damon-intheclinic-casestudies-herbstcases
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Kathryn P. |
This section is intended to share with clinicians some of the things I have learned after using the Herbst®* appliance for more than 24 years (see Flip Lock Herbst®*). My comments are based on observations made after having the opportunity to treat over 2,800 cases and following many of these cases for years posttreatment. The exciting thing about orthodontics is that our clinical observations combined with the improvements in technology can impact how we use and apply any system on a daily basis. My intent is to give an overview on how this wonderful technology is utilized in treating some of our most challenging cases. The Herbst®* is one of the most powerful treatment options we have in orthodontics. The combination of the new low-force/low-friction clinical system and the Herbst®* appliance gives the clinician the opportunity to convert very complex and long-term treatment situations into very straight forward, noncompliance mechanics with far better clinical results for the patient. After having the opportunity to lecture around the world, it has
become very apparent that many clinicians have a very negative
view of the Herbst®* appliance and its clinical application. Quite
frankly, many of these comments are justified when discussions
only center around the Herbst®*’s impact on ANB. My observation
is that there is a huge variable in what does or does not happen
to ANB. My interest in using the Herbst®*
appliance is focused far more on its functional impact on the whole
orofacial complex rather than just focusing on ANB. Yes, it is nice when ANB responds positively,
but in some cases, it simply does not change. Even though ANB may
not be impacted, there are so many positive things that happen
when the patient If the mandible is advanced slowly and over an extended period of time, the impact is very dramatic in both growing and nongrowing patients. We have all seen the narrowing of the upper arch in a severe Class II skeletal patient. This is an example of the “functional adaptation” of the alveolar process and dentition reacting to the patient’s musculature that is altered by the anteroposterior position of the mandible. If this mandibular position is slowly normalized, it is amazing to observe how the teeth and alveolar process respond laterally even without orthodontic intervention. Clinical PrinciplesWe all know that the growth of young patients occurs over a very long period of time. It has always made logical sense to me that time is needed to give the body the chance to react to a given functional change. The old adage of “form follows function” is appropriate when using the Herbst®*. My favorite time to start Herbst®* treatment is when the young patient’s growth starts to take off. (Some exceptions are very severe cases and those patients with self-esteem and special growth issues.) Average starting age for females is approximately 10_ to 11 years, while boys are later at 11 to 11_ years. I strongly recommend only advancing the Herbst®* 4 to 4_ mm at the beginning of treatment. There are so many advantages to activating slowly and over a long period of time. I like the concept of not advancing the condyle more than 2/3 the way down the articular eminence. This small advancement of the mandible lessens the Class II elastic effect of the musculature and therefore minimizes the “dumping” of the lower incisors. With this small advancement, I rely on the “functional effect” of the Herbst®* and muscles to naturally iNi-Tiate lateral upper arch adaptation, negating the need for higher-force palatal expansion prior to placing the Herbst®*. As the mandible is advanced with the Herbst®*, the combined impact of the V-shape of the mandible and the Herbst®* rods allow a very slow and natural lateral change in the maxilla with very little dental tipping. What is interesting is this lateral adaptation of the palate is not age specific. The second advancement of approximately 3 mm is done at 5 to 6 months into treatment. Once again, the activation is allowed a time interval of approximately 5 months for the muscles to adapt. Activations thereafter are done with the same principles applied to each patient’s specific needs for skeletal correction. In most cases, activation is stopped when the upper and lower anterior teeth are end to end. The average length of treatment is 14 to 16 months. (In very severe applications, that treatment time has been extended to 2 years or more.) If a patient tends to relapse during the full-bonded phase of treatment, I give the Herbst®* a second effort on the archwire. Some of the most successful cases I have treated have resulted from more than one application with the Herbst®*. Special retention for these Herbst®* cases is critically important (see Retention). Please observe in the following cases the length of time for a nightly splint to be worn following debonding. This “activator” type retainer is so important to the success of this type of treatment. SummaryThe powerful combination of the Herbst®* and high-technology clinical orthodontics allow the clinician to simplify treatment mechanics and convert our most challenging cases to routine clinical orthodontics. Advancing the Herbst®* slowly, letting it work for a long period of time, and retaining with a night splint are my key elements for success. Most of the Herbst®* research done to date has been done on patients that have been activated rapidly, treated over a much shorter period of time, and without anteroposterior retention. It is exciting when very special technologies can have such a profound benefit and impact for both the clinician and patient. Clinical Applications
I use the Herbst®* in several different ways both in timing and treatment
application.
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