|Year : 2022 | Volume
| Issue : 1 | Page : 3-11
Rapid Maxillary Expansion, Sleep-Disordered Breathing and Conductive Hearing Loss in Children: A Correlation
Mohit Sharma1, Balakrishnan Jayan1, Sanajeet Kumar Singh2, Shelka Dua2
1 Army Dental Centre, Research and Referral, New Delhi, India
2 Army Hospital, Research and Referral, New Delhi, India
|Date of Submission||10-Dec-2020|
|Date of Acceptance||26-Apr-2021|
|Date of Web Publication||05-Apr-2022|
Army Dental Centre, Research and Referral, New Delhi
Source of Support: None, Conflict of Interest: None
Aim: To evaluate the effects of Rapid Maxillary Expansion (RME) with respect to improvement in sleep disordered breathing(SDB) and conductive hearing loss in children
Material & Methods: The study was carried out at a tertiary care centre in the Dept of Orthodontics & Dentofacial Orthopedics in collaboration with the Dept of ENT and Dept of Physiology after due clearance from the institutional committee. A sample of 30 children between age of 8 to 15 years seeking orthodontic treatment, treated with RME and evaluated for improvement in SDB, conductive hearing loss and decrease in AHI parameters using pre and post lateral cephalograms, PA cephalograms and Acoustic Pharyngometry. Data acquired was statistically evaluated and presented along a median with p-value at 0.05 and the hypotheses were formulated using two tailed alternatives against each null hypothesis.
Results: Wilcoxon's signed rank test, showed that the distribution of post-treatment maxillary dentoalveolar parameters was significantly higher compared to the pre-treatment maxillary dentoalveolar parameters, post treatment cephalometric nasal and upper airway parameters were significantly higher compared to the pre-treatment, a positive impact on the upper airway especially NAS and VAS was observed, post treatment acoustic pharyngometry parameters (such as Mean volume, Mean area and Minimum area) which were significantly higher compared to the average pre-treatment parameters, AHI was significantly lower compared to the pre-treatment AHI showing marked improvement and conductive hearing loss improved post RME, leading to near normalization.
Conclusion: All maxillary dentoalveolar parameters, nasal width and transverse maxillary width improved, Nasopharyngeal and Velopharyngeal airway space showed improvement as the maxillary trnasverse width improved post RME, tongue posture improved to a more downward and forward position significantly. Apnea-Hypopnea Index reduced leading to improvement in sleep parameters and its associated signs and symptoms. Post RME, changes in the maxillary transverse width also improved the anatomical relationship of the associated muscle attachments especially the tensor and levator palatani muscle attachments, thereby improving the conductive hearing loss in the subjects.
Keywords: RME, sleep disordered breathing, conductive hearing loss, acoustic pharyngometry
|How to cite this article:|
Sharma M, Jayan B, Singh SK, Dua S. Rapid Maxillary Expansion, Sleep-Disordered Breathing and Conductive Hearing Loss in Children: A Correlation. J Dent Def Sect. 2022;16:3-11
|How to cite this URL:|
Sharma M, Jayan B, Singh SK, Dua S. Rapid Maxillary Expansion, Sleep-Disordered Breathing and Conductive Hearing Loss in Children: A Correlation. J Dent Def Sect. [serial online] 2022 [cited 2022 May 18];16:3-11. Available from: http://www.journaldds.org/text.asp?2022/16/1/3/342652
| Introduction|| |
Airway is the fourth dimension after the transverse, sagittal, and vertical dimension which needs to be carefully addressed during the clinical and radiological assessment for any orthodontic patient. Angell and Derichsweiler in 1860 described maxillary expansion and its positive effects on nasal permeability. The relationship between respiratory function and craniofacial morphology has been debated for more than a century and it has been proved that airway obstruction; either nasal or oral does effect the normal growth and development of the craniofacial complex and if not treated in time leads to compensated growth and development of the patient.
Sleep-disordered breathing (SDB) due to upper airway obstruction is commonly associated with snoring. In children, SDB reveals a wide variety of severity, ranging from snoring as being the mildest form to obstructive sleep apnea (OSA) as the severe presentation. The continuum of SDB in children has been steadily increasing and has also gained attention due to the deleterious health implications if left undiagnosed or untreated.,,,
Various studies have reported a positive relationship between craniofacial characteristics such as high palatal vault, narrow maxilla, a retrognathic mandible, increased facial height, and SDB in children.,,
Eustachian tube dysfunction has been related to a malfunction of the tensor and levator palatine muscles that result in the inability of the tube to open in response to negative pressure in the middle ear. The malfunction has been found to be more frequent in the presence of a high palatal vault. Studies are indicative of improvement in hearing, a few weeks after maxillary expansion., It is believed that improvement in conductive hearing loss after RME is due to stretching of tensor veli palati muscle, which opens the pharyngeal orifice of the Eustachian tube and allows air to enter and exit middle ear. Thus, the pressure on either side of the tympanic membrane is balanced and the vibration of the ossicular bones are normalized resulting in hearing improvement., Few reports provide a sketchy but definite course for evaluating the effect of RME on SDB and its effect on conductive hearing loss in children. Keeping the above in mind the present study was designed and ethical committee clearance was obtained from the institutional ethical committee. The aim was to evaluate subjectively and objectively the therapeutic benefits of rapid maxillary expansion (RME) with respect to improvement in SDB and conductive hearing loss in children. The objectives of the study were to (i) To compare baseline and posttreatment apnea-hypopnea index (AHI) scores, (ii) To compare baseline and posttreatment nasal cavity and maxillary transverse skeletal dimensions on posterior-anterior (PA) cephalogram, (iii) To compare baseline and posttreatment retroglossal velopharyngeal airway space (VAS), retropalatal posterior airway space (PAS) and nasopharyngeal airway space (NAS) on lateral cephalometric radiographs, (iv) To compare baseline and posttreatment conductive hearing loss using Audiometry tests and Tympanometry tests, and (v) To compare baseline and posttreatment pharyngeal airway space using Acoustic Pharyngometery.
| Subjects and Methods|| |
The study was carried out at a tertiary care center in the Department of Orthodontics and Dentofacial Orthopedics, in collaboration with the Department of ENT and Department of Physiology. A sample of 30 children between age of 8–15 years, reporting to the outpatient department of the Department of Orthodonticsand Dentofacial Orthopedics, seeking orthodontic correction of malocclusion and meeting the following inclusion and exclusion criteria were considered as the study sample after obtaining informed ascent and consent. Inclusion criteria was as follows: (a) Malocclusion characterized by maxillary transverse deficiency, (b) Clinically visible deep palatal vault, (c) Children with history of oral breathing, snoring, and the presence of nocturnal apneas, and (d) body mass index <24 kg/m2. Exclusion criteria were as follows: (a) Cases with adeno-tonsillar hypertrophy, (b) cases of cleft lip and palate, (c) craniofacial syndromes, (d) presence of nasal polyp and tumors, and (e) existing unidentified/untreated sensory deafness. Children meeting the above criteria would be subjected to comprehensive orthodontic examination, ENT examination and Type 1 polysomnography.
Standard clinical orthodontic examination of the face was carried out in all three planes of space, both extraorally and intraorally. All standard orthodontic records were recorded (orthopantomography, lateral cephalogram, PA cephalogram, models, intraoral and extraoral photographs). All patients underwent Type 1 polysomnography in the sleep lab. Sleep-wake states were based on electroencephalograms, electromyogram, electrocardiogram, body position, nasal and oral flow, thoracic and abdominal movement, snoring noise, and pulse oximetry. Abnormal events were considered present if longer than 2 breaths in duration. Events were classified as apnea or hypopnea based on airflow and as obstructive, mixed, or central based on thoracoabdominal movements and air flow. All patients underwent audiometry and tympanometry tests prior to initiation of treatment using the ALPS Audiometry Machine and GSI Machine for Tympanometry. Acoustic Pharyngometry was carried out using the ECOVISION PHARYNGOMETER ((sleep group solutions). Various measurements of the upper airway were carried out by passing sound waves through the upper airway, captured by the software, analyzed and a pharyngogram was produced.
On completion of record taking and pretreatment examination, the patients' records were subjected to various analysis (T0).
Lateral cephalograms were recorded at end of expiration and the study subjects were asked not to swallow during the process of radiography. The landmarks and reference planes, used for cephalometric analysis in the study is depicted vide [Figure 1]. PAS, VAS and NAS was measured and recorded.
- NAS: Measured from PNS to upper pharyngeal wall along the palatal plane
- VAS: Horizontal distance from the tip of the soft palate to pharyngeal wall
- PAS: Horizontal distance from the posterior margin of the tongue to pharyngeal wall measured on the Go-B line.
PA cephalograms were also recorded and nasal cavity width (NC-CN) and maxillary transverse width (JL-JR) were measured. Plaster models were subjected to the measurement for intermolar, inter canine and palatal depth using the Vernier caliper and Korakhaus gauge. Audiometry and tympanometry tests were carried out along with a Type I polysomnography and conductive hearing loss and AHI index were recorded.
Acoustic pharyngometry was carried out using the ECOVISION PHARYNGOMETER ((Sleep Group Solutions. Mean volume, mean area, minimum area and min pharyngeal distance was calculated by the software and a pharyngogram was generated [Figure 2].
RME was carried out with a banded appliance in situ. Three types of expansion screws were used in this study. Leone A0620/13 (Italy) and Forestadent 1671326 L (Germany) and Palatal screw-type “S” for extremely narrow palates. Standard clinical and lab criteria for fabrication of the appliance were followed. The activation schedule for all cases was standardized and on the first day, morning and evening, 03 consecutive activations were applied at 10 min intervals. From the second day onward only one activation was applied every morning and evening, i.e., 1 mm/day. Occlusal radiograph after 3 days of activation was used to confirm the opening of mid palatal suture. Maxilla was expanded so that the lingual cusps of maxillary molars and premolars are in line with buccal cusps of the corresponding mandibular teeth. All the study subjects and their parents were briefed on the diet and oral hygiene measures needed to be followed for the RME device to avoid any complications that would interfere with the expansion process. Post expansion, the RME screw was sealed to prevent relapse and the appliance was left in situ for 3 months. After 3 months, all records were repeated for measurements (T1).
The data acquired for the patients were subjected to various statistical analyses. The power and sample size calculation was based on the previously published data and was done a-priori. The true difference in the mean response of matched pairs for the variables under consideration was found to be 5 ± 3, hence using minimum sample size of 30 we would be able to reject the null hypothesis that this response difference is zero with probability (power) 0.90. The Type I error probability associated with this test of this null hypothesis was kept at 0.05. Furthermore, the power of the study ranged between 0.80 and 0.90 for the sample sizes between 25 and 30. Measurements of three maxillary dentoalveolar variables, three airway parameters on the lateral cephalogram, three acoustic pharyngometry variables, one sleep parameter (AHI), three audiometric parameters for the Right and Left ear, and tympanometry parameters were obtained from a sample of 30 patients (pre- and post-treatment assessments).
The data on all variables are presented as median along with minimum-maximum at the pre- and post-treatment stage of the study. The statistical significance of the difference in the study parameters was assessed by Wilcoxon's signed rank-sum test.
P < 0.05 were considered to be statistically significant. All the hypotheses were formulated using two-tailed alternatives against each null hypothesis (hypothesis of no difference). The entire data were statistically analyzed using the Statistical Package for the Social Sciences (SPSS ver 21; IBM Cop; Armonk NY) for MS Windows.
| Results|| |
All maxillary dentoalveolar variables, i.e., inter molar width, inter canine width and palatal depth were compared between pre- and post-treatment stages of the study [Table 1] and [Figure 3]. On Wilcoxon's signed-rank test, it was clear that the distribution of posttreatment maxillary dentoalveolar parameters (such as IM width and IC width) was significantly higher compared to the pretreatment maxillary dentoalveolar parameters (P < 0.05 for both). The distribution of posttreatment palatal depth did not differ significantly compared to the pretreatment palatal depth (P > 0.05). All maxillary dentoalveolar parameters improved on RME and expansion was achieved.
|Figure 3: Pre- and post-treatment comparison of maxillary dentoalveolar parameters|
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|Table 1: Pretreatment and posttreatment statistical comparison for maxillary dentoalveolar parameters|
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For PA cephalometric variables, i.e., two linear variables namely NC width and MT width, the distribution of median posttreatment cephalometric parameters (such as NC width and MT width) was significantly higher compared to the pretreatment cephalometric parameters (P < 0.05 for both) [Table 2] and [Figure 4]. The skeletal width of the maxilla and nasal cavity improved post-RME.
|Figure 4: Pre- and post-treatment comparison of posteroanterior cepahlogram parameters|
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|Table 2: Pretreatment and posttreatment statistical comparison for PA cephalogram parameters|
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The airway parameters were similarly compared and it was evident that the distribution of average (median) posttreatment airway parameters (such as NAS and VAS) were significantly higher compared to the pretreatment airway parameters (P < 0.05 for both). The distribution of average (median) posttreatment airway parameter i.e., PAS did not differ significantly compared to the pretreatment airway parameters (P > 0.05) [Table 3] and [Figure 5]. The results show a positive impact on the upper airway, especially NAS and VAS as the transverse width of the maxilla improved and the tongue took a more downward and forward position gradually due to an increase in oral volume.
|Figure 5: Pre- and post-treatment comparison of airway parameters studied on lateral cephalogram|
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|Table 3: Pretreatment and posttreatment statistical comparison for airway parameters on lateral cephalogram|
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The acoustic pharygometry variables studied, the distribution of average (median) posttreatment acoustic pharyngometry parameters (such as mean volume, mean area, and minimum area) were significantly higher compared to the average pretreatment parameters (P < 0.05 for all) [Table 4] and [Figure 6], showing an increase in all measurements of the upper airway.
|Figure 6: Pre- and post-treatment comparison of acoustic pharyngometry parameters|
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|Table 4: Pretreatment and posttreatment statistical comparison for airway parameters on acoustic pharyngometry|
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In the study, only sleep parameter, i.e., AHI was studied. The distribution of average (median) posttreatment AHI is significantly lower compared to the pretreatment AHI (P < 0.05) [Table 5] and [Figure 7]. Improvement was observed by lowering down of the AHI Index.
|Table 5: Pretreatment and posttreatment statistical comparison for polysomnography|
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Audiometry parameters studied, the distribution of average (median) posttreatment parameters measured on the Right ear and Left ear (such as AC, BC, and ABG) were significantly lower compared to the pretreatment audiometric parameters (P < 0.05 for all) [Table 6] and [Figure 8], [Figure 9]. Conductive hearing loss improved post-RME, leading to near normalization.
|Figure 8: Pre- and post-treatment comparison of audiometric (right) parameters studied|
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|Figure 9: Pre- and post-treatment comparison of audiometric (left) parameters studied|
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|Table 6: Pre-treatment and Post-treatment statistical comparison for Audiometry & Tympanometry|
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The acoustic pharyngometry parameters such as mean volume and mean area are positively and significantly correlated with NAS (P < 0.05 for both). Mean volume was negatively and significantly correlated with PAS (P < 0.05). Furthermore, the mean area is negatively and significantly correlated with VAS (P < 0.05) [Table 7]. The minimum area did not correlate with any of the airway parameters studied (P > 00.05 for all).
|Table 7: Correlation between Post-treatment Acoustic pharyngometry and Airway parameters.|
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The reliability analysis of the data was done using the normal (non-standardized) Cronbach's alpha method. One of the maxillary dentoaleveolar parameters was randomly chosen for testing the reliability. It was found that Cronbach's alpha value was 0.82 and it was within the acceptable limits. Hence, the repeated paired data had relatively higher reliability.
| Discussion|| |
Disturbances in craniofacial morphology are commonly seen in children who suffer from respiratory problems and SDB like snoring and OSA. Nasal obstruction associated with constricted maxilla may increase nasal resistance, alter tongue posture leading to narrowing of retroglossal and retro palatal airway space leading to sleep-disordered breathing.
RME proved to be a valuable procedure for the treatment of SDB for our study sample of 30 patients. Out of 30 patients, 91% of the children showed improvement in all parameters under study, i.e., dentoalveolar variables, airway variables, sleep parameters (AHI), and conductive hearing loss parameters.
All maxillary dentoalveolar variables, i.e., inter molar width, inter canine width, and palatal depth were compared between pre- and post-treatment stages of the study [Table 1] and [Figure 3] On Wilcoxon's signed-rank test, it was clear that the distribution of posttreatment maxillary dentoalveolar parameters (such as IM width and IC width) is significantly higher compared to the pretreatment maxillary dentoalveolar parameters (P < 0.05 for both). The distribution of posttreatment palatal depth did not differ significantly compared to the pretreatment palatal depth (P-value > 0.05). These results are in conjunction with the study conducted by Villa et al. They found that in 10 of the 14 patients who completed treatment (71.4%) the symptoms of SDB regressed and in 11/14 (78.5%) of treated patients the AHI significantly decreased.
RME has an impact on the width of the nasal cavity, which was assessed using the PA cephalogram. Two linear variables namely NC width and MT width, the distribution of median posttreatment cephalometric parameters (such as NC width and MT width) is significantly higher compared to the pretreatment cephalometric parameters (P < 0.05 for both) [Table 2] and [Figure 4]. Similar conclusions were drawn by previous studies,, suggesting a positive correlation between RME and increase in nasal cavity parameters.
Palatal depth did not show a statistically significant change in our study. This could be attributed to the presence of very deep palatal vaults in our sample and also the same is an angular measurement which may change due to any tipping of the alveolar segments. The results are in concordance with the study carried out by Oliveira De Felippe et al. They reported a change of only 5.88% in their sample.
The upper airway can also be visualized on the lateral cephalogram, especially the NAS, PAS, and the VAS. In this study, all the patients part of the study underwent a lateral cephalogram at T0 and T1. NAS, PAS, and VAS were evaluated and compared. It was evident that the distribution of average (median) posttreatment airway parameters such as VAS and NAS was significantly higher compared to the pretreatment airway parameters (P < 0.05). The distribution of average (median) post treatment airway parameters (PAS) did not differ very significantly compared to the pretreatment airway parameters (P > 0.05) [Table 3] and [Figure 4]. Basciftci et al. assessed the effects of RME and surgical assisted RME on the nasopharyngeal area. They concluded that the respiratory area and the ratio of the respiratory area to nasopharyngeal (RA/NA) area increased following RME. Nasal cavity width and maxillary width also increased. Following RME, various differences in both the maxilla and surrounding bones occurred and nasal width increased with a decrease in nasal airway resistance. At the end of treatment, there were increases in the width of the nasal floor near the midpalatal suture and nasal cavity. Nasal resistance decreased and respiratory area increased in patients treated with RME. The results of this study are also comparable as NAS, VAS significantly increased, thereby decreasing the nasal resistance and improving the airflow [Table 3] and [Figure 5].
Acoustic pharygometry variables studied, the distribution of average (median) posttreatment acoustic pharyngometry parameters (such as mean volume, mean area, and minimum area) were significantly higher compared to the average pretreatment parameters (P < 0.05 for all) [Table 4] and [Figure 6]. Various studies, have concluded that acoustic reflection is a minimally invasive and moderately effective method of quantifying airway changes.
AHI is a standard measurement which assesses the average number of apneas and hypopneas per hour of sleep. The comparison of pre-RME and post-RME data shows the distribution of average (median) posttreatment AHI is significantly lower compared to the pretreatment AHI (P < 0.05) [Table 5], [Figure 7]. Studies, have reported similar findings, RME done in children with OSA. They reported that AHI decreased significantly from T0 to T1 and SaO2 improved significantly. Total sleep time and stage 2 NREM percentages increased significantly, while stage 1 NREM percentage decreased from T0 to T1. The results of this study are in concordance showing that RME does have a positive effect on SDB. Similar decrease was observed in another study, cases planned for adenotonsillectomy followed by RME or vice versa. AHI scores markedly improved and obliviating the need for surgery in cases in which RME had been done prior.
RME also improved sleep characteristics. There was an increase in sleep efficiency on average after expansion when compared between different periods T0-T1-T2. AHI decreased in all subjects showing a definitive improvement in the airway. These results are similar to this study in which a positive improvement was seen in AHI of the subjects with definitive improvement in sleep characteristics.
RME is believed to stretch the tensor veli palatine muscle which opens the pharyngeal orifice of the Eustachian tube, thus facilitating entry and exit of air in the middle ear. The pressure on either side of the tympanic membrane is balanced and the vibration of ossicular bones minimized resulting in hearing improvement. The audiometry parameters studied, the distribution of average (median) posttreatment parameters measured on the Right ear and Left ear (such as AC, BC, and ABG) is significantly lower compared to the pretreatment audiometric parameters (P < 0.05 for all) [Table 6] and [Figure 8], [Figure 9]. These results show a positive impact of RME in decreasing conductive hearing loss in children suffering from SDB having a narrow maxilla. The results are similar to studies, done in the past including cases with recurrent otitis media.
| Conclusion|| |
This study was taken up to evaluate subjectively and objectively the therapeutic benefits of RME with respect to improvement in SDB and conductive hearing loss in children.
The subjects were evaluated with pre–post comparisons based on upper airway changes assessed on the lateral cephalogram, nasal cavity width changes along with maxillary transverse dimensional changes assessed using the PA cephalogram, baseline and post RME changes in AHI using polysomnography, pre–post changes in conductive hearing loss using audiometry and tympanometry. Dynamic assessment of changes in the upper airway was assessed using Acoustic Pharyngometry and also the changes observed were correlated between AP and lateral cephalogram for all subjects.
Within the limitations of the study, there was a statistical significant and clinically significant difference in all parameters studied.
- All maxillary dentoalveolar parameters, nasal width, and transverse maxillary width improved, thereby having a combination of skeletal and dental expansion and improving the skeletal and dental relationship between the skeletal bases
- The Nasopharyngeal and VAS also showed improvement as the maxillary transverse width improved post RME, as the tongue posture improved to a more downward and forward position significantly
- Due to all these changes in the upper airway the AHI reduced leading to improvement in sleep parameters and its associated signs and symptoms
- Post-RME, changes in the maxillary transverse width also improved the anatomical relationship of the associated muscle attachments, especially the tensor and levator palatani muscle attachments, thereby improving the conductive hearing loss in the subjects.
It can be concluded that RME is an efficacious and safe procedure in the treatment of children suffering with SDB and Conductive Hearing loss provided a detailed diagnosis of SDB patients is carried out. A multidisciplinary approach to this disorder shall help patients to be treated holistically, with more treatment options available which may be less invasive.
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Conflicts of interest
There are no conflicts of interest.
| References|| |
Angell EC. Treatment of irregularity of the permanent or adult teeth. Dent Cosmos 1860;1:540-44.
Derichsweiler H. Die Gaumennahtsprengung. Fortschr Kieferorthop 1953;14:5-23.
Carroll JL. Obstructive sleep-disordered breathing in children: New controversies, new directions. Clin Chest Med 2003;24:261-82.
Guilleminault C, Khramtsov A. Upper airway resistance syndrome in children: A clinical review. Semin Pediatr Neurol 2001;8:207-15.
Guilleminault C, Pelayo R, Leger D, Clerk A, Bocian RC. Recognition of sleep-disordered breathing in children. Pediatrics 1996;98:871-82.
Castronovo V, Zucconi M, Nosetti L, Marazzini C, Hensley M, Veglia F, et al
. Prevalence of habitual snoring and sleep-disordered breathing in preschool-aged children in an Italian community. J Pediatr 2003;142:377-82.
Baldassari CM, Mitchell RB, Schubert C, Rudnick EF. Pediatric obstructive sleep apnea and quality of life: A meta-analysis. Otolaryngol Head Neck Surg 2008;138:265-73.
Löfstrand-Tideström B, Hultcrantz E. Development of craniofacial and dental arch morphology in relation to sleep disordered breathing from 4 to 12 years. Effects of adenotonsillar surgery. Int J Pediatr Otorhinolaryngol 2010;74:137-43.
Löfstrand-Tideström B, Thilander B, Ahlqvist-Rastad J, Jakobsson O, Hultcrantz E. Breathing obstruction in relation to craniofacial and dental arch morphology in 4-year-old children. Eur J Orthod 1999;21:323-32.
Zucconi M, Caprioglio A, Calori G, Ferini-Strambi L, Oldani A, Castronovo C, et al
. Craniofacial modifications in children with habitual snoring and obstructive sleep apnoea: A case-control study. Eur Respir J 1999;13:411-7.
Villa MP, Malagola C, Pagani J, Montesano M, Rizzoli A, Guilleminault C, et al
. Rapid maxillary expansion in children with obstructive sleep apnea syndrome: 12-month follow-up. Sleep Med 2007;8:128-34.
Ghafari JG, Macari AT. The benefits of consulting with an Ear, Nose and Throat (ENT) specialist before and during orthodontic treatment. In: Krishnan V, Davidovitch Z, editors. Integrated Clinical Orthodontics. 1st
ed. Hoboken, New Jersey, USA: Blackwell Publishing Limited; 2012. p. 195-211.
Gray LP. Results of 310 cases of rapid maxillary expansion selected for medical reasons. J Laryngol Otol 1975;89:601-14.
Villano A, Grampi B, Fiorentini R, Gandini P. Correlations between rapid maxillary expansion (RME) and the auditory apparatus. Angle Orthod 2006;76:752-8.
Enoki C, Valera FC, Lessa FC, Elias AM, Matsumoto MA, Anselmo-Lima WT. Effect of rapid maxillary expansion on the dimension of the nasal cavity and on nasal air resistance. Int J Pediatr Otorhinolaryngol 2006;70:1225-30.
Smith T, Ghoneima A, Stewart K, Liu S, Eckert G, Halum S, et al
. Three-dimensional computed tomography analysis of airway volume changes after rapid maxillary expansion. Am J Orthod Dentofacial Orthop 2012;141:618-26.
Oliveira De Felippe NL, Da Silveira AC, Viana G, Kusnoto B, Smith B, Evans CA. Relationship between rapid maxillary expansion and nasal cavity size and airway resistance: Short- and long-term effects. Am J Orthod Dentofacial Orthop 2008;134:370-82.
Basciftci FA, Mutlu N, Karaman AI, Malkoc S, Küçükkolbasi H. Does the timing and method of rapid maxillary expansion have an effect on the changes in nasal dimensions? Angle Orthod 2002;72:118-23.
Baratieri C, Alves M Jr., de Souza MM, de Souza Araújo MT, Maia LC. Does rapid maxillary expansion have long-term effects on airway dimensions and breathing? Am J Orthod Dentofacial Orthop 2011;140:146-56.
Villa MP, Rizzoli A, Miano S, Malagola C. Efficacy of rapid maxillary expansion in children with obstructive sleep apnea syndrome: 36 months of follow-up. Sleep Breath 2011;15:179-84.
Guilleminault C, Quo S, Huynh NT, Li K. Orthodontic expansion treatment and adenotonsillectomy in the treatment of obstructive sleep apnea in prepubertal children. Sleep 2008;31:953-7.
Ashok N, Varma SN, Ajith VV, Gopinath S. Effect of rapid maxillary expansion on sleep characteristics in children. Contemp Clinic Dent 2014;5:489-94.
Kılıç N, Yörük Ö, Kılıç SC, Çatal G, Kurt S. Rapid maxillary expansion versus middle ear tube placement: Comparison of hearing improvements in children with resistance otitis media with effusion. Angle Orthod 2016;86:761-7.
[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6], [Figure 7], [Figure 8], [Figure 9]
[Table 1], [Table 2], [Table 3], [Table 4], [Table 5], [Table 6], [Table 7]