Evaluation of miniscrew-supported rapid maxillary expansion in adolescents: A prospective randomized clinical trial

Objectives:To evaluate and compare the dental and skeletal changes with conventional and miniscrew-supported maxillary expansion appliances in adolescents.Materials and Methods:Forty patients were divided into two groups, with one group receiving a tooth-borne expander and the other group receiving an expander supported by four miniscrews (bone-borne). Multiplanar coronal and axial slices obtained from cone-beam computed tomography images were used to measure the changes in transverse skeletal widths, buccal bone thickness, tooth inclination, and root length. Paired t-tests and independent-sample t-tests were used to compare the two expansion methods.Results:Bone-borne expansion increased the maxillary suture opening more than 2.5 times than tooth-borne expansion both anteriorly and posteriorly. Between the maxillary first premolars, sutural expansion accounted for 28% and 70% of the total transverse width increase in the tooth-borne and bone-borne expander groups, respectively. Similarly, 26% and 68% of the total expansion was of skeletal nature in the tooth-borne and bone-borne expander groups between the maxillary first molars. The pattern of expansion was variable, with most of the patients in both groups demonstrating a triangular-shaped sutural opening that was wider anteriorly. Subjects in the conventional group experienced significantly more buccal bone reduction and greater buccal inclination of the teeth. No significant differences were observed for root length measurements between the two groups.Conclusion:Use of bone-borne expansion in the adolescent population increased the extent of skeletal changes in the range of 1.5 to 2.8 times that of tooth-borne expansion and did not result in any dental side effects.     

2种上颌快速扩弓器临床效果的Meta分析

目的:比较牙支持式及混合支持式扩弓器进行上颌快速扩弓的临床效果.方法:计算机检索PubMed、Cochrane Library、EMbase、CBM、中国知网、维普、万方数据库,收集所有比较牙支持式及混合支持式扩弓器进行上颌快速扩弓的文献,检索时限均从建库至2015-10-31.按照纳入、排除标准,由2位研究者评价纳入研究的质量并提取资料后,采用RevMan 5.3软件进行Meta分析.结果:共纳入研究8篇,患者206例.Meta分析结果显示,牙支持式及混合支持式扩弓器相比,两者在扩弓矫治前后右侧第一磨牙倾斜角度变化[MD=-1.62,95％CI(-3.18,-0.07)]、第一前磨牙间距变化[SMD=-0.86,95％CI(-1.47,0.25)]、牙槽突倾斜角变化[SMD=-0.86,95％CI(-1.10,-0.20)]方面的差异有统计学意义.在扩弓矫治前后第一磨牙间距变化[SMD=-0.08,95％CI(-0.61,0.45)]、左侧第一磨牙倾斜角度变化[MD=-1.12,95％CI(-2.57,0.33)]、上颌骨横向宽度变化[SMD=-0.30,95％ CI(-1.08,0.47)]方面的差异无统计学意义.结论:牙支持式及混合支持式扩弓器对上颌牙弓的扩张效果相当,牙支持式扩弓器会造成更多的第一磨牙及牙槽突倾斜.     

Dentofacial changes from fan-type rapid maxillary expansion vs traditional rapid maxillary expansion in early mixed dentition: A prospective clinical trial

Objective:To test the null hypothesis that there is no difference between the effects of fan-type rapid (FRME) and rapid maxillary expansion (RME) used with an acrylic bonded expansion appliance on dentofacial structures in early occlusal stages.Materials and Methods:This was a prospective clinical trial. The FRME group had an anterior constricted maxillary width with a normal intermolar width, and the RME group had bilateral constricted maxillary width. The FRME group consisted of 20 patients (mean age, 8.96 ± 1.19 years), and the RME group consisted of 22 patients (mean age, 8.69 ± 0.66 years). Lateral and frontal cephalometric radiographs and dental casts were taken before and after expansion and 3 months after completing treatment for each patient. The data were compared using repeated-measures analysis of variance. The paired-samples t-test was used to evaluate treatment and retention effects, and the independent samples t-test was used to consider the differences between the two groups.Results:The maxilla moved downward and forward in both groups. The nasal cavity and maxillary width were expanded more in the RME group, and there were only a few relapses in this group during the retention period. There was significant labial tipping of the upper incisors in the FRME expansion group. The expansion of intercanine width was similar in both groups, but the expansion of intermolar width was significantly greater in the RME group.Conclusion:The null hypothesis was rejected. There was a difference between the effects of FRME and RME used with an acrylic bonded expansion appliance on dentofacial structures in the early occlusal stages.     

Facial soft-tissue changes after rapid maxillary expansion analyzed with 3-dimensional stereophotogrammetry: A randomized,controlled clinical trial

Objective:To evaluate three-dimensional (3-D) soft tissue facial changes following rapid maxillary expansion (RME) and to compare these changes with an untreated control group.Materials and Methods:Patients who need RME as a part of their orthodontic treatment were randomly divided into two groups of 17 patients each. Eligibility criteria included having maxillary transverse deficiency with crossbite, and to be in the normal range according to body mass index. In the first group (mean age  =  13.4 ± 1.2 years), expansion was performed. The second group received no treatment initially and served as untreated control (mean age  =  12.8 ± 1.3 years). Skeletal and soft tissue changes were evaluated using posteroanterior cephalograms and 3-D facial images. The primary outcome of this study was to assess the soft tissue changes. The secondary outcomes were evaluation hard tissue and soft tissue relations. Randomization was done with preprepared random number tables. Blinding was applicable for outcome assessment only. MANOVA, t-test, and correlation analyses were used (P  =  .05).Results:In both groups, there was a general trend of increase for the transverse skeletal measurements, but these increases were more limited in the control group. Alar base width was greater in the treatment group (P  =  .002). Pogonion soft tissue point (P  =  .022) was located more posteriorly in the expansion group compared with the control group.Conclusions:Soft tissue changes between groups were similar, except for the alar base, which became wider in the treatment group. Weak correlations were found between the skeletal and soft tissue changes.     

Tooth-borne vs bone-borne rapid maxillary expanders in late adolescence

Objective:To evaluate the immediate effects of rapid maxillary expansion (RME) on the transverse skeletal and dentoalveolar changes with bone-borne (C-expander) and tooth-borne type expanders using cone-beam computed tomography (CBCT) in late adolescents.Materials and Methods:A sample of 28 female late-adolescent patients was divided into two groups according to the type of expander: bone-borne (C-expander, n  =  15, age  =  18.1 ± 4.4 years) and tooth-borne (hyrax, bands on premolars and molars, n  =  13, age  =  17.4 ± 3.4 years). CBCT scans were taken at 0.2-mm voxel size before treatment (T1) and 3 months after RME (T2). Transverse skeletal and dental expansion, alveolar inclination, tooth axis, vertical height of tooth, and buccal dehiscence were evaluated on maxillary premolars and molars. Paired t-test, independent t-test, one-way analysis of variance, and Scheffé post hoc analysis were performed.Results:The C-expander group produced greater skeletal expansion, except in the region of the first premolar (P < .05 or < .01), which showed slight buccal tipping of the alveolar bone. The Hyrax group had more buccal tipping of the alveolar bone and the tooth axes, except in the region of the second molar (P < .05 or < .01 or < .001). Dental expansion at the apex level was similar in the banded teeth (the first premolar and the first molar). Vertical height changes were apparent on the second premolar in the hyrax group (P < .05 or < .01). Significant buccal dehiscence occurred at the first premolar in the hyrax group (P < .01 or < .001). There were no significant differences between tooth types for any variables in the C-expander group.Conclusions:For patients in late adolescence, bone-borne expanders produced greater orthopedic effects and fewer dentoalveolar side effects compared to the hyrax expanders.     

Short-term skeletal and dental changes following bone-borne versus tooth-borne surgically assisted rapid maxillary expansion: A randomized clinical trial study

AimTo evaluate and compare the short-term (post-retention) skeletal and dental changes following bone-borne and tooth-borne surgically assisted rapid maxillary expansion (SARME) using cone beam computed tomography (CBCT).Subjects and methodsIn this randomized clinical study, 30 patients with transverse maxillary deficiency underwent either tooth-borne (n = 15) or bone-borne (n = 15) SARME. Before treatment and immediately after the consolidation period, CBCT was obtained and the nasal floor width, interdental root distance, palatal bone width and interdental cusp distance were measured at first premolar and first molar regions of maxilla.ResultsTwenty eight patients completed the study protocol. In both tooth-borne (n = 13) and bone-borne (n = 15) groups the highest degree of expansion occurred in the dental arch, followed by palatal bone, and nasal floor (V-shaped widening in coronal dimension). The amount and pattern of expansion was comparable between anterior and posterior maxillary regions in each group (parallel posteroanterior expansion) and between the two groups.ConclusionDental and skeletal effects of tooth-borne and bone-borne devices were comparable. The overall complication rate was negligible. Selection of an expansion device should be based on each individual patient's requirements. Future long-term clinical trial studies to evaluate the stability and relapse of these two techniques are recommended.     

Dental arch response to Haas-type rapid maxillary expansion anchored to deciduous vs permanent molars: A multicentric randomized controlled trial

Objective:To assess maxilla and mandibular arch widths'' response to Haas-type rapid maxillary expansion (RME) anchored to deciduous vs permanent molars on children with unilateral posterior crossbite.Materials and Methods:Seventy patients with unilateral posterior crossbite recruited at the Universities of Genova, Siena, and Insubria (Varese) were randomly located into GrE (RME on second deciduous molars) or Gr6 (RME on first permanent molars) and compared.Results:Upper intermolar distance and permanent molar angulation increased significantly in Gr6 vs GrE at T1. Upper intercanine distance increased significantly in GrE vs Gr6 at T1 and T2. GrE showed significant increases for upper intermolar and upper intercanine widths. Gr6 showed statistically significant increases for upper intermolar widths, for upper and lower intercanine widths, and for increases of angulation of upper and lower permanent molars.Conclusions:GrE showed reduced molar angulation increases at T1 and reduced molar angulation decreases at T2 when compared with Gr6. At T2, the net increase of the upper intercanine distance in GrE was still significant compared with Gr6, indicating a more stable expansion in the anterior area.     

The effects of rapid maxillary expansion on voice function

Objective:To evaluate the effects of rapid maxillary expansion (RME) on vocal function in patients with bilateral maxillary crossbite.Materials and Methods:We designed our research as a prospective, controlled, clinical study. The treatment group and the control group each had 20 subjects for a total of 40 subjects. Acoustic voice samples were recorded from all patients at T₁ and T₂ by the Multi-Dimensional Voice Program (MDVP Model 5105) for acoustic analysis in Computerized Speech Lab (CSL).Results:No statistically significant differences were found between the treatment and control groups in the means of any parameters.Conclusions:RME does not change vocal quality or resonance, so it can be safely used with patients.     

Influence of activation protocol on perceived pain during rapid maxillary expansion

Objective:To investigate the influence of two different activation protocols on the timing and intensity of pain during rapid maxillary expansion (RME).Materials and Methods:A total of 112 prepubertal patients (54 males and 58 females, mean age 11.00 ± 1.80 years) with constricted maxillary arches underwent RME with two different activation protocols (group 1: one activation/day; group 2: two activations/day). Patients were provided with a numeric rating scale (NRS) and the Faces Pain Scale (FPS) to correctly assess their daily pain.Results:Subjects treated with RME at two activations/day reported statistically significantly greater amounts of pain than subjects treated with RME at one activation/day. Differences related to gender and skeletal maturity were found.Conclusion:The choice of activation protocol influences the perceived pain during RME, and less daily expansion is correlated to less pain. Pain reported during RME could be influenced by skeletal maturity and gender of the subjects under treatment.     

Pain and discomfort during the first week of rapid maxillary expansion (RME) using two different RME appliances: A randomized controlled trial

Objectives:To evaluate and compare perceived pain intensity, discomfort, and jaw function impairment during the first week with tooth-borne or tooth-bone–borne rapid maxillary expansion (RME) appliances.Materials and Methods:Fifty-four patients (28 girls and 26 boys) with a mean age of 9.8 years (SD 1.28 years) were randomized into two groups. Group A received a conventional hyrax appliance and group B a hybrid hyrax appliance anchored on mini-implants in the anterior palate. Questionnaires were used to assess pain intensity, discomfort, analgesic consumption, and jaw function impairment on the first and fourth days after RME appliance insertion.Results:Fifty patients answered both questionnaires. Overall median pain on the first day in treatment was 13.0 (range 0–82) and 3.5 (0–78) for groups A and B, respectively, with no significant differences in pain, discomfort, analgesic consumption, or functional jaw impairment between groups. Overall median pain on the fourth day was 9.0 (0–90) and 2.0 (0–71) for groups A and B, respectively, with no significant differences between groups. There were also no significant differences in pain levels within group A, while group B scored significantly lower concerning pain from molars and incisors and tensions from the jaw on day 4 than on the first day in treatment. There was a significant positive correlation between age and pain and discomfort on the fourth day in treatment. No correlations were found between sex and pain and discomfort, analgesic consumption, and jaw function impairment.Conclusions:Both tooth-borne and tooth-bone–borne RME were generally well tolerated by the patients during the first week of treatment.     

Asymmetric rapid maxillary expansion in true unilateral crossbite malocclusion: A prospective controlled clinical study

Objective:To investigate the short-term effects of the asymmetric rapid maxillary (ARME) appliance on the vertical, sagittal, and transverse planes in patients with true unilateral posterior crossbite.Materials and Methods:Subjects were divided into two groups. The treatment group was comprised of 21 patients with unilateral posterior crossbite (mean age  =  13.3 ± 2.1 years). Members of this group were treated with the ARME appliance. The control group was comprised of 17 patients with Angle Class I who were kept under observation (mean age  =  12.3 ± 0.8 years). Lateral and frontal cephalograms were taken before the expansion (T1), immediately after expansion (T2), and at postexpansion retention (T3) in the treatment group and at preobservation (T1) and postobservation (T2) in the control group. A total of 34 measurements were assessed on cephalograms. For statistical analysis, the Wilcoxon test and analysis of covariance were used.Results:The ARME appliance produced significant increases in nasal, maxillary base, upper arch, and lower arch dimensions (P < .01) and a clockwise rotation of the occlusal plane (P  =  .001).Conclusion:The ARME appliance created asymmetric increments in the transversal dimensions of the nose, maxilla, and upper arch in the short term. Asymmetric expansion therapy for subjects with unilateral maxillary deficiency may provide satisfactory outcomes in adolescents, with the exception of mandibular arch expansion. The triangular pattern of expansion caused clockwise rotation of the mandible and the occlusal plane and produced significant alterations in the vertical facial dimensions, whereas it created no displacement in maxilla in the sagittal plane.     

Short term effects of rapid maxillary expansion on breathing function assessed with spirometry: A case-control study

BackgroundThe aim of this work is to evaluate changes following rapid maxillary expansion (RME) on breathing function in two groups of patients: mouth breathers and nasal breathers.Materials and methodsTwenty-five oral breather patients (12 male, 13 female, mean age 15.2 ± 1.3), and 25 nasal breather patients (14 male, 11 female, mean age 15.3 ± 1.6) were treated with RME. Breathing function was evaluated by computerized spirometry. Forced vital capacity (FVC), forced expiratory volume in the first second (FEV1), Tiffenau index (FEV1/ FVC ratio, IT%), forced expiratory flow at 25–75% of vital capacity (FEF 25–75%), and Tidal volume (TV) were assessed. Breathing function analysis was performed before RME and 6 and 12 months after RME during follow-up appointments. The Shapiro–Wilk test was used to assess whether data were normally distributed. As data were not normally distributed, Mann–Whitney U and Friedman tests were used to perform comparisons between treatment groups and within group comparisons, respectively.ResultsOral breathers and nasal breathers showed statistically significant differences in FVC, FEF 25–75%, and TV at T0. They did not present any statistically significant difference in FEV1 and IT% at the same time point.Statistically significant differences were noticed for all indices in the oral breather group after maxillary expansion, while the nasal breather group showed statistically significant differences only in FCV, FEF 25–75%, and TV after treatment.There were no statistically significant differences in all indices 12 months after maxillary expansion between the oral breather and nasal breather groups.ConclusionsRME appeared to improve breathing function in both groups. Forced vital capacity (FVC), forced expiratory flow at 25–75% of vital capacity (FEF 25–75), and Tidal volume (TV) reached similar values in both groups after treatment with RME.     

Does rapid maxillary expansion induce adverse effects in growing subjects

Objective:To assess the scientific evidence that rapid maxillary expansion (RME) causes Adverse Effects on the midpalatal suture, vertical dimension, dental and periodontal structures in growing subjects.Materials and MethodsElectronic databases were searched for articles dated through December 2011. The quality of the studies was ranked on a 13-point scale in which 1 was the low end of the scale and 13 was the high end.Results:Thirty relevant articles were identified. The amount of midpalatal suture opening ranged from 1.6 to 4.3 mm in the anterior region and from 1.2 to 4.4 mm in the posterior region. At the end of the active phase, RME resulted in slight inferior movement of the maxilla (SN-PNS +0.9 mm; SN-ANS +1.6 mm), increased tipping of anchored teeth from 3.4° to 9.2° and bending of the alveolar bone from 5.1° to 11.3°. In the long term, RME did not modify the facial growth patterns, and no significant changes on dentoalveolar structures were observed. Of the 30 studies, 2 were medium-high quality, 8 were medium quality, and 20 were low quality.Conclusions:RME always opened the midpalatal suture in growing subjects. The vertical changes were small and transitory. In the long-term evaluation, an uprighting of anchored teeth was observed and periodontal structures were not compromised.