Featured Article
An article in the June 24, 2024, issue of the Journal of Oral and Maxillofacial Surgery, by Michael D. Han, DDS and his colleagues* at the University of Illinois Chicago College of Dentistry, titled "Does Maxillomandibular Fixation Technique Affect Occlusion Quality in Segmental LeFort I Osteotomy?" examines how different (MMF) techniques influence the accuracy of occlusal positioning. A double-blind in vitro study on experiment models to simulate a 3-piece LeFort I osteotomy, evaluated brackets, MMF screws, and embrasure wires.
We had the opportunity to sit down with Dr. Han to discuss the study. Here is a condensed version of our conversation:
What led you to conduct this study to assess the effects of MMF technique on occlusion quality in segmental LeFort I osteotomy?
"The impetus behind this study was to address the challenges of controlling dentate jaw segments during oral maxillofacial surgery, especially when you have three or more segments. Clinically, my colleagues and I observed that the more segments you have the more difficult it is to control, as there are more potential sources of error. Clinically we can only see a partial view of the dentition; we can never see 360 degrees. So there's a limit to how we can verify the accuracy of the occlusion intraoperatively. Our goal was to quantify how much occlusal control we have with commonly used MMF techniques."
How did you select the methods and techniques used in your study?
“We chose brackets because they are the default MMF option in many of our cases, and we chose embrasure wire based on our institutional preferences and universal availability of wire. IMF screws are commonly accessible and may be necessary at times. Minne Ties were considered but excluded due to their limited availability, especially outside the U.S., and their occlusal forces are similar to embrasure wires. We included MMF methods that most surgeons in the U.S. and other countries could easily access.”
What are the key takeaways from this study?
“The study gave us more confidence in using brackets for segmental cases to control occlusion, since many of our patients already have brackets on. For surgery-first, which we do regularly, or clear aligner orthognathic cases, now we know what to default to if we can’t get traditional fixed appliances. It also highlighted the limitations of using IMF screws, which I’m now somewhat hesitant to use unless I just don’t have a better alternative available.”
How do the results of this study apply, if at all, to other types of cases beyond LeFort I osteotomies?
“I think we can, with pretty good confidence, safely extrapolate the results to any multi-segment situation. Even if it's multiple mandible fractures within a dentate segment or a LeFort fracture with a concomitant palatal fracture, the results should apply.”
What challenges did you encounter in this study?
“One limitation was our use of in vitro models to make soft tissue analogs. This was necessary for a quantitative study, as evaluating occlusion in a quantitative manner in actual patients the way we did would have been impossible. The blinded evaluators needed to assess both buccal and lingual occlusion, which isn’t feasible with live patients. We also only examined occlusion in this study, so its impact on skeletal control further from the teeth is still undetermined. However, accurate occlusion (especially as assessed both buccally and lingually) likely indicates accurate segment control. Another challenge was the variability in wiring techniques. Some people might leave the embrasure wire slightly loose to avoid breaking it, so variations in individual techniques could have influenced the study.”
What future studies would you recommend based on your findings?
“The study design didn't look at proximity [of MMF devices] to the teeth as a factor, so future studies could explore different models where the location of the devices are better controlled to look at the impact of the distance from the occlusion. This could be done by using brackets that are attached closer to the cervical level, and varying the position of the IMF screws, using clear aligners, and so forth. I think, intuitively speaking, the farther away you are, the more you're going to sacrifice in the occlusion.”
* Michael D. Han, DDS, Sterling Gray, DDS,R, Emilie Grodman, DDS, R Michael Schiappa, DDS, R Budi Kusnoto, DDS, MS, and Michael Miloro, DMD, MD
Important Update
We are changing how we refer to the two Minne Ties sizes to better reflect their recommended use.
Minne Ties now come in two sizes, which have historically been referred to as:
• Large – solid green 1.00 mm Minne Ties. We will now refer to this size as Standard, since it is used over 80% of the time, and we always recommend using this size whenever possible.
• Medium – white and green striped 0.7 mm Minne Ties. We will now refer to this size as Supplemental Thin size, since we only recommend using it if the Standard size doesn’t fit in the embrasure.
Please note, the product codes and packaging remain the same. This update highlights our recommendation to use the larger, Standard size whenever possible, as it helps minimize the chance of "flossing out," where the Ties can pull through dental contact points.
As with most surgical procedures, there are risks associated with maxillomandibular fixation (MMF), including with Minne Ties. For complete information regarding indications for use, additional application and removal instructions, risks, contraindications, warnings, precautions and adverse events, please review the device’s Instructions for Use (IFU) included in the package and at www.minneties.com.
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