Three-dimensional assessment of morphologic changes of the maxilla: A comparison of 2 kinds of palatal expanders

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.)

Section: Discussionmentioning

confidence: 89%

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

Kanomi

Deguchi

Kakuno

et al. 2013

“…[21][22][23][24] As for root resorption, Do acrylic pads decrease it? Recently, Weisheimer et al 22 found that the hyrax expander had more of an orthopedic effect than did the Haas immediately after RME.…”

Section: Resultsmentioning

confidence: 99%

Evaluation and comparison of root resorption between tooth-borne and tooth-tissue borne rapid maxillary expansion appliances: A CBCT study

Di̇ndaroğlu

Doğan

2015

Objective: To compare volumetric root resorption after rapid maxillary expansion (RME) between tooth-borne and tissue-borne appliances using CBCT. Repair in resorption cavities after 6 months of fixed retention was also compared. Materials and Methods: A sample of 33 subjects were randomly divided into two groups: Hyrax (n 5 16) and Haas (n 5 17). CBCT scans were taken 6 months before expansion, immediately after expansion, and 6 months after fixed retention. Mimics Innovation V 16.0 software was used for segmentation and volumetric measurement of 198 teeth. Bland-Altman plots, independent samples t test, repeated measures analysis of variance, and the Friedman test were used for statistical analysis. Results: Differences in root resorption after RME and repair after retention were not significant between the hyrax and Haas appliances or between male and female. Significant differences were found between preexpansion and postexpansion root volumes in the first premolars and molarseven in unattached second premolars. When the percentage of root volume loss is considered, no significant difference was found between the first premolar, second premolar, and first molar. Volumetric changes after 6 months of retention were not statistically significant.

“…It has been claimed that tooth-tissue borne appliances with occlusal acrylic coverage produce more skeletal expansion than that of the others. [13][14][15] Hearing levels of patients in the previous studies have been assessed by means of pure-tone audiograms, whereas tympanometry is a sensitive measure of the tympanic cavity and eustachian tube. 16 Thus, tympanometric records should be included with the studies investigating the changes in hearing.…”

Section: Introductionmentioning

confidence: 99%

Effects of Rapid Maxillary Expansion on Conductive Hearing Loss

Kılıç

Kiki

Oktay

et al. 2008

Objective: To test the null hypothesis that rapid maxillary expansion (RME) with a rigid bonded appliance has no effect on conductive hearing loss (CHL) in growing children. Materials and Methods: Fifteen growing subjects (mean age 13.43 Ϯ 0.86 years) who had narrow maxillary arches and CHL participated in this study. Three pure-tone audiometric and tympanometric records were taken from each subject. The first records were taken before RME (T1), the second after maxillary expansion (T2) (mean ϭ 0.83 months), and the third after retention (mean ϭ 6 months) and fixed appliance treatment (approximately 2 years) periods (T3). The data were analyzed by means of analysis of variance (ANOVA) and least significant difference (LSD) tests. Results: Hearing levels of the patients were improved and air-bone gaps decreased at a statistically significant level (P Ͻ .001) during active expansion (T2-T1) and the retention and fixed appliance treatment (T2-T3) periods. Middle ear volume increased in all observation periods. However, a statistically significant increase was observed only in the T2-T3 period. No significant change was observed in the static compliance value. Conclusions: The hypothesis is rejected. RME treatment has a positive and statistically significant effect on both improvements in hearing and normal function of the eustachian tube in patients having transverse maxillary deficiency and CHL.