NCT07456917

Effects of BREA and MFT Expansion Appliances on Upper Airway Dimensions

Effects of BREA and MFT Expansion Appliances on Upper Airway Dimensions, Hyoid Bone Position and Palatal Morphology in Growing Children

• Status: Completed
• Phase: N/A
• Study type: Interventional
• Enrollment: 79 (actual)
• Sponsor: Medical University of Silesia · Academic / Other
• Sex: All
• Age: 4 Years – 12 Years
• Healthy volunteers: Accepted

Summary

This retrospective study evaluated whether orthodontic expansion using two types of appliances, a bimaxillary removable expansion appliance (BREA) and a maxillary fixed three screw palatal expander (MFT), influences upper airway dimensions, hyoid bone position, and palatal morphology in growing children. Seventy nine children aged 4 to 12 years were included. Fifty five patients received orthodontic expansion (BREA or MFT), and twenty four untreated patients served as controls. Lateral and posteroanterior cephalometric radiographs and digital dental models obtained before and after the observation period were analyzed. Measurements assessed nasal and hypopharyngeal airway dimensions, the position of the hyoid bone, and transverse and volumetric characteristics of the palate. Compared with untreated children, those who underwent expansion showed significant increases in selected airway dimensions, widening of the upper piriform aperture, and increased distance between the hyoid bone and the mandibular symphysis. Both appliances increased maxillary transverse widths, with greater maxillary expansion observed in the MFT group. Palatal volume increased significantly with BREA, whereas palatal surface area increased and palatal depth decreased significantly with MFT. These findings suggest that orthodontic expansion in growing children may favorably modify selected upper airway and palatal parameters. Further prospective studies are needed to determine the long term functional and clinical significance of these changes.

Detailed description

This retrospective observational study was designed to evaluate dentofacial and upper airway changes associated with orthodontic expansion in growing children. The analysis focused on two expansion modalities: a bimaxillary removable expansion appliance (BREA) and a maxillary fixed three screw palatal expander (MFT). The primary objective was to determine whether these appliances influence piriform aperture width, hypopharyngeal dimensions, hyoid bone position, and palatal morphology during active craniofacial growth. The study included children aged 4 to 12 years who underwent comprehensive orthodontic diagnostics in a private orthodontic practice. Eligible patients had no history of cleft lip or palate, no previous orthodontic treatment, and no interdental spacing or diastema. The treated cohort comprised patients managed with either BREA or MFT according to clinical indications. A control cohort consisted of patients who completed full orthodontic diagnostics at two time points but did not initiate treatment. Ethical approval was obtained from the Bioethics Committee of the Medical University of Silesia. Standardized lateral and posteroanterior cephalometric radiographs were obtained in natural head position with controlled occlusion and breathing conditions. Digital dental models were generated from alginate impressions and intraoral scanning. Two dimensional airway and hyoid measurements were derived from calibrated cephalograms using dedicated cephalometric software. Three dimensional palatal surface area, volume, depth, and transverse interdental distances were calculated from digital models using certified orthodontic software. The primary analytical approach compared longitudinal changes between treated and untreated groups. Independent samples tests and analysis of covariance were applied to two dimensional variables, adjusting for sex and baseline age. One way analysis of variance with post hoc testing was used for three dimensional comparisons between appliance subgroups. Statistical significance was predefined at p less than 0.05. The study was exploratory in nature and aimed to characterize morphologic trends associated with early orthodontic expansion rather than to establish causal clinical outcomes. No therapeutic interventions beyond routine orthodontic care were introduced for research purposes. The results are intended to inform future prospective investigations evaluating functional respiratory and craniofacial implications of expansion therapy in pediatric populations.

Conditions

• Maxillary Constriction in Growing Children
• Transverse Maxillary Deficiency
• Upper Airway Morphology in Children
• Orthodontic Expansion Effects
• Hyoid Bone Positional Changes

Interventions

Type	Name	Description
DEVICE	Maxillary fixed three screw palatal expander (MFT)	A fixed orthodontic maxillary expansion device anchored to posterior teeth with acrylic splints and incorporating one central Hyrax type expansion screw and two auxiliary transverse screws. The central screw was activated once daily (up to 28 turns) and the lateral screws once every five days (up to 10 turns) according to the clinical protocol. The appliance was used in growing children to achieve transverse maxillary expansion. Treatment and imaging were part of routine orthodontic care.
DEVICE	Bimaxillary removable expansion appliance (BREA)	A removable orthodontic appliance designed for simultaneous maxillary and mandibular transverse expansion. The device contains two expansion screws, one positioned in the maxillary arch and one in the mandibular arch. It was worn full time except during meals and oral hygiene. Both screws were activated once weekly in the horizontal plane according to the treatment protocol. The appliance was used in growing children as part of standard orthodontic management.

Timeline

• Start date: 2020-02-01
• Primary completion: 2026-02-01
• Completion: 2026-02-01
• First posted: 2026-03-09
• Last updated: 2026-03-09

Locations

1 site across 1 country: Poland