scholarly journals The effect of rapid maxillary expansion on the upper airway’s aerodynamic characteristics

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Xin Feng ◽  
Yicheng Chen ◽  
Kristina Hellén-Halme ◽  
Weihua Cai ◽  
Xie-Qi Shi
Keyword(s):  
Cfd Simulation ◽  
Three Dimensional ◽  
Upper Airway ◽  
3D Models ◽  
Aerodynamic Characteristics ◽  
Rapid Maxillary Expansion ◽  
Wilcoxon Test ◽  
Maxillary Expansion ◽  
Significant Difference ◽  
Group 2

Abstract Background The effect of rapid maxillary expansion (RME) on the upper airway (UA) has been studied earlier but without a consistent conclusion. This study aims to evaluate the outcome of RME on the UA function in terms of aerodynamic characteristics by applying a computational fluid dynamics (CFD) simulation. Methods This retrospective cohort study consists of seventeen cases with two consecutive CBCT scans obtained before (T0) and after (T1) RME. Patients were divided into two groups with respect to patency of the nasopharyngeal airway as expressed in the adenoidal nasopharyngeal ratio (AN): group 1 was comprised of patients with an AN ratio < 0.6 and group 2 encompassing those with an AN ratio ≥ 0.6. CFD simulation at inspiration and expiration were performed based on the three-dimensional (3D) models of the UA segmented from the CBCT images. The aerodynamic characteristics in terms of pressure drop (ΔP), maximum midsagittal velocity (Vms), and maximum wall shear stress (Pws) were compared by paired t-test and Wilcoxon test according to the normality test at T0 and T1. Results The aerodynamic characteristics in UA revealed no statistically significant difference after RME. The maximum Vms (m/s) decreased from 2.79 to 2.28 at expiration after RME (P = 0.057). Conclusion The aerodynamic characteristics were not significantly changed after RME. Further CFD studies with more cases are warranted.

scholarly journals The Effect of Rapid Maxillary Expansion on the Upper Airway’s Aerodynamic Characteristics

2020 ◽  
Author(s):  
Xin Feng ◽  
Yicheng Chen ◽  
Kristina Halme ◽  
Weihua Cai ◽  
Xie-Qi Shi
Keyword(s):  
Pressure Drop ◽  
Cfd Simulation ◽  
Maximum Velocity ◽  
Upper Airway ◽  
Aerodynamic Characteristics ◽  
Rapid Maxillary Expansion ◽  
Maxillary Expansion ◽  
Airway Function ◽  
Group 2 ◽  
Group 1

Abstract Background: The effect of rapid maxillary expansion (RME) on the upper airway (UA) has been studied earlier but without a consistent conclusion. This study aims to evaluate the outcome of RME on the upper airway function in terms of airflow resistance by applying a computational fluid dynamics (CFD) simulation.Methods: This retrospective cohort study consists of seventeen cases with two consecutive CBCT scans obtained before (T0) and after (T1) RME. Patients were divided into two groups with respect to patency of the nasopharyngeal airway as expressed in the adenoidal nasopharyngeal ratio (AN): group 1 was comprised of patients with an AN ratio < 0.6 and group 2 encompassing those with an AN ratio ≥ 0.6. CFD simulation at inspiration and expiration were performed based on the three - dimensional (3D) models of the UA segmented from the CBCT images. The aerodynamic characteristics in terms of pressure drop, midsagittal maximum velocity, and maximum wall shear stress were compared by independent samples t-test between the two groups at T0 and T1. Results: At T0, the pressure drop at expiration was significantly higher in group 2 compared to group 1, whereas the difference between the two groups was not significant at T1. The midsagittal maximum velocity of the two groups decreased to some extent at expiration, but without significant difference. The midsagittal maximum velocity of group 2 was at inspiration significantly higher than that of group 1 at T0 and T1. Conclusion: RME had a positive effect on UA airflow resistance in patients with an AN ratio ≥ 0.6. The findings provide positive evidence of RME in airway function and should thus be recommended to patients with both a narrow maxilla and enlarged adenoid.

Effect of Rapid Maxillary Expansion on Upper Airway Morphology: A Retrospective Comparison of Normal Patients versus Patients with Enlarged Adenoid Tissue.

2021 ◽  
Vol 45 (3) ◽  
pp. 208-215
Author(s):  
Xin Feng ◽  
Stein Atle Lie ◽  
Kristina Hellén-Halme ◽  
Xie-Qi Shi
Keyword(s):  
Nasal Obstruction ◽  
Upper Airway ◽  
3D Models ◽  
Rapid Maxillary Expansion ◽  
Maxillary Expansion ◽  
Cross Sectional ◽  
Computed Tomography Images ◽  
Significant Difference ◽  
Group 2 ◽  
Group 1

Objectives The present study evaluated the effect of rapid maxillary expansion (RME) on the morphology of the upper airway (UA) by calculating cross-sectional areas and volumes and comparing the effect in patients with a normal-sized adenoid with the effect in patients with an enlarged adenoid. Study design: Seventeen patients met the inclusion criteria. We constructed 3D models of the UA on cone-beam computed tomography images to calculate cross-sectional areas and volumes at the levels of the nasopharyngeal, retropalatal, and retroglossal airways. Patients were divided into two groups: group 1 was comprised of patients with an adenoidal nasopharyngeal (AN) ratio &lt; 0.6 and group 2 with an AN ratio ≥ 0.6. Paired samples t-tests assessed any area and volumetric changes of the UA after RME. Changes in degree of nasal obstruction, calculated as the AN ratio, was then compared for the two groups. An independent samples t-test compared volumetric changes in the nasopharynx between the two groups before and after RME. Results Changes in cross-sectional areas and volumes of the UA due to RME were not significant. The effects of RME on AN ratio (11 % vs 0 %) and nasopharyngeal volume (36.8 % vs 5.97%) were somewhat larger in group 2 patients who had adenoid-associated nasal obstruction compared with group 1 patients with a normal-sized adenoid; however, the differences were not significant. Conclusions After RME, the patients with an enlarged adenoid had more increases in nasopharyngeal volume compared with those with normal adenoid, despite there was no significant difference.

scholarly journals Three-dimensional evaluation of upper airway following rapid maxillary expansion: A CBCT study

2013 ◽  
Vol 84 (2) ◽  
pp. 265-273 ◽  
Author(s):  
Hakan El ◽  
Juan Martin Palomo
Keyword(s):  
Three Dimensional ◽  
Upper Airway ◽  
Rapid Maxillary Expansion ◽  
Control Group ◽  
Nasal Passage ◽  
Maxillary Expansion ◽  
Oropharyngeal Airway ◽  
Significant Difference ◽  
Group A ◽  
Maxillary Constriction

ABSTRACT Objectives: To evaluate, by using cone beam computed tomography, the skeletal, dental, oropharyngeal (OP) airway volume, and nasal passage (NP) volume changes that occur after rapid maxillary expansion (RME). Materials and Methods: Two groups were selected, each with 35 patients (15 males, 20 females), an RME group (mean age, 14.02 ± 1.46 years) and a control group (mean age, 14.10 ± 1.44 years). The RME group consisted of patients with maxillary constriction who were treated with Hyrax palatal expanders, and the control group comprised age- and sex-matched patients who underwent comprehensive orthodontic treatment without the use of a rapid maxillary expander. Results: All of the transverse skeletal (medial orbital width, lateral nasal width, maxillary width, and mandibular width) and interdental (intermolar, interpremolar, and intercanine) parameters were significantly enlarged in the RME group. A statistically significant increase in airway variables was seen in both groups between pretreatment (T0) and final records (T1). The mean increase of NP airway volume for the RME group (1719.9 ± 1510.7 mm3) was twofold compared with the control group (813.6 ± 1006.7 mm3), and no intergroup significant difference was found for the OP volume. Conclusions: Rapid maxillary expansion creates a significant increase in nasal passage airway volume but no significant change in the oropharyngeal airway volume.

scholarly journals Changes in the Upper and Lower Pharyngeal Airway Spaces Associated with Rapid Maxillary Expansion

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Fitin Aloufi ◽  
Charles B. Preston ◽  
Khalid H. Zawawi
Keyword(s):  
Orthodontic Treatment ◽  
Upper Airway ◽  
Rapid Maxillary Expansion ◽  
Lower Airway ◽  
Control Group ◽  
Maxillary Expansion ◽  
Pharyngeal Airway ◽  
Significant Difference ◽  
And Gender ◽  
Maxillary Constriction

Objectives. The primary objectives of this retrospective study were first to compare the upper and lower pharyngeal airway spaces between orthodontic patients with and without maxillary constriction and second to evaluate the effect of rapid maxillary expansion (RME) on these airway spaces. A secondary objective was to compare the mode of breathing between groups. Materials and Methods. The experimental (RME) group consisted of 30 patients (mean age, years, 16 boys and 14 girls) with maxillary constriction who were treated with hyrax-type RME. The control group comprised the records of age- and gender matched patients (mean age, years, 16 boys and 14 girls) with no maxillary constriction but requiring nonextraction comprehensive orthodontic treatment. Cephalometric measurements in the sagittal dimension of upper and lower airway spaces for the initial and final records were recorded. Mode of breathing and length of treatment were also compared. Results. The sagittal dimension of the upper airway increased significantly in the RME group ( mm) compared to the control group ( mm), . However, there was no significant difference in the lower pharyngeal airway measurement between the RME group () and the control group (), . There was no significant difference with respect to mode of breathing between the two groups (). Conclusion. Rapid maxillary expansion (RME) during orthodontic treatment may have a positive effect on the upper pharyngeal airway, with no significant change on the lower pharyngeal airway.

scholarly journals Comparison of Transversal Effects of Different Expansion Protocols: Alt-RAMEC versus RME

2021 ◽  
Vol 7 (2) ◽  
pp. 43-48
Author(s):  
Burak Kale ◽  
Muhammed Hilmi Büyükçavuş
Keyword(s):  
Rapid Maxillary Expansion ◽  
Maxillary Expansion ◽  
Treatment Protocols ◽  
Significant Difference ◽  
Expansion Protocol ◽  
Group 2 ◽  
Width Measurements ◽  
Student’S T ◽  
Digital Caliper ◽  
Student’S T Test

Abstract Objectives The aim of this study is evaluate the transversal effects of the Alt-RAMEC(Alternate Rapid Maxillary Expansion and Constriction) protocol on both craniofacial and dentoalveolar structures and to compare the transversal effects of the RME(Rapid Maxillary Expansion) protocol. Materials and Methods In our archive, selected patients were divided into two groups. Group 1 included 22 patients(12boys,10girls, mean age 11.61±2.11years) who had been treated with 5 weeks of Alt-RAMEC. Group 2 comprised 21 patients(11boys,10girls, mean age 11.66±1.23years) who had been treated with 1 week of RME. Transversal measurements were also performed on the study models pre-(T0) and post-treatment(T1) with digital caliper. Internasal, interzygomatic, interjugular and intergonial width measurements were made on posteroanterior radiographs. The initial measurements and the mean changes within the groups were analysed using a student’s t test. Results According to the results of the study, there was no statistically significant difference between the groups in terms of chronological age, gender distribution and initial values. The expansion protocols showed a statistically significant increase in the widths of intercanine, interpremolar, intermolar and alveolar base widths in the maxilla(p<0.05). No statistically significant changes were observed in both groups(p>0.05) in mandible. The changes in maxillary intercanine, interpremolar widths between the two groups were statistically significant(p<0.05). In the posteroanterior measurements, only statistically significant difference was found between the groups in internasal width(p<0.05). Conclusions Alt-RAMEC and RME protocols are effective treatment protocols for correction of transverse deficiency in growing patients. 5-weeks Alt-RAMEC protocol significantly increased intercanine and interpremolar widths compared to 1-week RME.  Clinical Relevance Since there are no studies in the literature comparing the effects of two different expansion protocols in the transverse direction, this is both the first. Most importantly, clinicians will see which of these two protocols is more singular in the treatment of transversal problems. Keywords: RME, Alt-RAMEC, tranversal measurements

scholarly journals Aerodynamic characteristics in upper airways among orthodontic patients and its association with adenoid nasopharyngeal ratios in lateral cephalograms

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Xin Feng ◽  
Yicheng Chen ◽  
Weihua Cai ◽  
Stein Atle Lie ◽  
Kristina Hellén-Halme ◽  
...  
Keyword(s):  
Cfd Simulation ◽  
Aerodynamic Characteristics ◽  
Upper Airways ◽  
Lateral Cephalogram ◽  
Lateral Cephalograms ◽  
Significant Difference ◽  
Orthodontic Patients ◽  
Aerodynamic Parameters ◽  
Group 2 ◽  
Group 1

Abstract Background Adenoid hypertrophy among orthodontic patients may be detected in lateral cephalograms. The study investigates the aerodynamic characteristics within the upper airway (UA) by means of computational fluid dynamics (CFD) simulation. Furthermore, airflow features are compared between subgroups according to the adenoidal nasopharyngeal (AN) ratios. Methods This retrospective study included thirty-five patients aged 9–15 years having both lateral cephalogram and cone beam computed tomography (CBCT) imaging that covered the UA region. The cases were divided into two subgroups according to the AN ratios measured on the lateral cephalograms: Group 1 with an AN ratio < 0.6 and Group 2 with an AN ratio ≥ 0.6. Based on the CBCT images, segmented UA models were created and the aerodynamic characteristics at inspiration and expiration were simulated by the CFD method for the two groups. The studied aerodynamic parameters were pressure drop (ΔP), maximum midsagittal velocity (Vms), maximum wall shear stress (Pws), and minimum wall static pressure (Pw). Results The maximum Vms exhibits nearly 30% increases in Group 2 at both inspiration (p = 0.013) and expiration (p = 0.045) compared to Group 1. For the other aerodynamic parameters such as ΔP, the maximum Pws, and minimum Pw, no significant difference is found between the two groups. Conclusions The maximum Vms seems to be the most sensitive aerodynamic parameter for the groups of cases. An AN ratio of more than 0.6 measured on a lateral cephalogram may associate with a noticeably increased maximum Vms, which could assist clinicians in estimating the airflow features in the UA.

Dentoskeletal Effects of Maxillary Protraction in Cleft Patients with Repetitive Weekly Protocol of Alternate Rapid Maxillary Expansions and Constrictions

2009 ◽  
Vol 46 (4) ◽  
pp. 391-398 ◽  
Author(s):  
Gustavoda Luz Vieira ◽  
Luciane Macedo de Menezes ◽  
Eduardo Martinelli S. de Lima ◽  
Susana Rizzatto
Keyword(s):  
Repeated Measures ◽  
Cleft Lip ◽  
Cleft Lip And Palate ◽  
Covariance Structure ◽  
Face Mask ◽  
Rapid Maxillary Expansion ◽  
Maxillary Expansion ◽  
Maxillary Protraction ◽  
Significant Difference ◽  
Group 2

Objective: To evaluate the amount of maxillary protraction with face mask in complete unilateral cleft lip and palate patients submitted to two distinct rapid maxillary expansion (RME) protocols. Material and Methods: The sample consisted of 20 individuals (nine boys and 11 girls; mean age of 10.4 ± 2.62 years) with unilateral complete cleft lip and palate who had a constricted maxilla in the vertical and transverse dimensions. Ten patients underwent 1 week of RME with screw activation of one complete turn per day, followed by 23 weeks of maxillary protraction (group 1). The other 10 patients underwent 7 weeks of alternate rapid maxillary expansion and constriction, with one complete turn per day, followed by 17 weeks of maxillary protraction (group 2); both groups underwent a total of 6 months of treatment. Cephalometric measurements were taken at different times: pretreatment (T1), soon after RME (T2), and after 6 months of treatment (T3). Each measurement was analyzed with mixed models for repeated measures, and the covariance structure chosen was compound symmetry. Results: The maxilla displaced slightly forward and downward with a counterclockwise rotation; the mandible rotated downward and backward, resulting in an increase in anterior facial height; the sagittal maxillomandibular relationship was improved; the maxillary molars and incisors were protruded and extruded; and the mandibular incisors were retroclined. Conclusion: There was no significant difference between the groups in evaluation time.

scholarly journals Retrospective CBCT analysis of airway volume changes after bone-borne vs tooth-borne rapid maxillary expansion

2019 ◽  
Vol 89 (4) ◽  
pp. 566-574 ◽  
Author(s):  
Golnaz Kavand ◽  
Manuel Lagravère ◽  
Katherine Kula ◽  
Kelton Stewart ◽  
Ahmed Ghoneima
Keyword(s):  
Nasal Cavity ◽  
Three Dimensional ◽  
Upper Airway ◽  
Cone Beam ◽  
Maxillary Expansion ◽  
Retention Period ◽  
Maxillary Molars ◽  
Computed Tomography Images ◽  
Significant Difference ◽  
Cbct Analysis

ABSTRACT Objectives: To compare changes in upper airway volume after maxillary expansion with bone- and tooth-borne appliances in adolescents and to evaluate the dentoskeletal effects of each expansion modality. Materials and Methods: This retrospective study included 36 adolescents who had bilateral maxillary crossbite and received bone-borne maxillary expansion (average age: 14.7 years) or tooth-borne maxillary expansion (average age: 14.4 years). Subjects had two cone beam computed tomography images acquired, one before expansion (T1) and a second after a 3-month retention period (T2). Images were oriented, and three-dimensional airway volume and dentoskeletal expansion were measured. Analysis of variance was used to test for differences between the two expansion methods for pretreatment, posttreatment, and prepost changes. Paired t-tests were used to test for significance of prepost changes within each method. Results: Both groups showed significant increase only in nasal cavity and nasopharynx volume (P &lt; .05), but not oropharynx and maxillary sinus volumes. Intermolar and maxillary width increased significantly in both groups (P &lt; .05); however, the buccal inclination of maxillary molars increased significantly only in the tooth-borne group (P &lt; .05). There was no significant difference between tooth- and bone-borne expansion groups, except for the significantly larger increase in buccal inclination of the maxillary right first molar after tooth-borne expansion. Conclusions: In adolescents, both tooth- and bone-borne RME resulted in an increase in nasal cavity and nasopharynx volume, as well as expansion in maxillary intermolar and skeletal widths. However, only tooth-borne expanders caused significant buccal tipping of maxillary molars.

scholarly journals Effects of different rapid maxillary expansion appliances on facial soft tissues using three-dimensional imaging

2015 ◽  
Vol 86 (4) ◽  
pp. 590-598 ◽  
Author(s):  
Sedat Altındiş ◽  
Ebubekir Toy ◽  
Faruk Ayhan Başçiftçi
Keyword(s):  
Soft Tissues ◽  
Three Dimensional ◽  
Rapid Maxillary Expansion ◽  
Maxillary Expansion ◽  
Upper Lip ◽  
Three Dimensional Imaging ◽  
3D Images ◽  
Significant Difference ◽  
3D Effects ◽  
Facial Soft Tissues

ABSTRACT Objective:  To determine three-dimensional (3D) effects of three different rapid maxillary expansion (RME) appliances on facial soft tissues. Materials and Methods:  Forty-two children (18 boys, 24 girls) who required RME treatment were included in this study. Patients were randomly divided into three equal groups: banded RME, acrylic splint RME, and modified acrylic splint RME. For each patient, 3D images were obtained before treatment (T1) and at the end of the 3-month retention (T2) with the 3dMD system. Results:  When three RME appliances were compared in terms of the effects on the facial soft tissues, there were no significant differences among them. The mouth and nasal width showed a significant increase in all groups. Although the effect of the acrylic splint RME appliances on total face height was less than that of the banded RME, there was no significant difference between the appliances. The effect of the modified acrylic splint appliance on the upper lip was significant according to the volumetric measurements (P &lt; .01). Conclusions:  There were no significant differences among three RME appliances on the facial soft tissues. The modified acrylic splint RME produced a more protrusive effect on the upper lip.

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