Evaluation of the effects of miniscrew incorporation in palatal expanders for young adults using finite element analysis

Abstract

ObjectiveThe aim of this study was to evaluate the stress distribution and displacement of various craniofacial structures after nonsurgical rapid palatal expansion (RPE) with conventional (C-RPE), bone-borne (B-RPE), and miniscrew-assisted (MARPE) expanders for young adults using three-dimensional finite element analysis (3D FEA).MethodsConventional, bone-borne, and miniscrew-assisted palatal expanders were designed to simulate expansion in a 3D FE model created from a 20-year-old human dry skull. Stress distribution and the displacement pattern for each circumaxillary suture and anchor tooth were calculated.ResultsThe results showed that C-RPE induced the greatest stress along the frontal process of the maxilla and around the anchor teeth, followed by the suture area, whereas B-RPE generated the greatest stress around the miniscrew, although the area was limited within the suture. Compared with the other appliances, MARPE caused relatively even stress distribution, decreased the stress on the buccal plate of the anchor teeth, and reduced tipping of the anchor teeth.ConclusionsThe findings of this study suggest that the incorporation of miniscrews in RPE devices may contribute to force delivery to the sutures and a decrease in excessive stress on the buccal plate. Thus, MARPE may serve as an effective modality for the nonsurgical treatment of transverse maxillary deficiency in young adults.

Uso da expansão rápida palatal assistida por mini-implantes (MARPE) em tratamentos ortopédicos maxilares – revisão de literatura e relato de caso

“…Através dela são observados menores efeitos adversos dentoalveolares como: deslocamento dentário, inclinações dentárias, recessões gengivais, deiscência óssea, reabsorções dentárias e o efeito no processo alveolar é insignificante quando comparado a disjuntores convencionais. Também possui a vantagem de ocasionar menor risco de complicações, quando comparado a um tratamento de disjunção cirúrgica (3,14,16,17,20,26,27,28,29). (22) o disjuntor MARPE deve ser usado de forma criteriosa em pacientes que apresentam pouca espessura de osso alveolar vestibular e crista alveolar baixa na região de pré-molares.…”

“…Seong et al (29) avaliaram a utilização de um disjuntor convencional com ancoragem dentária, um disjuntor com ancoragem óssea e um disjuntor com ancoragem dentária e óssea (MARPE). MARPE mostrou menor tensão sobre tábua óssea vestibular e dentes, quando comparado ao aparelho convencional, como também um menor grau de deformação nos mini-implantes, quando comparado ao aparelho de ancoragem exclusivamente óssea.…”

Mini-implant selection protocol applied to MARPE

“…There is increasing interest in the scientific literature in this field, with recent publications of case reports illustrating the different variations of MARPE devices and its expansion protocols; 19 - 21 besides a finite element study on the role of miniscrews in the distribution of forces in MARPE devices. 22 A retrospective clinical study conducted on young adults submitted to MARPE revealed opening of the midpalatal suture in 86.9% of cases, with stable outcomes at 30-month follow-up, by evaluation of posteroanterior cephalograms. 23 Cone-beam computed tomographies (CBCT) revealed significant increases in dentoalveolar and skeletal dimensions in young adults treated with MARPE and followed for one year after expansion.…”

Stability of bimaxillary surgery involving intraoral vertical ramus osteotomy with or without presurgical miniscrew-assisted rapid palatal expansion in adult patients with skeletal Class III malocclusion

“…The miniscrews can reduce stress on the anchor teeth when the appliance expands the maxillary arch, thus reducing the side effects on the anchor teeth. 9 Anterior and inferior movement of the maxilla and subsequent clockwise rotation of the mandible have been reported to occur with use of the aforementioned surgical and nonsurgical procedures for maxillary expansion. [10][11][12] If transverse maxillary expansion can lead to such vertical and anteroposterior changes in the maxillomandibular complex, any relapse can have considerable effects on the skeletal changes after orthognathic surgery.…”