Consideration in Micro-implant assisted rapid palatal expander（MARPE）

Currently, there are various ways to enlarge the maxillary dentition.

The use of maxillary expanders began in the late 19th century. Since then, many orthodontists have applied it clinically, and the design of the device has been gradually improved, and it is still used all over the world today.

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The most common type of orthodontic appliance used is a removable appliance called "floor braces". These devices apply a weak force to the teeth, causing them to tilt and expand.

In this method, there is no problem if the maxillary teeth are tilted to the extent that they are balanced with the mandibular teeth, but if they are greatly expanded, there is a risk that the teeth will be tilted farther outward than the foundation bone. The long-term prognosis in such a case is that the alveolar bone may be damaged, the dentition may not be stable, and problems such as gingival recession may occur, so care must be taken.

There is also a "rapid enlargement device" that can increase the width of the maxilla by applying jaw shaping force to open the mid palatal suture.

This is basically indicated for young people between the ages of 10 and 15 years old, before the various sutures of the maxillofacial region have fused. After that age, not only is it very difficult to release the median palatal suture as the patient ages, but the structure of the appliance, which requires the teeth to be the anchoring source, may cause undesirable reactions in orthodontic treatment such as tooth tilting, root resorption, gingival recession, and retroversion.

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In the past, most of the above two methods were used, but in recent years, there have been reports of a Micro-implant assisted rapid palatal expander（MARPE）that uses an orthodontic anchor screw as a fixation source for a rapid expansion device to dehiscate the median palatal suture. It has come to be seen.

Here, I would like to introduce one of the papers published in AJO-DO in June 2021.

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【Micro implant assisted rapid palatal expansion

vs

surgically assisted rapid palatal expansion

for maxillary transverse discrepancy treatment.】

〈Method〉

With a dentition of 4 mm or more with one-sided or two-sided crossbite

[MARPE] Rapid expansion using a dental CBCT with a screw 17 people

[SARPE] Rapid expansion of 15 people with surgical procedures

We compared and examined before and after treatment.

〈Result〉

①MARPE showed more remarkable bone enlargement compared to SARPE

②MARPE showed parallel expansion compared to SARPE.

③MARPE was found to have less amount of buccal tilt due to rapid expansion compared to SARPE.

④The area around the nasal cavity was greatly enlarged by the use of MARPE.

　The possibility of a more positive effect on the upper airway was observed.

Traditional surgical procedures have been to cut and enlarge the maxillary bone when enlargement is required in an adult who has finished growing. However, this method imposes a burden on the patient because he/she is hospitalized and the bone is cut under general anesthesia.

In contrast, orthodontic anchor screws allow skeletal expansion under local anesthesia, thus reducing the burden on the patient. Furthermore, maxillary bone expansion is now possible even for patients in their 30s or later.

In addition, in the above results, ② MARPE showed a parallel expansion compared to SARPE. In skeletal class III cases (receptacles) that use anterior maxillary traction devices, the resistance of the maxilla can be reduced by performing MARPE before using the face mask, so the effect of expansion is further demonstrated.

In summary, MARPE is highly useful in the orthodontic treatment of adults and may increase the variety of treatments.

【Micro-implant assisted rapid palatal expander(MARPE) Case】

After

Before

Case photo provided：https://www.aqua-kyousei.com/

“IOS” will provide the correct knowledge and accurate information on orthodontic treatment to a wide range of people, from the general public to dentists, based on international evidence.

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References：

1） Angell EH : Treatment of irregularity of permanent or adult teeth. Dent Cosmos,１：５４０－５４４，１８６０．

2)　MOSS JP : Rapid expansion of the maxillary arch, part Ⅱ. J. P. O,

２：２１５－２２３，１９６８．

3) Garib DG, Navarro R, Francischone CE, Oltramari PV : Rapid maxillary expansion using palatal implants. J Clin Orthod, ４２：６６５－７１，２００８.

4) Cibele BO, Priscila Ayub, Ingrid ML, Wilson HM, Selly SS, Dirceu BR, Ary SP :Microimplant assisted rapid palatal expansion vs surgically assisted rapid palatal expansion for maxillary transverse discrepancy treatment. AJO-DO, １５９, ７３３－７４２, ２０２１.

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