Rapid Maxillary Expansion (RME): An Otolaryngologic Perspective

Age-related changes in the midpalatal suture: Comparison between CBCT staging and bone micromorphology

The age-related maturation of the human midpalatal suture is challenging to predict, but critical for successful non-surgical rapid maxillary expansion (RME). While cone-beam computed tomography (CBCT) can be used to categorize the suture into stages, it remains unclear how well the stages predict the actual micromorphology of the palate. To address this clinically relevant question, we used CBCT together with three-dimensional micro-computed tomography (μCT) analysis on 24 human palate specimens from individuals aged 14-34 years. We first classified the specimens into stages (A-E) using CBCT images and then correlated the results with our comprehensive μCT analysis. Our analysis focused on several factors, including bone volume fraction (BV/TV), sutural width, volume, interdigitation, ossification, and their associations with age, CBCT stage, and sex. Our μCT analysis revealed a decrease in sutural width and volume after the age of 20 years, accompanied by sutural closure beginning in the palatal segment. The overall rate of ossification remained low but increased after the age of 20 years. No significant differences were found between males and females. Importantly, we also found no correlation between individual age and CBCT stages. Furthermore, there was no association between CBCT stages and patalal suture volume, ossification and interdigitation. Taken together, our findings cast doubt on the reliability of CBCT stage as a means of predicting skeletal maturity of the palatal suture, as it appears to lack the precision required to accurately assess the true micromorphology of the palatal suture. Future investigations should explore whether alternative CBCT parameters may be more useful in addressing the challenging question of whether RME requires surgical bone weakening.

A Retrospective Histological Study on Palatal and Gingival Mucosa Changes during a Rapid Palatal Expansion Procedure

The most common inflammatory reactions in the oral mucosa are found at the gingival level. The treatment of these inflammations requires, first of all, the removal of the causative factor; often, this maneuver is sufficient. The aim of this retrospective study was to evaluate clinical and histopathological changes that occur in terms of gingival and palatal mucosa enlargement during palatal expansion treatment and their evolution during treatment. Twenty-five (n = 25) research participants, aged between thirteen and twenty-six years old, were examined in this retrospective study. At the end of the treatment, fragments of tissue from the affected level were obtained via incisional biopsy and sent to the histopathology laboratory for a specialized examination. The changes identified were specific to mechanical traumatic injuries, thus excluding hyperplasia from other etiologies (infectious, tumoral, or non-mechanical traumatic). The examined fragments showed hyperplasia. The histopathological examination revealed the mechanical character of the lesion, strengthening the causal relationship between the insertion of the expander and the occurrence of hyperplasia of the palatal mucosa. The type of palatal expander influenced the degree of inflammation, with the severity of hyperplasia being more pronounced in the case of mini-implant-anchored rapid palatal expander (MARPE) usage than in the case of tooth-borne rapid palatal expander (RPE) usage. The analysis of the distance between the expander and the palatal mucosa did not provide conclusive results; the incidence and severity of the reaction were variable in patients with the same distance between the expander and the palatal or gingival mucosa.

Unusual systemic and nondental effects of maxillary expansion therapy: A comprehensive and updated review of literature

In dental practice, pediatric patients with a wide range of manifestations of malocclusion viz. crossbite, dental crowding, and skeletal Class III due to transverse discrepancy of the abnormally constricted maxilla or palate are found. However, the dental management of such kind of malocclusion with narrow palate needs a meticulous dental evaluation. Appliances used for treating such malocclusion conditions may include Slow-Maxillary Expansion (SME) or Rapid Maxillary Expansion (RME) orthodontic or orthopedic appliances. Considerable success has been described in the literature using the maxillary/palatal expansion modality. Unusual systemic and nondental effects of expansion appliances therapy have been described in some scientific studies. However, no comprehensive review article has been published describing the nondental and systemic effects of RME/SME therapy in Pediatric Dentistry. Considering the above scenarios, the updated and comprehensive review of the relevant literature is necessary for health professionals. Dental professionals including pediatric dentists and orthodontists need to consider such untoward or unexpected effects of RME/SME treatment modality. Hence, the current comprehensive review article has been written with the aim to meticulously describe the relevant scientific literature about nondental/extraoral and systemic effects of RME/SME appliances.

Automatic three-dimensional nasal and pharyngeal airway subregions identification via Vision Transformer

OBJECTIVES

Upper airway assessment requires a fully-automated segmentation system for complete or sub-regional identification. This study aimed to develop a novel Deep Learning (DL) model for accurate segmentation of the upper airway and achieve entire and subregional identification.

METHODS

Fifty cone-beam computed tomography (CBCT) scans, including 24,502 slices, were labelled as the ground truth by one orthodontist and two otorhinolaryngologists. A novel model, a lightweight multitask network based on the Swin Transformer and U-Net, was built for automatic segmentation of the entire upper airway and subregions. Segmentation performance was evaluated using Precision, Recall, Dice similarity coefficient (DSC) and Intersection over union (IoU). The clinical implications of the precision errors were quantitatively analysed, and comparisons between the AI model and Dolphin software were conducted.

RESULTS

Our model achieved good performance with a precision of 85.88-94.25%, recall of 93.74-98.44%, DSC of 90.95-96.29%, IoU of 83.68-92.85% in the overall and subregions of three-dimensional (3D) upper airway, and a precision of 91.22-97.51%, recall of 90.70-97.62%, DSC of 90.92-97.55%, and IoU of 83.41-95.29% in the subregions of two-dimensional (2D) crosssections. Discrepancies in volume and area caused by precision errors did not affect clinical outcomes. Both our AI model and the Dolphin software provided clinically acceptable consistency for pharyngeal airway assessments.

CONCLUSION

The novel DL model not only achieved segmentation of the entire upper airway, including the nasal cavity and subregion identification, but also performed exceptionally well, making it well suited for 3D upper airway assessment from the nasal cavity to the hypopharynx, especially for intricate structures.

CLINICAL SIGNIFICANCE

This system provides insights into the aetiology, risk, severity, treatment effect, and prognosis of dentoskeletal deformities and obstructive sleep apnea. It achieves rapid assessment of the entire upper airway and its subregions, making airway management-an integral part of orthodontic treatment, orthognathic surgery, and ENT surgery-easier.

Comparison of Different Types of Palatal Expanders: Scoping Review

Maxillary bone contraction is caused by genetics or ambiental factors and is often accompanied by dental crowding, with the possibility of canine inclusion, crossbite, class II and III malocclusion, temporomandibular joint disorder, and obstructive sleep apnea (OSAS). Transverse maxillary deficits, in which the maxillary growth is unusually modest, are frequently treated with maxillary expansion. The purpose of this study is to compare the dental and skeletal effects of different types of expanders, particularly the Leaf Expander, rapid and slow dental-anchored or skeletal-anchored maxillary expanders.

METHODS

We chose studies that compared effects determined by palatal expansion using a rapid palatal expander, expander on palatal screws, and leaf expander.

RESULTS

Reports assessed for eligibility are 26 and the reports excluded were 11. A final number of 15 studies were included in the review for qualitative analysis.

CONCLUSIONS

Clinically and radiographically, the outcomes are similar to those obtained with RME and SME appliances; Therefore, it might be a useful treatment choice as an alternative to RME/SME equipment in cases of poor patient compliance or specific situations. Finally, all of the devices studied produce meaningful skeletal growth of the palate. The use of skeletally anchored devices does, without a doubt, promote larger and more successful growth in adolescent patients.

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.