Posterior crossbite is relatively common in children. Early treatment produces desirable occlusion, as well as increasing the arch perimeter. The purpose of this study was to examine the relationship between palatal expansion and maxillary arch perimeter.A group of 12 children aged 8-10 years, with posterior dentoalveolar crossbite, were selected for this study.All cases were treated for their crossbite using a removable palatal expander. Changes in both intermolar width of maxillary second primary and first permanent molars were compared to changes in arch perimeter at the end of treatment.Results of this comparison using paired t-test revealed that by increasing the arch width, a significant increase could be seen in arch perimeter (p<0.001).Regression analysis revealed that by increasing intermolar width (second primary molar) , arch perimeter also increases. However, this correlation was not statistically significant and there was no linear relationship between these two parameters too. On the other hand, the same analysis showed that a significant correlation existed between changes in intermolar width ( first permanent molar) and changes in arch perimeter (p=0.027). There was also a linear relationship between these two parameters.conclusion: 1mm increase in intermolar width ( maxillary first permanent molar) will cause a mean increase of 0.96 ± 0.31 mm in arch perimeter and this change in arch perimeter must be considered in space analysis in patients with posterior crossbite.

Evaluation of dental arch changes after rapid palatal expansion by bonded palatal ‎expander. 10 patients (5 boys & 5 girls) with uni or bilateral crossbite in ‎mixed dentition period were selected and records including, both arches casts, ‎maxillary occlusal radiography, intra & extra- oral photographies obtained rapid ‎palatal expansion applied by acrylic bonded palatal appliance during 14 days (about 7 ‎mm expansion was done). After a period of three months retention, appliance replaced ‎by removable one and the same above records obtained. The average chages of arch ‎width in the first permanent molar & deciduous first molar and coanine area of both ‎arches were measured. Paired t-test was used for analysis. The minimum changes in ‎both arches were in deciduous canine area (3.7 mm expansion in maxilla & 0.5 mm in ‎mandible). The maximum changes in maxilla was 6.77 mm in deciduous first molar ‎area, in mandible was 0.86 mm in permanent molar area. In spite of spondtaneous ‎expansion in lower dental arch following maxillary expansion (correlation coefficient ‎‎0.82) we must expand lower arch independently in clinical use. Because the amount ‎of spontaneous expansion isn't significant clinically‏.‏

Background and purpose: Transverse problems in the maxilla (high arched-narrow hard plates) can cause respiratory disorders. Palatal expansion can be helpful in this way. The present study aimed at evaluating the effect of bone borne expansion and tooth borne palatal expansion on airway volume. Materials and methods: A review study was performed by search in Google Scholar, Scopus, PubMed, Embase, and Cochrane using the following keywords: maxillary expansion, palatal expansion, miniscrew-assisted palatal expansion, tooth borne, bone borne, rapid palatal expansion, airway dimension, and Cone beam computed tomography. The search was limited to articles published in January 2011-April 2021. Results: In the initial search, 343 articles were found. After reviewing the titles and abstracts only 20 papers were found that studied the effect of bone and tooth borne palatal expansion on airway dimensions and met the inclusion criteria. The studies indicated that both bone expansion and tooth borne palatal expansion could considerably increase airway volumes. However, only bone borne palatal expansion enabled more predictable and greater skeletal expansion and less teeth response. Conclusion: Both bone and tooth borne palatal expansion are efficient in increasing the airway volume. Further randomized clinical trials with large sample size and matched control groups, longer follow-up periods and measuring respiration index such as apnea-hypopnea index are suggested.

Background and Objective: Palatal expansion can be done with tooth-borne and bone-borne appliances,Bone maturity is one of the factors required placing a mini-screw in the palate for expansion. Expansion with bone-based appliance also has two dental and skeletal responses,Part of the skeletal response can be to increase the size of the airway. The present study evaluates the effect of Miniscrew-assisted palatal expansion on airway volume. Methods: Search was conducted for articles published between January 2010 to January 2021 in PubMed, Embase, Google Scholar, and Cochrane using the following inclusion criteria: 1) patients whose treatment with Miniscrew-assisted palatal expansion and who with transverse discrepancy 2) all languages, 3) Randomized clinical trials (RCTs) or non-randomized clinical trials (Non-RCTs) and retrospective studies were considered. Results: Of the 123 studies on miniscrew-assisted palatal expansion, only 7 studies clinically evaluated the effect of miniscrew-assisted palatal expansion on airway dimensions. The results of studies show that the miniscrew-assisted palatal expansion increasing airway dimensions,so that, increased nasal cavity volume and nasopharyngeal volume have been observed following this treatment. However, studies have shown that this approch does not effect on oropharyngeal, palatopharyngeal, glossopharyngeal and posterior areas. Conclusion: The results of the study demonstrated that Miniscrew-assisted palatal expansion is an effective and efficient treatment in increasing airway dimensions via its increasing nasal cavity and nasopharynx volume.

The purpose of this research was to evaluate the effect of palatal expansion in the treatment of nocturnal enuresis. Enuresis still remains a problem experienced by children and the reason is unclear. Finding a final solution is being sought by the medical profession.Nocturnal enuresis may lead to numerous physical and emotional problems. Currently available treatment options showed satisfactory results in some cases.A treatment sample of 6 boys and 4 girls who ranged in age from 6 to 9 years was selected. Research showed that with palatal expansion (4-7 mm), patients could breathe through their nose rather their mouth; as a result, enuresis is reduced significantly.

Transverse maxillary deficiency is relatively prevalent in orthodontic patients. This article reports the use of a Miniscrew-Assisted Rapid Palatal Expansion (MARPE) device for the correction of transverse skeletal maxillary constriction in an adult patient. The patient was a 20-year-old girl with a transverse maxillary deficiency and bilateral posterior crossbite. A MARPE device was positioned on her palate using 4 miniscrews. The activation protocol was one-quarter turn per day every other day, with a total activation duration of 10 weeks following with a 3-month retention period. Pre-MARPE and post-MARPE cone-beam computed tomography cross sections presented a skeletal expansion of maxilla. This report confirms the effective treatment of a mature patient with severe maxillary constriction, highly deep palate, and posterior crossbite using a custom-made modification of MARPE

Statement of the Problem: Refractory nocturnal enuresis possesses a heavy psychosocial burden for the affected child. Only a 15% spontaneous annual cure rate is reported.Purpose: This patient-level meta-analysis aimed to evaluate the efficacy of rapid palatal expansion to treat nocturnal enuresis among children.Materials and Method: A sensitive search of electronic databases of PubMed (since 1966), SCOPUS (containing EMBASE, since 1980), Cochrane Central Register of Controlled Trials, CINAHL and EBSCO till Jan 2014 was performed. A set of regular terms was used for searching in data banks except for PubMed, for which medical subject headings (MeSH) keywords were used. Children aged at least six years old at the time of recruitment of either gender who underwent rapid palatal expansion and had attempted any type of pharmacotherapy prior to orthodontic intervention were included.Results: Six non-randomized clinical trials were found relevant, of which five studies had no control group. Eighty children were investigated with the mean age of 118 (28.12) months ranged from 74 to 185 months. The median time to become completely dry was 2.87 months [confidence interval (CI) 95% 2.07-2.93 months]. After one year, the average rate of becoming complete dry was 31%. The presence of posterior cross bite [relative risk (RR): 0.31, CI 95%: 0.12-0.79] and signs of upper respiratory obstruction during sleep (RR: 5.1, CI 95%: 1.44-18.04) significantly decreased and increased the chance of improvement, respectively. Meanwhile, the other predictors did not significantly predict the outcome after simultaneous adjustment in Cox regression model.Conclusion: Rapid palatal expansion may be considered when other treatment modalities have failed. The 31% rate of cure is promising when compared to the spontaneous cure rate. Though, high-level evidence from the rigorous randomized controlled trials is scarce (Level of evidence: C).

Background: Rapid maxillary expansion (RME) is an important method for correcting maxillary transverse deficiency. Objectives: The aim of this study was to assess the variations of the palatal plane in the anteroposterior and vertical directions after RME observed under cone-beam computed tomography. Methods: The images using the cone-beam computed tomography were obtained from the skull of 15 patients (10 males, 5 females) with ages from 7 to 14 years, at the specialization course in orthodontics of the School of Dentistry at UFBA before (T0) and after (T1) RME using the Haas-type expander. The sagittal slices were obtained with Dolphin imaging program, premium version 11. 0, in order to visualize the most anterior and posterior extremities of the maxillary bone and the following points: Sella (S), nasion (N), anterior nasal spine (ANS) and posterior nasal spine (PNS). The distances between points S and PNS (L1) and between N and ANS (L2) and the angles formed by the intersection of line SN with the palatal plane (angle 1) and line SN with line N-ANS (angle 2) were measured. Results: The values obtained were statistically analyzed using Students t-test. At the time intervals assessed, no statistically significant difference was found in the linear measurements L1 and L2 (P = 0. 296 and P = 0. 674, respectively). No statistical significance was found when assessing angles 1 and 2 (P = 0. 673 and P = 0. 589, respectively). Conclusions: RME using the Haas-type expander does not cause any alterations in the vertical or sagittal position of the maxilla.

Objective: Several appliances have been used for palatal expansion for treatment of posterior cross bite. The purpose of this study was to evaluate the stress induced in the apical and crestal alveolar bone and the pattern of tooth displacement following expansion via removable expansion plates or fixed-banded palatal ex-pander using the finite element method (FEM) analysis.Materials and Methods: Two 3D FEM models were designed from a mesiodistal slice of the maxilla containing the upper first molars, their periodontium and alveolar bone. Two palatal expanders (removable and fixed) were modeled. The models were designed in Solid Works 2006 and then transferred to ANSYS Work-bench. The appliance halves were displaced 0.1 mm laterally. The von Mises stress in the apical, crestal, and PDL areas and also the vertical displacement of the cusps (palatal and buccal) was were evaluated.Results: The total PDL stress was 0.40003 MPa in the removable appliance (RA) model and 4.88e-2 MPa in the fixed appliance (FA) model and the apical stress was 9.9e-2 and 1.17e-2 MPa, respectively. The crestal stress was 2.99e-1 MPa in RA and 7.62e-2 MPa in the FA. The stress in the cortical bone crest was 0.30327 and 7.9244e-2 MPa for RA and FA, respectively and 3.7271 and 7.4373e-2 MPa in crestal area of spongy bone, respectively. The vertical displacement of the buc-cal cusp and palatal cusp was 1.64e-2 and 5.90e-2 mm in RA and 1.05e-4 and 1.7e-4 mm in FA, respectively.Conclusion: The overall stress as well as apical and crestal stress in periodontium of anchor teeth was higher in RA than FA; RA elicited higher stress in both cortical and spongy bone. The vertical displacement of molar cusps was more in re-movable than fixed palatal expander model.