CBCT of skeletal changes following rapid maxillary expansion to increase arch-length with a development-dependent bonded or banded appliance

Abstract

Objective: To assess the three-dimensional (3D) skeletal response to a standardized 5 mm of rapid maxillary expansion (RME) in growing children (6-15 years) with maxillary width deficiency and crowding. Materials and Methods: A bonded appliance was used prior to the eruption of the maxillary first premolars (Mx4s), and a banded appliance was used thereafter. A consecutive sample of 89 patients (29 boys and 60 girls) from a large pediatric dentistry and orthodontics practice was divided into four groups: 1) 6-8 years old (n 5 26), 2) 9-11 years old with unerupted Mx4s (n 5 21), 3) 9-11 years with erupted Mx4s (n 5 23), and 4) 12-15 years (n 5 19). For all patients, the 3D evaluation of dental and skeletal effects was performed with cone-beam computed tomography (CBCT). Results: For both appliances in all patients, CBCT confirmed a triangular pattern of expansion in both the frontal and sagittal planes. Overall, both appliances produced significant maxillary expansion (.80% of the 5-mm activation), but older children showed a progressively more dental (less skeletal) response. Comparison of the two types of expanders in the crossover sample, children aged 9-11 years, showed that the bonded RME produced the most efficient skeletal expansion in the preadolescent sample. Increased maxillary width at the level of the zygomaticomaxillary suture was the best indicator for development of maxillary arch circumference. Conclusion: Development-dependent appliances (bonded RPE before Mx4s erupt, and a banded device thereafter) provided optimal RME treatment for all children from age 6-15 years. (Angle Orthod. 2013;83:851-857.)

The Effects of Two Different Palatal Expanders on Nasal and Pharyngeal Airway Volumes as Measured by CBCT

“…(3)(4)(5)(6) Other in-vitro studies revealed the same results regarding nasal cavity widening specially the anterior and inferior parts. (7)(8)(9) Also the nasopharynx has expanded significantly as a result of inferio-anterior displacement of palatal shelves.…”

Differential treatment effects of two anchorage systems for rapid maxillary expansion: a retrospective cephalometric study

“…Pertinent studies became available following the introduction of CBCT to dentistry-and orthodontics [38]-in the late 1990s [52]. More recently, systematic reviews of CBCT studies on RME have become available [5,9,21,27,37,39,[57][58][59]. Given the natural advantages of CBCT, these studies have mainly reported on changes in the transverse plane, but maxillary movements in caudal and anterior directions have also been described [27].…”

Effects of different rapid maxillary expansion appliances on facial soft tissues using three-dimensional imaging

“…Patients with facial or nasal deformities and those younger than 11 years or older than 15 years were excluded from the study. Sample size was calculated based on data available in the literature, 4 and analysis was performed with G*Power Version 3.0.10 (Franz Faul, Universitä t Kiel, Germany) software. Based on a 1:1 ratio among groups, a total sample size of 42 was predicted to provide more than 80% confidence to detect differences at an a 5 .05 significance level.…”

“…[1][2][3] These appliances produce both orthopedic and orthodontic effects by tipping the posterior teeth buccally and enable dental extrusion and lateral rotations of the alveolar segments. [4][5][6] These effects of RME cause downward and backward rotation of the mandible and increased facial height. 2,7,8 In orthodontic evaluation, the most common ways to determine the soft tissue effects of the treatment are soft tissue analysis of the patient's cephalometric radiographs and photographs.…”