Changes in the mandibular arch after rapid maxillary expansion in children: A three-dimensional analysis using digital models

Abstract

Maxillary posterior crossbite is detectable in the deciduous dentition of nearly 20.81% of the child population. [1,2] This transverse discrepancy does not self-correct, whether it is functional or skeletal, unilateral, or bilateral. [3][4][5] Rapid maxillary expansion (RME) is indicated in patients with posterior crossbite to correct the transversal discrepancy between arches by opening the midpalatal suture and expanding the maxillary molars. [6] The effects of this procedure on the mandibular arch are not well understood. Some researchers believe that the intermolar width and arch perimeter increase due to better positioning of the tongue over the mandibular arch, leading to a physiological expansion as a result of the RME. Others contend that no association exists between the procedures.Measurements performed on digital casts have been described as reliable for orthodontic purposes, with the advantages of consuming less storage space and being easy to manipulate for the study. [7,8] The advantages of digital casts include the possibility of more precise analysis, the reduced need for storage, and the ease of handling, sharing, and forwarding them. [9] The objective of this retrospective study was to evaluate and compare the changes in distance between mandibular first molars and mandibular arch perimeters, before and after RME, using digital models. [9]

Rapid maxillary expansion for maxillary atresia and mandibular alignment: A mixed dentition case report

“…Ugolini et al (2016) (Ugolini et al, 2016) observed a beneficial effect on mandibular intermolar distance post-RME, indicating an adaptive response of the lower arch to maxillary arch changes . Conversely, Pacheco et al (2018) (Pacheco et al, 2018), found that RME, specifically with Haas-type appliances, does not significantly increase mandibular intermolar width or arch perimeter in growing patients.…”