The role of rapid maxillary expansion in the promotion of oral and general health

Comparison of the Effects of Different Palatal Morphology on Maxillary Expansion via RME and MSE: A Finite Element Analysis

OBJECTIVES

This study aims to compare and analyze the biomechanical effect and the displacement trend of RME and MSE on the maxillofacial complex under different palatal shapes by using finite element analysis.

METHODS

The three-dimensional model of maxillofacial complex was obtained from a computed tomography image of a person with a normal palate. Then, we modified the shape of the palate to obtain the model with a high palate. Additionally, two expander devices were considered. MSE and RME were created and four models were made: Model 1: Normal-palate craniomaxillofacial complex with RME expander; Model 2: Normal-palate craniomaxillofacial complex with MSE expander; Model 3: High-palate craniomaxillofacial complex with RME expander; Model 4: High-palate craniomaxillofacial complex with MSE expander. Then, lateral forced displacement was applied and the analysis results were obtained.

RESULTS

The lateral displacement of the palatal suture of Model 3 is greater than that of Model 1, and the maxilla has more rotation. The crown/root ratio of Model 1 is significantly greater than that of the other three groups. Compared with Model 1, Model 3 has greater stress concentration in the superstructure of the craniomaxillofacial complex. Both of them have greater stress in the anchorage area than Model 2 and Model 4.

CONCLUSION

Different shapes of the palate interfere with the effects of RME and MSE, and its influence on the stress distribution and displacement of the craniomaxillary complex when using RME is greater than MSE. The lateral displacement of the palatal suture of MSE is significantly larger than that of RME. It is more prone to tipping movement of the anchor teeth using RME under normal palate, and MSE may manage the vertical control better due to the smaller crown/root ratio than RME and intrusive movement of molars.

The Relationship between Nocturnal Enuresis and Obstructive Sleep Apnea in Children

BACKGROUND

The aim of this study is to determine the prevalence of nocturnal enuresis (NE) in children with obstructive sleep apnea (OSA), the effect of adenotonsillectomy (AT) and the width of the arches, and to compare them with control children without respiratory problems.

METHODS

Children from 2 to 12 years old were divided into three groups: children with OSA and NE (n = 51), children with OSA without NE (n = 79), and the control group (n = 168). NE was defined as at least one bedwetting incident per month. Arch widths were measured at the baseline and one year after. OSA was diagnosed by means of polysomnography, and the apnea-hypopnea index (AHI) was obtained. Parents completed the Pediatric Sleep Questionnaire (PSQ) to classify their children into those with and without NE.

RESULTS

NE was present in 39.2% of children with OSA compared to 28% in the control group (p = 0.04). After AT, 49% of the children with OSA and NE significantly improved. Both OSA groups had narrower arch widths than the control group (p = 0.012), with the NE group having the narrowest widths. NE is more prevalent in children with OSA and should be considered one of the first signs of breathing disorders. Adenotonsillectomy reduces NE in about half of the affected children. Both arch widths are narrower in children with OSA, particularly in those with NE.

Three-dimensional assessment on digital cast of spontaneous upper first molar distorotation after Ni-ti leaf springs expander and rapid maxillary expander: A two-centre randomized controlled trial

OBJECTIVE

The aim of this randomized controlled trial (RCT) was to evaluate the spontaneous distorotation of upper first permanent molars and the transverse dentoalveolar changes on digital casts in growing patients following maxillary expansion treatment using either the Leaf Expander® or the rapid maxillary expander (RME), both anchored to the deciduous second molar.

TRIAL DESIGN AND SETTING

This study was a two-arm, parallel-assignment, RCT with a dual-centre design conducted at two teaching hospitals in Italy.

PARTICIPANTS

Inclusion criteria included maxillary transverse deficiency, prepubertal development stage (cervical vertebra maturation stage [CVMS] 1-2) and early mixed dentition with fully erupted upper first permanent molars. Exclusion criteria were systemic diseases or syndromes, CVMS 3-6, agenesis of upper second premolars, unavailability of the second deciduous molar for anchorage and Class III malocclusion.

RANDOMIZATION

Patients were randomly assigned to the Leaf Expander® or RME group using a computer-generated randomization list created by a central randomization centre. Randomization was conducted immediately before the start of treatment.

INTERVENTION

The intervention involved treatment with either the Leaf Expander® or the RME. Both devices were anchored to the second deciduous molars. Following randomization, patients were further categorized based on the presence of no crossbite, unilateral crossbite or bilateral crossbite.

MAIN OUTCOME MEASURE

The primary outcome measure was the distorotation of the upper first molar (U6). Secondary outcomes included measurements of interdental linear dimensions, specifically upper inter-canine width (53-63), upper inter-molar width (MV16-MV26) and upper inter-deciduous second molar width (55-65).

BLINDING

The examiner analysing the digital casts was blinded to the treatment groups to prevent detection bias and ensure objective assessment. However, due to the nature of the intervention, blinding was not feasible for the patients and clinicians involved in administering the treatment.

RESULTS

A total of 150 patients were enrolled and randomly assigned to two groups: 75 to the Leaf Expander® group and 75 to the RME group. Recruitment started in November 2021 and was completed in November 2022. At the time of analysis, the trial was complete with no ongoing follow-ups. ANOVA tests revealed no significant differences between the three subgroups (no-cross, unilateral-cross and bilateral-cross) within both the Leaf Expander® and RME groups at T0. The Leaf Expander® demonstrated significantly greater distorotation in the unilateral crossbite subgroup compared to the RME (p = .014). In terms of total molar distorotation, the Leaf Expander® appliance showed a significantly greater effect (12.66°) compared with conventional RME (7.83°). Linear regression analysis demonstrated a significant correlation between the extent of expansion and the degree of molar rotation.

CONCLUSIONS

Maxillary expansion resulted in significant spontaneous molar distorotation when the appliance was bonded to the second deciduous molars. The Leaf Expander® exhibited significantly greater molar distorotation compared with conventional RME. The degree of molar distorotation was correlated with the extent of expansion obtained on the second deciduous molar.

TRIAL REGISTRATION

The trial was registered at ClinicalTrials.gov (ID: NCT05135962).

Dentoalveolar, periodontal and skeletal effects of maxillary expansion techniques assisted by temporary anchorage devices compared with conventional protocols in growing patients with transverse maxillary deficiency: A systematic review and meta-analysis

OBJECTIVES

To synthesise the dentoalveolar, periodontal and skeletal changes that occur when using maxillary expansion techniques assisted by temporary anchorage devices compared to conventional protocols.

METHODS

Five databases and grey literature were consulted, up to December 2023, focusing on intervention designs and excluding other type of studies. The quality assessment was conducted by using the adaptation for orthodontics of the CONSORT statement, the guidelines for reporting non-randomised studies, the RoB-2 tool, and the ROBINS-I tool. A descriptive summary and meta-analysis using RevMan 5.4 were performed.

RESULTS

Nine clinical trials were included (n=377 patients, mean age 13.2±0.6) with a diagnosis of transverse maxillary deficiency. The analysed studies showed qualitative dentoalveolar and periodontal changes after expansion, which were greater on the maxillary first premolars in tooth-borne appliances. Meta-analyses for some effects were included from two studies (n=64); patients who used tooth-borne appliances had greater effects of buccal intercoronal width between the premolars with statistically significant differences (Std Mean difference 2.34; 95% CI: 0.04-4.65 p=0.05). Conversely, those patients who used bone-borne or hybrid appliances had greater effects of buccal intercoronal width between molars with statistically significant differences (Std Mean difference -0.64; 95% CI: -1.38-0.10; p=0.09).

CONCLUSIONS

According to the studies analysed, all measurements increased in the intervention groups after expansion. Quantitative analyses show different findings at dentoalveolar level when tooth-borne, bone-borne or hybrid appliances are considered. Nevertheless, the results should be taken with caution due to the heterogeneity of the studies. The protocol was registered at PROSPERO (CRD42021283170), with no funding to report.

Successful treatment for an adult with bilateral posterior teeth crossbite by miniscrew-assisted rapid palatal expansion: A case report

Key Clinical Message

Successful treatment by miniscrew-assisted rapid expansion and clinical aligner therapy for an adult diagnosed with maxillary transverse deficiency (MTD) by clinical examinations and Yonsei transverse analysis.

Abstract

Adult orthodontic diagnosis and treatment with maxillary transverse deficiency (MTD) is challenging. Miniscrew-assisted rapid palatal expansion (MARPE) is a fast and low-risk method to expand the width of maxillary basal bone. This case report describes a 23-year-old female with mandible deviation and bilateral posterior teeth crossbite. She was diagnosed as MTD by the clinical examinations and Yonsei transverse analysis, and treated by the MARPE and clinical aligner therapy. After 26 months' treatment, cone-beam computed tomography (CBCT) images showed that the width of maxillary basal bone increased by 3.8 mm, that of zygomatic arch and nasal bone increased by 1.0 and 1.9 mm, respectively, and the bilateral posterior teeth crossbite was corrected. Furthermore, the dental midline of lower arch was consistent with that of upper arch and face, the molars arrived Angle Class II and canines was Class I relationships, the profile was maintained, the facial asymmetry was improved. The results of seventeen-month follow-up showed that the effect of orthodontic treatment is very stable. This case report demonstrates that MARPE is the effective approach for patients with MTD and facial asymmetry, which provide the alternative for the treatment of similar cases.

Impact of Invisalign® first system on molar width and incisor torque in malocclusion during the mixed dentition period

In orthodontic treatment of patients during the mixed dentition period, arch expansion and opening deep overbite are one of the objectives to achieve proper alignment of the teeth and correction of sagittal and vertical discrepancies. However, the expected outcomes of most therapeutic regimens are not clear, making it impossible to standardize early treatment effects. Therefore, this study was designed to evaluate the impact of the Invisalign® First System on the dental arch circumference and incisor inclination in patients during the mixed dentition period. A total of 21 children during the mixed dentition period (10 females and 11 males, with an average age of 8.76 years) were included in this study. The patients received non-extraction treatment through Invisalign® First System clear aligners, and no other auxiliary devices were used except Invisalign® accessories. Subsequently, the cooperation degree of patients during treatment and the oral measurement parameters at the beginning (T1) and the end (T2) of treatment were collected. All patients showed moderate/good cooperation degree during treatment. Besides, horizontal width of the maxillary first molar increased significantly; the designed arch expansion was 4.1 mm (±1.4 mm), while the actual arch expansion was 3.0 mm (±1.7 mm). Furthermore, the torque expression rate of upper anterior teeth reached 56.53%. Invisalign® First System clear aligners can effectively correct the teeth of patients during the mixed dentition period, widen the circumference of dental arch, and control the torque of incisors.

Exploring the potential of rapid maxillary expansion and masticatory muscle activity in unilateral posterior crossbite

Background

This systematic review and meta-analysis aimed to evaluate if rapid maxillary expansion improves the activity of the masticatory muscles (masseter and temporal) in patients with unilateral posterior crossbite.

Material and Methods

Searches were performed in PubMed/MEDLINE, Scopus, Web of Science, Embase, Cochrane Library, and grey literature. A manual search of orthodontic journals was also performed. Randomized clinical trials or longitudinal prospective studies were eligibles. Meta-analyses were conducted using R software with the "Meta" package, applying mean differences with a 95% confidence interval. Risk of bias was assessed using the Newcastle-Ottawa scale, and evidence certainty was evaluated using GRADE.

Results

Nine articles were included. Qualitative analysis showed that RME treatment in patients with unilateral posterior crossbite showed a positive correlation with improvement in masseter and temporalis muscle activity. Meta-analyses indicated a significant difference for all models of muscle activity after treatment with rapid maxillary expansion, except for the temporal muscle in the force exerted on the maximum voluntary clenching on cotton rolls. The studies showed low bias risk, and the evidence certainty for each analysis was generally low to very low.

Conclusions

This investigation demonstrated the benefits of R rapid maxillary expansion in treating unilateral posterior crossbite and its potential therapeutic effects on the masticatory muscles. Key words:Rapid maxillary expansion, masticatory muscles, unilateral posterior crossbite, systematic review, meta-analysis.

Feasibility of 3 Tesla MRI for the assessment of mid-palatal suture maturation: a retrospective pilot study

The maxilla occupies a key position in dentofacial orthopaedics, since its transversal development can be directly influenced by orthodontic therapy. The maturation stages of the mid-palatal suture, which are obtained from cone-beam computed tomography images (CBCT), present an addition to clinical decision-making in transversal discrepancies of the upper jaw. In an endeavour to reduce ionizing radiation in adolescents and young adults, who are particularly susceptible to long term stochastic irradiation effects, we investigated the feasibility of 3 Tesla (3T) MRI in detecting the maturation stages of the mid-palatal suture. A collective of 30 patients aged 24-93 years with routine neck MRI at 3T, underwent an additional three-dimensional isotropic T1 weighted study sequence of the midface. Image evaluation was performed on axial, multi-planar formatted reconstructions of the dataset aligned to the midline axis of the palate, and curved reconstructions aligned to the concavity of the palate. Inverted images helped to achieve an image impression similar to the well-known CBCT appearance. All datasets were reviewed by three readers and mid-palatal maturation was scored twice according to Angelieri et al. Intra- and inter-rater agreement were evaluated to measure the robustness of the images for clinical evaluation. 3T MRI deemed reliable for the assessment of mid-palatal suture maturation and hence for the appraisal of the hard palate and its adjacent sutures. The data of this pilot study display the feasibility of non-ionizing cross-sectional MRI for the determination of sutural maturation stages. These findings underline the potential of MRI for orthodontic treatment planning, further contributing to the avoidance of unnecessary radiation doses.

Breathing changes following mini-implant-supported maxillary skeletal expander treatment in late adolescent or adult patients : Assessment of objective and subjective functional breathing changes

PURPOSE

The aim of this study was to assess objective and subjective breathing changes in adult patients who underwent maxillary skeletal expansion with the mini-implant-supported maxillary skeletal expander (MSE).

METHODS

Twenty-nine patients (mean age 18.1 ± 4.3 years) who underwent expansion using the MSE were compared pre- and posttreatment and with a control group (mean age 19.9 ± 2.6 years) to assess objective and subjective functional breathing changes. Objective measurements of the airway including peak nasal inspiratory flow (PNIF) and peak oral inspiratory flow (POIF) were measured utilizing the In-Check medical device (Clement Clarke, Harlow, United Kingdom). Patients reported subjective breathing assessment utilizing the visual analog scale (VAS). Intragroup comparisons were performed with Wilcoxon tests and intergroup comparison with Mann-Whitney U tests. Spearman correlation coefficients were calculated among the studied variables (P < 0.05).

RESULTS

Following MSE treatment, there were significantly higher values for PNIF total (P < 0.0001), PNIF right (P < 0.0001), PNIF left (P < 0.0001), and POIF (P < 0.01) compared to pretreatment and control group results. Also, patients reported a significant decrease in troubled breathing as measured by the VAS for breathing through the right nostril (P < 0.01), left nostril (P < 0.001), and both nostrils (P < 0.01). Comparing the objective and subjective variables for both the pre-MSE or post-MSE groups, the results indicated no significant correlation between total PNIF and total VAS. However, the values had significant correlations between PNIF and VAS on each side when the patients were asked to block one nostril.

CONCLUSIONS

Objective functional breathing measurements were increased immediately after treatment with MSE. Subjective functional breathing measurements changes were significantly higher after MSE treatment and compared with the control group. MSE presents a nonsurgical alternative to achieving orthopedic expansion in adult patients which may provide a benefit for patients with nasal airway obstruction.

Long-term effects of maxillary skeletal expander treatment on functional breathing

Objective

: To investigate the long-term effects of maxillary skeletal expander (MSE) treatment on functional breathing.

Methods

Objective

measures of breathing, the peak nasal inspiratory flow (PNIF), and peak oral inspiratory flow (POIF), and subjective measures of breathing, the visual analog scale (VAS) and nasal obstruction symptom evaluation (NOSE) survey, were used to investigate the long-term effects of MSE in functional breathing. Seventeen patients, mean age 19.4 ± 3.9 years treated at the UCLA Orthodontics Clinic were assessed on their functional breathing at 3 timepoints: pre-expansion (T0), post-expansion (T1), and post-orthodontic treatment (T2).

Results

: Immediately after expansion (T1), all the objective functional breathing values were significantly increased in comparison to T0 (P < 0.05). The VAS total, VAS right and VAS left were significantly lower at T1 in comparison to T0 (P < 0.05). At 26.8 ± 3.9 months after MSE expansion (T2), PNIF total, PNIF right, PNIF left, and POIF were significantly higher when compared to T0 (P < 0.05). Also, VAS total, VAS right and VAS left were significantly lower at T2 when compared to T0 (P < 0.05). Additionally, there was a positive correlation between PNIF and the magnitude of expansion at anterior nasal spine and zygomaticomaxillary point (ZMA). There was a positive correlation between total VAS and the magnitude of expansion at the ZMA. There were no significant changes for the NOSE subjective breathing measurement at all time comparisons.

Conclusions

: Overall, MSE treatment produces an increased objective and subjective airway improvement that continues to remain stable in the long-term post expansion.

Comparison of the effects on facial soft tissues produced by rapid and slow maxillary expansion using stereophotogrammetry: a randomized clinical trial

OBJECTIVE

To compare the effects on facial soft tissues produced by maxillary expansion generated by rapid maxillary expansion (RME) versus slow maxillary expansion (SME).

MATERIALS AND METHODS

Patients in the mixed dentition were included with a transverse discrepancy between the two arches of at least 3 mm. A conventional RME screw was compared to a new expansion screw (Leaf expander) designed to produce SME. Both screws were incorporated in a fixed expander. The primary outcome was the difference of the facial tissue changes in the nasal area measured on facial 3D images captured immediately before application of the expander (T0) and after one year of retention, immediately after the expander removal (T1). Secondary outcomes were soft tissue changes of other facial regions (mouth, lips, and chin). Analysis of covariance was used for statistical analysis.

RESULTS

Fourteen patients were allocated to the RME group, and 14 patients were allocated to the SME group. There were no dropouts. Nasal width change showed a difference between the two groups (1.3 mm greater in the RME group, 95% CI from 0.4 to 2.2, P = 0.005). Also, intercanthal width showed a difference between treatments (0.7 mm greater in the RME group, 95% CI from 0.0 to 1.3, P = 0.044). Nasal columella width, mouth width, nasal tip angle, upper lip angle, and lower lip angle did not show any statistically significant differences. The Y-axis (anterior-posterior) components of the nasal landmark showed a statistically significant difference between the two groups (0.5 mm of forward displacement greater in the RME group, 95% CI from 0.0 to 1.2, P = 0.040). Also, Z-axis (superior-inferior) components of the lower lip landmark was statistically significant (0.9 mm of downward displacement in favor of the RME group, 95% CI from 0.1 to 1.7, P = 0.027). All the other comparisons of the three-dimensional assessments were not statistically significant.

CONCLUSIONS

RME produced significant facial soft tissue changes when compared to SME. RME induced greater increases in both nasal and intercanthal widths (1.3 mm and 0.7 mm, respectively). These findings, though statistically significant, probably are not clinically relevant. Trial registration ISRCTN, ISRCTN18263886. Registered 8 November 2016, https://www.isrctn.com/ISRCTN18263886?q=Franchi&filters=&sort=&offset=2&totalResults=2&page=1&pageSize=10.

Effects of novel microimplant-assisted rapid palatal expanders manufactured by 3-dimensional printing technology: A finite element study

INTRODUCTION

The expansion effects of several new microimplant-assisted rapid palatal expanders (MARPEs) manufactured by 3-dimensional printing technology were evaluated by finite element analysis (FEA). The aim was to identify a novel MARPE suitable for treating maxillary transverse deficiency.

METHODS

The finite element model was established using MIMICS software (version 19.0; Materialise, Leuven, Belgium). First, the appropriate microimplant insertion characteristics were identified via FEA, and several MARPEs with the above insertion patterns were manufactured by 3-dimensional printing technology. Then, the stress distribution and displacement prediction of the 4 MARPEs and hyrax expander (model E) were evaluated via FEA: bone-borne (model A), bone-tooth-borne (model B), bone-mucous-borne (model C), bone-tooth-mucous-borne (model D).

RESULTS

Monocortical microimplants perpendicular to the cortical bone on the coronal plane resulted in better expansion effects. Compared with a conventional hyrax expander, the orthopedic expansion of each of the 4 MARPEs was far larger, the parallelism was greater, and the posterior teeth tipping rate was lower. Among them, the expansion effects of models C and D were the best; the von Mises peak values on the surfaces of the microimplants were smaller than those of models A and B.

CONCLUSIONS

This study may demonstrate that the 4 MARPEs obtained more advantageous orthopedic expansion effects than a hyrax expander. Models C and D obtained better biomechanical effects and had better primary stability. Overall, model D is the recommended expander for treating maxillary transverse deficiency because its structure acts like an implant guide and is beneficial for the accurate insertion of the microimplant.

Comparison of nasal cavity changes between the expander with differential opening and the fan-type expander: a secondary data analysis from an RCT

INTRODUCTION

The aim of this study was to compare the nasal cavity skeletal changes between the expander with differential opening (EDO) and the fan-type expander (FE).

METHODS

This study was a secondary analysis of a previous randomized clinical trial. Forty-eight patients with posterior crossbite were randomly allocated into two study groups. Twenty-four patients (11 male, 13 female) with a mean initial age of 7.6 ± 0.9 years were treated with rapid maxillary expansion (RME) using the EDO. Twenty-four patients (10 male, 14 female) with a mean initial age of 7.8 ± 0.9 years were treated with the FE. Cone-beam computed tomography (CBCT) was performed before treatment and 1 to 6 months after the active phase of RME. Using frontal CBCT slices passing at the level of maxillary permanent first molars and maxillary deciduous canines, the width of the nasal cavity was measured in the lower, middle and upper thirds. Nasal cavity height was also evaluated in both slices. Intergroup comparisons of interphase changes were performed using t or Mann-Whitney tests (P < 0.05).

RESULTS

The two groups were similar regarding baseline data. EDO showed a greater transverse increase in the lower third of the nasal cavity in both canine (P = 0.007) and molar regions (P < 0.001). No intergroup difference was observed for changes in middle and upper widths and height of the nasal cavity.

CONCLUSIONS

Both expanders are effective in promoting an increase of the nasal cavity skeletal dimensions. The expander with differential opening produced a greater transverse increase in the lower third of the nasal cavity compared to the fan-type expander, both at the anterior and posterior regions of the maxilla.

CLINICAL RELEVANCE

EDO might be more beneficial to pediatric patients with oral breathing and obstructive sleep apnea compared to FE.

Near-Infrared Light-Controlled MicroRNA-21-Loaded Upconversion Nanoparticles to Promote Bone Formation in the Midpalatal Suture

Rapid maxillary expansion (RME) is a common therapy for maxillary transverse deficiency. However, relapses after RME usually occur because of insufficient bone formation. MicroRNA-21 (miR-21) was reported as an important post-transcriptional modulator for osteogenesis. Herein, a photocontrolled miR-21 (PC-miR-21)-loaded nanosystem using upconversion nanoparticles (UCNPs) modified with poly(ether imide) (PEI), i.e., UCNPs@PEI@PC-miR-21, was constructed to promote bone formation in the midpalatal suture. UCNPs@PEI was constructed as the light transducer and delivery carrier. The UCNPs@PEI@PC-miR-21 nanocomplexes have good aqueous dispersibility and biocompatibility. The in vitro cell experiment suggested that UCNPs@PEI could protect PC-miR-21 from biodegradation and release PC-miR-21 into the cytoplasm under near-infrared light (NIR) irradiation. Furthermore, UCNPs@PEI@PC-miR-21 upregulated the expression of the osteogenic key markers, ALP, RUNX2, and COL1A1, at the levels of both genes and proteins. Besides, the results of the in vivo RME mice models further corroborated that photocontrollable UCNPs@PEI@PC-miR-21 accelerated bone formation with upregulating osteogenic markers of ALP, RUNX2, and osteoprotegerin and inducing fewer osteoclasts formation. In conclusion, UCNPs@PEI@PC-miR-21 nanoparticles with a NIR light could facilitate the remote and precise delivery of exogenous miR-21 to the midpalatal suture to promote bone formation during RME. This work represents a cutting-edge approach of gene therapy to promote osteogenesis in the midpalatal suture during RME and provides a frontier scientific basis for later clinical treatment.

Extracellular vesicles derived from M1 macrophages enhance rat midpalatal suture expansion by promoting initial bone turnover and inflammation

BACKGROUND

Midpalatal suture (MPS) expansion can be affected by many factors, and researchers have attempted to regulate the initial inflammatory stage of expansion to optimize clinical outcomes and their underlying mechanisms. This study aimed to investigate the potential effects and mechanisms of M1 macrophage small extracellular vesicles during rat MPS expansion.

MATERIALS AND METHODS

RAW264.7 cells were induced to M1 or M2 polarization and, small extracellular vesicles were isolated from the polarized macrophages. Male Sprague-Dawley rats (6-7 weeks) were administered 70 ± 5 g expansion force devices for 7 days. Rats with expanders without force served as controls. M1/M2 small extracellular vesicles were injected into the MPS region (50 µg/day) in the M1 and M2 small extracellular vesicle-assisted groups, while 0.9% saline was injected into the expansion-only group. Suture width, bone mass, and morphological changes in the region of interest (ROI) were examined.

RESULTS

The M1 small extracellular vesicle-assisted group showed a significantly increased MPS suture width in vivo (P < 0.001), and less bone mass was observed in the ROI (P < 0.05). Histological examination showed that the M1 small extracellular vesicle-assisted group exhibited a wider palatal area and obvious fibrous tissue rearrangement. The expression of RANKL and the number of osteoclasts were increased (P < 0.01) in the bony edges, and the p65 protein expression was significantly higher (P < 0.001).

CONCLUSIONS

M1 macrophage-derived small extracellular vesicles have a positive effect in MPS expansion and increase p65 protein content and RANKL expression, thus promoting bone turnover. This study may contribute to the clinical application of small extracellular vesicles in the expansion of the palatal suture.

Comparison of the skeletal, dentoalveolar, and periodontal changes after Ni-Ti leaf spring expander and rapid maxillary expansion: a three-dimensional CBCT based evaluation

BACKGROUND

The aim of the present study was twofold:(1) three-dimensionally evaluate the quantitative skeletal and dentoalveolar changes after Ni-Ti leaf spring expander (leaf expander) and rapid maxillary expansion (RME) in mixed dentition patients;(2) analyze the modifications of the buccal alveolar bone plate of the maxillary first permanent molars.

METHODS

Patients who underwent CBCT scans before and after maxillary expansion were randomly selected from the records archived at the Department of Biomedical Surgical and Dental Sciences, University of Milan, Italy. Inclusion criteria were the following: no systemic disease or syndromes; maxillary transverse deficiencies (difference between the upper intermolar width and the lower intermolar width of at least 3 mm and/or clinical need based on radiographic evaluation), early mixed dentition with ages between 7 to 10 years old; cervical vertebra maturation stage (CVMS) 1 or 2; no pathologic periodontal status; skeletal class I or II; maxillary expander cemented on the upper second deciduous molars. Exclusion criteria were the following: patients with pubertal or post-pubertal stage of development (CVMS 3-6); late deciduous or late mixed dentition, impossibility to use the second primary molar as anchorage; skeletal class III malocclusion; craniofacial syndromes; patients unable to be followed during the treatment period. Twenty-three patients treated with Leaf Expander, 11 males (mean age 7.8 ± 0.6 years) and 12 females (mean age 8.1 ± 0.8 years), met the inclusion criteria and constituted the case group. Twenty-four (control group) treated with conventional RME, 12 males (mean age 8.4 ± 0.9 years) and 12 females (mean age 8.1 ± 0.7 years). The paired-sample T test was used for intra-group comparison to evaluate the difference between before (T1) and after (T2) maxillary expansion. Independent sample t-test was computed to perform between groups comparison of the skeletal, dentoalveolar, and periodontal changes.

RESULTS

The Leaf Expander and RME group showed a significant increase between T1 and T2 for most of the skeletal and dentoalveolar variables. Concerning the skeletal variables only the RME demonstrated a significant increase at the level of the posterior nasal (PNW) and apical base width (PABW) and maxillary mid-alveolar width (MMW). Despite this, when compare with the Leaf Expander, the RME group exhibited a statistically larger width increase for only two skeletal parameters: PNW (p = 0.03) and MMW (p = 0.02). No significant changes at the periodontal level were found in either group.

CONCLUSIONS

According to the current research, the authors confirm the effectiveness of the Leaf Expander and RME to produce similar skeletal and dentoalveolar effects in mixed dentition subjects. Moreover, the devices anchored to deciduous teeth did not reduce the thickness and height of the buccal bone at the level of the maxillary permanent first molars in either of the two groups.

Rapid maxillary expansion in pediatric patients with obstructive sleep apnea: an umbrella review

OBJECTIVE

To compare polysomnographic parameters with others from the literature in order to provide more accurate information about Rapid Maxillary Expansion (RME) for treating Obstructive Sleep Apnea (OSA) in children, through raising the question: Is RME a good option for treating OSA in children? Prevention of mouth breathing during children's growth remains a challenge with significant clinical consequences. In addition, OSA induces anatomofunctional changes during the critical period of craniofacial growth and development.

METHODS

The Medline, PubMed, EMBASE, CINAHL, Web of Science, SciELO and Scopus electronic databases were searched up to February 2021 for systematic reviews with meta-analysis in the English language. Among 40 studies on RME for treating OSA in children, we selected seven in which polysomnographic measurements of the Apnea-Hypopnea Index (AHI) had been made. Data were extracted and examined in order to clarify whether any consistent evidence exists for indicating RME as a treatment for OSA in children.

RESULTS

We found no consistent evidence favoring RME for long-term treatment of OSA in children. All the studies presented considerable heterogeneity due to variability of age and length of follow-up.

CONCLUSION

Through this umbrella review, the need for methodologically better studies on RME is supported. Moreover, it can be considered that RME is not recommended for treating OSA in children. Further studies and more evidence identifying early signs of OSA are necessary in order to achieve consistent healthcare practice.

The role of rapid maxillary expansion in pediatric obstructive sleep apnea: Efficacy, mechanism and multidisciplinary collaboration

This review aims to provide current knowledge about the efficacy, mechanism, and multidisciplinary collaboration of rapid maxillary expansion (RME) treatment in pediatric obstructive sleep apnea (OSA). OSA is a chronic disease characterized by progressively increasing upper airway resistance, with various symptoms and signs. Increasingly the evidence indicates that RME is a non-invasive and effective therapy option for children with OSA. Besides, the therapeutic mechanism of RME includes increasing upper airway volume, reducing nasal resistance, and changing tongue posture. Recent clinical researches and case reports also show that a multidisciplinary approach improves sleep-disordered breathing in children. Applied with adenotonsillectomy, mandibular advancement, continuous positive airway pressure, and comprehensive orthodontic treatment, RME can be more effective in recurrent or residual OSA.

STUDY OF THE STRESS-STRAIN STATE OF THE MAXILLA DURING ORTHODONTIC TREATMENT OF DENTOGNATHIC DEFORMATIONS IN CHILDREN WITH CONGENITAL CLEFT LIP AND PALATE

OBJECTIVE

The aim: To create a three-dimensional simulation mechanical-mathematical model of the biomechanical system "Orthodontic appliance-maxilla", to study peculiarities of the stress-strained state of the maxilla.

PATIENTS AND METHODS

Materials and methods: A simulation model of the biomechanical system "Orthodontic appliance-maxilla" was created using computed tomography (CBCT) data. Mathematical modeling was used to determine the stress-strain state of the simulation model.

RESULTS

Results: The patterns of changes in the stress state were determined and the values of deformation displacements in the structural elements of the biome-chanical system "Orthodontic appliance-maxilla" were determined under a force stress of the orthodontic device with an amplitude of 50 N.

CONCLUSION

Conclusions: Simulation computer modeling of the stress-strain state of the "Orthodontic appliance-maxilla" system showed that activation of the kinematic mechanism of the appliance with a force of 50 N causes the emergence of a complex stress-strain state of bones. When the orthodontic appliance is activated, there is an asymmetry in the distribution of stresses by Mises between the right and left sides both for the appliance itself and for the maxillary bone tissue.

Upper arch dimensional changes with clear aligners in the early mixed dentition : A prospective study

BACKGROUND

One goal of orthodontic treatment in mixed dentition is to expand the maxillary arch to allow proper tooth alignment and a correction of sagittal and vertical malocclusions. However, for most treatment protocols, expected outcome is not really clear to allow for a standardization of phase I orthodontic treatments. This lack of information makes it difficult for clinicians to predict tooth movements, including transverse expansion efficacy with Invisalign® (Align Technology, Santa Clara, CA, USA) in children. Therefore, the aim of the present study was to evaluate the transverse maxillary arch development with the Invisalign First System® in growing subjects.

METHODS

The study group included 23 subjects (9 females, 14 males, mean age 9.4 ± 1.2 years). Patients were treated nonextraction with Invisalign First System® clear aligners with no auxiliaries other than Invisalign® attachments. Transverse interdental widths were measured only in the upper arch on each model at the start (T1) and at the end (T2) of treatment. A paired t‑test was chosen to compare T2-T1 changes. The level of significance was set at 5%.

RESULTS

The greatest increase of maxillary width was detected at the level of the upper first deciduous molars (+3.7 ± 1.4 mm; P < 0.001), followed by the level of the second deciduous molars (+3.4 ± 1.6 mm; P < 0.001) and by the deciduous canine (+2.6 ± 2.0 mm; P < 0.001). Upper first molars showed a greater expansion in the intermolar mesial width (+3.2 ± 1.2 mm; P < 0.001) than in the intermolar distal (+1.7 ± 1.2 mm; P < 0.001) and transpalatal width (+1.2 ± 1.2 mm; P < 0.01).

CONCLUSIONS

The Invisalign First System® can be considered effective in growing patients who require maxillary arch development. The greatest net increase was detected at the level of upper first deciduous molars, whereas the upper first molars showed a greater expansion in the intermolar mesial width due to a rotation that occurs around its palatal root.

Gingival Margins' Modifications during Orthodontic Treatment with Invisalign First®: A Preliminary Study

The aim of the study was to assess modifications of gingival morphology at the end of Phase I treatment with Invisalign First. Eighteen subjects (ten females, eight males, mean age nine years) treated with Invisalign First were selected. The following parameters were measured on intraoral photographs before treatment (T0) and after the first set of aligners (T1) at level of permanent incisors, deciduous canines and molars: gingival margin height (GMH) and deciduous canine inclination (DCI). A paired t-test was used to evaluate T1-T0 changes. The level of significance was established at 5%. Deciduous canines' GMH showed a major reduction between T1 and T0 accounting for 0.87 mm and 0.86 mm, respectively on the right and left sides. DCI increased for all patients in the interval T0-T1 on both sides, +7.11° on the right and +7.5° on the left. Tooth movement during Invisalign First induced significant modifications of gingival contour resulting in a more harmonious smile.

Changes in hyoid bone and tongue position in Class I subjects after orthodontic treatment with rapid palatal expander

OBJECTIVE

To evaluate the effects of the rapid palatal expander (RPE) on the hyoid bone and tongue position in skeletal Class I patients, compared to control groups.

METHODS

Eighty-four Class I subjects, aged 6-14, were selected. Among these, 28 patients were treated with RPE, 28 with function-generating bite (FGB) appliance, and 28 were untreated. Lateral cephalograms taken before (T0) and after (T1) treatment were retrieved. Changes in the hyoid bone and tongue position were evaluated, and the area above the tongue was measured.

RESULTS

No significant difference in the hyoid and tongue posture was observed across the groups. However, there were significant differences for HC3 (distance from H-point to the third cervical vertebrae), H2H (distance from H-point to SN plane), and TT-Eb (tongue length) between T0 and T1 in all groups.

CONCLUSION

The results suggest that hyoid bone and tongue position changes were related to growth rather than treatment.

Dental Arch Changes with Two Different Trans-Palatal Arch

Background:

Rapid maxillary expansion (RME) is a dentofacial orthopedic treatment often used to treat patients with narrow palate and transverse maxillary growth deficiency.

Introduction:

This treatment leads to correction of posterior dental crossbites, coordination of the upper and lower arches and gaining arch perimeter in patients with tooth size/arch size discrepancies. To stabilize the results obtained with RME and to limit or avoid the relapse, the use of Transpalatal Arch (TPA) would be recommended.

Objectives:

The aim of this study is to evaluate short-term maxillary changes in patients treated with RME followed by TPA with and without palatal arms.

Materials and Methods:

30 patients, 16 females and 14 males (mean age of 9.7 yrs ranging between 9 and 12), were treated by expansion with palatal Hyrax-type expander. After this period, it was removed and one of the two different types of TPA was used.

The two different TPA were a 0.036-inch stainless steel wire with a loop directed mesially in the middle, one maintained the original design (TPA), the second one presented arms extended to canines (TPAa). Dental casts were collected for each patient for each treatment step; before (T0), after expansion (T1) and after TPA or TPAa (T2). To assess differences in dental arches after the two treatment phases, three-dimensional (3D) dental casts were used to make more predictable measurements compared with caliper measurements that presented intra-examiner and inter-examiner measurements errors.

Results:

In TPAa group, differences between the value at the end of the retention period and at the end of expansion showed no statistical significance. Instead in TPA group, the same measurements suggested a reduction of value in almost all dental transverse diameters. Statistically significant differences in dental measurements were found between TPAa and TPA.

Conclusion:

Results confirm the hypothesis that TPAa can allow to better maintain dental transverse dimensions.

Innovations in the Treatment of Pediatric Obstructive Sleep Apnea

Obstructive sleep apnea affects a large proportion of otherwise healthy children in the context of interactions between craniofacial elements, adenotonsillar hypertrophy and other anatomical factors, and neuromuscular reflexes of the upper airway. In light of the adverse consequences of sleep apnea, it is important not only to proceed with early diagnosis but also to implement adequate treatment that is guided by the pathophysiological determinants of the disease in each child. Here, we will describe the current standard of care approaches to the treatment of pediatric obstructive sleep apnea, and will also explore novel management strategies that should enable more personalized therapy in the near future.

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

BACKGROUND

The 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 METHODS

Twenty-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.

RESULTS

Oral 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.

CONCLUSIONS

RME 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.

Novel Digital Measurement Technique to Analyze the Palatine Suture Expansion after Palatine Rapid Maxillary Expansion Technique

The aim of the study was to validate a novel digital measurement method to quantify the volume of the midpalatal suture after rapid maxillary expansion (RME). Material and methods: Eight patients with maxillary skeletal transverse deficiency were submitted to palatine suture expansion using the McNamara orthodontic appliance during a period of nine months. After 30 days of treatment, all patients were exposed postoperatively to a cone-beam computed tomography (CBCT) scan. Afterwards, the scans were uploaded into the three-dimensional orthodontic-planning software to allow the volumetric assessment of the palatine suture expansion through palatine rapid maxillary expansion using a McNamara appliance. The repeatability was analyzed by repeating twice the measures by a single operator and reproducibility was analyzed by repeating three times the measures by two operators, and Gage R&R statistical analysis was performed. Results: The expansion of the midpalatal suture by means of the rapid maxillary expansion technique, in terms of digital volume measurement, showed a repeatability value of 0.09% and between the two operators a reproducibility value of 0.00% was shown. Conclusions: The novel measurement technique demonstrated a high repeatability and reproducibility rate for volume assessment of the palatine suture expansion through palatine rapid maxillary expansion technique.

Influence of rapid maxillary expansion on nocturnal enuresis in children

OBJECTIVES

To evaluate the influence of rapid maxillary expansion (RME) on nocturnal enuresis (NE) in children to discuss whether RME can be indicated as an alternative treatment for NE in those patients.

MATERIALS AND METHODS

An electronic search was performed in the following databases: PubMed/MEDLINE, Cochrane Library, Scopus, Science Direct, Google Scholar and LILACS. The literature review was blindly performed by two reviewers. References of each selected study were manually searched to identify articles that were not found by the electronic search. Kappa statistics were used to analyze interexaminer agreement after the selection of the articles. After reading the selected full-text articles, the studies that met the inclusion criteria were assessed qualitatively using the Risk Of Bias In Non-randomized Studies of Interventions (ROBINS-I) and the Revised Cochrane risk-of-bias tool for randomized controlled trials-2 (RoB 2). The certainty level of evidence was assessed through the Grading of Recommendations, Assessment, Development and Evaluation tool. Kappa tests were used to analyze the interexaminer concordance level after the quality assessment of the studies.

RESULTS

A total of 488 articles were found; however, after applying the inclusion and exclusion criteria, only 8 studies were selected for the systematic review. A low certainty level of evidence suggested that RME seems to promote a variable reduction in frequency or a remission of NE in children in both the short (4, 6, and 8 months) and long term (13, 36, 48, and 120 months).

CONCLUSIONS

Based on currently available information, RME seems to promote an improvement in NE in children. However, the low quality of the existing evidence weakens the recommendation.

Tomographic analysis of midpalatal suture prior to rapid maxillary expansion

INTRODUCTION

In Orthodontics and Facial Orthopedics, the timing of treatment onset may be critical and individual analysis should be applied to promote a favorable treatment planning. In this study, individual analysis of midpalatal suture (MS) and palatal measurements were performed in teenagers and young adult patients treated with rapid maxillary expansion (RME).

DESCRIPTION

Twenty-six patients submitted to RME with a tooth-supported appliance (Hyrax) were evaluated. The inclusion criteria were: minimum age of 14 years, presenting all posterior teeth, diagnosed with transverse maxillary discrepancy, and with a clinical indication for maxillary expansion. The pretreatment CBCT scans of these patients were assessed to obtain the stages of MS maturation (MSM); density ratio (MSD); and palatal length, thickness (anterior, intermediate and posterior) and sagittal area.

RESULTS

The maturation stages present were C, D or E; the density ranged from 0.6 to 1, and lower density (MSD < 0.75) and higher density (MSD ≥ 0.75) groups were determined. Individuals with higher MSD presented smaller sagittal area, compared to the lower density group. Individuals in D and E MSM stages presented smaller sagittal area and intermediate thickness, compared to stage C.

CONCLUSIONS

Smaller palatal sagittal area was observed in the high MSD groups and in the stages D and E of MSM.

Comparison of the dento-skeletal effects produced by Leaf expander versus rapid maxillary expander in prepubertal patients: a two-center randomized controlled trial

OBJECTIVE

This study aimed to compare the skeletal and dentoalveolar effects produced by slow maxillary expansion (SME) with the Leaf expander versus the conventional rapid maxillary expansion (RME) on digital dental casts, lateral and postero-anterior cephalometric radiographs.

TRIAL DESIGN

This is a superiority, two-center, two arms parallel balanced randomization trial.

METHODS

Patients in the mixed dentition were included with a transverse interarch discrepancy of at least 3 mm. An expansion screw using moderate continuous forces (Leaf group) was compared to a conventional RME screw (RME group). The primary response variable was the difference in maxillary intermolar width (U6-U6) measured at baseline (T0) and one-year follow-up (T1) on the digital dental casts. Other dento-skeletal variables were also measured on digital dental casts and cephalograms. Computer-generated block randomization was used with allocation concealed in sequentially numbered opaque sealed envelopes. The examiner was blinded on the type of expander used. Linear models were used for statistical analysis.

RESULTS

Twenty-eight patients in the Leaf group and 28 patients in the RME group were randomized and included in the study. There were no dropouts. U6-U6 did not show a statistically significant difference between the two groups (-0.4 mm in favor of the RME group, 95% CI from -1.2 to 0.5, P = 0.365). As for the other secondary variables no statistically significant differences were found between the two groups except maxillary intercanine width (U3-U3, -0.9 mm in favor of the RME group, 95%CI from -1.5 to -0.3, P = 0.005) and maxillary skeletal width (Mx-Mx, -1.4 mm in favor of the RME group, 95%CI from -2.4 to -0.3, P = 0.013).

CONCLUSIONS

No significant differences between the RME and Leaf groups were detected for any of the analyzed dento-skeletal variables except the T1-T0 differences in U3-U3 and Mx-Mx that were significantly greater in the RME group.

REGISTRATION

The study was registered in the ISRCTN register on 08/11/2016 with the number ISRCTN18263886.

FUNDING

No funding or conflict of interest to be declared.

Pediatric Obstructive Sleep Apnea Syndrome: Emerging Evidence and Treatment Approach

OSA pediatric subjects suffer from episodes of upper airway obstruction that can be partial or complete, with atypical sleep patterns and blood-gas level alteration. If poor treated and/or diagnosed, it can cause cardiovascular disease, learning difficulties, behavioural issues, and retardation of growth. In the literature, there are conflicting evidence about OSA assessment and treatment in pediatric age, so the aim of this paper is to highlight the multidisciplinary approach in the management of sleep disorders, stressing the role of the pediatric dentist in both diagnosing and treating the OSAS in children, according to the current evidence of the treatment options effectiveness of the syndrome itself. Conclusions. Scientific evidence shows that OSAS management requires a multidisciplinary approach in order to make an early diagnosis and a correct treatment plan. The orthodontic treatment approach includes orthopedic maxillary expansion and mandibular advancement using intraoral appliances. Hence, the orthodontist and the pediatric dentist play an important role not only in early diagnosis but also in the treatment of pediatric OSAS.

Safety and Effects of the Rapid Maxillary Expander on Temporomandibular Joint in Subjects Affected by Juvenile Idiopathic Arthritis: A Retrospective Study

BACKGROUND

In Juvenile Idiopathic Arthritis (JIA) temporo-mandibular joints are often affected causing skeletal and dental malocclusions. The most frequent condition is mandibular hypoplasia, that may be associated with maxillary hypoplasia. The aim of this retrospective case control study is to investigate the effects and the safety of rapid maxillary expansion (RME) in growing patients affected by JIA. It was evaluated whether RME could be performed without complications on TMJs of JIA patients using DC/TMD protocol, and naso-maxillary transversal parameters were compared with the ones obtained on healthy patients.

METHODS

Twenty-five patients affected by JIA that ceased to manifest TMJ (Temporo-Mandibular Joint) symptoms in the previous year were treated with RME to solve the maxillary transverse hypoplasia. Postero-anterior cephalometric tracings were collected before and after treatment; linear measurements were obtained to study maxillary and nasal cavity modifications. Data were compared to those of a similar group of twenty-five healthy patients. Paired t-test and Independent t-test were used to evaluate changes before and after treatment in each group and to perform a comparison between the groups.

RESULTS

All patients demonstrated a statistically significant increase in nasal cavity width, maxillary width and upper and lower intermolar width. No patients presented a worsening of their TMJs condition. Intragroup comparisons revealed significant changes of cephalometric measurements, but no difference was found when comparing JIA and healthy patients.

CONCLUSIONS

Growing patients with JIA that ceased to show signs of active TMJ involvement for at least one year could be safely treated with RME, expecting similar benefits to those of healthy patients. Dentists and rheumatologists should be informed of safety and potential benefits of palatal expansion in JIA patients in order to improve the outcome of orthodontic treatment and reduce the indication for more invasive procedures (i.e., Surgical Assisted Rapid Maxillary Expansion).

Buccal Bone Changes Around First Permanent Molars and Second Primary Molars after Maxillary Expansion with a Low Compliance Ni-Ti Leaf Spring Expander

Background: Vestibular bone thickness changes and dento-alveolar buccal tipping of second primary molars and of first molars after maxillary expansion performed with a slow maxillary expansion protocol was investigated. Methods: Twenty patients (mean age 7.3 ± 0.9 years old; 9 male and 11 female) were treated according to the Leaf Expander protocol. Buccal alveolar bone thickness (BT), buccal alveolar bone height (BH), inter-dental angle (TIP), and inter-molar width (IW) regarding first molars and second primary molars were calculated before and after expansion on cone beam computed tomography (CBCT) images. Descriptive statistics and paired t-tests were used to assess changes between the pre-treatment and post-treatment measurements. Results: Bone thickness vestibular to second primary molars and intermolar width of both teeth were the only variables that showed statistically significant changes. Conclusions: It appears that buccal bone thickness vestibular to first molars was not significantly reduced after maxillary expansion with the Leaf Expander. The clinical use of a slow maxillary expander with Ni-Ti springs appears efficient and safe in in the correction of maxillary hypoplasia during mixed dentition.

Three-dimensional analyses of short- and long-term effects of rapid maxillary expansion on nasal cavity and upper airway: A systematic review and meta-analysis

INTRODUCTION

The purpose of this systematic review was to evaluate the three-dimensional (3D) changes occurring at short- and long-term follow-up after rapid maxillary expansion (RME) in nasal cavity (NC) and upper airway (UA) in growing patients.

METHODS

A literature search up to 1 July 2019 was performed. Randomized and non-randomized clinical trials and cohort studies comparing the effects of RME in a paediatric population using 3D analyses based on computed tomography (CT), cone-beam CT and MRI were included. The risks of bias of the included studies were assessed using the Cochrane Collaboration's risk of bias tool, the GRADE approach and a customized tool. The random-effects meta-analyses of the mean differences and 95% confidence intervals of NC and UA volume changes were carried out, followed by subgroup analyses.

RESULTS

Twenty-seven studies were included, with 18 selected for quantitative synthesis. Immediately after expansion, the nasopharynx and oropharynx increased significantly. After 3 months of retention, only the NC and nasopharynx showed a significant volume increase. Two studies mentioned the use of a sleep-disordered breathing questionnaire, and one study reported the difference before and after RME. None of the 27 articles included assessed the correlation between the skeletal widening and NC or UA volume changes after RME.

CONCLUSIONS

The existing evidence confirmed only the short-term positive effect of RME on expanding the volume of the NC and the upper part of the UA. However, long-term stability could not be sustained.

Effects on the Facial Growth of Rapid Palatal Expansion in Growing Patients Affected by Juvenile Idiopathic Arthritis with Monolateral Involvement of the Temporomandibular Joints: A Case-Control Study on Posteroanterior and Lateral Cephalograms

BACKGROUND

Juvenile idiopathic arthritis (JIA) affecting temporomandibular joints (TMJ) in growing patients results in maxillofacial deformities, especially if only one condyle has been affected by the rheumatic disease. Mandibular hypoplasia is the most common issue and it may be associated with maxillary hypoplasia. The aim of this retrospective case-control study is to evaluate the effects of rapid maxillary expansion (RME) in these patients.

METHODS

25 growing patients affected by maxillary hypoplasia, currently in a quiescent phase of JIA for at least one year and monolateral involvement of the TMJs, were treated with RME. Data gathered from posteroanterior and lateral cephalograms before and after 1 year from RME were compared to those of 25 non-JIA controls.

RESULTS

Nasal cavity width, maxillary width and upper and lower intermolar width statistically increased. Maxillary and mandibular symmetry indexes presented a statistically significant increase, so did the skeletal class. No signs or symptoms of TMJ activity of JIA occurred according to Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) criteria. No difference was found when comparing JIA and non-JIA patients apart from the better improvement of several mandibular symmetry indexes in the affected TMJ side of JIA patients. This event is allegedly due to a worse baseline asymmetry in JIA patients that underwent a bigger relative improvement after treatment.

CONCLUSIONS

Results suggest that solving maxillary hypoplasia and, therefore, premature contacts are likely to have allowed mandibular repositioning and condylar growth. RME is a safe and effective solution that can substantially improve maxillary and mandibular symmetry in growing patients affected by JIA with TMJ involvement.

Midpalatal Suture Density Evaluation after Rapid and Slow Maxillary Expansion with a Low-Dose CT Protocol: A Retrospective Study

Background and objectives: The aim of the present paper is to use low-dose computed tomography (CT) to evaluate the changes in the midpalatal suture density in patients treated with rapid maxillary expansion (RME) and slow maxillary expansion (SME). Materials and Methods: Thirty patients (mean age 10.2 ± 1.2 years) were retrospectively selected from the existing sample of a previous study. For each patient, a low-dose computed tomography examination was performed before appliance placement (T0) and at the end of retention (T1), seven months later. Using the collected images, the midpalatal suture density was evaluated in six regions of interest. Results: No significant differences were found between the timepoints in the rapid maxillary expansion group. Three out of six regions of interest showed significant decreases between the timepoints in the slow maxillary expansion group. No significant differences were found in comparisons between the two groups. Conclusions: The midpalatal suture density showed no significant differences when rapid maxillary expansion groups were compared to slow maxillary expansion groups, suggesting that a similar rate of suture reorganization occurs despite different expansion protocols.

Evaluation of sagittal airway dimensions after face mask therapy with rapid maxillary expansion in Class III growing patients

OBJECTIVE

The aim of this investigation was to analyze the effects of RME and FM on the airway dimensions in Class III patients compared with untreated controls.

METHODS

A sample of 47 Class III patients treated with RME and FM was analyzed. The treated group was compared with 18 untreated controls. Lateral cephalograms for each patient at T1, T2, and T3 were digitized.

RESULTS

At long-term evaluation a significant increase in airway size and a significant decrease in adenoid size were found in the treated group as well as an improvement in the pharynx dimension. During active treatment the treated group showed a significant improvement in lower airway size and in lower pharynx dimension. A significant decrease in adenoid size was also found.

CONCLUSION

The treatment with RME and FM produced favorable stable changes in the airway dimensions in Class III subjects when compared with untreated controls.

Three-dimensional assessment of craniofacial asymmetry in children with transverse maxillary deficiency after rapid maxillary expansion: A prospective study

OBJECTIVE

The aim of this study was to evaluate craniofacial asymmetry in children with transverse maxillary deficiency, with or without functional unilateral posterior crossbite (UPC), before and after rapid maxillary expansion (RME).

SETTING AND SAMPLE POPULATION

A sample of 51 children with cone beam computed tomography scans obtained before RME (T1) and a year after RME (T2).

MATERIAL AND METHODS

This prospective study consisted of 2 groups: 25 children with functional UPC (6.77 ± 1.5 years) and 26 children without UPC (7.41 ± 1.31 years). Linear and angular measurements were obtained from zygomatic, maxilla, glenoid fossa and mandible, using original and mirrored 3D overlapped models. All right and left side comparisons in both groups and intergroups asymmetries were compared using MANOVA and t test for independent samples, respectively, statistically significant at P < .05.

RESULTS

The UPC group showed no side differences, but mandibular horizontal rotation at T1, and this asymmetry was improved in T2. The non-UPC group showed at baseline significant lateral asymmetry in orbitale, position of palatine foramen, respectively, in average 2.95 mm and 1.16 mm, and 0.49 mm of average asymmetry in condylar height. The glenoid fossa was symmetric in both groups at T1 and T2.

CONCLUSIONS

Children with transverse maxillary deficiency showed slight morphological asymmetry, located in the mandible position in cases of UPC, and in the orbital and maxillary regions in cases without UPC. One year after RME, patients improved their craniofacial asymmetry, with significant changes in the mandible and correction of the mandibular rotation in patients who presented UPC.

Mandibular Behavior after Rapid Maxillary Expansion: A Clinical Study

Background:

Rapid Maxillary Expansion (RME) is a primary part of the contemporary orthodontic treatment plans. In addition to the maxilla, it is important to know its effect on the other dentofacial components. Some studies showed dentofacial changes after RME in the sagittal and vertical planes. The clinical importance of these changes is controversial.

Objective:

To investigate the mandibular changes after RME as the only treatment intervention in the sagittal and vertical planes.

Methods:

Twenty-eight growing patients aged 4-14 years were included in the current study. The bonded acrylic splint expander was used. Lateral cephalometric radiographs were taken at the beginning of the treatment (T1) and after a retention phase of six months (T2). The mandibular changes were assessed using vertical parameters (SN.MP, MMA, LAFH/TAFH, S.AR/AR.GO) and sagittal parameters (SNB, S.N.POG, N.A.POG). The changes between T1 and T2 were examined by paired samples T-test.

Results:

Two parameters showed a backward rotation in the vertical plane. The parameter S.AR/AR.GO showed a significant increase. The skeletal convexity increased with no clinical significance.

Conclusion:

There were statistically significant changes in the sagittal and vertical planes with no clinical importance. RME may affect the mandibular condyle position.

[Obstructive sleep disordered breathing and orthodontics: primum non nocere]

Obstructive sleep apnoea syndrome is a widespread and under-diagnosed condition, making it a major public health and safety issue. The objective of this article was to clarify some of the evidence-based elements of therapeutic decision-making and the information provided to the patient and family on the benefit-cost-security ratio of several of his therapeutic options. Published data on the effectiveness of oral appliances and functional orthopaedic appliances for obstructive sleep apnea (OSA) in children, the durability of their effects, the therapeutic possibilities of maxillary or bimaxillary expansion, and the interrelationships between permanent teeth extractions and obstructive sleep disordered breathing, were researched and analyzed. Based on available evidence, in growing patients with Class II malocclusion, treatment with functional orthopedic devices can increase the volume of the pharyngeal airway and thus hopefully reduce the risk of developing OSA. An improvement in the apnea-hypopnea index and lower oxygen saturation was observed in children treated with rapid maxillary expansion. Permanent teeth extractions prescribed for the treatment of teeth crowding in an orthodontic age patient do not result in any significant change in the upper airway. The role of the orthodontist in the multidisciplinary team in the screening and management of Obstructive Sleep Disordered Breathing (OSDB) is essential. By combining clinical experience with published data on various therapeutic approaches, the orthodontist helps the patient to benefit from better adapted care and a more sustainable outcome, while taking into account his or her preferences.

[Comparing the effects of fast and slow expansion on nasal cavity and maxilla structure]

OBJECTIVE

This study aims to compare the effects of fast and slow expansion on nasal cavity structure.

METHODS

A total of 40 patients were selected and randomly divided into two groups. Cone-beam computer tomography (CBCT) was obtained before and after surgery and used for comparing the changes in nasal structure before and after treatment.

RESULTS

Fast expansion had resulted in greater changes in the basilar and nasal bone arch extension structures than slow expansion. No significant difference at maxillary width and nasal parenchyma.

CONCLUSIONS

Rapid expansion therapy has more beneficial effects on nasal function.

Parents’ Perceptions of Breathing Pattern Changes, Sleep Quality, and Fatigue in Children after Rapid Maxillary Expansion: A Survey and Case Series Study

Background:

Rapid Maxillary Expansion (RME) aims to re-establish balance between the widths of the jaws. It is mainly utilized to treat skeletal and dental manifestations associated with transverse maxillary constriction and to improve facial structures involving the nasal cavity.

Objectives:

This study aimed to investigate parents’ perceptions of breathing pattern changes after their child had undergone RME and the associated effects on sleep quality and fatigue. We also evaluated nasal cavity changes in three dimensions in six randomly selected patients.

Methods:

Ninety-one children aged 5-13 years with transverse maxillary deficiency and no major systemic diseases or syndromes were recruited. Their parents completed a 16-item questionnaire pre-treatment and 6 months post-treatment. The questionnaire included items pertaining to changes in (1) sleep apnea and breathing patterns, (2) sleep quality and fatigue, and (3) behavior. The cone beam computed tomography scans from six randomly chosen patients were also subjected to stereolithographic reconstruction of the midface pre-RME and post-RME.

Results:

Responses in the three domains exhibited good reliability. Significant improvements were observed in 59% of the items post vs. pre-RME. The overall rates of dry mouth in the morning, snoring half of the time, and heavy breathing decreased by ≥30%. The percentage change in headache in the morning, snoring loudly, and snoring half of the time was >80%. In addition, in the series of six cases, the mean difference in nasal cavity area post-RME was 4.1 mm2.

Conclusion:

Post-RME, parents perceived that their children exhibited improved behavior and were less fatigued during the day. Enhanced sleep quality and breathing patterns were also observed, but to a lesser extent.

Corticopuncture Facilitated Microimplant-Assisted Rapid Palatal Expansion

Introduction

Microimplant-assisted rapid palatal expansion (MARPE) has been considered an alternative to avoid extensive surgical procedures. In order to obtain skeletal results of MARPE, force should be enough to overcome areas of resistance and the first one that is required to be disrupted is the midpalatal suture, which becomes increasingly interdigitated after adolescence.

Objective

The present study aimed at providing a novel approach using a minimally invasive method called corticopuncture (CP) in association with MARPE illustrated by a case report of a 35-year-old Brazilian female Caucasian patient presenting maxillary transverse deficiency.

Method

Treatment plan started with an orthopedic correction of the transverse problem using a MARPE device. After many unsuccessful attempts to activate MARPE, corticopunctures were performed along the midpalatal suture. CP procedure at the midpalatal suture included 8 perforations (2 mm apart), performed after previous predrilling followed by miniscrew insertion (5 mm thread length and 1.8 mm diameter).

Results

After CP and new activation protocol, the opening of the midpalatal suture was observed by CBCT images, showing skeletal results, suture split of 3.14 mm (premolar area) and 2.06 (molar area), an increase of 4.3 mm (premolar) and 3.03 mm (molar) in basal bone width, 4.43 mm (premolar) and 3.1 mm (molar) in cortical bone width, and minimal dental effects (mean of 1.2° of tooth tipping).

Conclusion

The combination of MARPE and corticopuncture method was proved to be a nonsurgical treatment option to correct maxillary transverse deficiency in an adult patient. CP was able to weaken suture interdigitation thus facilitating the split.

Efficacy of ketoprofen lysine salt and paracetamol/acetaminophen to reduce pain during rapid maxillary expansion: A randomized controlled clinical trial

BACKGROUND

Rapid maxillary expansion (RME) is an orthopaedic procedure indicated for a wide variety of clinical conditions.

AIM

The aim of the study was to compare the effects of ketoprofen lysine salt (KLS) vs paracetamol/acetaminophen (P) on pain perception during RME.

DESIGN

One hundred and fifty-one subjects (mean age 8.6 year) were enrolled in this prospective controlled clinical trial according to inclusion criteria: prepuberal stage of development, negative posterior transverse interarch discrepancy, non-concurrent use of other drugs. First phase: n.40 allocated to Group 1 used 40 mg of KLS, n.40 to Group 2 used 250 mg of P, n.36 to Group 3 as control group. Second phase: n.35 allocated to Group 4 used 40 mg ketoprofen lysine salt once a day for the first 3 days of activation. Pain experience was reported on a numeric rating scale (0-4) and a 100-mm visual analogue scale. Pain perception was tested with the Mann-Whitney test (P < 0.05).

RESULTS

Pain perception was higher during the first 3 days of activation and it was described as mild to moderate. Group 1 experienced significantly less pain during the fourth, fifth, and sixth day (P < 0.05) compared with Group 2. Patients of the Group 4 reported significantly lower pain during the whole period of RME activation (P < 0.05).

CONCLUSIONS

The perceived higher pain was reported during the second and third day of expansion. The analgesic effect of KLS is more effective than P during the fourth, fifth, and sixth day. The use of KLS during the first 3 days of activation seems to be able reducing pain during the whole active phase.

Rapid maxillary expansion in the treatment of the functional posterior crossbite: joint noise and electromyographic activity analysis

Abstract Introduction The rapid maxillary expansion (RME) reduces the risk of developing structural and functional disorders in the stomatognathic system. Objective To examine the effects of the RME as a treatment for the posterior crossbite, related with the electromyographic activity of the masticatory muscles and the TMJ noises in a population of children. Material and method 13 girls and 7 boys, regardless of the type of malocclusion, with a mean age of 9 years old (± 3), were treated with RME. The electrovibratography analyzed the TMJ noise, and the electromyography analyzed the masticatory muscles before treatment (T0) and after three months of a short-term follow-up (T1). The comparisons of the affected and unaffected sides by the crossbite were performed using Mann-Whitney’s test, and to compare data before and after treatment the Wilcoxon’s test was used (level of significance: 5%). Result No significant differences were found in the parameters of joint noise in comparison to the sides affected and unaffected by the crossbite, in both T0 and T1 (p>0.05); only the side without the crossbite observed decrease in the peak amplitude of the joint noises after treatment. In the static electromyographic analysis, inter-side differences were observed before and after treatment, since the deliberate unilateral chewing showed greater asymmetry activity in T0 for both sides, which has been corrected after treatment, improving the functional chewing. Conclusion The proposed treatment did not lead to the occurrence of joint noises and improved the functional pattern of electromyographic activity during chewing at the end of treatment.