Immediate effects of rapid maxillary expansion on the nasal cavity using Haas-type and Hyrax-type expanders in CBCT

Abstract

Purpose: To evaluate and compare the immediate effects of rapid maxillary expansion (RME) on the nasal cavity dimensions in subjects treated with Haas-type and Hyrax-type expanders using cone-beam computed tomography (CBCT).Methods: Thirty-one growing patients (mean age=10.8 years old) with transverse maxillary deficiency were randomly divided into two groups: Haas group (n=16) and Hyrax group (n=15). All patients had RME with initial screw activation of 4 quarter turns followed by activations of ½ turns per day (0.4mm) until the expansion reached 8mm opening at the screw. CBCT scans were taken before RME (T1) and at the end of the active phase of expansion (T2). Vertical and transverse measurements were performed at different regions of nasal cavity for comparison between groups and treatment times. Intraclass correlation coefficient (ICC), paired Student's t-test and repeated measures ANOVA (α-level p<0.05) were calculated.Results: RME procedure increased every vertical and lateral nasal cavity dimensions (p<0.001). The most significant gains were observed in the lower portions of the nasal cavity located at the anterior and medial regions. Conclusions:Both appliances were able to create significant changes in the dimensions of the nasal cavity immediately after RME. However, the Hyrax-type expander presented greater transverse effects on the airway.

Skeletal and Dentoalveolar Changes in Growing Patients Treated with Rapid Maxillary Expansion Measured in 3D Cone-Beam Computed Tomography

“…3. Nasal base width (NBW): the most posterior cut of the nasal cavity was taken, and a straight line was drawn from right to left from the base of the nasal cavity at its most inferior portion [58] (Figure 3B). 4.…”

Obstructive sleep apnea: a review for the orthodontist

“…Due to the proximity to the oral cavity, the volume and area of the upper airway and nasal cavity can be changed by RME. Immediately, RME promotes displacement of circumaxillary sutures in the three planes of space 77 and a significant increase in vertical and lateral dimensions of the nasal cavity, 78 , 79 as well as in the nasopharyngeal volumes and area of greater UA constriction. 79 El and Palomo 80 evaluated, by CBCT, the UA volume of 35 patients treated with RME and followed up for to 2 years.…”

"Skeletal and Dentoalveolar Changes in Growing Patients Treated with Maxillary Expansion"

“…For the sutural opening, a straight line was drawn from right to left of the suture at the incisal level, as this is where a greater quantity of expansion is produced by the fanshaped opening pattern of the midpalatal suture after expansion [28] (Figure 6). For the width of the base of the nose, the posterior part of the nasal cavity was taken and then a straight line was traced from right to left of the base of the nose, in its lower portion [29] (Figure 7). For the width of the upper jaw JR-JL the lowest point of intersection of the zygomatic bone with the maxillary tuberosity was taken, from right (JR) to the left (JL) of the patient [30] (Figure 8) (Tables 2-5).…”