Tratamento da classe III com disjunção maxilar e tração reversa da maxila: relato de caso clínico / Class III treatment weth maxillary disjunction and reverse maxillary traction: clinical case report

Objetivo: A má oclusão classe III de Angle se caracteriza por protrusão mandibular, retrusão maxilar ou pela combinação de ambas. Além de prejudicar a estética facial do paciente, essa má oclusão pode causar alterações funcionais e respiratórias. Uma das alternativas de tratamento para esses casos é o uso da máscara de Petit e do aparelho disjuntor de Hyrax. Este estudo tem como objetivo avaliar por meio da cefalometria ortodôntica se o tratamento com expansão maxilar em conjunto com a tração reversa da maxila diminuem os agravos estéticos e funcionais do paciente Classe III. Relato de caso: o relato de caso descrito no presente trabalho é sobre uma paciente que foi submetida a esse tratamento, sendo descrito por meio de análises cefalométricas, exames radiográficos, fotos intrabucais e achados clínicos. Considerações finais: A verificação dos resultados obtidos após o término do tratamento mostrou que a paciente teve uma boa adesão ao uso desses aparelhos e obteve resultados satisfatórios na sua função mastigatória, na sua oclusão e na sua estética facial e dentária.(AU)

Objective: Angle class III malocclusion is characterized by mandibular protrusion, maxillary retrusion or a combination of both. In addition to impairing the patient's facial aesthetics, this malocclusion can cause functional and respiratory changes. One of the treatment alternatives for these cases is the use of the Petit mask and the Hyrax breaker device. This study aims to evaluate, through orthodontic cephalometry, whether the treatment with maxillary expansion in conjunction with the reverse traction of the maxilla reduces the aesthetic and functional problems of Class III patients. Case report: the case report described in the present work is about a patient who underwent this treatment, being described through cephalometric analysis, radiographic examinations, intraoral photos and clinical findings. Final considerations: The verification of the results obtained after the end of the treatment showed that the patient had a good adherence to the use of these devices and obtained satisfactory results in her masticatory function, in her occlusion and in her facial and dental aesthetics.(AU)

Hyrax versus Leaf expander in growing patients, what about adverse dental effects? A retrospective study.

OBJECTIVES: Transverse discrepancy is a Common problem in young patients. Many devices are employed to expand the palatal dimension, with different characteristics and biomechanical aspects. The Leaf expander, a new-born appliance containing nickel-titanium springs, free from activation by parents. We compared the maxillary and mandibular dental effects of Leaf expander to conventional Hyrax in growing patients. METHODS: All patients who met the eligibility criteria between the period from January 2017 to December 2019 were included. The patients had transverse inter-arch discrepancy of at least 5mm and were treated with Hyrax expander (HEX) or Leaf expander (LEX). All patients had complete follow-up of expansion by remote monitoring. An algorithm established distances between the teeth. It was also used to measure the change in dental axes. RESULTS: In the maxilla, LEX caused more tipping on the canines and premolars but significantly less on the molars compared to HEX: -0.154̊ vs. 3.05̊ (P<0.001). In the mandible, LEX caused a greater increase in arch widths and tipping (P<0.02) in the molars and second premolars, but not in the other teeth. No correlation was demonstrated between mandibular dental movements and increased maxillary arch widths. Alternatively, for the two devices, expansion and tipping were correlated within each dental arch (r>0.4). CONCLUSIONS: The LEX produced more tooth movement on average than the HEX, except for the maxillary first molars. Several correlations exist between the movements within each arch for the two devices, most often between tipping and expansion.

Influence of the hyrax expander screw position on displacement and stress distribution in teeth: A study with finite elements.

INTRODUCTION: This study aimed to simulate the different positions of the hyrax appliance expander screw and evaluate tooth displacement and the stress distribution standard on the periodontal ligament using the finite element method. METHODS: Part of the maxilla with anchorage teeth, periodontal ligament, midpalatal suture, and the hyrax appliance was modeled, and finite element method models were created to simulate 6 different screw positions. There were 2 vertical positions at distances of 20 mm and 15 mm from the occlusal plane. Another position was anteroposterior, the center of the screw placed between and equidistant from the mesial face of the first molar and the distal face of the first premolar, aligned to the center of the crown of the first molar, with the anterior edge of the screw aligned to the distal face of the first molar. A 1 mm activation of the expander screw was simulated. The displacement (total, vertical, and buccolingual) and the stress distribution on the periodontal ligament of supporting teeth in each model were registered. RESULTS: The model simulating the expander screw in a more occlusal and anterior position presented higher displacement values and higher stress concentration, followed by the model with the screw in a more posterior but same vertical position. With the exception of the first premolar, the teeth presented cervical-apical displacement in the vestibular face and apical-cervical displacement in palatal faces. This displacement is compatible with the vestibular inclination associated with the activation of the expander screw. The first premolar presented an atypical tendency for the mesial and lingual displacement of the vestibular surface and counterclockwise rotation. CONCLUSIONS: The supporting teeth presented a tendency for vestibular crown displacement and lingual root displacement associated with compression areas in the vestibular-cervical region and tensile strength in the linguoapical region. Placing the expander screw in a more occlusal and anterior position generated more mechanical stress transfer, resulting in greater dental displacement.

A pilot study of mandibular expansion in combination with a fixed-appliance for increasing the effective space of the mandibular arch: Finite element analysis and three-dimensional cone-beam computed tomography.

ABSTRACT: Techniques for enhancing the effective space of the mandibular arch are urgently needed. Therefore, this study aimed to perform mandibular expansion in combination with a fixed-appliance technique, with preliminary monitoring by finite element analysis and 3-dimensional cone-beam computed tomography (CBCT).Finite element models were structured according to CBCT images of a 14-year-old girl. The von Mises stress of the alveolar bone and tooth displacement were assessed in different models. The technique was also applied in an 11-year-old boy. CBCT was performed at post-expansion, post-retention, post-treatment and 2 years after treatment. Tooth movement and alveolar bone stress were assessed by the CAD software.Finite element analysis suggested that the teeth tended to stand upright in the buccal side in the expander model compared with the expander-remove model. However, minimum tooth change was observed in the normal model, indicating highest stability. The von Mises stress of the alveolar bone was decreased in the normal model compared with the expander model, suggesting that buccal-inclined teeth could more easily lead to alveolar bone stress than normal ones. Based on CBCT data and the 3D mandibular dentition model fitting, mandibular teeth tended to be upright in the buccal side after retention compared with the post-expansion condition, which somewhat differed from finite element analysis results. Furthermore, dehiscence and fenestration were not observed.This expansion technique is expected to increase the effective space after mandibular expansion and reduce buccal alveolar bone stress.

Does Mini Screw Assisted Rapid Palatal Expansion (MARPE) have an influence on airway and breathing in middle-aged children and adolescents? A systematic review.

OBJECTIVE: This systematic review assessed the effects of tooth-borne (TB), tooth-bone-borne (TBB) and bone-borne (BB) micro-implant assisted rapid maxillary expansion (RPE) on airway dimensions and function in young children and adolescents (10- to 17-years-old). MATERIALS AND METHODS: Unrestricted search in 5 electronic databases until June 6th, 2020 was undertaken. This was supplemented with search in 6 additional resources for published, unpublished and ongoing trials up. Randomized (RCT) and non-randomized (Non-RCT) prospective studies that assessed the influence of the mini-screw-assisted rapid palatal expansion (MARPE) approach on airway and breathing in young children and adolescents were included. Two reviewers performed the study selection and data extraction blindly and in duplicate by two authors while disagreements. A random-effects model with a 95% confidence interval (CI), I2 and Chi2 tests were done. ROBINS-I, Cochrane Risk of Bias and GRADE tools were used. Reporting of this review was based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. RESULTS: Overall, 518 articles were retrieved; only 3 studies (2 RCT and one non-RCT) met the inclusion criteria. Both TB RPE and BB RPE improved on a short-term basis the dimensions of the airway, though the difference was not significant (P>0.05). TBB RPE significantly improved nasal airflow [(Mean difference (MD) 52.7 cm3/s, 95% confidence interval (95% CI) 9.0-96.4), P=0.020)], reduced nasal resistance (MD -0.20Pa/cm3, 95% (-0.38)-(-0.02), P=0.028), and changed respiratory muscle strength variables (P>0.05). No correlation was found between the anatomical dimensions of the airway and the functional airway parameters (P>0.05). CONCLUSIONS: The short-term airway volumetric changes secondary to MARPE were not significant. The influence of MARPE appliances on breathing is still not clear. Registration PROSPERO database (CRD42020183340).

Orthopedic outcomes of hybrid and conventional Hyrax expanders.

OBJECTIVES: To compare the effects of a hybrid miniscrew-supported expander versus a conventional Hyrax (CH) expander in growing patients. MATERIALS AND METHODS: Forty patients were randomized into two groups: a hybrid Hyrax (HH) expander group using a Hyrax expander with two miniscrews and a CH expander group. The final sample had 18 subjects (8 female, 10 male; initial age of 10.8 years) in the HH group and 14 subjects (6 female, 8 male; initial age of 11.4 years) in the CH group. Cone-beam computed tomography examinations and digital dental models were obtained before expansion and 11 months postexpansion. The primary outcomes included the orthopedic transverse effects of expansion. Intergroup comparison was performed using analysis of covariance (P < .05). RESULTS: Significantly greater increases in the nasal cavity width, maxillary width, and buccal alveolar crest width were found for the HH group. No intergroup differences were observed for dental arch width or shape changes. CONCLUSIONS: The HH group showed greater increases in the nasal cavity width, maxillary width, and buccal alveolar crest width. No differences were observed for intermolar, interpremolar, or intercanine widths; arch length; or arch perimeter. Arch size and shape showed similar changes in both groups.

Radiological evaluation of the bone and soft tissue thicknesses of the palate for using a miniscrew-supported maxillary skeletal expander.

PURPOSE: The purpose of this study was to determine the palatal bone and soft tissue thicknesses using a miniscrew-supported maxillary skeletal expander (MSE) in Class III malocclusion. METHODS: The thicknesses of the palatal bone and soft tissue were measured in cone-beam computed tomography images obtained from 58 patients. All 20 points were crossing points between five levels, which were defined at 3 mm intervals relative to the line connecting the central fossae of the first molar (Level 0), and 2 mm and 4 mm lateral to the anteroposterior reference line (AP line). RESULTS: The palatal bone was significantly thicker in males than females in the anterior palate up to Level 0, while there was no significant sex-related difference in the posterior palate. There was a tendency for the thickness to decrease in the posterior direction, except in females at 2 mm lateral to the AP line. The palatal soft tissue was significantly thicker in males than females in all positions. At 2 mm lateral to the AP line, the palatal soft tissue thickness decreased in the posterior direction. A 4 mm lateral to the AP line, it initially decreased in the posterior direction, and then increasing again at Level - 6 (6 mm posterior of Level 0). As the lateral distance from the AP line increased, the palatal bone thickness decreased while the palatal soft tissue thickness increased. CONCLUSIONS: These findings provide quantitative data on the palatal bone and soft tissue thicknesses for the miniscrew-supported MSE in the posterior palate.

Impact of Wearing Palatal Expanders on the Quality of Life of Children Aged 8 to 10 Years

ABSTRACT Objective: To assess the impact of wearing palatal expanders on the oral health-related quality of life (OHRQoL) of children aged 8 to 10 years. Material and Methods: The sample consisted of 35 children aged 8 to 10 years treated at the orthodontics and pediatric dentistry outpatient clinics affiliated with the Dental School. Children were divided in two groups: 17 were submitted to palatal expansion treatment (Group 1), while 18 just received coronal polishing and topical fluoride application (Group 2). The Brazilian version of the Child Perceptions Questionnaire (CPQ8-10) was used to assess children's OHRQoL. The questionnaire was administered before the expander was placed, at the end of its activation, and before its removal. Intervals between the interviews were similar in the two groups. Descriptive statistics and ANOVA were used for data analyses. Results: The overall CPQ8-10 score was not significantly different between the groups. The results show statistically significant differences between the two groups only for the functional limitations domain after activation of the appliance (p=0.001). Conclusion: Palatal expanders may negatively affect children's functions only during the initial wearing period.

Dentoalveolar Effects Following Maxillary Expansion: Comparison Between Dental and Skeletal Anchorage

ABSTRACT Objective: To compare the dento-alveolar effects between dental and skeletal anchored expansion devices to achieve maxillary expansion in different groups of patients: pure dental anchorage was used in growing patients and skeletal anchorage in adult patients. Linear, angular and volumetric parameters have been analysed. Material and Methods: 22 patients has been selected from the total archive of patients treated in the Orthodontics Department of the University of Ferrara, Italy, divided into 3 groups according to the appliance used to obtain the transversal maxillary correction. Digital files of the upper arch were obtained from scans performed using an intro-oral scanner before treatment (T0) and at the end of expansion (T1). Therefore, linear, angular and volumetric measurements have been performed. Results: There is a highly significant statistic variation of the 3-3, 4-4 and 6-6 diameter as a function of time. There was a statistically significant variation of the palatal vault angle and of the 6-6 distance at the cusp level as a function of time. Moreover, it appears that these parameters are reduced in the group with skeletal anchored expander. No tooth considered have encountered a statistically significant change in tip and torque values, no matter the type of RPE and the treatment time. For all patients, we have recorded the superimposition of the maxillary dental cast before and after treatment. Conclusion: In all patients, we obtained a resolution of the maxillary transverse deficit. Patients treated by pure skeletal anchored devices have recorded a less variations of palatal vault angle and the distance between first molar cusps, as if the expansion was gained more parallel. The expansion obtained showed reduced dental side effects, as tip and torque values haven't changed in a statistically significant way.

Spontaneous Transversal Changes of Lower Arch Following Palatal Skeletal Expansion

ABSTRACT Objective: To evaluate how the lower arch spontaneously change after upper rapid palatal expansion in a group of patients with transversal skeletal deficit. Material and Methods: Twenty-four patients treated by the same orthodontist with a rapid palatal expander (RPE) bounded on a deciduous molar have been selected. The sample was divided into two groups: no treatment was provided for group one, while group two was treated using a lip bumper or Schwarz appliance. For each patient, dental casts were collected when the RPE was bounded (T0) and at the end of treatment, 9 months ± 3 months later (T1). Each outcome was analyzed, providing descriptive statistics, main effects significance tests and post-hoc analyses with the objective to evaluate the variations between pre-treatment (TO) and post-treatment (T1) of each of them. Results: If the linear measurements are considered, a significant beneficial effect on both arches is observed. However, the upper arch always shows a major increase of all values at T1 with respect to the lower arch. Even though the post-hoc tables indicate that time differences are all statistically significant across considered partitions, the lower arch's increase is more pronounced in group two, where patients were treated in both arches. If the angular measurements are concerned, the increase of lingual crown inclination was found in all patients, independently from the type of treatment in lower arch. Conclusion: All patients show normalization of upper diameters, regardless of whether the lower arch was treated or not.

A randomized clinical trial to assess the sagittal effects of Transforce transverse appliance (TTA) and NiTi palatal expander (NPE) on skeletal class II malocclusion in growing patients during retention phase - A cephalometric study using a historical control group.

OBJECTIVES: To evaluate and compare the skeletal changes during the retention period after expansion with "Transforce Transverse lingual or palatal Appliance®" (TTA) and "NiTi Palatal Expander®" (NPE) in growing subjects with class II division 1 malocclusion and to compare these changes with a matched historical control. SUBJECTS AND METHODS: A unicentric two arm, parallel randomized clinical trial with additional historical control group was conducted over a period of six years. The subjects in the age group of 9-13 years were screened and recruited as they reported. The inclusion criteria were: late mixed/early permanent dentition, class II or end on molar relationship, posterior transverse inter-arch discrepancy 4-8mm, overjet≥5mm, cephalometrically ANB>4° and CVMI stage CS2-CS3. Subjects were randomly allocated to two study groups (SG), TTA and NPE using block randomization. Appliances in both SG were managed and followed by a single clinician with equal standards of care. The lateral cephalograms in digital form were obtained at the beginning of the treatment (T1), post-expansion (T2) and after ten months retention period (T3). Linear positional change>1mm and angular change>0.75° were considered as a clinically significant change. Due to the ethical reasons a historical control of ten patients (CG) comparable to the SG for age and inclusion criteria was used to rule out the growth changes on serial lateral cephalograms. All Cephalometric measurements were done by a single operator blinded for the group allocation. Operator's measurement error was estimated. The study was single-blinded in regard to statistical analysis. Inter-group comparisons between SG were made by using an unpaired Student's t-test. ANOVA with post-hoc analysis was used for comparison among the study and control groups. RESULTS: A total of 36 subjects were recruited, 18 in each SG. Average time required to achieve the desired expansion in the TTA and NPE group was 13.6 weeks and 9.8 weeks respectively. The TTA group showed significant increase in SNB (1.54±0.33°) when compared with the control group (0.53±0.37°) and with the NPE group (0.74±0.29°) (P<0.0001). Significant differences were observed when post-retention changes in SNB, ANB, Wits appraisal, and N perpendicular to Pogonion, were compared among the three groups (ANOVA, P<0.0001). Tukey's multiple comparison showed that these mandibular sagittal changes were significantly greater in the TTA group than in NPE and the control group (P=<0.007, Bonferroni corrected value). CONCLUSION: Cephalometrically significant sagittal advancement of mandible took place after expansion with TTA and NPE compared to untreated control. TTA appears to be more efficient for the sagittal positional changes than the NPE. Additional studies with larger samples are warranted to elucidate individual variations in skeletal response to the expansion protocol with these appliances.

Early class III treatment with hybrid rapid palatal expander combined with facemask.

BACKGROUND: Class III patients are characterized by a deficiency of the maxilla and/or a prognathism of the mandible and require early treatment. DIAGNOSIS: This case report describes the treatment of a 5-year-old patient with a skeletal class III relationship, a significant mandibular symphysis deviation towards the right side and a different height of the mandibular angles. MANAGEMENT AND OUTCOME: The patient was treated with rapid maxillary expander combined with miniscrew, facemask and aligners. A functional and aesthetic occlusion in an improved facial profile was established at the end of the orthodontic treatment. Pre-treatment, post-treatment and one year retention records for the patient are presented. DISCUSSION: Class III patients require early treatment in order to optimize the traditional expander effects; subsequently hybrid anchorage allowed to maximize skeletal advancement. In addition, loss of space for the erupting teeth and dento-alveolar tipping were avoided. The good results of the phase I treatment and of the active retainer meant that a complex case would become relatively simple at the phase II treatment.

Long term skeletal and dental changes between tooth-anchored versus Dresden bone-anchored rapid maxillary expansion using CBCT images in adolescents: Randomized clinical trial.

OBJECTIVE: The aim of this study was to determine long-term skeletal and dental changes in tooth-anchored versus Dresden bone-anchored rapid maxillary expansion using CBCT images in adolescents. MATERIALS AND METHODS: In all, 29 adolescent patients (11-17 years of age) needing skeletal expansion were randomly allocated to two different groups treated by either a Dresden bone-anchored expander or a conventional hyrax expander. Patients included did not have previous orthodontic treatment, were non-syndromic and had all teeth present in mouth. CBCT images were taken before expansion and two or more years after expansion. An independent T-test was used to determine the statistical significance between treatment groups and paired T-test was used to compare the results before and after expansion in each group. RESULTS: Neither treatment group showed overall long-term different skeletal and dental changes in the transverse, anterior-posterior and vertical planes (P<0.05). Both treatment groups showed mild asymmetric skeletal expansion, but these were clinically insignificant. CONCLUSIONS: Both expanders had similar skeletal and dental results. The greatest changes were in the transverse plane. Changes in vertical and anterior-posterior were negligible.

Riesgos asociados al uso de Expansión Rápida del Maxilar / Risks associated with the use of Maxillary Rapid Expansion

INTRODUCCIÓN: Las anomalías dentomaxilares corresponden a un grupo de alteraciones que dificultan el desarrollo armónico de los maxilares, donde encontramos las anomalías transversales. La expansión rápida del maxilar (ERM) se utiliza como tratamiento de anomalías transversales, su objetivo es aumentar la distancia transversal por la separación de ambas hemiarcadas a nivel de la sutura palatina, utilizando un aparato expansor fijo y rígido. Los disyuntores más utilizados son los expansores Hass, Hyrax y de McNamara. OBJETIVO: El objetivo de la presente revisión es identificar los riesgos de la RME reportados en la literatura relacionados con disyuntores Hass, Hyrax y Mc Namara. METODOLOGÍA: Se realizó una búsqueda en PubMed, Scielo, Science Direct, Trip Database y Google Acadèmico utilizando los tèrminos: "Rapid Maxillary Expansion", "Risks", "Child", "Maxillary Expansion", "RME", "Palatal Expansion", "Hyrax", "Hass". Se incluyeron estudios en inglès y español, sin límites en el año de publicación o tipo de estudio. Como criterios de exclusión consideramos la expansión quirúrgica, expansión lenta u otro tratamiento simultáneo durante la fase de expansión activa. RESULTADOS: De los artículos encontrados, veinte cumplieron los criterios de inclusión. Dentro de los riesgos se encuentran: deglución accidental del dispositivo de activación del expansor, bacteremia transitoria, desviación del septum nasal, reabsorción radicular, compromiso periodontal, cambio posicional de los cóndilos, cambios faciales de tejido blando y cambios esqueletales. CONCLUSIÓN: La ERM es un procedimiento ortopèdico eficaz, sus indicaciones en el tratamiento precoz han aumentado debido a resultados positivos. De acuerdo con la bibliografía encontrada los beneficios superan considerablemente a los efectos negativos

INTRODUCTION: The dentomaxillary anomalies correspond to a group of alterations that hinder the harmonic development of the jaws, where we find the transversal anomalies. Rapid Maxillary Expansion (RME) is used as a treatment for transverse anomalies, its objective is to increase the transversal distance by separating both hemiarchies at the level of the palatal suture, using a fixed and rigid expander. The most used are the Hass, Hyrax and McNamara expanders. OBJECTIVE: The objective of this review is to identify the EMR risks reported in the literature related to Hass, Hyrax and Mc Namara expander. METHODOLOGY: A search was made in PubMed, Scielo, Science Direct, Trip Database and Google Scholar using the terms: "Rapid Maxillary Expansion", "Risks", "Child", "Maxillary Expansion", "RME", "Palatal Expansion", "Hyrax", "Hass". Studies in English and Spanish were included, without limits in the year of publication or type of study. As exclusion criteria, we consider surgical expansion, slow expansion or other simultaneous treatment during the active expansion phase. RESULTS: Of the articles found, twenty met the inclusion criteria. Among the risks are: accidental swallowing of the expander activation device, transient bacteremia, deviation of the nasal septum, root resorption, periodontal involvement, positional change of the condyles, soft tissue facial changes and skeletal changes. CONCLUSION: RME is an effective orthopedic procedure, its indications in early treatment have increased due to positive results. According to the bibliography found, the benefits considerably outweigh the negative effects

Transverse, vertical, and anterior-posterior changes between tooth-anchored versus Dresden bone-anchored rapid maxillary expansion 6 months post-expansion: A CBCT randomized controlled clinical trial.

OBJECTIVE: The main aim of this randomized clinical trial was to determine 3 dimensional skeletal and dental changes six months after the use of bone-anchored versus tooth-anchored rapid maxillary expanders in adolescents. The secondary aim was to determine the symmetrical or asymmetrical expansion pattern between both appliances. MATERIALS AND METHODS: Fifty adolescents with skeletally constricted maxilla (mean age 13-14 years) were randomly assigned into: Dresden B-RME, Hyrax T-RME, or untreated control groups. CBCT scans were taken at initial and expander removal (6 months). Three-dimensional references and treatment landmarks were identified. Orthogonal distances were calculated from those landmarks. The main outcome was to compare skeletal and dental changes in each group and the secondary outcome was to verify if these changes were symmetric or not. Data was analysed using descriptive statistics and repeated measure MANCOVA and MANOVA. RESULTS: Both treatment groups showed significant skeletal and dental expansion compared to controls. T-RME group had greater mean inter-molar crown expansion (5.66mm) than the B-RME group (4.17mm). Both T-RME and B-RME groups showed significant skeletal maxillary expansion compared to controls (mean 1.27mm and 1.31mm respectively, both p<0.01), although no significant difference was found between both appliances. B-RME group showed a lower ratio of dental to skeletal expansion than T-RME group. T-RME showed a symmetrical expansion pattern, whereas the B-RME showed an asymmetrical pattern relative to mid-sagittal plane. The extent of molar crown expansion was 1.84mm greater on the TAD-side compared to the Implant-side. T-RME group showed significant anterior movement of the maxillary first premolar and molar (1.5mm, p<0.05), and vertical dental extrusion (1.8mm). No significant dental vertical or anterior-posterior changes were noted in the B-RME group. CONCLUSIONS: T-RME and B-RME produced similar amounts of skeletal expansion. B-RME group produced a lower component of dental expansion. Due to the Dresden B-RME configuration, asymmetrical expansion was noted.

Effects of transverse maxillomandibular distraction osteogenesis on obstructive sleep apnea syndrome and on the pharynx.

PURPOSE: To assess the effects of transverse maxillomandibular distraction osteogenesis (TMDO) on the treatment of obstructive sleep apnea (OSA) and on the morphology of the pharynx. METHODS: A clinical trial was conducted with seven patients with OSA and with transverse maxillomandibular deficiency, two women and five men aged on average 41.16 ± 10.9 years on the day of surgery. All participants were submitted to computed tomography (CT) and full-night polysomnography (PSG) before and approximately 9 months after surgery. A 95% confidence interval was defined. RESULTS: The AHI and RDI of the participants were reduced by about 62% (from 27.65 ± 36.65 to 10.73 ± 11.78, p = 0.031 and from 41.21 ± 32.73 to 15.30 ± 13.87, p = 0.015, respectively). The airway showed a surprising mean reduction in volume of 10% (from 5.78 ± 2.53 to 4.71 ± 1.42, p = 0.437, for the upper pharynx; from 6.98 ± 2.23 to 6.23 ± 2.05, p = 0.437, for the lower pharynx; and from 12.76 ± 1.56 to 10.94 ± 2.42, p = 0.625, for the total pharynx). However, the site of the smallest area of the pharynx was considerably increased both in the anteroposterior and transverse direction and in its total area (from 0.88 ± 7.11 to 0.99 ± 0.39, p = 0.625; from 1.78 ± 0.81 to 2.05 ± 0.61, p = 0.812; and from 0.99 ± 0.74 to 1.40 ± 0.51, p = 0.180, respectively). CONCLUSION: TMDO proved to be efficient in reducing or curing OSA, producing modifications of upper pharynx morphology with an increase of the smallest area of the pharynx.

Efficiency evaluation of rapid maxillary expansion treatment on nasal septal deviation using tortuosity ratio from cone-beam computer tomography images.

BACKGROUND AND OBJECTIVE: This study aims to assess the effect of Rapid Maxillary Expansion (RME) on Nasal Septal Deviation (NSD) changes from three-dimensional (3D) images. METHODS: In this study, cone-beam computed tomography (CBCT) images from 15 patients with maxillary constriction (mean age 12 ± 1.6 years) were included. RME treatment with Hyrax appliance was performed in all patients. CBCT scans were taken at three different times; before appliance insertion (T0), after active expansion (T1) and 3 months after appliance insertion (T2). We developed a novel Matlab-based application to quantify NSD based on the tortuosity ratio by dividing the actual length of the septum by the ideal length in the mid-sagittal plane by using this application. RESULTS: Tortuosity ratio (TR) values were found as 1.03 ± 0.03 (T0), 1.02 ± 0.02 (T1), and 1.02 ± 0.02 (T2). Differences of TR values among these groups were evaluated using the statistical method of ANOVA (ANalysis Of VAriance) for repeated measures with the significance level of p ≤ .05. Results showed significant reductions in TR values between T0-T1 (p ≤ .05) and between T0-T2 (p ≤ .05). Nonetheless, a significant difference between T1-T2 was not determined (p > .05). CONCLUSIONS: As a result, we can conclude that the NSD degree is affected by the RME treatment. The developed application can be used for both educational and research purposes.

Modified bonded acrylic expander in patient with anterior crossbite and pseudo-class III.

The open-bite treatment can be considered one of the most difficult malocclusions to treat in children as well as in adult patients. Several papers show that the traditional maxillary expander device contribute to increase the vertical face dimension and bite opening due to posterior rotation of the mandible, buccal tipping of lateral segments and cuspal interferences. Other more specific studies compared the effects of traditional maxillary expander to those of bonded acrylic expander and evidenced that the acrylic expander can better control the vertical effects of the maxillary expansion by the resin bite plane on which the heavy occlusal forces are exerted. We decided to use an acrylic expander in order to prevent worsening of anterior openbite after a careful assessment of nasal airflow by the otorhinolaryngologist.

Transverse and torque dental changes after passive self-ligating fixed therapy: A two-year follow-up study.

INTRODUCTION: Self-ligating appliances are purposed to expand the arches, but evidence on stability of the result is lacking. We measured the width of maxillary and mandibular arches and torque changes after treatment with the use of passive self-ligating appliances and assessed stability at the 2-year follow-up. METHODS: Maxillary and mandibular 3-dimensional (3D) models from 32 subjects (mean initial age 14.9 ± 0.9 years), consecutively treated with the use of self-ligating appliances, were obtained before, immediately after, and 2 years after treatment. Dental arches were examined with the use of 3D software to evaluate differences in transverse arch dimensions and torque values. RESULTS: An incremental increase of arch widths was recorded, especially regarding maxillary and mandibular premolars. The increase in the transverse diameters was associated with a significant positive torque gain. No significant changes in arch perimeter and depth were recorded. In the retention period, slight significant changes in transverse diameters were recorded, and a transverse diameter constriction detected. Torque values remained almost unchanged in the follow-up period. CONCLUSIONS: Transverse arch dimensions, along with torque values, increased significantly after treatment with the use of a passive self-ligating appliance. In the 2 years following treatment, a tendency to transverse diameter restriction, especially for the maxillary and mandibular premolars, was observed.