Does rapid maxillary expansion have long-term effects on airway dimensions and breathing?

Medium-term effects of rapid maxillary expansion on nasal cavity and pharyngeal airway volumes considering age as a factor: A retrospective study

OBJECTIVES

The medium-term effects of rapid maxillary expansion (RME) on nasal cavity (NC) and upper airway (UA) dimensions based on chronological age are still unclear. This retrospective study evaluated the medium-term changes occurring in the NC and pharyngeal airways (PA) after RME in two distinct age-based cohorts of patients.

METHODS

This retrospective study included 48 subjects who underwent RME grouped in two cohorts: a 6-9-year-old group (EEG group: early expansion group - 25 subjects) and an 11-14-year-old group (LEG group: late expansion group - 23 subjects). NC and PA volumes were analyzed from CBCT imaging segmentation before RME (T0) and twelve months after RME (T1). The amount of maxillary expansion (PW) and minimal cross-sectional area (CSmin) were also considered.

RESULTS

All PAs' volumetric sub-regions, CSmin and PW showed a significant volumetric increment (p < 0.05). Inter-group comparisons showed significant differences (p < 0.05) for nasopharynx and CSmin parameters (p < 0.05), while no significant changes were recorded for the other UA's sub-regions and PW (p > 0.05). According to a deviation analysis, part of the UA increase (more marked for the nasopharynx area) may have occurred due to reduced adenotonsillar tissues, which were larger in the EEG group.

CONCLUSIONS

Twelve months after treatment, clinicians should not expect changes in the UAs dimensions to be solely related to treatment effects of RME; instead, normal craniofacial growth changes and spontaneous regression of the adenotonsillar tissue could represent the most significant factors influencing UAs changes.

CLINICAL SIGNIFICANCE

From the clinical perspective, the results of the present study encourage caution when considering the therapeutic effects of RME on airways dimensions.

Miniscrews position for a tissue bone borne palatal C-expander affects the displacement pattern of nasomaxillary complex: a finite element study

This study aimed to evaluate the difference in expansion patterns based on the position of miniscrews for a tissue-bone-borne palatal C-expander using a finite element method. Ten expansion models were examined, each representing a different position of miniscrews on the palate. Models A and B had miniscrews symmetrically placed 7 mm and 15 mm below the cementoenamel junction (CEJ), respectively. Models C to J had miniscrews positioned in a triangular manner at 7 mm and 15 mm below CEJ. Stress, displacement, angular changes of the bone and teeth, and changes in the nasomaxillary complex were measured using elastoplastic behavior models through static-nonlinear simulation employing an implicit method. The anterior and posterior parts of paramidpalatal suture area were identified as ANT, TPS-M, and TPS-L, and their ratio was assessed. Model A, which featured three miniscrews located 7 mm below the CEJ, exhibited the least molar inclination and the smallest amount of skeletal expansion. Model I, with two miniscrews placed between the first and second molars, demonstrated the greatest lateral displacement at point N on the nasal cavity wall, along with the smallest ratio of ANT to TPS-M or TPS-L. This finding suggests that the posterior expansion of the palate in relation to the anterior expansion was maximized. The results of this study indicate that strategic positioning of miniscrews is effective in achieving various expansion patterns based on the targeted correction areas within the nasomaxillary complex.

International Consensus Statement on Obstructive Sleep Apnea

BACKGROUND

Evaluation and interpretation of the literature on obstructive sleep apnea (OSA) allows for consolidation and determination of the key factors important for clinical management of the adult OSA patient. Toward this goal, an international collaborative of multidisciplinary experts in sleep apnea evaluation and treatment have produced the International Consensus statement on Obstructive Sleep Apnea (ICS:OSA).

METHODS

Using previously defined methodology, focal topics in OSA were assigned as literature review (LR), evidence-based review (EBR), or evidence-based review with recommendations (EBR-R) formats. Each topic incorporated the available and relevant evidence which was summarized and graded on study quality. Each topic and section underwent iterative review and the ICS:OSA was created and reviewed by all authors for consensus.

RESULTS

The ICS:OSA addresses OSA syndrome definitions, pathophysiology, epidemiology, risk factors for disease, screening methods, diagnostic testing types, multiple treatment modalities, and effects of OSA treatment on multiple OSA-associated comorbidities. Specific focus on outcomes with positive airway pressure (PAP) and surgical treatments were evaluated.

CONCLUSION

This review of the literature consolidates the available knowledge and identifies the limitations of the current evidence on OSA. This effort aims to create a resource for OSA evidence-based practice and identify future research needs. Knowledge gaps and research opportunities include improving the metrics of OSA disease, determining the optimal OSA screening paradigms, developing strategies for PAP adherence and longitudinal care, enhancing selection of PAP alternatives and surgery, understanding health risk outcomes, and translating evidence into individualized approaches to therapy.

Rapid maxillary expansion and its consequences on the nasal and oropharyngeal anatomy and breathing function of children and adolescents: An umbrella review

OBJECTIVE

To identify, qualify, and summarize the evidence from different systematic reviews about the outcomes of Rapid Maxillary Expansion (RME) on upper airway dimensions and breathing function in young patients.

METHODS

A literature search (from 2000 to December 2022) was conducted through PubMed (MEDLINE), the Cochrane Library, EMBASE, and Dentistry & Oral Science Source. The authors conducted the following umbrella review phases: research question, study selection criteria (systematic reviews involving randomized clinical trials and longitudinal observational designs), data extraction, and critical appraisal (bias risk assessment) of selected articles through the ROBIS tool.

RESULTS

The initial search yielded 65 potential references. After screening titles and summaries, and the elimination of duplicated publications, 15 articles were eligible for the evaluation of the full-text document. Finally, 11 systematic reviews (5 combined with meta-analysis) were selected, reporting 132 single studies; 38 of them were unrepeatable. Risk-of-bias assessment showed an average global moderate/high quality among the included studies. There was high heterogeneity between the systematic reviews' (and meta-analyses') methodologies used.

CONCLUSIONS

The present umbrella review concludes that significant and stable increases in the nasal and oropharyngeal space volumes and a decrease in airway resistance of growing children and adolescents, occur immediately after RME and at 3, 6- and 12-months follow-up.

Age-dependent effects on palate volume and morphology during orthodontic RME treatment

OBJECTIVES

Rapid maxillary expansion (RME) shows different age-dependent effects. It has been shown that RME leads to a parallel expansion prior to the age of 10, while later and especially from the age of 12, a V-shaped expansion happens (transverse, anterior > posterior; horizontal, inferior > superior). However, it is not clear to what extent these effects influence palatal volume and morphology and eventually maxillary functional space. The aim of the present study was to examine possible age-related effects of treatment with a dental anchored RME appliance upon volume and width/height ratio of the anterior and posterior palate.

MATERIALS AND METHODS

Sixty children and adolescents with documented treatment histories after RME were divided into three equal groups according to age at treatment begin (PG 1, < 10 years, n=20; PG 2, 10 ≤ 12 years, n=20; PG 3, > 12 years, n=20). Maxillary dental casts before and after therapy were digitised. Changes in palatal volume were determined using 3D analyses.

RESULTS

In all patients, the palatal volume increases significantly after RME. Older patients experienced smaller increases in total and posterior volume in absolute and percentage terms. The anterior palate volume increases are almost equal in all patients. Since palatal width increases more markedly than palatal height, the width/height ratio always increases. Except for the posterior region in PG 3, its increase is significant in all groups, both anteriorly and posteriorly. After successful RME, the palatal morphology appears normal anteriorly in PG 1, PG 2 and PG 3 and rather steep posteriorly in PG 3.

CONCLUSIONS

RME treatment with identical force application causes different, age-dependent effects upon palate volume and morphology. Width changes have a greater influence on palate volume than height changes.

CLINICAL RELEVANCE

It is preferable to use an RME prior to the age of 10 if homogeneous changes of the anterior and posterior palate regarding maxillary symmetry and functional space are desired.

Effects of Rapid Palatal Expansion on the Upper Airway Space in Children with Obstructive Sleep Apnea (OSA): A Case-Control Study

Obstructive Sleep Apnea (OSA) in children needs a multidisciplinary approach. Even if the first-line treatment of pediatric OSA is adenotonsillectomy, nowadays rapid palatal expansion (RPE) is considered a valid additional treatment. The aim of this study is to evaluate cephalometric changes in upper airways dimensions after rapid palatal expansion (RPE) in children suffering from Obstructive Sleep Apnea (OSA). A total of 37 children (range age 4-10 years) with diagnosis of OSA referred to Dentistry Unit of Bambino Gesù Children's Research Hospital IRCCS (Rome, Italy) were included in this pre-post study and underwent lateral radiographs at the start (T0) and at the end (T1) of a RPE treatment. Inclusion criteria were: diagnosis of OSA confirmed by cardiorespiratory polygraphy (AHI > 1) or pulse oximetry (McGill = >2), skeletal maxillary contraction evaluated by presence of posterior crossbite. A control group of 39 untreated patients (range age 4-11 years), in good general health, was set up. A paired T-test was used to investigate the statistical differences between T0 and T1 values in both groups. The results showed a statistically significant increase of nasopharyngeal width in the treated group after RPE treatment. Moreover, the angle that identifies mandibular divergence compared to palatal plane (PP-MP°) was significantly reduced. In the control group, no statistically significant differences were observed. The present study showed that RPE treatment determines a significant sagittal space increase in the upper airways space and a counterclockwise mandibular growth in children with OSA compared to a control group. These results suggest that a widening of the nasal cavities induced by RPE may support a return to physiological nasal breathing and promote a counterclockwise mandibular growth in children. This evidence confirms the crucial role of the orthodontist in the management of OSA in pediatric patients.

Rapid Maxillary Expansion (RME): An Otolaryngologic Perspective

Background. To evaluate the possible effects of Rapid Maxillary Expansion (RME), such as nasal breathing problems, middle ear function, Obstructive Sleep Apnea (OSA) in the otolaryngology field. RME has already been introduced in orthodontics to expand the maxilla of young patients affected by transversal maxillary constriction. Methods. A literature search was performed using different databases (Medline/PubMed, EMBASE, and CINAHL), from May 2005 to November 2021, according to the PRISMA guidelines. Results. The application of RME in children has shown good results on nasal function, reducing nasal resistances, independently from a previous adenotonsillectomy. These results are not only related to the increasing of nasal transverse diameters and volume, but also to the stiffening of airway muscles, enabling the nasal filtrum function and avoiding mouth opening, thereby decreasing respiratory infections. Positive effects have also been reported for the treatment of conductive hearing loss and of OSA, with the reduction of Apnea Hypopnea Index (AHI), possibly due to (i) an increased pharyngeal dimensions, (ii) a new tongue posture, and (iii) reduced nasal respiratory problems. Conclusions. Otolaryngologists should be aware of the indications and benefits of the RME treatment, considering its possible multiple beneficial effects.

Rapid Maxillary Expansion and Upper Airway Volume: Systematic Review and Meta-analysis on the Role of Rapid Maxillary Expansion in Mouth Breathing

Objective

Rapid maxillary expansion (RME) has been extensively used in orthodontic practice for over a century, and it is claimed to benefit upper airway morphology. However, its effect in actually alleviating mouth breathing has remained unexplored. This systematic review was planned with an objective to provide a comprehensive synthesis of the effects of RME on upper airway volume and most importantly, its role in alleviating mouth breathing.

Methods

A literature search of electronic databases were done for the time period of 2000-2018. Randomized controlled trials (RCTs) and non-RCTs conducted on 8-15-year-old children who received bonded or banded RME and upper airway measured using three-dimensional (3D) imaging were included.

Results

Twelve studies (two RCTs, nine nonrandomized clinical trials, and one non-RCT) were included in this systematic review, and nine studies were included for meta-analysis. Among the evaluated parameters, nasal cavity volume showed a significant increase which was maintained even after the retention phase, whereas nasopharyngeal and oropharyngeal volume did not report a significant change.

Conclusion

Based on this systematic review, it can be concluded that RME causes a significant increase in nasal cavity volume, but its effect on nasopharyngeal and oropharyngeal volume is not statistically significant in majority of studies. This increase in volume may not be considered as an equivalent for enhancement of airway and function unless proven so. In order to establish its significance in the improvement of breathing, it is necessary to conduct more well-designed RCTs with samples actually comprising mouth breathers.

How to cite this article

Balasubramanian S, Kalaskar R, Kalaskar A. Rapid Maxillary Expansion and Upper Airway Volume: Systematic Review and Meta-analysis on the Role of Rapid Maxillary Expansion in Mouth Breathing. Int J Clin Pediatr Dent 2022;15(5):617-630.

Nasal Septal Deviation After Surgically Assisted Rapid Maxillary Expansion

Background and Aim

Surgically assisted rapid maxillary expansion (SARME) is a surgical technique widely used to correct deficiency of the transverse maxillary dimension. Although some studies investigated the effect of SARME on nasal and facial alterations, there is no evidence that correlates nasal septal deviation (NSD) to SARME as a possible postoperative sequel. The aim of this study is to address and quantify possible variations in the position of the nasal bony septum after SARME and identify any NSD as a postoperative outcome of this surgical technique.

Patients and Methods

This is a retrospective study, conducted at the Department of Oral and Maxillofacial Surgery of the University Hospital of Araraquara (Unesp, faculty of dentistry), SP, Brazil. Twenty-nine patients who underwent SARME were studied; every patient was evaluated by cone-beam computerized tomography (CBCT) before (T0) and six months after surgery (T1), and we collected the variation of nasal septal position by measuring the distance between the bony septum and the nasal lateral wall. Our measurements were carried out at the level of the head, midpoint and tail of the inferior turbinate.

Results

A mean NSD ranging from 0.4 to 1.2 mm was measured, and it is more pronounced at the anterior part of the bony septum. Twenty-seven patients (93.1%) presented minor changes in bony septum position; in 2 cases (6.8%), a significant NSD was found (p < 0.05).

Conclusion

A variation of bony nasal septum position can be expected in any direction after SARME, and it is more pronounced at anterior portion.

Is maxillary expansion effective in treatment of obstructive sleep apnoea syndrome? A systematic review of systematic reviews

Background Maxillary expansion (ME) might be beneficial in improving airway dimensions and obstructive sleep apnoea syndrome (OSAS) in patients with constricted maxillae. The aim of this overview is to present clinicians with a summary of the evidence. Data from systematic reviews and meta-analyses were evaluated to investigate the effect of ME on OSAS.Methods An electronic search was commenced in five databases, in addition to a manual search until July 2021. Screening of articles started with title and abstract followed by full-text assessment. Systematic reviews with/without meta-analyses were included. Critical appraisal was done using A Measurement Tool to Assess Systematic Reviews (AMSTAR) 2, Level of Research Design scoring and criteria of body of evidence scores. The search, study selection and critical appraisal were completed by three reviewers.Results In total, 14 systematic reviews with/without meta-analyses were included. The quality of available evidence ranged between low to high, based on the overall quality evaluation.Conclusions Based on the available evidence, maxillary expansion might be able to improve the nasal airway volume and OSAS in both growing and adult patients in the short term. ME can be considered as one of the treatment options in cases with OSAS.

A reproducible and repeatable digital method for quantifying nasal and sinus airway changes following suture palatine expansion

Purpose

The airway complex is modified by palatine expansion. Computer tomography has been used in the past to determine the change in volume, but there was a lack of a specific, reproducible method for this purpose. The present study sought to determine the accuracy, reproducibility, and repeatability of an innovative digital measurement technique for analyzing the volume of maxillary and nasal sinus airways following suture palatine expansion performed with the Hyrax disyuntor appliance.

Methods

Patients underwent preoperative and postoperative cone-beam computed tomography (CBCT) scans. The datasets were subsequently uploaded into a digital treatment planning software to record the volume of the right and left maxillary sinus, as well as the nasal and maxillary sinus airway complex. The Gage Repeatability & Reproducibility statistical analysis methodology was used to evaluate the repeatability and reproducibility of this measurement technique when measuring the volume of maxillary and nasal sinus airways following suture palatine expansion with the Hyrax disyuntor appliance. Additionally, comparative analysis between preoperative and postoperative measures was performed using Student’s t-test for statistical analysis.

Results

In 5 patients, paired t-tests found statistically significant differences before and after treatment in the volumes of the left maxillary sinus (p = 0.002), right maxillary sinus (p = 0.001), and nasal and maxillary sinus airway complex (p = 0.005) after suture palatine expansion with the Hyrax disyuntor appliance.

Conclusion

The proposed digital technique is an accurate, repeatable, and reproducible measurement technique for analyzing the volume of maxillary and nasal sinus airways following suture palatine expansion using the Hyrax disyuntor.

Impact of rapid maxillary expansion on palatal morphology at different dentition stages

Objective

Rapid maxillary expansion (RME) is an established and frequently used procedure to overcome maxillary constriction. In-depth studies about morphological changes of the alveolar process and its immediate surroundings are missing. Therefore, the aim of the present study was to examine the treatment effects of a dentally anchored, rapid maxillary expander at different dentition stages upon palatal width, height and shape.

Material and methods

The dental casts of 114 patients—taken immediately before and after RME—were three-dimensionally analysed. Depending on the dentition stage, the patients were divided into two groups (each n = 57, group 1, early mixed dentition; group 2, late mixed or permanent dentition).

Results

The width increases were highly significant, both in the overall and in the individual groups (p < 0.001). While the width increase was greater in the posterior area than anteriorly in the early group, the widening in the late group happened significantly greater anteriorly than posteriorly. Palatal height increased anteriorly and posteriorly in both groups to a significant extent (p < 0.001). The height increase was more pronounced in the anterior region than in the posterior region in the late group. The palatine index according to Kim revealed a change in palatal morphology both anteriorly and posteriorly in the early group but only anteriorly in the late group.

Conclusions

Maxillary expansion occurs more parallel in early treatment compared to V-shaped opening in the later treatment approach.

Clinical relevance

RME is more advantageous in an early dentition.

The role of the dentist in the diagnosis and management of pediatric obstructive sleep apnea

The objective of this article is to review the role of the dentist in the early diagnosis of pediatric obstructive sleep apnea (OSA) and to provide an in-depth review of the best evidence-based practices available to treat and/or to refer these patients for intervention.

Material and methods

A narrative review was performed using indexed data bases (PubMed, Medline, EMBASE, OVID, Scopus and Cochrane) up to year 2020, and approximately 1000 articles were reviewed. The articles included were those with the best information provided.

Results

Detailed review of the literature suggests that the role of the dentist has been redefined owing to their expertise in the orofacial region. Every patient consulting a dental practice is not merely a dental patient; he/she also requires a comprehensive medical review. The role of the dentist is pivotal in pediatric patients once diagnosed with OSA; as the patients grow, growth modification can be achieved, and future management will be easier. Initiating dental treatments during growth can benefit patients two-fold, saving them from malocclusion, and intervening in orofacial structural growth can help to avoid cumbersome treatments, such as CPAP and various surgeries. Proper diagnosis and management of systemic illnesses can prevent compromised quality of life, delays in treatment, morbidity and, in some cases, mortality.

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.

Cone beam CT evaluation of skeletal and nasomaxillary complex volume changes after rapid maxillary expansion in OSA children

OBJECTIVE

The first objective of this study was to evaluate skeletal changes and changes in dimensions and volume of the upper airways before and after rapid maxillary expansion (RME) therapy in children with obstructive sleep apnoea (OSA), by Cone Beam computed tomography (CBCT). The second objective was to evaluate if RME therapy could improve both the patency of the nasal airways and the Obstructive Sleep Apnoea Syndrome (OSAS).

METHODS

19 children with OSA and malocclusion took CBCT scans with a Dentascan and 3D reconstruction program before (T0) and 4 months after (T1) RME. Patients underwent an ENT visit with auditory and respiratory tests, including a daytime sleepiness questionnaire, a 19-channel polysomnography, and an orthognatodontic examination before orthodontic therapy (T0), after 2 months (T1) with the device still on, and 4 months after the end of the orthodontic treatment (T2).

RESULTS

In all cases opening of the mid-palatal suture was demonstrated. Nasal osseous width, volume of the total upper airways, nasal cavity and nasopharynx and oropharynx increased significantly (P, .001). The increased W-ANS, W-mid and WPNS were closed linked to the enlarged midpalatal suture (P, .001). The increased WPNS were closed linked to the enlarged pterygoid processes (P, .001). The increased V-NC and V-NPA was closely linked to the enlarged W-PNS (P, .001) as well as VOPA and consequently to the enlarged midpalatal suture and pterygoid processes.

CONCLUSION

RME treatment had a positive effect on children affected by chronic snoring and OSA, causing an increase in volume of the nasal cavity and nasopharynx, with expansion of the nasal osseous width and maxillary width. Enlarged nasal width at the PNS plane contributed to the increase in nasopharynx volume. Enlarged maxillary width showed a direct correlation to increased airways volume, bringing a functional improvement. The results show that the RME therapy can restore and improve a normal nasal airflow with disappearance of obstructive sleep breathing disorder.

Effects of rapid maxillary expansion or alternating rapid maxillary expansion and constriction on nasal mucociliary clearance : A randomized clinical trial

PURPOSE

This parallel trial aimed to evaluate the changes in nasal mucociliary clearance (MCC) after a rapid maxillary expansion (RME) protocol or an alternating rapid maxillary expansion and constriction (Alt-RAMEC) protocol in orthodontic patients.

METHODS

This trial included 36 patients with a mean age of 14.38 years, with a narrow maxillary arch, bilateral posterior crossbite, no narrowing of the mandibular arch, no previous orthodontic treatment, and no nasal or systemic disease. Patients were randomly distributed into two groups (n = 18 each)-one group was treated with the RME protocol and the other group was treated with the Alt-RAMEC protocol. MCC was evaluated using the saccharine transit time (STT) test, which was measured for each individual before expansion (T0), after expansion (T1), and after a 4-month retention phase (T2). The study was single blinded, and blinding was applied only to the outcome assessor. The primary objective was to evaluate the effect of the Alt-RAMEC and RME protocols on MCC. The secondary objective was to determine the relationship between age, sex, and MCC. The χ ² test and independent samples t‑test were used to evaluate the data.

RESULTS

The STT decreased after expansion and retention in the RME group. In the Alt-RAMEC group, the STT decreased after expansion and slightly increased after retention. When the RME and Alt-RAMEC groups were compared, the STT showed a significant difference after expansion and retention (p < 0.05). No significant relationship was observed between age and sex and STT (p > 0.05).

CONCLUSION

This study demonstrated that the Alt-RAMEC protocol improved MCC and had a positive effect on nasal physiology by increasing the nasal volume more than that achieved by RME.

Nasal ventilation and rapid maxillary expansion (RME): a randomized trial

OBJECTIVE

To assess three rapid maxillary expansion (RME) appliances in nasal ventilation.

TRIAL DESIGN

Three-arm parallel randomized clinical trial.

METHODS

Sixty-six growing subjects (10-16 years old) needing RME as part of their orthodontic treatment were randomly allocated (1:1:1 ratio) to three groups of 22 patients receiving Hyrax (H), Hybrid-Hyrax (HH), or Keles keyless expander (K). The primary outcome of nasal ventilation (pressure and velocity) and secondary outcomes (skeletal, dental, soft tissue, and nasal obstruction changes) were blindly assessed on the initial (T0) and final (T1, 6 months at appliance removal) cone-beam computed tomography (CBCT) data by applying computational fluid dynamics (CFD) method. Differences across groups were assessed with crude and adjusted for baseline values and confounders (gender, age, skeletal maturation, expansion amount, mucosal/adenoid hypertrophy, nasal septum deviation) regression models with alpha = 5%.

RESULTS

Fifty-four patients were analysed (19H, 21HH, 14K). RME reduced both nasal pressure (H: -45.8%, HH: -75.5%, K: -63.2%) and velocity (H: -30%, HH: -58.5%, K: -35%) accompanied with nasal obstruction resolution (H: 26%, HH: 62%, K: 50%). Regressions accounting for baseline severity indicated HH expander performing better in terms of post-expansion maximum velocity (P = 0.03) and nasal obstruction resolution (P = 0.04), which was robust to confounders. Mucosal/adenoid hypertrophy and nasal septum deviation changes were variable, minimal, and similar across groups. The HH resulted in significantly greater increase in the nasal cross-sectional area (62.3%), anterior (14.6%), and posterior (10.5%) nasal widths. Nasal obstruction resolution was more probable among younger (P = 0.04), skeletally immature (P = 0.03), and male patients (P = 0.02) without pre-treatment mucosal hypertrophy (P = 0.04), while HH was associated with marginal greater probability for obstruction resolution.

CONCLUSIONS

RME resulted in improvement of nasal skeletal parameters and simulated ventilation with the former being in favour of the HH and the latter not showing significant differences among the three appliances.

LIMITATION

Attrition in the K group due to blocked activation rods possibly leading to limited sample to identify any existing group differences.

HARMS

Replacement of blocked Keles expanders for finalizing treatment.

PROTOCOL

The protocol was not published before the trial commencement.

REGISTRATION

Australian and New Zealand Clinical Trial Registry; ACTRN12617001136392.

The upper airway volume effects produced by Hyrax, Hybrid-Hyrax, and Keles keyless expanders: a single-centre randomized controlled trial

OBJECTIVE

To assess upper airway volume changes after rapid maxillary expansion (RME) with three different expanders.

TRIAL DESIGN

Three-arm parallel randomized clinical trial.

METHODS

Sixty-six patients, 10-16 years old, in permanent dentition, with maxillary transverse deficiency were recruited and assigned with block randomization (1:1:1 ratio) and allocation concealment to three groups of 22 patients each (Hyrax, Hybrid-Hyrax, and Keles keyless expander). The primary outcome (overall upper airway volume change) and secondary outcomes (volume changes in the nasal cavity, nasopharynx, oropharynx, and hypopharynx) were blindly assessed on the initial (T0) and final (T1, 6 months at appliance removal) cone beam computed tomography. Differences across groups were assessed with crude or adjusted for confounders (gender, age, growth stage, skeletal pattern, baseline airway volume, and amount of expansion) linear regression models.

RESULTS

Fifty-one patients were analysed (19, 19, and 13 in the Hyrax, Hybrid-Hyrax, and Keles groups). Maxillary expansion resulted in considerable increases in total airway volume in the Hybrid-Hyrax group (+5902.1 mm3) and less in the Hyrax group (+2537.9 mm3) or the Keles group (+3001.4 mm3). However, treatment-induced changes for the primary and all secondary outcomes were of small magnitude and no significant difference was seen among the three expanderes in the total airway volume in either crude or adjusted analyses (P > 0.05 in all instances). Finally, among pre-peak patients (CVM 1-3), the Hybrid-Hyrax expander was associated with significantly greater increases in total airway volume compared to the Hyrax expander (P = 0.02).

CONCLUSIONS

RME resulted in relatively small increases in total upper airway volume and its separate compartments, with mostly no statistically significant differences across the Hyrax, Hybrid-Hyrax, and Keles groups.

LIMITATIONS

Significantly greater attrition was found in the Keles group due to appliance failure. The current trial might possibly be under-powered to detect differences between groups, if such exist.

HARMS

Keles expanders blocked during activations and required substitution for completion of treatment.

PROTOCOL

The protocol was not published before trial commencement.

REGISTRATION

Australian and New Zealand Clinical Trial Registry (ACTRN12617001136392).

Long-term effect on adenoid dimensions and craniocervical angulation after maxillary expansion with fixed or functional appliances

Background

Maxillary expansion is a common orthodontic procedure that could have a positive effect also on airway patency. The aim of the present study was to evaluate the long-term effects of rapid maxillary expansion (RME) on nasopharyngeal area and cranio-cervical angulation in growing patients, compared to controls treated with a function-generating bite appliance (FGB).

Material and Methods

Sixty patients aged 6-14 consecutively treated with RME or FGB were selected retrospectively and divided into two groups. Lateral cephalograms taken before and after treatment were retrieved, and the nasopharyngeal area, delimited superiorly by a sella-posterior nasal spine (PNS) line and inferiorly by a basion-PNS line, and the cranio-cervical angulation were measured.

Results

The mean observation time was 17.6 ± 8 months. No differences were present between the two groups regarding age and gender. The nasopharyngeal area increased significantly in both groups after treatment, but with no statistically significant difference between them. The cranio-cervical angulation showed no differences within or between groups.

Conclusions

Maxillary deficiency treatment with either RME or FGB was followed by a comparable increase in nasopharyngeal area.

Key words:Rapid maxillary expansion, Airway, Nasopharyngeal area, Adenoid.

Opening up on airways: the purported effect of nasorespiratory obstruction on dentofacial growth

Nasorespiratory obstruction has been purported to influence dentofacial growth adversely. This has sparked considerable debate for decades with a resurgence in interest in 'airway friendly orthodontics' among both general and specialist dental practitioners. This critical review aims to evaluate the current literature relating to two questions: does nasorespiratory obstruction alter dentofacial growth, and does early intervention targeted at alleviating nasorespiratory obstruction improve dentofacial growth? The strength of association between nasorespiratory obstruction, mouth breathing and a long face is weak. The common methodological flaws in research include unblinded and cross-sectional study designs, a lack of adequate controls, inadequate follow-up, subjective assessments and inadequate statistical power. Vertical dentofacial growth has a strong genetic influence, which implies a relatively minor contribution of environmental factors including airway obstruction. The current evidence does not support recommending procedures, such as adenotonsillectomy and maxillary expansion, with the singular aim of negating a hyperdivergent (vertical) dentofacial growth pattern. In light of low-quality evidence, both the World Health Organization guidelines and ethical principles dictate that greater emphasis is placed on avoiding harm and wastage of resources over alternative options. These findings call for quality improvement in undergraduate and postgraduate curricula and continuing professional development for health professionals.

Oropharyngeal 3-dimensional changes after maxillary expansion with 2 different orthodontic approaches

INTRODUCTION

The objective of this research was to compare the oropharyngeal volume and minimal cross-sectional area (MCA) changes after maxillary expansion using either the Damon system or Hyrax appliances as assessed through cone-beam computed tomography (CBCT) imaging.

METHODS

Patients aged between 11 and 17 years with skeletal maxillary transverse discrepancy in need of maxillary expansion were included and allocated randomly into 1 of the 2 treatment groups, Damon or Hyrax. Patients underwent CBCT imaging at 2 time points: T1, after initial clinical evaluation before treatment, and T2, after completion of full orthodontic treatment. The CBCT data were assessed using Dolphin software (Dolphin Imaging & Management Solutions, Chatsworth, Calif). In addition, a qualitative assessment of breathing function was done using the modified Nasal Obstruction and Septoplasty Effectiveness Scale questionnaire.

RESULTS

A statistically significant increase in the oropharyngeal volume (2.23 mL; P = 0.005) and MCA (29.72 mm²; P = 0.007) after the completion of treatment (T2 - T1) for the Hyrax group was suggested. No statistically significant difference was found in the Damon group for volume (1 mL; P = 0.311) and for MCA (7.32 mm²; P = 0.643). In addition, no statistically significant difference was found in the breathing function in both treatment groups (P >0.05).

CONCLUSIONS

Hyrax expansion followed by fixed appliances produced more dimensional upper airway changes at the oropharyngeal level than the Damon system approach. No breathing functional changes were noted in either samples.

The effect of rapid maxillary expansion in children: a meta-analysis

INTRODUCTION

Craniofacial growth is modified by chronic mouth breathing. Rapid maxillary expansion leads to separation of the mid-palatal suture, improving the occlusion and the upper airway size.

AIM

Systematically evaluate scientific articles on the effects of rapid maxillary expansion on airway dimensions and classify the quality of the evidence of the information.

METHODS

Searches on PUBMED, LILACS, EMBASE, SCOPUS, WEB OF SCIENCE and COCHRANE, as well as in the grey literature were performed. The articles found were selected and evaluated both for the risk of bias (ROBINS-I) and for the quality of evidence (GRADE).

RESULTS

Of the 309 works found, 26 papers were selected for full reading, of which 22 were excluded. Data compilation and analysis were performed in four papers, two being controlled non-randomized clinical trials and two non-randomized and uncontrolled clinical trials. No randomized clinical trial was found.

CONCLUSIONS

The meta-analysis found an increase in the internasal and inter-zygomatic distances and oropharyngeal volume after rapid maxillary expansion, which, together with clinical findings, makes the recommendation favorable to the intervention. The quality of the evidence for each outcome was considered very low.

Short-term and long-term effects of rapid maxillary expansion on the nasal soft and hard tissue

OBJECTIVES

To evaluate nasal soft and hard tissue changes immediately post-rapid maxillary expansion (RME) and to assess the stability of these changes using cone beam computed tomography (CBCT).

MATERIALS AND METHODS

A total of 35 treatment group (TG) patients (18 girls, 17 boys; 9.39 ± 1.4) had a pre-RME CBCT and a post-RME CBCT approximately 66 days after expansion, and 25 patients had a follow-up CBCT 2.84 years later. A total of 28 control group (CG; no RME) patients (16 girls, 12 boys; 8.81 ± 1.6) had an initial CBCT and a CBCT an average of 2.25 years later. Soft and hard tissue nasal landmarks were measured in transverse, sagittal, and coronal planes of space on CBCT scans. Differences within the same group were evaluated by paired t-tests or Wilcoxon signed-rank tests. Long-term comparisons between TG and CG were evaluated by independent-sample t-tests or Wilcoxon rank-sum tests.

RESULTS

Immediately post-RME, there were statistically significant mean increases of 1.6 mm of alar base width, 1.77 mm of pyriform height, and 3.57 mm of pyriform width (P < .05). CG showed the significant increases over 2.25 years (P < .001). Compared with CG, the long-term evaluation of TG demonstrated only pyriform height and pyriform width showed a statistically significant difference (P < .01).

CONCLUSIONS

Although RME produced some significant increase on the nasal soft tissue immediately after expansion, it regressed to the mean of normal growth and development over time. However, long-term evaluation of TG compared with CG showed only pyriform height and pyriform width to be affected by RME.

Advanced interdisciplinary treatment protocol for pediatric obstructive sleep apnea including medical, surgical, and orthodontic care: a narrative review

OBJECTIVE

To suggest an updated interdisciplinary treatment protocol for pediatric obstructive sleep apnea (POSA) based on the integration of craniofacial growth modification into medical and surgical sleep practice.

METHODS

PubMed, Scopus, and Cochrane library were searched up to February 2020 using keywords. Among 184 articles, 80 studies were finally included. An integrated treatment protocol for POSA encompassing craniofacial skeletal management as well as medical and surgical care was attempted.

RESULTS

A differential diagnostic workflow for identifying the phenotype of POSA was suggested, and a phenotype-based treatment protocol for POSA was proposed. Despite the lack of high level of evidence, timely skeletal growth modification in three dimensions using craniofacial growth potential could be valuable treatment for upper airway development in POSA patients with craniofacial phenotypic cause.

CONCLUSION

A novel precision treatment protocol will advance clinicians to determine the primary option or to apply the combined strategy for POSA patients.

Surgically Assisted Rapid Palatal Expansion to Correct Maxillary Transverse Deficiency

Background

Transverse maxillomandibular discrepancies are widespread. Treatment is comprised of orthodontic expansion in patients younger than 15 years or by surgically assisted rapid palatal expansion (SARPE) in skeletally mature patients where the possibility of successful orthodontic maxillary expansion decreases as sutures close and resistance to mechanical forces increases.

Aim

To present our experience of treating transverse maxillary deficiency using a unique L-shaped osteotomy and to demonstrate stable results.

Patients and Methods

32 patients aged between 19 and 54 years exhibiting transverse maxillary deficiency. L-shaped osteotomy was performed laterally from the pterygoid plate posteriorly to above the roots of the second incisive anteriorly continuing with a vertical osteotomy between the lateral incisive and canine teeth toward the horizontal osteotomy. In 18 patients with dysgnathia, bimaxillary surgery was performed one year following the SARPE procedure.

Results

Mean transverse maxillary expansion of 6.2mm at the canine incisal and 6.4mm at the first molar occlusal regions were obtained. One year postoperatively results were relatively stable, 5.8mm and 6.2mm respectively. The SARPE procedure resulted in overcoming the maxillary buttress resistance, expansion of the anterior dental arch and bilateral distraction creating bone on both sides of the premaxilla contributing to better alignment of the anterior teeth and superior stability.

Conclusions

We conclude that SARPE is an effective and stable method for addressing severe maxillary transverse discrepancy in adults while the unique osteotomy performed allowed for maintaining proper position of the premaxilla and maxillary midline and allowing for division of the newly created bone bilaterally thus resulting in a more stable outcome.

Effect of rapid maxillary expansion on nasal cavity assessed with cone-beam computed tomography

Introduction:

Rapid maxillary expansion (RME) is assumed as a well established procedure; although, some effects on facial complex are not yet fully understood.

Objective:

The aim of this research was to verify, using cone-beam computed tomography, the effect on linear dimensions of the nasal cavity.

Methods:

Sample consisted of twenty patients aged 7 to 16 years, with skeletal deformity that justified the use of CT scans, and who required the RME as part of the orthodontic treatment planning. Scans were taken before clinical procedures were performed (T₀) and after stabilizing the expander screw (T₁). Dolphin Imaging v. 11.5 3D software was used to measure six areas on nasal cavity: three at the anterior portion (upper, middle, and lower) and other three at the posterior portion (also upper, middle, and lower). Data were statistically treated using Shapiro-Wilk test to verify normality. Differences between T₀ and T₁ were calculated using the Spearman correlation and paired Student’s t-test, with a significance level of 5%.

Results:

All linear measurements presented a significant increase (p< 0.05) after RME, both in the anterior and posterior regions, suggesting some parallelism on the opening pattern, especially at the lower portion (p< 0.001).

Conclusions:

RME was able to significantly modify the internal dimensions of the nasal cavity.

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.

Efficiency evaluation of rapid maxillary expansion treatment on nasal septal deviation using tortuosity ratio from cone-beam computer tomography images

BACKGROUND AND OBJECTIVE

This study aims to assess the effect of Rapid Maxillary Expansion (RME) on Nasal Septal Deviation (NSD) changes from three-dimensional (3D) images.

METHODS

In this study, cone-beam computed tomography (CBCT) images from 15 patients with maxillary constriction (mean age 12 ± 1.6 years) were included. RME treatment with Hyrax appliance was performed in all patients. CBCT scans were taken at three different times; before appliance insertion (T0), after active expansion (T1) and 3 months after appliance insertion (T2). We developed a novel Matlab-based application to quantify NSD based on the tortuosity ratio by dividing the actual length of the septum by the ideal length in the mid-sagittal plane by using this application.

RESULTS

Tortuosity ratio (TR) values were found as 1.03 ± 0.03 (T0), 1.02 ± 0.02 (T1), and 1.02 ± 0.02 (T2). Differences of TR values among these groups were evaluated using the statistical method of ANOVA (ANalysis Of VAriance) for repeated measures with the significance level of p ≤ .05. Results showed significant reductions in TR values between T0-T1 (p ≤ .05) and between T0-T2 (p ≤ .05). Nonetheless, a significant difference between T1-T2 was not determined (p > .05).

CONCLUSIONS

As a result, we can conclude that the NSD degree is affected by the RME treatment. The developed application can be used for both educational and research purposes.

[Orthodontic management of obstructive sleep-disordered respiratory disorders]

Through his/her knowledge of cranio-facial growth, the orthodontist plays a leading role within the multidisciplinary team that tracks and treats sleep-disordered breathing (SDB) in children. Correction of craniofacial risk factors (maxillary deficiency and retrognathia) is commonly used by practitioners alongside orthodontic treatment such as OMA and RME in the optimal conditions afforded by childhood growth. Myofunctional therapies are performed to restore correct stomatognathic function and play a central role in the management of SDB in children. The orthodontist is therefore a key player in the medical treatment chain of these children.

Systematic reviews in orthodontics: Impact of the PRISMA for Abstracts checklist on completeness of reporting

INTRODUCTION

This study evaluated and compared the completeness of reporting of abstracts of orthodontics systematic reviews before and after the publication of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) extension for Abstracts Checklist (PRISMA-A).

METHODS

Abstracts of systematic reviews and meta-analyses in orthodontics published in PubMed, Latin American and Caribbean Health Sciences Literature, and the Cochrane Database of Systematic Reviews databases before March 23, 2018, that met the predefined inclusion and exclusion criteria, were evaluated using the 12 items of PRISMA-A, scoring each item from 0 to 2. Abstracts were classified into 2 groups: before and after publication of the PRISMA-A checklist. Three calibrated evaluators (intraclass correlation coefficient and kappa > 0.8) assessed the scores for compliance with the checklist. The number of authors, country of affiliation of the first author, performance of meta-analysis, and topic of the article were recorded. A regression analysis was performed to assess the associations between abstract characteristics and the PRISMA-A scores.

RESULTS

Of 1034 abstracts evaluated, 389 were included in the analysis. The mean PRISMA-A score was 53.39 (95% CI, 51.83-54.96). The overall score for studies published after the publication of the checklist was significantly higher than for studies published before (P ≤ 0.0001). The components returning significantly higher scores after publication of PRISMA-A were title (P = 0.024), information from databases (P = 0.026), risk of bias (P ≤ 0.0001), included studies (P ≤ 0.0001), synthesis of results (P ≤ 0.0001), interpretation of results (P = 0.035), financing and conflict of interest (P ≤ 0.0001), and registration (P ≤ 0.0001). These results showed the positive effect of PRISMA-A had on the quality of reporting of orthodontics systematic reviews. Nevertheless, the poor adherence revealed that there is still need for improvement in the quality of abstract reporting.

CONCLUSIONS

The quality of reporting of abstracts of orthodontic systematic reviews and meta-analyses increased after the introduction of PRISMA-A.

Expansion in the absence of crossbite – rationale and protocol

Transverse maxillomandibular discrepancies are a major component of several malocclusions. Clinically, posterior crossbite is a common and valid indicator of maxillary transverse problems and orthopedic and orthodontic forces are routinely used to correct maxillary transverse deficiency. However, crossbite and transverse discrepancies are not a homologous group but must be viewed as a continuum with varying degree of abnormality. The etiology, diagnostic protocol, rationale, and procedures employed for correcting maxillary transverse discrepancy in the absence of crossbite are discussed in the article.

Effects of maxillary expansion on the upper airways: Evidence from systematic reviews and meta-analyses

BACKGROUND

Constricted maxilla is frequently associated with reduced nasal airway dimensions. Wheatear skeletal maxillary expansion (ME) is effective on the dimension of the upper airways is still a debated issue.

OBJECTIVES

This overview aimed to report the evidence provided by systematic reviews (SRs) on the effect of ME on the upper airways and to assess the methodological quality of the included SRs.

METHODS

Six electronic databases have been explored up to November 2017. After title and abstract screening, SRs addressing the effects of fixed palatal expanders on the dimension and function of the nasal airways were included. The methodological quality of the included SRs was assessed using the updated version of A Measurement Tool to Assess Systematic Review (AMSTAR-2).

RESULTS

Eight SRs were included. The methodological quality of most of the included SRs ranged between low and critically low. One SR was rated of high quality. A significant increase in nasal linear dimensions was reported both in the short and long term, but supported by low-/critically low-quality SRs. The significant increase in nasal cavity volume was the only outcome supported by a high-quality SR Controversial results were found with regards to nasal function.

CONCLUSION

Whenever a constricted maxilla is present general dentists, paediatricians and ENTs should be familiar with the potential improvement provided by ME. However, due to the low/critically low quality of SRs supporting these results, ME cannot be indicated only for upper airways enhancement, but should be supported by an orthodontic indication.

Effects of non-surgical rapid maxillary expansion on nasal structures and breathing: A systematic review

OBJECTIVE

This systematic review aims to determine the effects of non-surgical rapid maxillary expansion (RME) on breathing and upper airway structures.

MATERIALS AND METHODS

An electronic search of the scientific literature from January 2005 to June 2016 was done using Web of Science, Dentistry & Oral Sciences Source and PubMed databases. A combination of search terms "rapid maxillary expansion", "nasal", "airway" and "breathing" were used. Studies that involved surgical or combined RME-surgical treatments and patients with craniofacial anomalies were excluded.

RESULTS

The initial screening yielded a total of 183 articles. After evaluation of the titles, abstracts and accessing the full text, a total of 20 articles fulfilled both inclusion/exclusion criteria and possessed adequate evidence to be incorporated into this review.

CONCLUSIONS

Non-surgical RME was found to improve breathing, increase nasal cavity geometry and decrease nasal airway resistance in children and adolescents.

Skeletal changes after rapid maxillary expansion in children with obstructive sleep apnea evaluated by low-dose multi-slice computed tomography

OBJECTIVE

The objective of this study was to evaluate the skeletal effects of rapid maxillary expansion (RME) therapy performed using teeth as anchors, in obstructive sleep apnea (OSA) children, by low-dose computed tomography (CT) of the midpalatal suture opening, maxillary base width, nasal cavities width, first molar angulation and, unlike most studies in the literature, on the pterygoid processes distance.

METHODS

Fourteen children (mean age 8.68 years) with OSA presenting a malocclusion characterized by upper-jaw contraction had 16-Multislice CT (MSCT) scans taken before (T0) and after (T1) RME. All exams were performed using a rigid protocol to ensure reproducibility of image collection over time, with a 16-row MSCT scanner equipped with a Dentascan reconstruction program. Scanning parameters were as follows: scout view in the anteroposterior (AP) and laterolateral (LL); 1.25-mm slice thickness with 0.6-mm collimation from the dentoalveolar and basal areas of the maxilla up to the nasal cavity, parallel to the palatal plane; 80 kV, 100 mA with an 11.25-mm table speed/rotation, rotation time 0.6 s. Matrix size was 512 × 512.

RESULTS

Opening of the midpalatal suture was demonstrated in all cases. The results showed statistically significant T0 to T1 increments in all treated cases and clear imaging findings.

CONCLUSION

Use of three-dimensional (3D)-CT for follow-up studies requires a very rigid protocol to maintain reproducible positions in the scanner over time. The images confirm the real remodeling of craniofacial structure. However, to be valid such an imaging approach needs great attention to reproducibility of anatomic images over time. The changes in volume of the UA, even with a rigid protocol, cannot be affirmed with 3D-CT. There is a need to improve the definition of markers using this imaging approach when performing longitudinal studies; currently this issue is unresolved.

Volumetric upper airway changes after rapid maxillary expansion: a systematic review and meta-analysis

Background

Although Rapid Maxillary Expansion (RME) has been used for over a century, its effect on upper airways has not yet adequately been assessed in an evidence-based manner.

Objective

To investigate the volumetric changes in the upper airway spaces following RME in growing subjects by means of acoustic rhinometry, three-dimensional radiography and digital photogrammetry.

Search methods

Literature search of electronic databases and additional manual searches up to February 2016.

Selection criteria

Randomized clinical trials, prospective or retrospective controlled clinical trials and cohort clinical studies of at least eight patients, where the RME appliance was left in place for retention, and a maximum follow-up of 8 months post-expansion.

Data collection and analysis

After duplicate data extraction and assessment of the risk of bias, the mean differences and 95 per cent confidence intervals (CIs) of upper airway volume changes were calculated with random-effects meta-analyses, followed by subgroup analyses, meta-regressions, and sensitivity analyses.

Results

Twenty studies were eligible for qualitative synthesis, of which 17 (3 controlled clinical studies and 14 cohort studies) were used in quantitative analysis. As far as total airway volume is concerned patients treated with RME showed a significant increase post-expansion (5 studies; increase from baseline: 1218.3mm3; 95 per cent CI: 702.0 to 1734.6mm3), which did not seem to considerably diminish after the retention period (11 studies; increase from baseline: 1143.9mm3; 95 per cent CI: 696.9 to 1590.9mm3).

Limitations

However, the overall quality of evidence was judged as very low, due to methodological limitations of the included studies, absence of untreated control groups, and inconsistency among studies.

Conclusions

RME seems to be associated with an increase in the nasal cavity volume in the short and in the long term. However, additional well-conducted prospective controlled clinical studies are needed to confirm the present findings.

Registration

None.

Funding

Australian Society of Orthodontics Foundation for Research and Education Inc.

Applications of stem cells in orthodontics and dentofacial orthopedics: Current trends and future perspectives

A simple overview of daily orthodontic practice involves use of brackets, wires and elastomeric modules. However, investigating the underlying effect of orthodontic forces shows various molecular and cellular changes. Also, orthodontics is in close relation with dentofacial orthopedics which involves bone regeneration. In this review current and future applications of stem cells (SCs) in orthodontics and dentofacial orthopedics have been discussed. For craniofacial anomalies, SCs have been applied to regenerate hard tissue (such as treatment of alveolar cleft) and soft tissue (such as treatment of hemifacial macrosomia). Several attempts have been done to reconstruct impaired temporomandibular joint. Also, SCs with or without bone scaffolds and growth factors have been used to regenerate bone following distraction osteogenesis of mandibular bone or maxillary expansion. Current evidence shows that SCs also have potential to be used to regenerate infrabony alveolar defects and move the teeth into regenerated areas. Future application of SCs in orthodontics could involve accelerating tooth movement, regenerating resorbed roots and expanding tooth movement limitations. However, evidence supporting these roles is weak and further studies are required to evaluate the possibility of these ideas.

Effects of rapid palatal expansion (RPE) and twin block mandibular advancement device (MAD) on pharyngeal structures in Class II pediatric patients from Cluj-Napoca, Romania

Objective: To compare cephalometric changes of pharyngeal structures after rapid palatal expansion (RPE) with those induced by a twin block mandibular advancement device (MAD) with palatal expansion capability. Methods: This retrospective study investigated 55 Class II pediatric patients, divided into two groups: 29 patients treated with RPE and 26 patients treated with MAD. Lateral cephalometric measurements were compared before and after treatment. Results: Changes in pharyngeal airway space were statistically significant in both groups (p < 0.001) from a pre-treatment mean distance measured between the lower posterior pharyngeal wall and the hyoid bone (LPF-H) of 25.42 mm in the MAD group and 28.62 mm in the RPE group, to a post-treatment mean LPF-H of 27.96 mm in the MAD group and 31.52 mm in the RPE group. Conclusion: Significant changes in pharyngeal space may be obtained in Class II patients through both rapid palatal expansion and mandibular advancement devices with palatal expansion capability.

Effect of Rapid Maxillary Expansion on Glenoid Fossa and Condyle-Fossa Relationship in Growing Patients (MEGP): Study Protocol for a Controlled Clinical Trial

Aims and Objectives:

Rapid maxillary expansion (RME) is an orthodontic nonsurgical procedure aiming at increasing the width of the maxilla by opening mainly the intermaxillary suture in patients presenting a transverse maxillary skeletal deficiency. The objectives of the current prospective controlled clinical and radiographic study are to evaluate the hypothesis that RME in growing patients will result in radiographic changes at the level of interglenoid fossa distance, condyle-fossa relationship, and nasal cavity widths compared to the group who received no treatment initially and served as untreated control.

Materials and Methods:

In this prospective controlled clinical and radiographic study, forty healthy growing patients selected from a school-based population following a large screening campaign, ranging in age between 8 and 13 years, presenting a maxillary constriction with bilateral crossbite, and candidates for RME are being recruited. The first group will include participants willing to undergo treatment (n = 25) and the other group will include those inclined to postpone (n = 15).

Results:

The primary outcome is to compare radiologically the interglenoid fossa distance and the condyle-fossa relationship; nasal cavity width will be a secondary outcome. A multivariable analysis of Covariance model will be used, with the assessment of the time by group interaction, using age as covariate. The project protocol was reviewed and approved by the Ethics Committee of the Lebanese University, National Institute in Lebanon (CUEMB process number 31/04/2015). The study is funded by the Lebanese University and Centre National de Recherche Scientifique, Lebanon (Number: 652 on 14/04/2016).

Conclusion:

This prospective controlled clinical trial will give information about the effect of RME on the glenoid fossa and condyle-fossa relationship and its impact on the nasal cavity width.

Trial Registration:

Retrospectively registered in BioMed Central (DOI10.1186/ISRCTN77788053).

Effect of semi-rapid maxillary expansion in children with obstructive sleep apnea syndrome: 5-month follow-up study

BACKGROUND

The purpose of this study was to investigate the effect of semi-rapid maxillary expansion (SRME) orthodontic treatment on biomarkers and respiratory parameters in children with obstructive sleep apnea syndrome (OSAS) and maxillary transverse deficiency.

METHODS

Thirty children with OSAS were included in this study. Fifteen children were enrolled as control, and 15 children were subjected to SRME orthodontic treatment method for 5 months. Beside respiratory parameters, pharyngeal area, dental arch, and postero-anterior widths and the levels of OSAS biomarkers in serum and urine were measured.

RESULTS

Pharyngeal airway space, dental arch, and postero-anterior widths were increased after SRME treatment. Sleep tests showed a decrease in the apnea-hypopnea index (AHI) after 5-month control/treatment duration. Serum kallikrein (KLK)1 levels decreased significantly in the treatment group. There was a significant increase in serum orosomucoid (ORM)2 levels and a decrease in urine perlecan levels in the control group after a 5-month follow-up. A significant negative correlation between serum ORM2, perlecan, gelsolin, and KLK1 levels and intercanin width, as well as between serum ORM2 and KLK1 levels and intermolar width, was observed.

CONCLUSIONS

SRME treatment can be considered as a useful approach in children with OSAS. A further investigation of OSAS-related biomarkers and their relationship with sleep and orthodontic parameters is needed for providing easier and reliable modulatory strategies in the treatment of OSAS.

Evaluation of Facial Appearance in Patients with Cleft Lip and Palate by Laypeople and Professionals: A Systematic Literature Review

Objective

To identify whether laypeople and professionals rate the facial appearance of patients with cleft lip and palate (CLP) similarly based on viewing full facial images.

Design

Several electronic databases were searched. A hand search was performed among reference lists and relevant journals. Studies that assessed the full facial appearance of patients with CLP based on two-dimensional (2D) photographs, 3D images, or clinical examination by laypeople and professionals using a visual analog scale (VAS) or a categorical rating scale were included. Two authors independently assessed articles using methodologic-quality scoring protocol.

Result

Eleven articles were included in qualitative synthesis, including four high-level and seven moderate-level papers. Three studies found that laypeople were more critical than professionals, three found there was no significant difference between laypeople and professionals, and five reported that professionals were more critical than laypeople when assessing facial appearance of patients with CLP.

Conclusions

It still remains unknown whether laypeople are more or less critical than professionals when rating facial appearance of patients with repaired CLP. Professionals are more familiar with the esthetic outcomes and difficulties of treating patients. The opposite maybe true for laypeople; this disparity between what is achievable by professionals and what is expected by laypeople may be a source of dissatisfaction in facial appearance outcome. Further well-designed studies should be carried out to address this question and the clinical significance of the difference in rating scores for patients with CLP.

Retention and relapse in clinical practice

Maintaining teeth in their corrected positions following orthodontic treatment can be extremely challenging. Teeth have a tendency to move back towards the original malocclusion as a result of periodontal, gingival, occlusal and growth related factors. However, tooth movement can also occur as a result of normal age changes. Because orthodontics is unable to predict which patients are at risk of relapse, those which will remain stable and the extent of relapse that will occur in the long-term, clinicians need to treat all patients as if they have a high potential to relapse. To reduce this risk, long term retention is advocated. This can be a significant commitment for patients, and so retention and the potential for relapse must form a key part of the informed consent process prior to orthodontic treatment. It is vital that patients are made fully aware of their responsibilities in committing to wear retainers as prescribed in order to reduce the chance of relapse. If patients are unable or unwilling to comply as prescribed, they must be prepared to accept that there will be tooth positional changes following treatment. There is currently insufficient high quality evidence regarding the best type of retention or retention regimen, and so each clinician's approach will be affected by their personal, clinical experience and expertise, and guided by their patients' expectations and circumstances.

Nasal septum changes in adolescent patients treated with rapid maxillary expansion

Objective:

To analyze cone-beam computed tomography (CBCT) scans to measure changes in nasal septal deviation (NSD) after rapid maxillary expansion (RME) treatment in adolescent patients.

Methods:

This retrospective study involved 33 patients presenting with moderate to severe nasal septum deviation as an incidental finding. Out of these 33 patients, 26 were treated for transverse maxillary constriction with RME and seven, who did not undergo RME treatment, were included in the study as control group. CBCT scans were taken before appliance insertion and after appliance removal. These images were analyzed to measure changes in nasal septum deviation (NSD). Analysis of variance for repeated measures (ANOVA) was used.

Results:

No significant changes were identified in NSD regardless of the application or not of RME treatment and irrespective of the baseline deviation degree.

Conclusion:

This study did not provide strong evidence to suggest that RME treatment has any effect on NSD in adolescent patients; however, the results should be interpreted with caution, due to the small sample size and large variation amongst individual patient characteristics.

Effects of Rapid Maxillary Expansion on Head Posture, Postural Stability, and Fall Risk

Objective

The aim of this study was to investigate the effects of rapid maxillary expansion (RME) on head posture, postural stability, and fall risk.

Materials and Methods

A sample of 51 adolescent patients was randomly divided into two groups. In the first group, which consisted of 28 patients (15 females and 13 males), RME was performed as a part of routine orthodontic treatment. The remaining 23 individuals (12 females and 11 males) served as the control group. Lateral cephalometric radiographs taken in natural head position, postural stability, and fall risk scores were obtained during the first visit. They were repeated on average 3.8 months and 3.5 months later for the study and control groups, respectively. The changes were analyzed using the Wilcoxon signed-rank test, paired samples t-test, Mann–Whitney U-test, and independent samples t-test.

Results

As a result of RME, a statistically significant decrease was detected in the fall risk score (P < 0.05) in the study group, while the head position and postural stability remained unchanged. For the control group, no significant changes were observed in all measurements.

Conclusions

The result of the present study suggests that RME has a capacity of improving fall risk.

Rapid Maxillary Expansion and Upper Airway Morphology: A Systematic Review on the Role of Cone Beam Computed Tomography

OBJECTIVE

This study aimed to investigate the quality of cone beam computed tomography (CBCT) studies evaluating the effects of rapid maxillary expansion on upper airway morphology.

MATERIALS AND METHODS

A database search was conducted using PubMed, Ovid, and Cochrane Library up to December 2016. Studies in which CBCT was adopted to visualize the upper airway before and after rapid maxillary expansion were included. The population target was growing patients. Methodological quality assessment was performed.

RESULTS

The screening process resulted in the exclusion of 1079 references, resulting in only 9 remaining papers that fulfilled the inclusion criteria. No randomized clinical trials were found. The quality scores ranged from 36% to 68% of the maximum achievable, and the mean quality score of the studies was 50%. No good quality studies were detected in our sample.

CONCLUSIONS

Inconsistencies in the CBCT protocols utilized were detected between studies. Head posture, tongue position, and segmentation protocols were not consistent. These discrepancies were reflected in the different results obtained in the studies. A valid and consistent protocol with regard to head and tongue positioning, as well as nasal cavity volume segmentation, is required.

Short-term evaluation of tegumentary changes of the nose in oral breathers undergoing rapid maxillary expansion

Introduction

Rapid maxillary expansion is an orthodontic and orthopedic procedure that can change the form and function of the nose. The soft tissue of the nose and its changes can influence the esthetics and the stability of the results obtained by this procedure.

Objective

The objective of this study was to assess the changes in nose dimensions after rapid maxillary expansion in oral breathers with maxillary atresia, using a reliable and reproducible methodology through computed tomography.

Methods

A total of 30 mouth-breathing patients with maxillary atresia were analyzed and divided into a treatment group who underwent rapid maxillary expansion (20 patients, 10 of which were male and 10 female, with a MA of 8.9 years and a SD of 2.16, ranging from 6.5 to 12.5 years) and a Control Group (10 patients, 5 of which were male and 5 female, with a MA of 9.2 years, SD of 2.17, ranging from 6.11 to 13.7 years). In the treatment group, multislice computed tomography scans were obtained at the start of the treatment (T1) and 3 months after expansion (T2). The patients of the control group were submitted to the same exams at the same intervals of time. Four variables related to soft tissue structures of the nose were analyzed (alar base width, alar width, height of soft tissue of the nose and length of soft tissue of the nose), and the outcomes between T1 and T2 were compared using Osirix MD software.

Results

In the TG, the soft tissues of the nose exhibited significant increases in all variables studied (p < 0.05), whereas, changes did not occur in the control group (p > 0.05). In the treatment group, mean alar base width increased by 4.87% (p = 0.004), mean alar width increased by 4.04% (p = 0.004), mean height of the soft tissues of the nose increased by 4.84% (p = 0.003) and mean length of the soft tissues of the nose increased by 4.29% (p = 0.012).

Conclusion

In short-term, rapid maxillary expansion provided a statistically significant increase in the dimensions of the soft tissues of the nose.