What is functional orthodontic treatment?

Functional orthodontic treatment is a treatment in which we use the natural forces present in the body (functional forces) to achieve a therapeutic effect. Functional treatments have existed since the beginning of the orthodontic era. This is done with various devices, most of which are removable, meaning they are not glued to the teeth, and the patient can remove them by themselves. The device, when worn, causes a certain change in the oral cavity, activating specific muscles or altering the position of the lower jaw, which leads to a change in the environment inside the mouth, adaptation to the new state, and accelerated or slowed growth in specific directions.

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What is the Twin Block appliance?

The Twin Block is one of the most popular functional appliances, designed to treat the problem of misalignment between the upper and lower jaws, caused by a retrognathic or too short lower jaw. The Twin Block consists of a pair of bite-plates that the patient wears—one for each jaw. Each plate alone has no effect, but when both plates are worn together, the appliance directs the lower jaw into a forward position during closing. The forward position of the lower jaw causes several simultaneous effects on both the jaws and the teeth:

1. Effects on the jaws:                                 

   a. Promoting the forward growth of the lower jaw.            

   b. Inhibiting the forward growth of the upper jaw.

   2. Effects on the teeth:                                                                                

   a.  Lower front teeth move forward.                

   b. Upper front teeth move backward.

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Is the Twin Block appliance effective, and in which cases?

The device has proven to be highly effective in cases of children with a skeletal jaw discrepancy, particularly with a retrognathic or short lower jaw.

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Is the Twin Block appliance suitable for adults?

The appliance is not suitable for those nearing the end of their growth phase or after growth has ended, as its function relies on the presence of active growth, which allows the lower jaw to be repositioned while stimulating growth in the jaw joint.

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Is it easy to adapt to the Twin Block appliance good?

Typically, the adaptation to the device takes several weeks, during which the patient gradually increases the hours of wear. Side effects in the first weeks may include pain and discomfort in the lower jaw, especially around the jaw joint. This discomfort generally resolves after this period.

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Does the Twin Block appliance really cause the lower jaw to grow?

Findings in this area can be divided into two periods:

1. Short-term: It has been found that there is indeed improvement in the position of the lower jaw and the relationship between the jaws as a result of using the appliance.

2. Long-term: Findings here do not definitively support excessive growth of the lower jaw as a result of using the appliance. Since the growth of the jaws is genetically controlled and continues until growth ends, it is possible that after the device is removed, the additional growth might cause the treatment results to "blend in" within the total jaw growth.

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How long does treatment with the Twin Block appliance last, and what is the next phase after treatment with the device?

Treatment with the appliance lasts several months, and progress is monitored by the orthodontist. Once the goals of the appliance are achieved, braces are applied, and the process of tooth alignment continues.