Carotid cavernous fistula after surgically assisted rapid maxillary expansion with a bone anchored appliance

Surgically assisted rapid maxillary expansion (SARME) is an effective and stable method for treating severe maxillary transverse discrepancies in skeletally mature individuals, but it has potential complications. The authors report the case of a 34-year-old woman who developed carotid cavernous fistula after undergoing SARME with a bone anchored appliance and discuss the possible etiological basis of this condition.     

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

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  =  26), 2) 9–11 years old with unerupted Mx4s (n  =  21), 3) 9–11 years with erupted Mx4s (n  =  23), and 4) 12–15 years (n  =  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.     

Buccal alveolar bone changes following rapid maxillary expansion and fixed appliance therapy

ObjectivesTo assess factors that may be associated with buccal bone changes adjacent to maxillary first molars after rapid maxillary expansion (RME) and fixed appliance therapy.Materials and MethodsPretreatment (T1) and posttreatment (T2) cone-beam computed tomography scans were obtained from 45 patients treated with RME and preadjusted edgewise appliances. Buccal alveolar bone thickness was measured adjacent to the mesiobuccal root of the maxillary first molar 4 mm, 6 mm, and 8 mm apical to the cementoenamel junction, and anatomic defects were recorded. Paired and unpaired t-tests were used to compare alveolar bone thickness at T1 and T2 and to determine whether teeth with posttreatment anatomic defects had thinner initial bone. Correlation analyses were used to examine relationships between buccal alveolar bone thickness changes and amount of expansion, initial bone thickness, age at T1, postexpansion retention time, and treatment time.ResultsThere was a statistically significant reduction in buccal alveolar bone thickness from T1 to T2. Approximately half (47.7%) of the teeth developed anatomic defects from T1 to T2. These teeth had significantly thinner buccal bone at T1. Reduction in alveolar bone thickness was correlated with only one tested variable: initial bone thickness.ConclusionsRME and fixed-appliance therapy can be associated with significant reduction in buccal alveolar bone thickness and an increase in anatomic defects adjacent to the expander anchor teeth. Anchor teeth with greater initial buccal bone thickness have less reduction in buccal bone thickness and are less likely to develop posttreatment anatomic defects of buccal bone.     

Skeletal alterations associated with the use of bonded rapid maxillary expansion appliance

Bonded maxillary expansion appliances have been suggested to control increases in the vertical dimension of the face after rapid maxillary expansion (RME). However, there is still no consensus in the literature about its real skeletal effects. The purpose of this prospective study was to evaluate, longitudinally, the vertical and sagittal cephalometric alterations after RME performed with bonded maxillary expansion appliance. The sample consisted of 26 children, with a mean age of 8.7 years (range: 6.9-10.9 years), with posterior skeletal crossbite and indication for RME. After maxillary expansion, the bonded appliance was used as a fixed retention for 3.4 months, being replaced by a removable retention subsequently. The cephalometric study was performed onto lateral radiographs, taken before treatment was started, and again 6.3 months after removing the bonded appliance. Intra-group comparison was made using paired t test. The results showed that there were no significant sagittal skeletal changes at the end of treatment. There was a small vertical skeletal increase in five of the eleven evaluated cephalometric measures. The maxilla displaced downward, but it did not modify the facial growth patterns or the direction of the mandible growth. Under the specific conditions of this research, it may be concluded that RME with acrylic bonded maxillary expansion appliance did promote signifciant vertical or sagittal cephalometric alterations. The vertical changes found with the use of the bonded appliance were small and probably transitory, similar to those occurred with the use of banded expansion appliances.     

上颌快速扩弓与直丝弓矫治器联合应用的临床研究

目的 评价上颌快速扩弓和直丝弓矫治器联合应用对牙弓、基骨宽度的影响。方法 对18例恒牙早期牙列中度拥挤病例以上颌快速扩弓和直丝弓矫治器进行联合治疗，通过对矫治前后牙牙台石膏模型的测量比较，观察牙弓、基骨宽度的变化。结果 治疗后牙弓、基骨的宽度比治疗前增加，统计学分析有显著性差异。结论 上颌快速扩弓和直丝弓矫治器联合应用能使牙弓、基骨宽度快速增加，对牙列拥挤病例是一种安全、有效的治疗方法。     

上下颌联合快速扩弓结合固定矫治器矫治前后牙弓形态变化的研究

目的：研究分析上下颌联合快速扩弓结合 MBT 直丝弓矫治器矫治错(牙合)畸形患者的临床疗效。方法：选择36例进行上下颌联合快速扩弓结合直丝弓矫治器治疗结束的患者,治疗前后分别对每位患者进行模型测量和头影测量分析。结果：矫治后上下颌牙弓宽度和牙弓周长均增加,牙弓宽度增加主要在前磨牙区,牙弓前段深度减小（P ＜0．05）。联合扩弓在骨性垂直方向上的变化无差异（P ＞0．05）,U1-SN、U1-NA 减小,L1-MP、L1-NB 增大（P ＜0．05）。结论：上下颌联合扩弓结合直丝弓矫治技术可以有效地解除拥挤并保持良好的咬合状态,颌骨在垂直方向上没有产生不利影响。     

Effects of a bonded rapid maxillary expansion appliance during orthodontic treatment.

The aim of this prospective study was to evaluate changes in the transverse plane following use of an acrylic bonded rapid maxillary expansion (RME) appliance in growing individuals during the active phase of treatment. The sample comprised 14 consecutively treated orthodontic patients (11 girls, 3 boys) who required the use of an RME device on the basis of their individual treatment plans. The mean patient age at the start of treatment was 12.8 years, and the mean overall treatment time was 3.08 years. Seven posteroanterior cephalometric and two dental cast measurements were assessed. Repeated measure analysis of variance and Duncan's multiple range test were used to assess treatment changes. Lower nasal and maxillary base widths and angles, and upper intermolar width increased significantly during RME treatment. Upper intermolar and intercanine widths measured from the dental casts also increased significantly. Except for upper intercanine width, all measurements remained constant at the end of orthodontic treatment. The results of this study suggest that dentoskeletal changes in the transverse dimension following the use of an acrylic bonded RME are maintained satisfactorily at the end of fixed appliance therapy.     

Skeletal changes of maxillary protraction without rapid maxillary expansion: a comparison of the primary and mixed dentition

Objective:To determine potential differences in treatment efficiencies of face mask therapy without rapid maxillary expansion (RME) at different early dental stages.Materials and Methods:Forty-nine Class III children who were treated with a face mask without RME were divided into two groups according to their pretreatment dental stage. The primary dentition treatment group consisted of 26 subjects and the mixed dentition treatment group consisted of 23 subjects. Lateral cephalograms before treatment (T0), at the end of treatment (T1), and at least 1 year after the end of treatment (T2) were calculated and analyzed. Fourteen cephalometric variables were evaluated by t-test to identify any significant differences in skeletal changes between the two groups during T1-T0, T2-T1, and T2-T0.Results:The primary dentition group showed not only a greater response to maxillary protraction without RME than did the mixed dentition group during T1-T0, but also a greater relapse tendency during T2-T1. As a result, no significant differences were noted between the two groups in the treatment effects of face masks without RME over the time period T2-T0.Conclusion:This study suggests that face mask therapy without RME may be postponed to the early to mid mixed dentition period because the therapy induces similar skeletal changes when initiated at primary or mixed dentition.     

Nasal airway changes due to rapid maxillary expansion timing

The purpose of this study was to evaluate the effect of rapid maxillary expansion (RME) on nasal minimum cross-sectional area (MCA) using acoustic rhinometry (AR) in two groups of subjects who were treated before and after the pubertal growth spurt. The sample consisted of 29 patients with maxillary constriction and a control sample of 15 subjects. Both samples were divided into two groups according to individual skeletal maturation as assessed by the cervical vertebral maturation (CVM) method. Group I T (early-treated) consisted of 16 patients (eight girls and eight boys). Group I C (early-control) consisted of eight patients, and both groups had not reached the pubertal peak (CVM Stage 1-3). Group II T (late-treated) consisted of 13 patients (eight girls and five boys). Group II C (late-control) consisted of seven patients, and both groups were at a stage during or after the pubertal peak (CVM Stage 4-6). AR records were obtained for each treated subject before treatment (T1), after expansion (T2), and immediately after a three-month retention period (T3); only T1 and T3 records were obtained for controls. The overall increase in MCA was significantly greater in the early- and late-treated groups (group I T, group II T) as compared with the early and late controls. (group I C, group II C) (P < .05). The results of the present study suggest that even the overall (T1-T3) increase for MCA in group I T is greater (0.34 mm) than the increase for MCA in group II T (0.19 mm), but the difference was not significant (P > .05).     

Pulpal blood flow changes due to rapid maxillary expansion

Objective:To determine the pulpal blood flow (PBF) changes in anchorage teeth associated with the high forces of a rapid maxillary expansion (RME) appliance.Materials and Methods:The study was performed with 14 girls and 7 boys for a total of 21 patients between 10 and 15 years of age (mean, 13.1 ± 1.39 years). A modified acrylic bonded RME appliance was used as an expansion appliance. Laser Doppler flowmetry was used for the pulpal perfusion measurements. Records were taken from 42 upper central incisors, 28 canines, and 42 first molars at the following time intervals: just before expansion (T1); at the first week of expansion (T2); at the end of the expansion process (T3); and at the third (T4), seventh (T5), and 12th weeks of retention (T6). The data gained were statistically evaluated by parametric tests.Results:PBF values of the anchorage teeth were doubled at the first week of expansion; however, these values began to decrease because of separation of the median palatal suture. PBF values tended to reach their initial values during the retention period. Pulpal perfusion changes of all examined anchorage teeth were similar to each other from the beginning to the end of the evaluation.Conclusion:PBF changes that occur with RME are reversible.     

Surgically assisted rapid maxillary expansion compared with orthopedic rapid maxillary expansion

The objective of this study is to evaluate and compare the dental and skeletal changes occurring during orthopedic rapid maxillary expansion (RME) and surgically assisted RME during the active phase of treatment. The study was divided into two groups. The first group of 10 patients (six males, four females; mean age, 15.51 years) received orthopedic RME. The second group of 10 patients (seven males, three females; average age: 19.01 years) received surgically assisted RME (SARME). All patients underwent maxillary expansion with occlusal-coverage Hyrax-type expanders activated two turns a day (0.25 mm per turn). Preexpansion and postexpansion lateral and posteroanterior cephalograms were obtained for each patient. Statistically significant differences between the SARME and RME groups were found in the N-ANS, SN/ PP (P < .01) and SNA, SNB, mandibular dentoalveolar, and maxillary bony base (P < .05) measurements. Clinically, there is no difference in patient response between the RME and SARME groups. The only difference between the groups was their indication for RME or SARME, which is based on the age and skeletal maturation of the patient.     

Long-term skeletal changes with rapid maxillary expansion: a systematic review

The objective was to evaluate long-term transverse, anteroposterior and vertical skeletal changes after rapid maxillary expansion (RME). The data were clinical trials that assessed skeletal changes through cephalometric analysis. No surgical or other simultaneous treatment during the evaluation period was accepted. Electronic databases (PubMed, Medline, Medline In-Process & Other Non-Indexed Citations, Cochrane Database of Systematic Reviews, ASP Journal Club, DARE, CCTR, Embase, Web of Sciences and Lilacs) were searched with the help of a senior Health Sciences librarian. Abstracts that appeared to fulfill the initial selection criteria were selected by consensus. The original articles were then retrieved. A methodological checklist was used to evaluate the quality of the selected articles. Their references were also hand-searched for possible missing articles. Articles without an adequate control group to factor out growth changes were excluded. Only three articles (one measuring transverse and two anteroposterior and vertical changes) measured RME stability after active expansion, all of them had some methodological flaws, which limit the attainable conclusions. An individual analysis of these articles was made. Long-term transverse skeletal maxillary increase is approximately 25% of the total dental expansion for prepubertal adolescents. Better long-term outcomes are expected in transverse changes because of RME in less skeletally mature patients. RME appears not to produce clinically significant anteroposterior or vertical changes in the position of the maxilla and mandible. The conclusions from this systematic review should be considered with caution because only a secondary level of evidence was found. Long-term randomized clinical trials are needed.     

Arch perimeter changes on rapid palatal expansion

Relationships between changes in arch perimeter and arch width resulting from rapid palatal expansion with the Hyrax appliance were analyzed with the use of dental study casts of 21 adolescent patients. Photographs and measurements from the dental casts obtained before treatment and approximately 3 months after stabilization were used. Regression analysis indicated that changes in premolar width were highly predictive of changes in arch perimeter (r2 = 0.69) at approximately 0.7 times the premolar expansion. Without any orthodontic appliances attached to the mandibular teeth in 16 of the 21 patients, buccal uprighting of the posterior teeth was observed because of the redirection of occlusal forces. In addition, posterior movement of the maxillary incisors and buccal tipping of the anchor teeth were quantified. The prediction of arch perimeter change for a given amount of expansion is helpful in the treatment planning of rapid palatal expansion cases and may facilitate nonextraction orthodontic treatment.     

Dental arch changes following rapid maxillary expansion

The purpose of this research was to evaluate changes in upper arch dimension and form following rapid maxillary expansion (RME) using a modified Haas appliance in the primary dentition. The sample comprised 49 children [17 males, 32 females, mean age 7 years 5 months, standard deviation (SD) 1 year 1 month] with a crossbite or maxillary crowding. Twenty patients had a normal SN-GoGn angle (7 males, 13 females, mean 33.25 degrees, SD 2.10), three were low angle (1 male, 2 females, mean 27.67 degrees, SD 2.31), and 22 were high angle (8 males, 14 females, mean 39.95 degrees, SD 3.15). The vertical dimensions of four patients could not be measured, due to the unavailability of radiographs. Expansion was undertaken to either correct a crossbite or treat maxillary crowding. The upper dental casts were analysed using a computerized system: before treatment (T1), at appliance removal (T2), and 2 years 4 months after appliance removal (T3). Using bootstrap statistical analysis applied to distance ratio values [Euclidean distance matrix analysis (EDMA)], it was found that 48 patients showed a change in arch form. In 40.82 per cent (n = 20, group A), the arch form changed from T1 to T2, T1 to T3, and T2 to T3. In 32.65 per cent (n = 16, group B), it varied from T1 to T2 but relapsed at T3 to the form of T1. For 24.5 per cent (n = 12, group C), it changed from T1 to T2 but maintained the same form at T3. The favourable characteristics for obtaining expansion, identified by logistic regression analysis, were being male, of an immature stage of dental development (lateral incisor not fully erupted) and the presence of a lateral crossbite. Intercanine and intermolar widths, arch length, and the distance between the interincisive point and the line joining the canines (depth of the intercanine arch) at the different time points were analysed using a two-tailed t-test (P < 0.05). For the whole group, the increase in intercanine and intermolar width and in the depth of the intercanine arch was significant. Comparison between groups A, B, and C was undertaken using an analysis of variance, but there was no significant difference between the groups. This modified type of Haas appliance was able to increase the transverse dimension of the maxillary dental arch in the mixed dentition. The most appropriate timing for treatment appears to be before the eruption of the permanent lateral incisors.     

Soft tissue profile changes after rapid maxillary expansion with a bonded expander

The aim of this study was to evaluate the short- and long-term treatment effects of rapid maxillary expansion (RME) on the soft tissue facial profile of subjects treated with a modified acrylic-hyrax device. The sample comprised 10 males and 10 females in the mixed dentition. Their average age was 9.3 years ± 10 months pre-treatment (T1), with a narrow maxilla and posterior crossbite, treated with a modified fixed maxillary expander with an occlusal splint. Lateral cephalometric radiographs obtained at T1, immediately post-expansion (T2), and after retention (T3) were used to determine possible changes in the soft tissue facial profile. The means and standard deviations for linear and angular cephalometric measurements were analysed statistically using analysis of variance and Tukey's test (α = 0.05). The measurements at T2 differed significantly from those at T1 and T3. However, RME did not produce any statistically significant alteration (P > 0.05) in the soft tissue profile for any of the cephalometric landmarks evaluated when compared at T1 and T3. The use of a fixed expander associated with an occlusal splint did not cause significant alterations in the soft tissue facial profile at T3. This modified device is effective for preventing the adverse vertical effects of RME such as an increase anterior face height in patients with a crossbite.     

螺旋CT测量快速扩弓后上颌骨位置三维变化

目的观察快速扩弓(RME)治疗前后上颌骨位置三维方向的变化。方法使用螺旋CT,测量10例恒牙患者RME治疗前后上颌骨各测量点的位置和角度改变。使用配对符号秩检验对比分析各项数据结果。结果RME治疗后上颌骨各测量点均向前、向下移位。代表硬腭的PNS′-ANS连线在正中矢状平面上的投影顺时针旋转0·9°,而代表上颌骨腭突的PNS′-ANS在正中矢状平面上投影的角度变化不明显。冠状平面观,两侧上颌骨下部扩开量较上部大,二者相互向外侧呈楔形倾斜。腭中缝呈前后较小中间稍大的纺锤形扩大。结论RME治疗前后上颌骨位置在矢状向、垂直向和水平向上均发生了相应的改变。应用螺旋CT可以对这种三维位置变化进行详细研究。     

Alveolar bone changes after asymmetric rapid maxillary expansion

Objective:To quantitatively evaluate the effects of asymmetric rapid maxillary expansion (ARME) on cortical bone thickness and buccal alveolar bone height (BABH), and to determine the formation of dehiscence and fenestration in the alveolar bone surrounding the posterior teeth, using cone-beam computed tomography (CBCT).Materials and Methods:The CBCT records of 23 patients with true unilateral posterior skeletal crossbite (10 boys, 14.06 ± 1.08 years old, and 13 girls, 13.64 ± 1.32 years old) who had undergone ARME were selected from our clinic archives. The bonded acrylic ARME appliance, including an occlusal stopper, was used on all patients. CBCT records had been taken before ARME (T1) and after the 3-month retention period (T2). Axial slices of the CBCT images at 3 vertical levels were used to evaluate the buccal and palatal aspects of the canines, first and second premolars, and first molars. Paired samples and independent sample t-tests were used for statistical comparison.Results:The results suggest that buccal cortical bone thickness of the affected side was significantly more affected by the expansion than was the unaffected side (P < .05). ARME significantly reduced the BABH of the canines (P < .01) and the first and second premolars (P < .05) on the affected side. ARME also increased the incidence of dehiscence and fenestration on the affected side.Conclusions:ARME may quantitatively decrease buccal cortical bone thickness and height on the affected side.     

快速上颌扩展矫治替牙期上颌狭窄拥挤伴中线偏斜

目的探讨快速上颌扩展(RME)配合固定矫治技术对替牙期上颌狭窄、上牙列轻中度拥挤伴中线偏斜的矫治方法。方法选择24例替牙期上颌狭窄,上前牙轻中度拥挤,上中线偏斜大于2mm,前牙覆正常的患者,年龄8.2～11.4岁,平均9.8岁。临床检查及曲面断层片、头颅侧位定位片排除功能因素。采用Hyrax支架式快速扩大,开展的速度每日旋转2次,螺旋开大0.5mm至上后牙的舌尖咬在下后牙的颊尖为止,中切牙之间的间隙大于2mm。在快速扩弓保持期内配合固定矫治技术移动前牙,调整中线。结果腭中缝扩大后,上牙弓宽度增加,牙弓周长增加,为排齐牙列调整中线提供间隙,6个月保持期间配合固定矫治排齐上前牙,对正中线。结论 RME配合固定矫治技术能有效的矫治替牙期上颌狭窄、轻中度拥挤和中线偏斜。