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

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 < .05), but not oropharynx and maxillary sinus volumes. Intermolar and maxillary width increased significantly in both groups (P < .05); however, the buccal inclination of maxillary molars increased significantly only in the tooth-borne group (P < .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.

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Brandon J. Seubert ◽  
Laurence Gaalaas ◽  
Brent E. Larson ◽  
Thorsten Grünheid

AbstractThis study aimed at quantifying the annual transverse growth of the maxilla using skeletal landmarks in three different regions on cone-beam computed tomography (CBCT) scans. CBCT scans taken before and after orthodontic treatment of 100 child and adolescent patients (50 male, 50 female) without maxillary transverse deficiencies were used to determine the transverse linear distances between the greater palatine foramina (GPFd), the lateral walls of the nasal cavity (NCd), and the infraorbital foramina (IOFd). We found that all distances increased significantly with growth in both genders (p < 0.001). The overall average annual change was 0.5 mm for GPFd, 0.3 mm for NCd, and 0.7 mm for IOFd. Males generally had greater annual changes than females for GPFd and IOFd, but not NCd. There were weak, statistically not significant (p > 0.05) correlations between patient age and the annual changes in GPFd, NCd, and IOFd. These results suggest that the positions of the greater palatine foramina, the lateral walls of the nasal cavity, and the infraorbital foramina change consistently with maxillary transverse growth. Clinicians can use the growth rates as population averages to more confidently estimate the amount of skeletal transverse deficiency or evaluate the long-term effects of maxillary expansion treatment.


2018 ◽  
Vol 11 (4) ◽  
pp. 273-277
Author(s):  
Guilherme dos Santos Trento ◽  
Lucas Borin Moura ◽  
Rubens Spin-Neto ◽  
Philipp Christian Jürgens ◽  
Marisa Aparecida Cabrini Gabrielli ◽  
...  

The interest about upper airway evaluation has increased lately. Therefore, many softwares have been developed aiming to improve and facilitate the analysis of airway volume. The objective of this study was to compare two different softwares packages, Mimics and Dolphin, in their accuracy and precision in upper airway space measurements. Preoperative cone beam computed tomography scans of nine nonsyndromic patients submitted to surgically assisted rapid maxillary expansion were included in this study. The imaging exams were converted to DICOM (digital imaging and communications in medicine) files and imported to the softwares. The mean volume for the Dolphin group (G1) was 10.791 cm3 (SD = 4.269 cm3) and for the Mimics group (G2) was 10.553 cm3 (SD = 4.564 cm3). There was no statistically significant difference between the two groups ( p = 0.105).


2015 ◽  
Vol 86 (4) ◽  
pp. 617-624 ◽  
Author(s):  
Carolina Morsani Mordente ◽  
Juan Martin Palomo ◽  
Martinho Campolina Rebello Horta ◽  
Bernardo Quiroga Souki ◽  
Dauro Douglas Oliveira ◽  
...  

ABSTRACTObjective: To evaluate the anterior and posterior maxillary width, the nasal passage volume, the oropharyngeal minimum axial area, and volume changes in unilateral cleft lip and palate patients treated with one of the following four expanders: Hyrax, Fan-Type, inverted mini-hyrax supported on the first permanent molars (iMini-M), or inverted mini-hyrax supported on the first premolars (iMini-B).Materials and Methods: A total of 40 patients with transverse maxillary deficiency who were submitted for rapid maxillary expansion were divided in four groups according to type of expander used. Cone-beam computed tomography images were taken before and 3 months after expansion. One-way analysis of variance was used to analyze the differences among the groups, and paired t-tests were used to evaluate the changes in each group.Results: All groups showed a significant increase in the anterior maxillary width, with no intergroup differences. The iMini-B was the only group that did not show a significant increase in the posterior maxillary width. The intergroup comparison demonstrated differences among all groups except between Hyrax and iMini-M, which showed the greatest posterior expansions. The intragroup analysis showed a significant increase in the nasal passage volume in hyrax and inverted mini-hyrax on the molar groups, but the intergroup comparison revealed a significant difference only between Fan-Type and inverted mini-hyrax on the molars. None of the expanders caused significant changes in the oropharyngeal measurements.Conclusions: Only the Hyrax and inverted mini-hyrax on the molar expanders effectively increased the nasal passage volume, and none of the expanders evaluated in this study modified the oropharyngeal airway.


2013 ◽  
Vol 84 (2) ◽  
pp. 265-273 ◽  
Author(s):  
Hakan El ◽  
Juan Martin Palomo

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.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Xin Feng ◽  
Yicheng Chen ◽  
Kristina Hellén-Halme ◽  
Weihua Cai ◽  
Xie-Qi Shi

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.


2021 ◽  
Vol 45 (3) ◽  
pp. 208-215
Author(s):  
Xin Feng ◽  
Stein Atle Lie ◽  
Kristina Hellén-Halme ◽  
Xie-Qi Shi

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.


2011 ◽  
Vol 81 (5) ◽  
pp. 843-849 ◽  
Author(s):  
Mariko Fuyamada ◽  
Hiroyuki Nawa ◽  
Momoko Shibata ◽  
Kazuhito Yoshida ◽  
Yoshitaka Kise ◽  
...  

Abstract Objective: To compare the reproducibility of landmark identification on three-dimensional (3D) cone-beam computed tomography (CBCT) images between procedures based on traditional cephalometric definitions (procedure 1) and those tentatively proposed for 3D images (procedure 2). Materials and Methods: A phantom with embedded dried human skull was scanned using CBCT. The acquired volume data were transferred to a personal computer, and 3D images were reconstructed. Eighteen dentists plotted nine landmarks related to the jaws and teeth four times: menton (Me), pogonion (Po), upper-1 (U1), lower-1 (L1), left upper-6 (U6), left lower-6 (L6), gonion (Go), condyle (Cd), and coronoid process (Cp). The plotting reliabilities of the two procedures were compared by calculating standard deviations (SDs) in three components (x, y, and z) of coordinates and volumes of 95% confidence ellipsoid. Results: All 27 SDs for procedure 2 were less than 1 mm, and only five of them exceeded 0.5 mm. The variations were significantly different between the two procedures, and the SDs of procedure 2 were smaller than those of procedure 1 in 21 components of coordinates. The ellipsoid volumes were also smaller for procedure 2 than procedure 1, although a significant difference was not found. Conclusions: Definitions determined strictly on each three sectional images, such as for procedure 2, were required for sufficient reliability in identifying the landmark related to the jaws and teeth.


2020 ◽  
Vol 90 (3) ◽  
pp. 432-441 ◽  
Author(s):  
Qiming Li ◽  
Hongyi Tang ◽  
Xueye Liu ◽  
Qing Luo ◽  
Zhe Jiang ◽  
...  

ABSTRACT Objectives To evaluate changes in dimensions and volume of upper airway before and after mini-implant assisted rapid maxillary expansion (MARME) and observe correlations between changes of upper airway and vertical skeletal pattern in young adults. Materials and Methods In this retrospective study, 22 patients (mean age, 22.6 ± 4.5 years; 4 male 18 female) with transverse discrepancy underwent MARME. Cone beam computed tomography was taken before and 3 months after expansion. Vertical and horizontal dimensions and volume of the nasal cavity, nasopharyngeal, retropalatal, retroglossal and hypopharyngeal airway were compared before and after MARME. Correlations between changed volume and dimensions were explored, as well as the vertical skeletal pattern. Results Nasal osseous width, maxillary width, volume of the nasal cavity and nasopharynx increased significantly (P &lt; .05). Enlarged nasopharyngeal volume correlated with increased nasal width at the PNS plane (P &lt; .05). There were no correlations between expanded volume and maxillary width. No measurements except nasal cavity volume had a correlation with Sum angle. Increased maxillary width correlated negatively with hard palate thickness (P &lt; .05). Conclusions (1) MARME caused an increase in volume of the nasal cavity and nasopharynx, with expansion of nasal osseous width and maxillary width. (2) Enlarged nasal width at the PNS plane contributed to the increase in nasopharynx volume. Enlarged maxillary width showed no direct relation with increased volume. (3) In this study, it was unclear about the association between changes of the upper airway and vertical skeletal pattern because of complex structures. (4) Palate thickness affected skeletal expansion of the maxilla in MARME.


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