Dr. Martin Baxmann discusses an apparatus for Class II treatment
The lack of dependence on patient cooperation is one of the key issues for the long-term development of fixed Class II type equipment.
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This type of equipment is distinguished by a high level of efficiency, ease of use, high comfort in wear, and patient acceptance, all the while maintaining the lowest possible manufacturing costs.
Despite extensive development and the introduction of new concepts, this is yet to be fully achieved, and only limited progress has been achieved. Nevertheless, we can observe a continuous process of improvement in the existing equipment and constant development of new technologies. One of these promising new developments is the Baxmann Mini Telescope™ (BMT, Figure 1), produced and distributed by Adenta.
The specific purpose behind the development of the BMT was to create an apparatus that consists of a minimal number of individual parts, with an identical installation sequence for both sides of the jaw, in addition to the upper and lower parts of the jaw. It is extremely intuitive and does not require elaborate laboratory work. This has been successfully achieved by taking an existing concept and rearranging it, thus creating a very compact, concise apparatus that is barely visible to the patient. It is also characterized by its small size and high comfort in wear, as well as freedom of movement.
A treatment kit consists of a complete apparatus including all accessories. Two kits are needed for symmetrical Class II therapy (kits for the right left side are identical). The apparatus consists of a telescopic tube and a telescopic pole, each with a mounting lug. These include two pins for attachment. These are attached to the first molars with a band on the buccal tubes (headgear tubes). It is advisable to use double-welded loops in order to obtain the best possible shape and achieve a high level of stability of the bands even when very strong chewing forces are applied.
Correction of a bilateral Class II with a prominent lip
In the case of a Class II in adolescents, there is the possibility to apply functional orthodontic treatment with removable appliances, such as the Twin Block or similar equipment. In this situation, a complete permanent dentition was already present at the age of 11 years. It seemed effective to skip the pretreatment and combine the needed therapy with a multi-bracket appliance and the BMT (Figures 2A-2F: MB apparatus and BMT were used at the same time). During the leveling, only the molars are stabilized by the transpalatal and lingual arches. As a result, this treatment could be completed in just 16 months and proceed to the retention phase.
The BMT was removed after 10 months, so that finishing and initial settling could be achieved without the use of a fixed Class II device (Figures 3A-3C). The ability to loosen the apparatus during each appointment is especially useful in the application of the BMT. For this purpose, the telescoping rod is pulled out of the tube during a maximum passive opening of the mouth. This takes about a minute per side, including the reactivation phase. It is then possible to check the actual bite of the patient while avoiding phenomena such as a dual bite. This case also shows very clearly the extent of possible movement while wearing the device. A lateral cephalogram can reveal that a bite gap may be almost completely avoided with the use of an intermaxillary elastic band (Figures 4A and 4B). At the same time, it is also possible to achieve an excellent profile improvement through the use of the BMT as illustrated in the reference profile photos (Figures 5A and 5B).
Greatly enlarged, heavily protrusive sagittal incisors (overjet)
An enlarged overjet does not have to be caused by a pronounced skeletal Class II feature (Figure 6). In the case of this 13-year-old boy, an overjet of 7 mm is present at the start of treatment. However, this was mainly caused by the pronounced Curves of Spee in the upper and lower jaw, and less so by a heavy skeletal component (Figure 7).
The goal of the treatment here was to reduce the overjet significantly in order to stabilize both sides of the Class I molar and canine region, and to regulate the overbite. To this end, a non-extraction treatment. was carried out with a multi-bracket appliance using the Straight Wire system. Additionally, a transpalatal arch was used to control the upper molars. For a precise leveling, .014 NiTi, .018 NiTi, and .018 steel archwires were used on both jaws. Then the BMT was used on both sides and treated further with the 19 x 25 NiTi, 17 x 25 steel arches (Figure 8). Following that, remaining gaps were closed using the 19 x 25 steel archwire, and final corrections applied. The BMT was then removed after a period of 6 months along with the rest of the MB device, which means that the apparatus was worn for a total of 13 months (Figures 9 and 10A-10C). If during that time, the equipment caused a minimal posterior open bite, this can easily be optimized by natural settling during the retention phase. Those who prefer to actively achieve this may choose a positioner, if necessary.
Correction of a unilateral Class II
This case of a 12 year-old girl illustrates the correction of a unilateral Class II, which was primarily caused by a rotation of the mandible. While the center line in the upper jaw proceeded along the facial axis, the mandibular midline was, however, shifted to the left (Figure 11). Accordingly, an Angle Class I was present in the right molars region, as well as a ½ Class II to the left. The lower facial height was low, and there was a deep bite tendency. The treatment was carried out without extractions with a fixed appliance using the Straight Wire technique. After the leveling phase (from .018 steel arch in the 22nd slot system), the BMT was used on the left side to achieve a center correction by a unilateral post-development of the mandible (Figures 12A-12C). At the same time, it is important to pay attention to the proper arch coordination of the upper and lower jaw, as well as to take into account vertical components in the unilateral Class II therapy. The treatment time was 18 months using the multi-bracket appliance. The BMT was used after 6 months and removed again after 15 months, which meant a total wearing period of 9 months. The therapy targets — the middle and neutroclusion correction — could therefore be successfully implemented in an acceptable time frame (Figures 13A-13C).
Class II therapy in adults
If, in the absence of growth, the development of a Class II occurs, in the past, there was only the possibility to perform orthognathic surgery or to camouflage extraction therapy. Nowadays, however, it is also known that a fixed Class II device can be used successfully in these cases. Surgery was not an option for the 28-year-old female patient presented here. Due to her profile, an extraction treatment did not result in a satisfactory outcome either (Figure 14). Hence, the treatment of choice was a multi-bracket treatment with less esthetically pleasing ceramic brackets and a barely visible apparatus for correcting the skeletally caused defect of the mandible (Figures 15A and 15B). The Baxmann Mini Telescope was used directly together with the MB appliance. The upper molars were supported by means of transpalatal arches. It has now worked without complications with the standard arch sequence: .014 NiTi, .018 NiTi, .018 steel, 19 x 25 NiTi, 17 x 25, and 19 x 25 steel (Figures 16A-16C). The BMT (17 x 25 steel) was left in place for up to 12 months, and during each follow-up visit (every 6 weeks), the stability of the jaw position was checked. It was a simple and practical way to make sure that the new jaw position was set not only temporarily, but could actually be stabilized in the long term. The active treatment was completed after a total period of 15 months (Figures 17A-17C). Following that, the retention was performed with Hawley retainers and nightly Class II rubber bands. After another 3 months, the elastics were eliminated entirely, and the wearing time reduced from 14 hours a day to just nighttime. Further retention protocol proceeds individually after that.
Summary
The BMT is a new apparatus that fits into the line of rigid, fixed Class II equipment. In this article, it was tested in practical cases and successfully used in various orthodontic situations. The BMT was used on just one side or used on both sides depending on the starting position. It is therefore particularly pleasing to the practitioner that the corresponding components are identical on the right and left, and that the attachment of the apparatus is performed identically to conventional molar bands in all four quadrants. Consequently, the use of the BMT does not require special skills or expensive laboratory steps. The range of its application is very broad thanks to the exclusive attachment in the molar region. As a result, the Baxmann Mini Telescope can be used early on, from treating children, all the way to adult therapy. Especially in the case of esthetically demanding patients, the small dimension of the apparatus can be considered as “invisible,” which is very appropriate. Not only is it barely visible with the mouth open with the BMT, the pronounced protrusion of the lower lip, which is often observed when using larger equipment, does not occur.
Those who have tried using the BMT have come to love the ease and reliability of the apparatus. Finally, it should be noted that the BMT has proven itself to be simple to use, in addition to achieving a high level of comfort in wear and very pleasing esthetics. It also has clinically proven effectiveness as an interesting and practical alternative within the family of Class II equipment.
For more information, visit Adenta USA at www.adentausa.com, email info@adentausa.com, or call toll free 1-888-942-2070.
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