahoo.com
Subject: Call for registration - 11th International Symposium on Dentofacial Development and Function
Date: Tue, 18 Apr 2006 10:12:47 -0500

11TH INTERNATIONAL SYMPOSIUM ON DENTOFACIAL DEVELOPMENT AND FUNCTION

June 18 - 22, 2006 Sheraton Chicago Hotel and Towers, Chicago, IL USA

The 11th International Symposium on Dentofacial Development and Function, one of the most important events in the fields of craniofacial biology, orthodontics, and dentofacial orthopedics, to be held in Chicago at the Sheraton Chicago Hotel and Towers from June 18-22, 2006. We are requesting your sponsorship, participation, and friendship.

The meeting presents an opportunity for clinicians and researchers to meet dentofacial specialists from all over the world and gain exposure to the latest advances in research, techniques, and products through educational courses and a trade exhibition. An exciting interactive program has been assembled based around the following themes: Craniofacial Genetics, Bioengineering and Technology, Tooth Agenesis and Craniofacial Anomalies, Management of Functional and Behavioral Problems, Clinical Orthodontics, and Clinical Pediatric Dentistry. In addition to an exciting scientific and clinical program on the Chicago lakefront, an outstanding social program is planned to promote greater audience participation and communication with the speakers and exhibitors. Don't miss this opportunity to join your peers in one of the most exciting cities in North America-- Chicago . Network with dentofacial specialists from all over the world while gaining exposure to the latest advances in research and techniques through an extensive educational course and trade exhibit.

Welcome to visit the Symposium website at http://www.uic.edu/depts/dort/symposium.html for detailed information on our speakers, programs, registration, and abstract submission.

Questions? E-mail caevans@uic.edu

Organization Committee
Department of Orthodontics
University of Illinois at Chicago
801 S. Paulina St. , M/C 841
Chicago , IL 60612

PROUDLY SPONSORED BY: Quintessence, 3M Unitek, RMO, Palodex Group Instrumentarium, Dolphin Imaging, OraMetrix, TP Orthodontics, GAC, OrthoExpand, OrthoCAD, Raintree Essix



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