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

Retention period after treatment of posterior crossbite with maxillary expansion: a systematic review

OBJECTIVE:

The aim of this systematic review was to evaluate the duration of the retention period in growing patients undergoing maxillary expansion and its relation with posterior crossbite stability.

METHODS:

Search strategies were executed for electronic databases Cochrane Library, Web of Science, PubMed and Scopus, which were completed on January 15, 2016. The inclusion criteria included randomized, prospective or retrospective controlled trials in growing subjects with posterior crossbite; treated with maxillary expanders; retention phase after expansion; post-retention phase of at least 6 months. The exclusion criteria were anterior crossbite, craniofacial anomalies, surgery or another orthodontic intervention; case reports; author’s opinions articles, thesis, literature reviews and systematic reviews. The risk of bias of selected articles was assessed with Cochrane risk of bias tool for RCTs and Downs and Black checklist for non-RCTs.

RESULTS:

A total of 156 titles/abstracts was retrieved, 44 full-texts were examined, and 6 articles were selected and assessed for their methodological quality. The retention period after maxillary expansion ranged between 4 weeks and 16 months. Fixed (acrylic plate, Haas, Hyrax and quad-helix) or removable (Hawley and Hawley expander) appliances were used for retention.

CONCLUSIONS:

Six months of retention with either fixed or removable appliances seem to be enough to avoid relapse or to guarantee minimal changes in a short-term follow-up.

Non-surgical treatment of transverse deficiency in adults using Microimplant-assisted Rapid Palatal Expansion (MARPE)

INTRODUCTION

Maxillary transverse deficiency is a highly prevalent malocclusion present in all age groups, from primary to permanent dentition. If not treated on time, it can aggravate and evolve to a more complex malocclusion, hindering facial growth and development. Aside from the occlusal consequences, the deficiency can bring about serious respiratory problems as well, due to the consequent nasal constriction usually associated. In growing patients, this condition can be easily handled with a conventional rapid palatal expansion. However, mature patients are frequently subjected to a more invasive procedure, the surgically-assisted rapid palatal expansion (SARPE). More recently, researches have demonstrated that it is possible to expand the maxilla in grown patients without performing osteotomies, but using microimplants anchorage instead. This novel technique is called microimplant-assisted rapid palatal expansion (MARPE).

OBJECTIVE

The aim of the present article was to demonstrate and discuss a MARPE technique developed by Dr. Won Moon and colleagues at University of California - Los Angeles (UCLA).

METHODS

All laboratory and clinical steps needed for its correct execution are thoroughly described. For better comprehension, a mature patient case is reported, detailing all the treatment progress and results obtained.

CONCLUSION

It was concluded that the demonstrated technique could be an interesting alternative to SARPE in the majority of non-growing patients with maxillary transverse deficiency. The present patient showed important occlusal and respiratory benefits following the procedure, without requiring any surgical intervention.

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.

Maxillary expansion in an animal model with light, continuous force

OBJECTIVES

Maxillary constriction is routinely addressed with rapid maxillary expansion (RME). However, the heavy forces delivered by most RME appliances to expand the palate may lead to deleterious effects on the teeth and supporting tissues. The objective of this study was to explore a more physiologic maxillary expansion with light continuous force.

MATERIALS AND METHODS

Twenty 6-week-old Sprague-Dawley rats were equally divided into experimental (EXPT) and control (CTRL) groups. A custom-fabricated archwire expansion appliance made from 0.014-inch copper-nickel-titanium wire was activated 5 mm and bonded to the maxillary molar segments of animals in the EXPT group for 21 days. The force applied to each maxillary segment was 5 cN. Microfocus x-ray computed tomography and histological analyses were used to compare the tooth movement and bone morphology in the midpalatal suture and buccal aspect of the alveolar process between the EXPT and CTRL groups. Descriptive statistics (mean ± standard error of the mean) and nonparametric statistical tests were used to compare the outcomes across groups.

RESULTS

Compared to the CTRL group, there was a statistically significant increase in buccal tooth movement and expansion of the midpalatal suture in the EXPT group. There was no difference in the bone morphologic parameters between groups. The mineral apposition rate was increased on the buccal surface of the alveolar process in the EXPT group.

CONCLUSIONS

Application of light, continuous force resulted in maxillary osseous expansion due to bilateral sutural apposition and buccal drift of the alveolar processes. This animal experiment provides a more physiologic basis for maxillary expansion.

Rapid Maxillary Expansion in Obstructive Sleep Apnea in Young Patients: Cardio-Respiratory Monitoring

OBJECTIVE(S)

Obstructive sleep apnea syndrome (OSAS) is a respiratory disorder which affects from 1 to 3 % of people during development. OSAS treatment may be pharmacological, surgical or based on application of intraoral devices to increase nasal respiratory spaces. The purpose of this study was to determine the efficacy of the Rapid Maxillary Expander in OSAS young patients by measuring cardio-respiratory monitoring parameters (AHI, the average value of complete and incomplete obstructed respiration per hour of sleep, and SAO₂, the percentage of oxygen saturation).

STUDY DESIGN

The study was conducted on 11 OSAS young subjects (mean age 6.9±1.04 years), all treated with rapid maxillary expansion (RME). Cardio-respiratory monitoring (8-channel Polymesam) was performed at the beginning (diagnostic, T0) and after 12 months of treatment.

RESULTS

The mean values of cardio-respiratory parameters at TO were: AHI=6.09±3.47; SAO₂=93.09%±1.60. After 12 months of treatment, the mean values of the same polysomnographic parameters were: AHI=2.36 ± 2.24;SAO₂=96.81% ±1.60. These changes were associated with an improvement in clinical symptoms, such as reduction of snoring and sleep apnea.

CONCLUSION(S)

This study confirms the therapeutic efficacy of RME in OSAS young patients. This orthopedic-orthodontic treatment may represent a good option in young patients affected by this syndrome.

Cellular Midpalatal Suture Changes after Rapid Maxillary Expansion in Growing Subjects: A Case Report

The present case report aimed to investigate immediate histologic changes in midpalatal suture in humans following rapid maxillary expansion compared to control. Three patients (mean age 8.3 ± 0.9 years) were enrolled in the case report and underwent midpalatal suture biopsy. Two patients underwent treatment before biopsy. The third patient did not show transversal maxillary deficiency and was enrolled as a control. Biopsy samples of midpalatal suture at 7 (subject 1) and 30 days (subject 2) after maxillary expansion as well as of one control (subject 3) were collected and processed for histology. In the control (subject 3) inter-digitations at the palatal suture gap were observed. At 7 days (subject 1) mature bone with small marrow spaces and trabecular bone with the peculiar storiform appearance inside the soft tissue and collagen fibers running parallel only in the central part were present. At 30 days (subject 2), a greater number of newly-formed bone trabeculae with a perpendicular orientation to the long axis of the suture could be seen. At 30 days the fibrous component of bone tissue was less represented compared to the sample at 7 days. Data from the preliminary histological results showed that bone formation was observed in the gap after rapid maxillary expansion, although the healing process was still ongoing.

Rapid maxillary expansion and obstructive sleep apnea: A review and meta-analysis

Background

OSAS during childhood leads to significant physical and neuropsychomotor impairment. Thus, it needs to be recognized and treated early in order to avoid or attenuate the chronic problems associated with OSAS, which are deleterious to a child’s development. Adenotonsillectomy and, in select cases, continuous positive airwaypressure (CPAP) have been the preferred treatments for OSAS in children, and yet they are ineffective at fully ameliorating the disease. Minimally invasive treatments have recently been proposed, comprising intra-oral and extra-oral devices as well as speech therapy. Objetive: to conduct a meta-analysis on studies from around the world that used rapid maxillary expansion (RME) to treat OSAS in children.

Material and Methods

We performed a meta-analysis of studies using RME for OSA treatment in children. A literature survey was conductedusing PubMed and Medline for English articles published up to December 2014 with the following descriptors: Sleep Apnea, Obstructive, Children, Treatment, Orthodontic, Othopaedic, Maxillaryexpansion. Studies were included in the meta-analysisif they were case-controlled studies, randomized, and involved non-syndromic children aged 0 to 12years old diagnosed with OSA by the polysomnography apnea-hypopnea index (AHI) before and after the intervention, submitted RME only.

Results

In all, 10 articles conformed to the inclusion criteria and were included in this meta-analysis. The total sample size across all these articles was 215 children, having a mean age of 6.7 years,of whom58.6%were male. The mean AHI during the follow-up was -6.86 (p <0.0001).

Conclusions

We concluded that rapid maxillary expansion (RME) in children with OSAS appears to be an effective treatment for this syndrome. Further randomized clinical studies are needed to determine the effectiveness of RME in adults.

Key words:Rapid maxillary expansión, obstructive sleep apnea, meta-analysis.