There are various types of orthodontic mechanisms. The orthodontist decides which type of mechanism is appropriate for each patient taking into consideration the nature of their problem.
If the problem is skeletal and manifests itself in the shape and position of the jaws, it is best treated with removable appliances that can affect the development of the jaws towards the desired direction.
Purely dental problems are best treated with fixed appliances which exercise precise forces that lead the teeth towards their appropriate position.
Finally, if the problem has to do both with the patient’s teeth and the skeleton, a combined use of both types of mechanisms are indicated.
1. REMOVABLE APPLIANCES
These are mechanisms that the patient can put on and remove on his own. They primarily intend to tackle problems related to the shape, size and position of the jaws; they are widespread used on children and adolescents where skeletal growth is underway. They are very successful at attaining the changes required. Having the advantage of being removable, they facilitate oral hygiene. They are used according to the instructions of the orthodontist 24 hours a day or only at night.
Removable appliances are also retentive mechanisms that are used at the end of active orthodontic treatment to retain the orthodontic result. Functional appliances also belong to the category of removable appliances. They are used in periods of skeletal growth and are therefore only suitable for children and adolescents. These devices use orthopedic forces to correct various problems in the development of the jaws. Among them are the face bow, the activator, the facial mask, etc. The cooperation of the patient in wearing these appliances for the recommended periods is absolutely essential for these appliances to be effective.
2. FIXED APPLIANCES
These devices are fixed on the teeth and cannot be removed by the patient. Using them, one implements precise movements of teeth along the upper or lower dental arch, or entire dental groups.
They consist of many different parts that function as a system and gradually achieve the desired tooth movement, being adjusted periodically throughout the course of the treatment. The analysis of the parts that compose the fixed appliances is as follows:
RINGS: The rings are placed in the molars (back teeth). They are fixed on the tooth by means of special glue that contains fluoride to prevent decalcification of the tooth’s surface during the treatment. Welding is of great strength and can withstand the forces of mastication.
BRACKETS: Those parts of the mechanism are fixed on each tooth in order to keep the arch wire attached. The arch is fixed on a groove of the bracket. The brackets are glued directly onto the teeth. They are metallic or ceramic. Being bonded onto the enamel, they are more likely than the rings to be accidentally detached from the teeth.
ARCHES: The arches are shaped to fit around the teeth and are placed in special slots (grooves) on the brackets. The arches are held in place by a series of small rubber rings (bands) that hold the arch onto the brackets. The teeth move due to forces exerted on them by the arches. These forces are controlled by the orthodontist by shaping specific curves and corners on the arch so that it guides the teeth toward the desired positions. ANY DEFORMATION OF THE ARCH CAUSED BY FOOD OR A HARD BLOW CAN MOVE THE TEETH TO UNDESIRED POSITIONS.
TYING: Thin rubber bands or wires which hold the arch in place in the slots of the brackets.
HOOKS: Small tabs on the brackets used to attach rubber rings.
SPRING: The spring is positioned on the arch between two braces and applies specific forces on the teeth.
CHAINS: These are rubber chains that can move the teeth along the arch.
ELASTIC RINGS: These are rubber rings placed by the patient between the upper and lower arch at the suggestion of the orthodontist.
3. RETENTION MECHANISMS
Retention is the last and most serious phase of an orthodontic treatment. It seeks to preserve the teeth and jaw in the new location. Retentive devices are applied after the removal of the fixed appliances. Without such retention mechanisms, teeth can migrate back to their old positions and the treatment is therefore partially lost. The orthodontist will indicate the duration of the retention phase, as well as the frequency of application of the retention devices.
Types of retention mechanisms:
It consists of an acrylic body and retentive wires, keeping the teeth in their new positions.
It consists of clear plastic. It’s easy to use and almost invisible.
Permanent metal mechanism:
This is a wire constructed so that abuts the inner surface of the teeth. It is virtually invisible and ensures a 24-hour action.
Instructions related to retentive devices
- Removable retention mechanisms must be worn exactly as recommended by the orthodontist to give time to the bone and the soft tissue around the teeth (gums) to firmly embrace their new positions.
- Remove the retentive mechanisms only during the meal and while brushing your teeth. When not in use they should be kept clean in the box.
- They should be cleaned twice a day with a toothbrush and toothpaste.
- Please be very careful as far as your retention appliances are concerned. If lost, not only will you be charged additional treatment costs, but most important, the result of your treatment will be jeopardized.