Hello.

This is Apgujeong Yonsei Baro Dental Clinic, a dental clinic specializing in orthodontics in Gangnam.

Today, we would like to introduce a case of a scissor bite treated with Invisalign in a patient in their 40s.

Orthodontic treatment can feel burdensome for anyone in their 30s or 40s.

This is especially true when premolar extractions are required due to protruding teeth or crowded teeth.

Extraction-based orthodontic treatment usually takes about two years, but considering the patient's age, it may take even longer than two years.

It can feel even more burdensome because this is a time when the gums may begin to feel weaker.

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Here is a case in which the treatment goals were set lower despite the need for extractions, and simple treatment was completed within 10 months using Invisalign Lite.

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The patient's main concern was that the front tooth on the patient's left side was positioned too low and protruded outward.

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The upper teeth covered the lower teeth extensively, showing a deep bite.

The rearmost molar indicated by the blue arrow had a scissor bite, with the upper and lower teeth biting past each other.

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The protrusion of the front teeth can be seen from the side.

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The second molar can be seen leaning toward the tongue.

As a result, it did not occlude properly with the opposing upper second molar, resulting in a scissor bite.

A condition in which the teeth are crossed and do not occlude properly in this way is called a scissor bite.

To achieve a complete improvement in the molar occlusion and protrusion, comprehensive orthodontic treatment would be necessary, including premolar extractions, and the treatment period would be at least two years.

The patient's only concern was the left front tooth, so they did not want to invest that much time and money in treatment.

With Invisalign Lite, we decided to accept certain limitations, improve the front teeth within the possible range, and address the scissor bite and protrusion as much as possible.

From March to July 2024, treatment continued for four months, with the 14 aligners in the first set changed sequentially at seven-day intervals.

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To achieve a clear improvement in the scissor bite, a miniscrew was placed in the palate.

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Similarly, a miniscrew was placed to reliably upright the rearmost molar, which was leaning over.

A total of two miniscrews were placed.

Since Invisalign Lite is originally intended for mild malocclusion, placing miniscrews is not common.

They were placed to achieve the best possible results within the permitted treatment period.

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To correct the remaining issues, additional aligners were fabricated. After wearing the 14 aligners in the second set for four months from August to December 2024, the result was as follows.

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While proceeding with the second set, partial MTA appliances were attached and wires were placed to upright the leaning molar with greater force.

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This is the result after completing treatment.

The deep bite, in which the front teeth bit too deeply, was improved.

The size of the black triangles could be reduced through interproximal reduction, but because excessive interproximal reduction should be avoided, small black triangles remained.

Let's look at the results before and after treatment.

Left – before treatment / Right – after treatment

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Improvement in the protruding appearance of the front teeth through interproximal reduction

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Improvement in the alignment of the front teeth and the scissor bite

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The leaning molar was successfully uprighted.

Improvement in the alignment of the lower front teeth through interproximal reduction

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Improvement in the deep bite and dental midline

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If the patient wears the Invisalign aligners diligently and the treating doctor develops a treatment plan that accepts certain limitations while making every effort, including the use of miniscrews and mini-tube attachments, Invisalign Lite can also produce good results in a short period.

Key Points of This Case

This case does not mean that avoiding extraction-based orthodontic treatment was the better treatment option.

If the goal were ideal occlusion, comprehensive orthodontic treatment, including extractions, would still have been necessary in this case.

However, by setting realistic goals after considering the patient's treatment objectives, time, cost, and treatment duration, satisfactory improvement was achieved in a relatively short period of approximately 10 months.

In addition, Invisalign Lite is not limited to simple treatment alone.

If the treating doctor

• develops an appropriate treatment plan,

• actively uses miniscrews when necessary,

• appropriately combines partial fixed-wire orthodontic treatment, and

• the patient wears the aligners faithfully,

there are cases in which Invisalign Lite alone can achieve results beyond expectations.