Impact of rapid maxillary expansion on nasomaxillary complex volume in mouth-breathers

Abstract

Objective: To assess the volumetric changes that occur in the nasomaxillary complex of mouth-breathing patients with transverse maxillary deficiency subjected to rapid maxillary expansion (RME). Methods: This was a controlled, prospective intervention study involving 38 mouth-breathing patients presenting with transverse maxillary deficiency, regardless of malocclusion type or race. Twenty-three of them comprised the experimental group, which was composed of 11 (47.8%) boys, and 12 (52.2%) girls, with a mean age of 9.6 years, ranging from 6.4 to 14.2 years and standard deviation of 2.3 years; and 15 of them comprised the control group, composed of 9 (60%) boys and 6 (40%) girls with an mean age of 10.5 years, ranging from 8.0 to 13.6 years, and standard deviation of 1.9 years. All patients were scanned (CT) according to a standard protocol: Initial CT (T1), and CT three months thereafter (T2), and the patients in the experimental group were treated with RME using a Hyrax expander for the correction of maxillary deficiency during the T1-T2 interval. The CT scans were manipulated using Dolphin® Imaging version 11.7 software for total and partial volumetric assessment of the nasomaxillary complex. Results: The results revealed that in the experimental group there was a significant increase in the size of the structures of interest compared to the control group, both in general aspect and in specific regions. Conclusions: Rapid maxillary expansion (RME) provided a significant expansion in all the structures of the nasomaxillary complex (nasal cavity, oropharynx, right and left maxillary sinuses).

Three‐dimensional analyses of short‐ and long‐term effects of rapid maxillary expansion on nasal cavity and upper airway: A systematic review and meta‐analysis

“…One study was excluded from the quantitative synthesis because only the mean values of the difference between before and after treatment were provided 42 . After these processes, 27 24‐26,38,39,41‐62 and 18 studies 24‐26,39,43,46,47,49,51,52,54,55,57‐62 were included in the qualitative and quantitative synthesis, respectively (Figure 2).…”

“…Descriptive data for the studies included are summarized in Table 1a‐c. Regarding study design, one study was a randomized controlled clinical trial, 24 six were case‐controlled studies (two prospective trials 45,46 and four retrospective 42,44,49,54 ), and the other 20 articles were cohort studies 25,26,38,39,41,43,47,48,50‐53,55‐62 …”

“…A total of 666 patients (mean age range 7.1‐14.7 years) were included (Table 1a), with 300 males (45%) and 340 females (51%), while one study didn't supply clear gender information 42 . Six studies had a control group for a total of 127 subjects (age range 8.8‐14.1 years) 42,44‐46,49,54 . Four studies had comparison groups: two compared different types of appliances, 57,61 while two compared different expansion protocols 24,62 .…”

“…Fifteen studies included patients with a constricted maxilla. 25,26,38,41,43,46,50‐52,55‐60 In addition, posterior crossbite was a requirement for 11 studies, 25,26,38,39,41,43,47,50,52,55,58 while it was optional in three studies 51,57,60 . Five studies reported skeletal maturity of the patients, according to the cervical vertebral maturation method, 38,39,41,45,50 while one study used hand‐wrist radiographs 48 …”

“…Regarding the treatment protocol, the expansion appliances included Hyrax‐type expanders, 24‐26,42,44,46,47,49,52,59‐62 Haas‐type expanders, 38,39,45,48 bonded Hyrax with occlusal coverage, 51,58 a cast‐cap splint expander, 43 a butterfly‐shaped expander 41 and a modified Biederman, 55 while two studies did not specify the type of maxillary expander used 53,54 . Additionally, three studies used more than one type of expander.…”