It was thanks to these advances in plastics processing that Carl GUGINO and Osamu YOSHII came up with the idea of using the elastic properties of a material to build flexible appliances out of injected elastomer: polyvinyl silicone.
In addition, this material has three compatible and juxtaposable degrees of hardness.
This is the concept of elastopositioning.
The appliance consists of a bimaxillary splint, built from a therapeutic model that incorporates the orthopedic and/or orthodontic treatment objectives defined by the practitioner for the patient concerned.
This model must be built from casts mounted on an S.A.M. articulator to integrate the patient's occlusal reference points.
The possibilities offered by the material, combined with individualized reflection and the precision of the therapeutic model, enable the manufacture of flexible devices.
What's more, the material's three possible degrees of hardness allow you to vary the elasticity in the chosen zones, from firmer to softer, depending on the objectives you have set.
There are several types of elastopositioning devices (4), depending on the treatment objectives envisaged:
1. ELASTO OSAMU combines the therapeutic capability of mandibular
advancement (comparable to that of a rigid activator), with the possibility of slight tooth displacement.
Like rigid activators, the Elasto Osamu flexible activator can be fitted with AEO-type auxiliaries and/or an internal arch for improved transverse coordination.
Its construction obviously requires measurement of the amplitude of mandibular propulsion, and is carried out on a MPV (mandibular position variator) which quantifies the descent of the mandibular condyles.
The indications for Elasto-Osamu are reserved for low-amplitude skeletal misalignments associated with slight malocclusion problems. Larger misalignments can be treated, provided that several successive devices are used, each individually programmed for the patient concerned.
It's important to note that, while the treatment concept has changed thanks to
these new materials, the operating principle of the activators remains the same and should not be overlooked under any circumstances.
2. ELASTO ALIGNEUR: locks are affixed to teeth requiring displacement.
The appliance built from the therapeutic model is clipped onto these locks and encourages the tooth to come into the required occlusion.
3. THE ELASTO FINISHER: this is where the concept of elastopositioning comes into its own: the appliance, consisting of a bimaxillary splint, is built from a therapeutic model that incorporates the occlusal data required for the patient concerned.
These occlusal data have been thought out and ordered by the practitioner on the basis of the articulator mounting of the patient's models in the orthodontic finishing phase.
This is occlusal individualization.
The unitary "tooth" by "tooth" action (the appliance being clipped onto the locks) allows the occlusion to settle perfectly while respecting the notions of centering and guiding (ref Orthlieb).
This revolutionary approach to occlusal finishing enables faster debugging, with the gradual development of an individualized functional occlusion.
This concept is particularly valuable in the post-surgical phase, where occlusal finishing must be fast and precise to ensure perfect stability of the ortho-surgical results.
4. ELASTOPOSITIONER: a flexible, fully individualized positioner based on the same concept (partial or total mock-up).
