An assessment of the maxilla after rapid maxillary expansion using cone beam computed tomography in growing children

Abstract

IntroductionWith the advent of cone beam computed tomography (CBCT), it is now possible to quantitatively evaluate the effects of rapid maxillary expansion (RME) on the entire maxillary complex in growing patients. ObjectiveThe purpose of this study is to use three-dimensional images to evaluate the displacement that occurs at the circummaxillary sutures (frontonasal, zygomaticomaxillary, intermaxillary, midpalatal, and transpalatal sutures) following rapid maxillary expansion in growing children. MethodsThe CBCT scans of 25 consecutively treated RME patients (10 male, 15 female) with mean age of 12.3 ± 2.6 years, were examined before expansion and immediately following the last activation of the expansion appliance. ResultsStatistically significant (P < 0.05) amounts of separation were found for the displacement of the bones of the frontonasal suture, the intermaxillary suture, the zygomaticomaxillary sutures, and the midpalatal suture. The change in angulation of the maxillary first molars due to RME was also statistically significant. There was no statistically significant displacement of the transpalatal suture. ConclusionsRapid maxillary expansion results in significant displacement of the bones of circummaxillary sutures in growing children.

CBCT in orthodontics: assessment of treatment outcomes and indications for its use

“…Specifically, CBCT has been used to address two questions related to RME treatment, namely how expansion forces affect different regions of the maxilla and the effect of age on the relative magnitude of skeletal expansion vs dental tipping. 74,76,142,143 These studies show that tooth-borne RME treatment in growing children result in separation of several circum-maxillary sutures contributing to an increase in not only the transverse dimension but also in the sagittal and vertical dimension. 142,143 Not surprisingly, younger children (6-8 years old) demonstrate greater skeletal expansion than older children (9-11 years old) who show greater dental tipping following RME treatment.…”

“…74,76,142,143 These studies show that tooth-borne RME treatment in growing children result in separation of several circum-maxillary sutures contributing to an increase in not only the transverse dimension but also in the sagittal and vertical dimension. 142,143 Not surprisingly, younger children (6-8 years old) demonstrate greater skeletal expansion than older children (9-11 years old) who show greater dental tipping following RME treatment. 144,145 Treatment with four-banded maxillary expanders also reveal that although the first premolar, second premolar and first molar all have similar magnitudes of total overall expansion (which includes skeletal expansion, dental tipping and alveolar bone bending), the skeletal expansion is greater in the anterior than in the posterior maxilla.…”

Deviating dental arch morphology in mild coronal craniosynostosis syndromes

“…The clinical implications for orthodontic treatment of patients with Muenke and Saethre-Chotzen syndromes or TCF12-related craniosynostosis lie in the high prevalence of smaller dental arch dimensions and posterior crossbites that should be seen in relation to craniosynostosis. In a case series of CT scans in healthy children that were undergoing rapid palatal expansion, it was shown that the maxillary sutures were expanded and the maxillary molars were inclined [28]. Therefore, orthodontic expansion of the maxilla should be done with care to prevent inclination of molars.…”

Three dimensional evaluation of alveolar bone changes in response to different rapid palatal expansion activation rates

“…, 6 Ghoneima et al 13 reported that maxillary alveolar width increases more than maxillary base width, supporting the idea that bone tipping might explain the majority of expansion 13 . Krebs 14 indicated that, in adolescents, 65% of the total expansion was shown to be the result of dental movement or tipping.…”