Tooth-borne Rapid Maxillary Expansion Research Articles

Efficacy of clear aligners vs rapid palatal expanders on palatal volume and surface area in mixed dentition patients: A randomized controlled trial

This study aimed to evaluate the efficacy of Invisalign First Phase I treatment compared with tooth-borne rapid maxillary expansion (RME) in mixed dentition patients by examining changes in palatal volume, palatal surface area, and maxillary interdental transverse measurements. In this open-label, 2-arm, parallel, randomized controlled trial, patients with a posterior transverse discrepancy≤6 mm were allocated into the clear aligner therapy (CAT) group (Invisalign First Phase I treatment) and RME group (tooth-borne RME) according to a computer-generated randomization list immediately before the start of treatment. Digital models were obtained before the beginning of the treatment (T0) and at the end of the retention period/treatment (T1) using an intraoral scanner. Palatal volume was measured as the primary outcome, and palatal surface area and intermolar and intercanine transverse widths at the cusps and gingival level were measured as secondary outcomes. Patients and interventionists were not blinded because of the nature of the intervention. Out of 50 patients, 41 (19 males and 22 females; mean age, 8.12 ± 1.53 years) were enrolled and divided into 2 groups: 20 in the CAT group and 21 in the RME group. Two participants did not receive the allocated intervention for different reasons (1 patient discontinued the intervention in the CAT group, and another patient was lost to follow-up in the RME group). Thus, 19 patients (5 males and 14 females; mean age, 8.48 ± 1.42 years) were analyzed from the CAT group, and 20 patients (12 males and 8 females; mean age, 7.83 ± 1.19 years) from the RME group. Regarding intragroup comparisons, all outcome measures significantly increased from T0 to T1 in both groups. In terms of intergroup comparisons, there were no significant differences in the variation (Δ) of outcome measures between the 2 groups from T0 to T1, except for the intermolar width at the gingival level (P<0.005). The change in palatal volume was 532.01 ±540.52 mm³ for the RME group and 243.95 ± 473.24 mm³ for the CAT group (P = 0.084), with a moderate effect size (d = 0.57). RME showed trends favoring better outcomes compared with Invisalign First Phase I treatment across all assessed measures. The only parameter that showed statistically significant differences between the 2 groups was variation in intermolar width at the gingival level, suggesting the occurrence of buccal tipping in patients undergoing Invisalign First Phase I treatment. The trial was registered at ClinicalTrial.gov (no. NCT04760535).

External root resorption and rapid maxillary expansion in the short-term: a CBCT comparative study between tooth-borne and bone-borne appliances, using 3D imaging digital technology

BackgroundThe aim of the study was to analyze and compare external root resorption (ERR) in patients treated with tooth-borne (TB) and bone-borne (BB) rapid maxillary expansion (RME).MethodsThe sample included 40 subjects who received tooth-borne RME (TB group, average age: 13.1 ± 1.08 years) or bone-borne RME (BB group, average age: 14.5 ± 1.11 years) and Cone-beam computed tomography (CBCT) scans before treatment (T0) and after 3-month of retention (T1). A specific 3D Imaging technology was used to generate 3D models of posterior dentition (M1 = maxillary first molars, P2 = second premolars, P1 = first premolar) and calculate volumetric data (mean and percentage values) and shape changes, the latter obtained from deviation analysis between the radicular models at different time points. Evaluation of radicular length changes was performed for each tooth. Data were statistically analysed to perform intra-timing and inter-groups comparisons.ResultsA significant reduction of radicular volume and length was found in posterior dentition in both groups (p < 0.05), and the M1 (volume) and its palatal root (length) were mostly involved in this response. No differences were found between M1, P1 and P2 (p > 0.05) when volumetric changes were calculated as percentage of the total volume. Deviation analysis revealed that the radicular areas mostly affected by shape change were the apex and bucco-medial side. The amount of ERR was significantly greater in TB group compared to BB group.ConclusionsBB-RME treatment could reduce the amount of ERR at the post-expansion stage.

Effects of Rapid Maxillary Expansion on Upper Airway Volume in Growing Children: A Three-Dimensional Cone-Beam Computed Tomography Study.

Background: Rapid maxillary expansion (RME) is a common orthodontic procedure that widens the maxillary arch to treat moderate to mild overcrowding and transverse skeletal and dental abnormalities. Orthodontic equipment applies lateral tension on posterior maxilla teeth or palate mucosa to the mid-palatal suture. The maxilla may grow transversely when force is applied at right angles to the mid-palatal suture, which is usually inactive in children and adolescents. This study used cone-beam computed tomography (CBCT) and an authorized upper respiratory airway volume measurement approach to compare RME cohort pharyngeal airway volume changes to healthy controls. Materials and Methods: This retrospective analysis included 52 RME patients and 52 healthy controls. The RME category's expansion regimen entailed twisting the screw of expansion on a tooth-attached Hyrax-type expansion equipment by 0.25 mm daily for at least 14 days. After six months, a few RME participants used fixed orthodontic gear. The comparison group used fixed orthodontic appliances for minor malocclusions without extractions (without RME). CBCT scans from 1021 orthodontic patients who visited a dental hospital between 2012 and 2022 were examined. The registry comprised only anonymized photographs. Volume, minimum cross-sectional area (MCA), molar width, and inter-molar width were measured before and after therapy. Results: The control group had 12227.12 mm3 at T0 and 15805.54 mm3 at T1. The control group's T0-T1 volume difference was statistically significant (p = 0.007). The RME group has 12884.84 mm3 at T0 and 17471.08mm3 at T1. The RME group had a significant volume difference at T0 and T1 (p = 0.002). The volume RME effect was ±1011.92and statistically insignificant. (p > 0.05). MCA in the control group was 126.04 mm2 at T0 and 170.61 mm2at T1. MCA at T0 and T1 in the control group was statistically significant (p = 0.041). RME group MCA was 126.53 mm3 at T0 and 164.69 mm2 at T1. The RME group had a significant volume difference at T0 and T1 (p = 0.002). The MCA, RME effect was 5.92 and statistically insignificant (p > 0.05). Both the control and RME groups had statistically significant volume and MCA differences at T0 and T1. However, the intergroup analysis showed no significant differences across the groups. Conclusion: Tooth-borne RME does not affect upper airway or MCA volume in children compared to controls. Upper airway changes were better with younger skeletal ages before treatment. The findings may aid RME for young children.

External root resorption (ERR) and rapid maxillary expansion (RME) at post-retention stage: a comparison between tooth-borne and bone-borne RME

BackgroundThe study aimed to compare external root resorption (ERR) three-dimensionally in subjects treated with tooth-borne (TB) versus bone-borne (BB) rapid maxillary expansion (RME). Forty subjects who received tooth-borne RME (TB group, average age 13.3 years ± 1.10 years) or bone-borne RME (BB group, average age 14.7 ± 1.15 years) were assessed using CBCT imaging before treatment (T0) and after a 6-month retention period (T1). 3D reconstructions of the radicular anatomy of maxillary first molars (M1), first and second premolars (P1 and P2) were generated to calculate volumetric (mean and percentage values) and shape changes (deviation analysis of the radicular models) obtained at each time point. 2D assessment of radicular length changes was also performed for each tooth. Data were statistically analyzed to perform intra-group (different teeth) and inter-group comparisons.ResultsIn both groups, all the investigated teeth showed a significant reduction in radicular volume and length (p < 0.05), with the first molars being the teeth most affected by the resorption process (volume and palatal root length). When volumetric radicular changes were calculated as a percentage of the pre-treatment volumes, no differences were found among the investigated teeth (p > 0.05). Based on the deviation analysis from radicular models superimposition, the areas most affected by shape change were the apex and bucco-medial root surface. Overall, the amount of ERR was significantly greater in the TB group (mm3: M1 = 17.03, P1 = 6.42, P2 = 5.26) compared to the BB group (mm3: M1 = 3.11, P1 = 1.04, P2 = 1.24).ConclusionsDespite the statistical significance, the difference in the amount of ERR of the posterior maxillary dentition between TB-RME and BB-RME remains clinically questionable.

THE EFFICIENCY OF TOOTH-ANCHORED VERSUS BONEANCHORED RAPID MAXILLARY EXPANSION IN YOUNG AND LATE ADOLESCENT PATIENTS

Relevance of the problem. Incidence of posterior cross­bite has been reported to be 8–23% and it is a com­mon problem often seen in children and adolescents. An effective treatment of the skeletal transversal maxillary deficiency usually involves rapid maxillary expansion (RME). The expansion can be achieved using different types of expanders: bone anchored, tooth anchored or hybrid. The variety of clinical results comparing bone-borne and tooth-borne RME influence lack of unanimous treatment plan for adolescents. Aim. To compare the efficiency of tooth-borne expanders with bone-borne expanders by comparing dentoskeletal changes evaluated by CBCT. Material and methods. Electronic database search was carried out according to PRISMA principles. Five electro­nic research databases were searched including Medline (via PubMed), Cochrane Library, ProQuest, Wiley On­line Library and Web of Science. PICOS framework was used to form a focused question and the risk of bias was assessed using the Cochrane tool for randomized trials (RoB 2) by two individual researchers. Included studies were randomized clinical trials, published less than 10 years ago, with minimum follow-up period of 9 months with CBCT. Results. Two studies proved that bone borne RME produ­ced greater results in skeletal expansion, however other two studies failed to confirm these findings. Regarding alveolar bone loss, the results were also contradictory: two studies found no significant difference in both RME groups, however, other two studies found that bone borne RME exhibit less alveolar bone loss. As for den­tal tipping, the results were also different in all studies: In a study performed by Lagravere et al (2013), dental tipping occurred regardless of RME treatment for molar teeth, however in the premolar group, increased tipping was noticed in the tooth-anchored group. Another study by the same author concluded similar results: in the to­oth borne RME group no significant tipping in molars was seen, while in premolars, buccal crown tipping was observed, which was significant (p&lt;0.003). In the bone borne RME group significant dental tipping was obser­ved in molars. Contrary to these findings, two studies concluded that dental tipping is experienced significantly less in the bone-borne RME group and one study per­formed by Davami et al found no significant difference in both groups. Conclusion. To conclude, current evidence suggests contradictory results in maxillary expansion using bone borne or tooth borne RME devices. Though the evidence is limited, both types of RME have similar outcomes. More studies with a higher number of patients are nee­ded to determine conclusive results.

Comparison of the short-term effects of tooth-bone-borne and tooth-borne rapid maxillary expansion in older adolescents.

To compare the short-term effects of tooth-bone-borne and tooth-borne rapid maxillary expansion (RME) devices on dentofacial structures in older adolescents. The retrospective study reviewed pre- and posttreatment lateral and posteroanterior cephalometric images and orthodontic model records of patients who underwent maxillary expansion. Two groups were formed, in which the same upper jaw expansion protocol was applied with two different maxillary expansion devices: the first group consisted of 15individuals treated with tooth-bone-borne (hybrid) RME (HRME; 9girls and 6boys; mean age, 16.9 ± 0.42years) and the second group consisted of 15individuals treated with tooth-borne (conventional) RME (CRME; 8girls and 7boys; mean age, 16.74 ± 0.54years). Cephalometric and orthodontic model measurements were conducted on the records taken before and after treatment. Significant skeletal and dental expansions were observed in both groups (p < 0.05). However, the increase in nasal width measurements in the HRME group (2.24 ± 0.61 mm) was significantly higher than the increase in the CRME group (1.12 ± 0.25 mm; p < 0.01). Buccal tipping of the premolars was significantly less in the HRME group (0.46 ± 0.35°) than in the CRME group (2.46 ± 0.63°; p < 0.01). The amount of tipping of the molars was higher in the HRME group (4.76 ± 0.88°) compared to the CRME group (2.9 ± 1.03°; p < 0.01). Although the HRME device increase the nasal width in older adolescents to agreater extent, more dental side effects were seen at the maxillary first molars.

Short-Term and Long-Term Changes of Nasal Soft Tissue after Rapid Maxillary Expansion (RME) with Tooth-Borne and Bone-Borne Devices. A CBCT Retrospective Study.

The objective of the study was to assess the changes in nasal soft tissues after RME was performed with tooth-borne (TB) and bone-borne (BB) appliances. Methods. This study included 40 subjects with a diagnosis of posterior cross-bite who received tooth-borne RME (TB, average age: 11.75 ± 1.13 years) or bone-borne RME (BB, average age: 12.68 ± 1.31 years). Cone-beam computed tomography (CBCT) was taken before treatment (T0), after a 6-month retention period (T1), and one year after retention (T2). Specific linear measurements of the skeletal components and of the soft-tissue region of the nose were performed. All data were statistically analyzed. Results. Concerning skeletal measurements, the BB group showed a greater skeletal expansion of the anterior and posterior region of the nose compared to the TB group (p < 0.05) immediately after RME. Both TB and BB RME induce a small increment (>1 mm) of the alar base and alar width, without significant differences between the two expansion methods (p > 0.05). A high correlation was found between skeletal and soft-tissue expansion in the TB group; instead, a weaker correlation was found in the BB group. Conclusion. A similar slight increment of the alar width and alar base width was found in both TB and BB groups. However, the clinical relevance of these differences, in terms of facial appearance, remains questionable.

Differences in dentoskeletal and soft tissue changes due to rapid maxillary expansion using a tooth-borne expander between adolescents and adults: A retrospective observational study.

ObjectiveThe purpose of this study was to compare the differences in dentoskeletal and soft tissue changes following conventional tooth-borne rapid maxillary expansion (RME) between adolescents and adults.MethodsDentoskeletal and soft tissue variables of 17 adolescents and 17 adults were analyzed on posteroanterior and lateral cephalograms and frontal photographs at pretreatment (T1) and after conventional RME using tooth-borne expanders (T2). Changes in variables within each group between T1 and T2 were analyzed using Wilcoxon signed-rank test. Mann–Whitney U test was used to determine the differences in the pretreatment age, expansion and post-expansion durations, and dentoskeletal and soft tissue changes after RME between the groups. Spearman’s correlation between pretreatment age and transverse dentoskeletal changes in the adolescent group was calculated.ResultsDespite similar amounts of expansion at the crown level in both groups, the adult group underwent less skeletal expansion with less intermolar root expansion after RME than the adolescent group. The skeletal vertical dimension increased significantly in both groups without significant intergroup difference. The anteroposterior position of the maxilla was maintained in both groups, while a greater backward displacement of the mandible was evident in the adult group than that in the adolescent group after RME. The soft tissue alar width increased in both groups without a significant intergroup difference. In the adolescent group, pretreatment age was not significantly correlated with transverse dentoskeletal changes.ConclusionsConventional RME may induce similar soft tissue changes but different dentoskeletal changes between adolescents and adults.

Effectiveness of miniscrew-assisted rapid maxillary expansion: a systematic review and meta-analysis.

To compare the effectiveness and side effects of miniscrew-assisted rapid maxillary expansion (MARME) with conventional rapid maxillary expansion (RME) in the treatment of transverse maxillary deficiency. We conducted a systematic review and meta-analysis of randomized controlled trials (RCTs). We searched in the MEDLINE, Embase, and Cochrane Central databases. The quality of included RCTs was evaluated using the Cochrane risk-of-bias tool. The primary outcome was the extent of dentoskeletal expansion achieved. Secondary outcomes were the dental and periodontal side effects. We calculated summary weighted mean differences (MD) with 95% confidence intervals (CI) using random-effects meta-analysis. Six RCTs involving 287 participants met the inclusion criteria. Compared to conventional RME, MARME was associated with a greater palatal suture opening (mm) measured at the anterior nasal spine (MD = 1.21, 95% CI 0.75 to 1.66), first premolars (MD = 1.13, 95% CI 0.72 to 1.55), first molars (MD = 1.18, 95% CI 0.28 to 2.09), and posterior nasal spine (MD = 1.14, 95% CI 0.30 to 1.98), increased palatal width (mm) at the first molars (MD = 0.75, 95% CI 0.30 to 1.20), and reduced buccal inclination (degrees) of the first premolars (MD = - 6.06, 95% CI - 10.36 to - 1.76) and first molars (MD = - 3.17, 95% CI - 5.35 to - 0.99). MARME is associated with the following advantages over traditional tooth-borne RME: increased palatal suture opening, increased palatal width, and reduced buccal tooth inclination. This study is registered with PROSPERO, CRD42021256750. MARME may be preferred over conventional RME in cases with fused mid-palatal sutures or where further buccal tooth inclination is undesirable.

Tooth-borne versus tooth-bone-borne rapid maxillary expanders according to a stereophotogrammetric evaluation of facial soft tissues: A randomized clinical trial.

To evaluate the effects of tooth-borne and tooth-bone-borne rapid maxillary expansion (RME) on soft tissue with stereophotogrammetry. Thirty two patients (15 males and 17 females) who met inclusion criteria were divided into two groups. In the first group, tooth-borne RME appliance (hyrax) was applied to 16 patients (9 males and 7 females mean age 13.4±1.3years), and in the second group, tooth-bone-borne RME appliance (hybrid hyrax) was applied to 16 patients (6 males and 10 females, mean age 13.05±1.24years). Changes in soft tissues before RME (T0) and post-retention (T1) period were evaluated by stereophotogrammetry. Linear and angular measurements were performed. Independent- and dependent-sample t tests were used to compare intra- and inter-group differences at P<.05 significance level. The data revealed statistically significant changes in nasal width, mid-face width, upper lip vermillion length/lower lip vermillion length ratio and upper lip angle in hyrax group. (P<.05) Also nasal width, lower lip length, lower lip vermillion length, anterior face height, lower face height, convexity angle and mandibular angle showed statistically significant changes in hybrid hyrax group. (P<.05) In the inter-group evaluation, no significant differences were found except upper lip and mandible angle. (P<.05). Both hyrax and hybrid hyrax expanders had effects on soft tissue profile. Anterior face height and lower face height increased in both groups. Upper lip length increased by 0.36mm in the hybrid group and 0.10mm in the hyrax group. This trial was registered at Clinicaltrials.gov (Identifier: NCT04828213).

A postero-anterior cephalometric evaluation of different rapid maxillary expansion appliances

The purpose of the study was to evaluate dental and skeletal changes induced by tooth-bone-borne, tooth-tissue-borne, and tooth-borne rapid maxillary expansion (RME) appliances using postero-anterior (PA) cephalometric radiographs. A total of 54 patients' (25 boys, 29 girls) PA cephalometric radiographs who had bilateral posterior crossbite and RME treatment were included and divided into three groups according to the type of appliance used during treatment: tooth-bone-borne RME appliance (hybrid Hyrax) (7 boys, 11 girls, mean age 13.28 ± 1.20 years), tooth-tissue-borne RME appliance (TTB) (8 boys, 10 girls, mean age 13.08 ± 1.06 years) and tooth-borne RME appliance (Hyrax) (10 boys, 8 girls, mean age 12.05 ± 1.35 years). Pretreatment (T0) and posttreatment (T1) PA cephalometric radiographs were analyzed with Dolphin software v. 11.7 (Chatsworth, CA). The comparisons of the groups were performed with Two-way analysis of variance. P < 0.05 was considered statistically significant. Significant and equal increase of right molar relationship and upper intermolar molar widths occurred in all groups. Dental midline discrepancy showed significant increase in only hybrid Hyrax group between T0 and T1. Significant increases were reported for lateronasal width in hybrid Hyrax and tooth-tissue-borne groups (P < 0.05). Both skeletal and dental changes were observed after RME in all groups. However, the greatest skeletal changes were seen in hybrid Hyrax and tooth-tissue-borne groups.

Correlation between midpalatal suture stage on cone-beam CT images and its cervical vertebral maturation stage for 1 076 Chinese children and youth

Objective: To investigate the correlation between cone-beam CT (CBCT) morphological stage of midpalatal suture (MPS) and cervical vertebral maturation stage (CS) of Chinese children and youth. Methods: This study was a retrospective observational study. A total of 1 076 CBCT images (male: 401, female: 675, age≥ 6.0 years old and<21.0 years old) taken from January 2013 to April 2018 in Peking University School and Hospital of Stomatology were included. MPS and CS of each sample were recorded according to previous studies. MPS included five stages: MPS 1, MPS 2, MPS 3, MPS 4s1 (substage), MPS 4s2 (substage), and MPS 5. CS included six stages: CS 1-6. Correlation between MPS and CS (ordinal categorical variables) was investigated by Spearman correlation coefficient and diagnostic test analysis. Results: Spearman coefficient between CS and MPS was 0.803. Diagnostic pairs with the best diagnostic performance include: CS 6-MPS 5, CS 5-MPS 4s2, CS 1-MPS 1, CS 4-MPS 4s1, CS 2-MPS 1, CS 3-MPS 3. The 90.9% (309/340) of individuals at CS 1-3 were at MPS 1-3 and 9.1% (31/340) were at MPS 4s1. The 33.0% (107/324) of individuals at CS 4 were at MPS 3 and 46.6% (151/324) were at MPS 4s1. Conclusions: CS has a close relationship with MPS. Individuals at CS 4 are recommended to take pre-treatment CBCT, so as to estimate feasibility of skeletal expansion with traditional tooth-borne rapid maxillary expansion.

Does Mini Screw Assisted Rapid Palatal Expansion (MARPE) have an influence on airway and breathing in middle-aged children and adolescents? A systematic review

This systematic review assessed the effects of tooth-borne (TB), tooth-bone-borne (TBB) and bone-borne (BB) micro-implant assisted rapid maxillary expansion (RPE) on airway dimensions and function in young children and adolescents (10- to 17-years-old). Unrestricted search in 5 electronic databases until June 6th, 2020 was undertaken. This was supplemented with search in 6 additional resources for published, unpublished and ongoing trials up. Randomized (RCT) and non-randomized (Non-RCT) prospective studies that assessed the influence of the mini-screw-assisted rapid palatal expansion (MARPE) approach on airway and breathing in young children and adolescents were included. Two reviewers performed the study selection and data extraction blindly and in duplicate by two authors while disagreements. A random-effects model with a 95% confidence interval (CI), I2 and Chi2 tests were done. ROBINS-I, Cochrane Risk of Bias and GRADE tools were used. Reporting of this review was based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Overall, 518 articles were retrieved; only 3 studies (2 RCT and one non-RCT) met the inclusion criteria. Both TB RPE and BB RPE improved on a short-term basis the dimensions of the airway, though the difference was not significant (P>0.05). TBB RPE significantly improved nasal airflow [(Mean difference (MD) 52.7 cm3/s, 95% confidence interval (95% CI) 9.0-96.4), P=0.020)], reduced nasal resistance (MD -0.20Pa/cm3, 95% (-0.38)-(-0.02), P=0.028), and changed respiratory muscle strength variables (P>0.05). No correlation was found between the anatomical dimensions of the airway and the functional airway parameters (P>0.05). The short-term airway volumetric changes secondary to MARPE were not significant. The influence of MARPE appliances on breathing is still not clear. Registration PROSPERO database (CRD42020183340).

Evaluation of pulp cavity/chamber changes after tooth-borne and bone-borne rapid maxillary expansions: a CBCT study using surface-based superimposition and deviation analysis.

To compare volume and shape changes of pulp chamber of maxillary posterior teeth between tooth-borne and bone-borne maxillary expansions in adolescents. This study included 36 adolescents with bilateral maxillary crossbite who received tooth-borne rapid maxillary expansion (TB group, average age 14.4years) or bone-borne rapid maxillary expansion (BB group, average age 14.7years). Cone beam computed tomography (CBCT) was taken before treatment (T1) and after a 6-month retention period (T2). Volumetric and shape changes of pulp chamber of maxillary first molars and premolars were detected by referring to a specific 3D digital technology involving deviation analysis of T1/T2 CBCT-derived models of pulp chamber. Student's t tests were used to (1) compare T1 and T2 volumes of pulp chambers in TB and BB groups and (2) assess differences between the two groups in the post-treatment volumetric changes and in the percentage of matching of 3D pulp models. All investigated teeth showed a reduction of pulp volume, being this difference significant in both TB (p < 0.0001) and BB (p < 0.0001) groups. The volumetric reduction was greater in the TB group; also, subjects in the TB group showed a lower percentage of matching between T1 and T2 pulp models (p < 0.0001). The area most affected by shape change was that of pulp horns. TB expander could induce a higher volumetric reduction of pulp chamber of posterior teeth compared with BB expander, in the short term. The present findings add new information concerning the effects of RME protocols on pulp tissue.

Effects of rapid maxillary expansion on upper airway volume: A three-dimensional cone-beam computed tomography study.

To compare changes in pharyngeal airway volume and minimal cross-sectional area (MCA) between patients undergoing rapid maxillary expansion (RME) and a matched control group and to identify markers for predicting airway changes using cone-beam computed tomography (CBCT). Pre- and posttreatment CBCT scans were selected of children who had RME (14 girls and 12 boys; mean age, 12.4 years) along with scans of a control group (matched for chronological age, skeletal age, gender, mandibular inclination) who underwent orthodontic treatment for minor malocclusions without RME. Changes in airway volume and MCA were evaluated using a standardized, previously validated method and analyzed by a mixed-effects linear regression model. Upper airway volume and MCA increased significantly over time for both the RME and matched control groups (P < .01 and P = .05, respectively). Although the RME group showed a greater increase when compared with the matched controls, this difference was not statistically significant. A reduced skeletal age before treatment was a significant marker for a positive effect on the upper airway volume and MCA changes (P < .01). Tooth-borne RME is not associated with a significant change in upper airway volume or MCA in children when compared with controls. The younger the skeletal age before treatment, the more positive the effect on the upper airway changes. The results may prove valuable, especially in RME of young children.

Retrospective CBCT analysis of airway volume changes after bone-borne vs tooth-borne rapid maxillary expansion.

To compare changes in upper airway volume after maxillary expansion with bone- and tooth-borne appliances in adolescents and to evaluate the dentoskeletal effects of each expansion modality. This retrospective study included 36 adolescents who had bilateral maxillary crossbite and received bone-borne maxillary expansion (average age: 14.7 years) or tooth-borne maxillary expansion (average age: 14.4 years). Subjects had two cone beam computed tomography images acquired, one before expansion (T1) and a second after a 3-month retention period (T2). Images were oriented, and three-dimensional airway volume and dentoskeletal expansion were measured. Analysis of variance was used to test for differences between the two expansion methods for pretreatment, posttreatment, and prepost changes. Paired t-tests were used to test for significance of prepost changes within each method. Both groups showed significant increase only in nasal cavity and nasopharynx volume (P < .05), but not oropharynx and maxillary sinus volumes. Intermolar and maxillary width increased significantly in both groups (P < .05); however, the buccal inclination of maxillary molars increased significantly only in the tooth-borne group (P < .05). There was no significant difference between tooth- and bone-borne expansion groups, except for the significantly larger increase in buccal inclination of the maxillary right first molar after tooth-borne expansion. In adolescents, both tooth- and bone-borne RME resulted in an increase in nasal cavity and nasopharynx volume, as well as expansion in maxillary intermolar and skeletal widths. However, only tooth-borne expanders caused significant buccal tipping of maxillary molars.

Evaluation of a novel palatal suture maturation classification as assessed by cone-beam computed tomography imaging of a pre- and postexpansion treatment cohort.

To test the reliability and usefulness of the midpalatal suture maturation classification and methodology proposed in 2013 by Angelieri et al. for successful prediction of rapid maxillary expansion (RME) treatment results. Reliability testing focused on 16 patients aged 9.5-17 years with early mixed to full permanent dentition, representing all proposed palatal maturation stages, from available preexpansion cone-beam computed tomography (CBCT). A retrospective observational longitudinal (cohort) study evaluated 63 preadolescent and adolescent patients aged 11-17 years with full permanent dentition treated with tooth-borne RME appliances who had CBCT records taken at pre- (T1) and postexpansion (T2). CBCT three-dimensional landmarking produced skeletal and dental widths and dental angulations used to evaluate the extent of skeletal and/or dental expansion. A regression model was used to assess the prediction capability of the T1 palatal suture classification of each subject for dental and skeletal changes. There was almost perfect intraexaminer agreement and slight to poor interexaminer agreement, differing from previously reported reliability, affected by necessary operator calibration and the degree of postacquisition image sharpness and clarity. Further exploration of its scientific basis suggested that the proposed classification was ill-founded. Results from the cohort study were also wholly unsupportive of efficacy of the proposed palatal suture maturation classification in predicting the magnitude of portrayed changes. Clinicians should be cautious in applying this classification. Although it has merits, the palatal classification still needs much more research and validation.

Differential Benefit of Two Different Tooth-Borne Rapid Maxillary Expansion Appliances in Female Subjects.

The aim of the present study was to evaluate the effects of tooth-borne acrylic-bonded rapid maxillary expansion (RME) appliances with or without the anterior teeth anchorage on the skeletal and dentoalveolar structures, as well as soft tissues. This study included 44 patients who were treated with two different tooth-borne bonded acrylic RME appliances. Lateral cephalometric radiographs were taken before the treatment (T0) and in the post-retention (T1) phase of the RME treatment. The posterior-bonded RME appliance group and full-bonded RME appliance group were created as the two different groups of treatment. The following statistical analyses were performed: intra- and inter-group comparisons were made using the paired t-test, Wilcoxon test, independent t-test, and Mann-Whitney U-test for normal and non-normal distribution data. Significant increases were observed in R1-A, R1-ANS, R1-U1, R1-AR, R1-St, R1-Li, and R1-Pn in both groups. R1-PNS, R1-Ls, R1-Sn, and R1-B' were found to be significantly larger at T1 than at T0 in the posterior-bonded RME appliance group. R2-A, R2-ANS, R2-L1, R2-A', and R2-Pn were significantly larger at T1 than at T0 in the full-bonded RME appliance group. The R2-A' was significantly different between the groups. The soft tissue A point appears to be the most important differing matter between the two different RME appliances, and a full acrylic-bonded RME appliance may be beneficial for subjects with a maxillary retrognathic profile.

Effects on nasal airflow and resistance using two different RME appliances: a randomized controlled trial.

To evaluate and compare the effects of tooth-borne (TB) and tooth-bone-borne (TBB) rapid maxillary expansion (RME) on nasal airflow and resistance. Fifty-four consecutive patients who met the eligibility criteria were recruited from September 2010 to December 2015. Of these 54 subjects, 40 agreed to participate in the part of the study involving evaluation of nasal flow and resistance. The 40 subjects were allocated to either the TB group, mean age 9.7 years (SD 1.5), or the TBB group, mean age 10.2 years (SD 1.4). All subjects performed rhinomanometric registration at baseline (T0), but only 30 attended the post-expansion registration (T1), of whom 16 had been randomized to the TB group and 14 to the TBB group. The study outcomes, nasal airflow and nasal airway resistance, were evaluated with linear regression adjusted for baseline variable of the outcome to compare the study groups with complete cases strategy as well as after multiple imputation (MI). Participants were randomly allocated in blocks of different sizes, using the concealed allocation principle in a 1:1 ratio. The randomization list was computer generated to ensure homogeneity between groups. Blinding was done only for outcome assessor due to clinical limitations. The care providers at the ENT unit who conducted all the rhinomanometry examinations were blinded to which group the patients were allocated to. Complete case analysis showed significantly higher post-expansion nasal airflow values for the TBB group compared with the TB group, mean difference 51.0 cm3/s (P = 0.018). The evaluation after MI showed a similar significant mean difference, 52.7 cm3/s (P = 0.020) in favour of the TBB group when taking into account the missing values from the T1 examination. Even reduction in nasal airway resistance showed similar pattern in favour of the TBB group. Our results represent the short-term effects. A longer follow-up period would have been preferable. The TBB RME induced significantly higher nasal airway flow and lower nasal resistance values than TB RME. It might be wiser to use TBB RME in cases with constricted maxilla and upper airway obstruction. This trial was not registered in any external sites. The protocol was not published before trial commencement.

The effects of maxillary expansion on the soft tissue facial profile.

The aims of this retrospective study were to evaluate the possible changes in soft tissue facial profile induced by orthopedic rapid maxillary expansion (RME) and surgically assisted rapid maxillary expansion (SARME), and to correlate them with the underlying hard tissue alterations. 16 patients who received bone borne SARME and 25 patients who were subjected to RME using metal cast splint hyrax appliance were analyzed retrospectively. This research was conducted on lateral cephalometric radiographs taken on 2 occasions: before expansion (T1) and at the beginning of any further orthodontic treatment (T2). Investigated lateral cephalometric parameters consisted of Holdaway soft tissue measurements with some supplementary soft tissue, skeletal and dental assessments. The acquisition of T2 cephalograms which conforms to the initiation of further orthodontic treatment corresponded to 83.25±3.51 days for SARME and 85.68±4.37 days for RME after the expansion was completed. The only significant change in soft tissue profile of the SARME group was a decrease in upper lip thickness (p<0.05), whereas in the RME group, decrease in soft tissue facial profile angle and increase in H angle were found to be statistically significant (p<0.05 for each). For the RME group, the changes in soft tissue facial profile angle and H angle correlated only with the changes in SNB angle (p<0.05). While bone-borne SARME did not seem to possess the potential to alter soft tissue profile, tooth-borne RME caused a more convex soft tissue profile related to a reduction in SNB.