A maxillary expander, also known as an orthodontic or palatal expander, is a dental appliance that is used to widen the upper jaw (maxilla) through the palatal shelves. It is typically used in children and adolescents during the growing period to correct a variety of dental alignment issues such as crowding, overbite, and underbite. Additionally, it can be used in adulthood tocorrect significant jaw width discrepancies and improve Bite Function.
Usage
Maxillary expanders are most commonly used in children and adolescents between the ages of 8 to 18 years old. They can also be used in adults, but it is important to note that the procedure may be more painful and time-consuming due to the older age of the patient. A patient who opts for a maxillary expander may also have a surgical separation of the maxilla, as an alternative to achieve the desired expansion results. Often, a maxillary expander is followed by orthodontic treatment with braces to properly align the teeth.
Indications
Maxillary expansion is indicated in cases where there is a significant difference in the width of the upper jaw compared to the lower jaw (equal to or greater than 4 mm). The measurement is typically taken from the width of the first molars on the maxilla to compare with the lower jaw. Due to the way molars compensate for the difference by向外 tipping, rapid palatal expansion is often used to achieve a change in the position of the molars as well.
Types of Expansion
Rapid Palatal Expansion (RPE) or Rapid Maxillary Expansion (RME)
Rapid palatal expansion is a dental expansion technique where the maxilla is expanded at a rate of 0.5-1mm per day until the posterior crossbite is alleviated. This expansion technique uses a key to turn a central expansion screw, which pushes the arms of the expander apart. The expansion typically takes between three to six months to achieve the desired results, with the expander remaining in the patient's mouth for stability. A retainer is typically given to the patient for retainment of proper tooth alignment following expansion. RPE can be tooth-supported, bone-supported, or both.
Slow Expansion
Slow expansion techniques expand the maxilla at a slower rate compared to rapid maxillary expansion. A maxillary skeletal expander (MSE) is adapted for adults, and the expansion is usually done non-surgically. The treatment time can vary according to the severity of the condition, but it generally takes several weeks to solidify the end result.
###Implant-Assisted Expansion
Mini-implant-Assisted Rapid Palatal Expansion (MARPE) involves placing mini-dental implants in the palate vault area of the maxilla toanchor the RME appliance to the screws. The patient is then asked to turn the jackscrew with the rapid approach over two weeks. This technique is particularly useful for young adults whose palatal suture is already fused.
Adverse Effects
Maxillary expansion can cause a variety of side effects, including trouble with speech, pain, sores on the tongue, diastema, fenestration of the buccal bone, compression of the periodontal ligament, extrusion of the posterior teeth, increased lingual bone thickness, and decreased buccal bone thickness. These side effects typically resolve over time as the bone adjusts to the new expansion.
History
Maxillary expanders have been used in orthodontic treatment for over 100 years. The first maxillary expander was placed on the maxillofacial region by Westcott in 1859. Subsequently, numerous expansion techniques have been developed and refined, including the use of keys, quick expansion, slow expansion, implant-assisted expansion, and surgically assisted rapid palatal expansion (SARPE).
