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Orthodontic tooth movement (OTM) represents a dynamic process in which the alveolar bone undergoes resorption at compression sites and deposition at tension sites, orchestrated by osteoclasts and osteoblasts, respectively. This mechanism serves as a valuable model for studying various aspects of bone adaptation, including root resorption and the cellular response to mechanical force stimuli. The protocol outlined here offers a straightforward approach to investigate OTM, establishing 0.35 N as the optimal force in a mouse model employing a nickel-titanium (NiTi) coil spring. Utilizing micro-computed tomography analysis, we quantified OTM by assessing the discrepancy in the linear distance at the cement-enamel junction. The evaluation also included an analysis of orthodontic-induced inflammatory root resorption, assessing parameters such as root mineral density and the percentage of root volume per total volume. This comprehensive protocol contributes to advancing our understanding of bone remodeling processes and enhancing the ability to develop effective orthodontic treatment strategies.
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Técnicas de Movimiento Dental , Microtomografía por Rayos X , Animales , Ratones , Técnicas de Movimiento Dental/métodos , Microtomografía por Rayos X/métodos , Níquel/química , Titanio/químicaRESUMEN
OBJECTIVE: To analyze and compare the effects of a traditional laboratory-fabricated Hyrax expander (T-Hyrax) and two different 3D-printed Hyrax expander models relative to tension points, force distribution, and areas of concentration in the craniofacial complex during maxillary expansion using finite element analysis. MATERIALS AND METHODS: Three maxillary expanders with similar designs, but various alloys were modeled: a T-Hyrax, a fully printed Hyrax (F-Hyrax), and a hybrid printed Hyrax (H-Hyrax). The stress distributions and magnitude of displacements were assessed with a 5 mm expansion in a symmetrical finite element model. The areas of interest included the teeth, alveolar processes, midpalatal suture, nasal complex, circummaxillary sutures (CS), and the expanders themselves. RESULTS: The highest stress value (29.2 MPa) was found at the midpalatal suture of the F-Hyrax, while the lowest stress (0.90 MPa) was found at the temporozygomatic suture in the T-Hyrax. On average, the F-Hyrax increased stress at the CS by 24.76% compared with the T-Hyrax and H-Hyrax. The largest displacements were found at the upper incisor (U1) and anterior nasal spine (ANS). The findings indicated an average increase of 12.80% displacement at the CS using the F-Hyrax compared to the T-Hyrax. CONCLUSION: The F-Hyrax exerts more stress and displacement on the maxilla than both the T-Hyrax and H-Hyrax, where the weak link appears to be the solder joint.
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Damanes , Maxilar , Humanos , Animales , Análisis de Elementos Finitos , Incisivo , Impresión TridimensionalRESUMEN
OBJECTIVES: The objectives of this article were the following: (1) to analyze bone thickness and height (BTH) of the buccal shelf area (BS) quantitatively in four different potentially eligible sites for miniscrew insertion; (2) to compare and contrast BTH and the changes in spatial position of the inferior alveolar nerve canal (IANC); and (3) to assess differences with age among vertical facial patterns (hypodivergent, normodivergent, and hyperdivergent) and well as by sex. MATERIALS AND METHODS: Cone-beam computed tomography scans of 205 individuals (110 women and 95 men) were divided into groups according to age, vertical facial pattern, and sex. The BTH of the BS and the BTH to the IANC were measured in the mesial and distal roots of the first and second molars. RESULTS: BTH progressively increased in a posterior direction (P < .001), while BTH to the IANC increased and decreased (P < .001) for thickness and height, respectively, in the same direction in all age groups, for the three different vertical facial patterns, and in both sexes. Women showed significantly less BTH to the IANC (P < .002). Hypodivergent patients had greater BTH (P < .024) and a smaller bone height to the IANC (P < .018) only in the first molar region. Patients over 40 years of age had lower bone height in the second molar area (P < .003). CONCLUSIONS: The ideal place for BS miniscrew insertion is the region of the distal root of the second molars, regardless of facial pattern, sex, and age. The BS in women has less BTH and less BTH to the IANC.
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INTRODUCTION: The Sayers and Newton questionnaire was developed in England to assess the child's and parent's expectations about orthodontic treatment. OBJECTIVE: The aim of this study was to carry out the cross-cultural adaptation of the questionnaire for the Brazilian Portuguese language, to test its reliability, and to compare patients' and their parents' expectations of orthodontic treatment. METHODS: After translation and cross-cultural adaptation, the questionnaire was applied to 98 patients (12-14 years), who had been referred for treatment, and their caregivers. The internal consistency of the instrument was assessed by Cronbach's Alpha Coefficient and the test-retest reliability, by Intraclass Correlation Coefficient (ICC). RESULTS: Internal reliability was confirmed by a Cronbach's alpha coefficient of 0.75. Test-retest reliability revealed satisfactory reproducibility (ICC = 0.85). The results showed some significant differences between the expectations of the patients and their caregivers (p < 0.05). There were no significant gender differences (p > 0.05). CONCLUSIONS: The process of cross-cultural adaptation of the Sayers and Newton questionnaire for the Brazilian Portuguese was concluded. This study demonstrated that this instrument is reliable and applicable to assess the child's and parent's expectations about orthodontic treatment in Brazil, and it has acceptable psychometric properties.
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Comparación Transcultural , Motivación , Brasil , Niño , Humanos , Padres , Psicometría/métodos , Reproducibilidad de los Resultados , Encuestas y Cuestionarios , TraduccionesRESUMEN
INTRODUCTION: The present study aimed to evaluate the consequences of rapid maxillary expansion in the buccal bone thickness and dehiscence of subjects with unilateral cleft lip and palate. METHODS: This prospective cohort study consisted of 30 participants, 20 males and 10 females, between 8 and 15 years old. Participants were allocated into 3 groups, according to the type of maxillary constriction, and were treated with different types of expanders: G1, hyrax; G2, fan-type; G3, inverted mini-hyrax. Cone-beam computed tomography scans were performed immediately before treatment and after 90 days of retention. Linear measurements were obtained by the same calibrated and blinded examiner. RESULTS: An average of 0.8 mm decrease in buccal bone thickness (P <0.001) and a 0.5 mm increase in dehiscence (P <0.001) were observed. There was no significant difference between the cleft and noncleft side for all variables (P >0.05), as there was no significant difference between groups (P >0.05). CONCLUSION: The findings in this study allow the conclusion that the orthopedic forces of rapid maxillary expansion lead to a decrease in the posterior buccal bone volume in unilateral cleft lip and palate patients.
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Labio Leporino , Fisura del Paladar , Adolescente , Niño , Labio Leporino/diagnóstico por imagen , Labio Leporino/terapia , Fisura del Paladar/diagnóstico por imagen , Fisura del Paladar/terapia , Tomografía Computarizada de Haz Cónico/métodos , Femenino , Humanos , Masculino , Maxilar/diagnóstico por imagen , Técnica de Expansión Palatina , Estudios ProspectivosRESUMEN
INTRODUCTION: Due to the anatomical constraints of the mandible, mandibular dental arch usually serves as a guideline to determine the required changes in the maxillary transverse dimension. The Schwarz appliance and the Lip Bumper are the traditional orthodontic appliances for mandibular arch expansion in patients with borderline amounts of crowding, and/or transverse discrepancy. However, they often require patient cooperation, which may be a concern for orthodontists in daily practice. OBJECTIVES: This article illustrates a simple fixed orthodontic device as an alternative to achieve mandibular arch expansion in patients with moderate tooth-size/arch-length discrepancy. The four reported cases refer to 8 to 10-year-old patients in the mixed dentition, with an Angle Class I or Class II malocclusion, transverse deficiency in both arches, moderate crowding and/or posterior crossbite, combined with compromised smile aesthetics. The patients were treated with rapid maxillary expansion (RME) using Hass expander appliance and the modified Arnold expander (MAE). CONCLUSION: This low-cost compliance-free orthodontic appliance provided dentoalveolar decompensation by means of uprighting the posterior teeth, with minimal or no adjustments during treatment. The final results were achieved in only three to four months, and fulfilled all treatment objectives, such as an increase in the arch perimeter and width, and a better teeth alignment.
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Arco Dental , Maloclusión , Dentición Mixta , Estética Dental , Humanos , Maloclusión/terapia , Técnica de Expansión PalatinaRESUMEN
OBJECTIVES: To determine the three-dimensional changes of the nasal septum (NS), alveolar width, alveolar cleft volume, and maxillary basal bone following rapid maxillary expansion (RME) in consecutive patients with unilateral cleft lip and palate (UCLP). MATERIALS AND METHODS: A retrospective investigation was conducted based on the analysis of cone-beam computed tomography (CBCT) data of 40 consecutive patients with UCLP (mean age 11.1 ± 2.2 years). Scans were acquired prior to RME (T0) and after removal of the expander (T1) before graft surgery. A three-dimensional analysis of the effects of RME on the nasal septum, alveolar width, alveolar cleft volume, and maxillary basal bone was performed. RESULTS: No changes in the NS deviation were observed following RME (P > .05). Significant increases of the alveolar transverse dimension were found in the anterior (14.2%; P < .001) and posterior (7.7%; P < .001) regions as well as in the volume of the alveolar cleft (19.6%; P < .001). No changes in the basal bone dimensions and morphology were observed (P > .05). CONCLUSIONS: Following RME, no changes were observed in the NS and maxillary basal bones of patients with UCLP despite the significant gain in the anterior and posterior alveolar width and the increase of the alveolar cleft defect. Clinicians should be aware that maxillary changes following RME in patients with UCLP are restricted to the dentoalveolar region.
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Labio Leporino , Fisura del Paladar , Adolescente , Niño , Labio Leporino/diagnóstico por imagen , Fisura del Paladar/diagnóstico por imagen , Fisura del Paladar/cirugía , Tomografía Computarizada de Haz Cónico , Humanos , Maxilar/diagnóstico por imagen , Tabique Nasal/diagnóstico por imagen , Técnica de Expansión Palatina , Estudios RetrospectivosRESUMEN
The treatment of incisor protrusion by means of tooth extraction can be challenging for orthodontists, especially during the space closure phase. Moreover, the level of difficulty may increase when anterior movement of the posterior teeth is not desirable. Treatment alternatives may include the use of mini implants, mini plates, and extraoral devices to reinforce anchorage; however, some patients may oppose these aggressive methods. This article describes the use of frictionless segmented mechanics that provide differential moments for controlled space closure during full retraction of the incisors without using extraoral forces or temporary anchorage devices.
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Implantes Dentales , Métodos de Anclaje en Ortodoncia , Cefalometría , Humanos , Incisivo , Cierre del Espacio Ortodóncico , Técnicas de Movimiento DentalRESUMEN
OBJECTIVE: The authors' objective was to determine, by means of cone-beam computed tomography (CBCT), if there is a significant difference between the cephalometric and condylar measurements obtained in maximum intercuspation (MIP) and those obtained in centric relation (CR), which would interfere in orthodontic diagnosis and planning. METHODS: The sample consisted of 30 randomly selected patients (15 men and 15 women, mean age 14 years, CR ≠ MIP between 1 mm and 2 mm) who had undergone orthodontic treatment. This retrospective study used CBCT scans, one in MIP and the other in CR. Cephalometric measurements and sagittal, axial, and vertical condylar variations between the CR and MIP positions were analyzed in a tridimensional (3D) imaging software. RESULTS: Patients with a small CR-MIP discrepancy (<2 mm) presented significant differences in the cephalometric analysis carried out in CR and MIP, although these differences might be of low clinical significance. The condyle-fossa relationships in sagittal, coronal, and axial planes did not seem to be relevant, because only one measurement presented significant change between CR and MIP positions. CONCLUSIONS: Class II malocclusion in patients with a large CR-MIP discrepancy may be exacerbated in the CR position, which may in turn increase treatment difficulty. In these cases, not only must cephalometrics be registered in CR, but dental casts and photographs of the patient are needed to permit orthodontists to plan an appropriate treatment.
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Oclusión Dental Céntrica , Maloclusión , Adolescente , Relación Céntrica , Tomografía Computarizada de Haz Cónico , Femenino , Humanos , Masculino , Cóndilo Mandibular , Estudios RetrospectivosRESUMEN
OBJECTIVE: This study aimed to identify possible risk factors for external apical root resorption (EARR) in the maxillary incisors after orthodontic treatment. METHODS: The root length of 2,173 maxillary incisors was measured on periapical radiographs of 564 patients who received orthodontic treatment. The Kappa test was performed to evaluate intraexaminer and interexaminer reproducibility. Multiple binary logistic regression was used to determine the association between EARR and various factors. Odds ratios and 95% confidence intervals were reported. RESULTS: The risk of developing EARR was 70% higher in orthodontic treatment with maxillary premolar extraction (p = 0.004), 58% higher in patients with increased overjet (p = 0.012), 41% lower in two-phase orthodontic treatment (p = 0.037), and 33% lower in patients with deep bite (p = 0.039). The lateral incisors were 54% more likely to develop EARR (p < 0.001), dilacerated roots were 2.26 times more likely to develop EARR (p < 0.001), and for each additional millimeter of root length, the risk of EARR increased by 29% (p < 0.001). CONCLUSIONS: The potential risk factors for EARR after orthodontic treatment included treatment with maxillary premolar extraction, increased overjet at the beginning of treatment, and dilacerated roots.
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The unerupted and impacted tooth is a common problem and the reason for many orthodontic and pediatric dental referrals, yet the approach to their management is still an area of controversy. This article presents two cases of severely impacted teeth that spontaneously erupted in the maxillary and mandibular arches. The first patient, a 9-year-old girl, presented a severe impaction of mandibular right and left second premolars. The second patient, a 7-year-old girl, presented with a severely impacted maxillary central incisor. In both cases, the teeth spontaneously erupted into excellent positions without surgical procedures and orthodontic traction. This raises important questions concerning the possible treatment options for such teeth as well as the timing of any interceptive treatment. In cases of unerupted or impacted teeth, a multidisciplinary approach is indicated involving orthodontics, paedodontics and oral surgery to establish the optimal treatment plan. Key words:Tooth eruption, tooth, impacted, orthodontics, interceptive, case reports.
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A high-fat (HF) diet leads to detrimental effects on alveolar bone (AB); however, the mechanisms linking adiposity to bone loss are poorly understood. This study investigated if AB resorption induced by an HF diet is associated with the regulation of inflammatory gene expression and if adipocytes can directly interfere with osteoclastogenesis. We also evaluated the effects of diet restriction (DR) on bone phenotype. C57BL6/J mice were fed normal chow or an HF diet for 12 weeks. Samples of maxillae, femur, blood and white adipose tissue were analyzed. In vitro co-culture of bone marrow-derived osteoclasts and mature adipocytes was carried out. The results revealed an increased number of osteoclasts and fewer osteoblasts in animals fed the HF diet, which led to the disruption of trabecular bone and horizontal AB loss. Similar effects were observed in the femur. The metabolic parameters and the deleterious effects of the HF diet on AB and the femur were reversed after DR. The HF diet modulated the expression of 30 inflammatory genes in AB such as Fam3c, InhBa, Tnfs11, Ackr2, Pxmp2 and Chil3, which are related to the inflammatory response and bone remodeling. In vitro, mature adipocytes produced increased levels of adipokines, and co-culture with osteoclasts resulted in augmented osteoclastogenesis. The results indicate that the mechanisms by which an HF diet affects bone involve induction of osteoclastogenesis and inflammatory gene expression. Adipokines apparently are key molecules in this process. Strategies to control diet-induced bone loss might be beneficial in patients with preexisting bone inflammatory conditions.
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Remodelación Ósea/efectos de los fármacos , Dieta Alta en Grasa/efectos adversos , Adipocitos/patología , Adipoquinas/metabolismo , Pérdida de Hueso Alveolar/etiología , Animales , Diferenciación Celular/efectos de los fármacos , Técnicas de Cocultivo , Fémur/efectos de los fármacos , Fémur/fisiopatología , Regulación de la Expresión Génica , Inflamación/etiología , Inflamación/genética , Masculino , Ratones Endogámicos C57BL , Osteoblastos/efectos de los fármacos , Osteoblastos/patología , Osteoclastos/patologíaRESUMEN
The consumption of different types of diets influences not only body health but the bone remodeling process as well. Nutritional components can directly affect maxillary and mandibular alveolar bone microarchitecture. In this review, we focus on the current knowledge regarding the influence of diets and dietary supplementation on alveolar bone. Accumulating evidence from experimental models suggests that carbohydrate- and fat-rich diets are detrimental for alveolar bone, whereas protective effects are associated with consumption of calcium, ω-3, and bioactive compounds. Little is known about the effects of protein-free and protein-rich diets, boron, vitamin C, vitamin E, zinc, and caffeine on alveolar bone remodeling. Adipokines and direct effects of nutritional components on bone cells are proposed mechanisms linking diet and bone. Results from animal models substantiate the role of nutritional components on alveolar bone. It is a well-built starting point for clinical studies on nutritional monitoring and intervention for patients with alveolar bone disorders, especially those who are treatment refractory.
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Densidad Ósea , Dieta , Maxilares/ultraestructura , Adipoquinas/sangre , Animales , Calcio de la Dieta/administración & dosificación , Carbohidratos de la Dieta/administración & dosificación , Grasas de la Dieta/administración & dosificación , Proteínas en la Dieta/administración & dosificación , Suplementos Dietéticos , Ácidos Grasos Omega-3/administración & dosificación , Humanos , Micronutrientes/administración & dosificación , Modelos Animales , Evaluación NutricionalRESUMEN
OBJECTIVES: The aim of this prospective cohort study was to determine the effects of rapid maxillary expansion (RME) on the first molar roots of cleft lip and palate subjects along different root development stages. MATERIALS AND METHODS: Thirty participants with unilateral cleft lip and palate were divided into three groups (n = 10), according to the type of expander used: Hyrax, iMini and Fan-type. A cone beam CT scan was performed before (T1) and 3 months after stabilization of the appliance (T2). Measurements of root lengths of the first permanent maxillary molars were taken to evaluate root development and external apical root resorption (EARR). RESULTS: Roots presenting open apexes before treatment exhibited a statistically significant increase in root length after treatment (P < .001). Conversely, there were no significant changes in the root length of roots that had closed apexes at the beginning of treatment (P > .05). Furthermore, there were no differences among groups, or correlation between cleft side and gender was found vis-à-vis to changes in the root length (p > .05). CONCLUSIONS: Orthopaedic forces of RME were neither able to interrupt the root development process nor to cause EARR in cleft subjects. CLINICAL RELEVANCE: As the RME is the most common orthodontic procedure in patients with cleft lip and palate, understanding its impact on dental structures is of fundamental importance.
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Labio Leporino/terapia , Fisura del Paladar/terapia , Diente Molar/diagnóstico por imagen , Técnica de Expansión Palatina , Raíz del Diente/anatomía & histología , Raíz del Diente/diagnóstico por imagen , Adolescente , Niño , Labio Leporino/diagnóstico por imagen , Fisura del Paladar/diagnóstico por imagen , Tomografía Computarizada de Haz Cónico , Femenino , Humanos , Masculino , Maxilar , Diente Molar/anatomía & histología , Diente Molar/crecimiento & desarrollo , Estudios Prospectivos , Interpretación de Imagen Radiográfica Asistida por Computador , Reproducibilidad de los Resultados , Raíz del Diente/crecimiento & desarrolloRESUMEN
Extraction spaces may be needed to achieve specific orthodontic goals of positioning the dentition in harmony with the craniofacial complex. However, the fundamental reality that determines the occlusion final position is the control exerted by the orthodontist while closing the extraction spaces. A specific treatment objective may require the posterior teeth to remain in a constant position anteroposteriorly as well as vertically, while the anterior teeth occupy the entire extraction site. Another treatment objective may require the opposite, or any number of intentional alternatives of extraction site closure. The present case report describes a simple controlled segmented mechanic system that permitted definable and predictable force systems to be applied and allowed to predict the treatment outcome with confidence. This case was presented to the Brazilian Board of Orthodontics and Dentofacial Orthopedics (BBO) in partial fulfillment of the requirements for Diplomate certification.
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Maloclusión Clase II de Angle/terapia , Cierre del Espacio Ortodóncico/métodos , Técnicas de Movimiento Dental , Adulto , Femenino , Humanos , Modelos Dentales , Radiografía Panorámica , Extracción DentalRESUMEN
OBJECTIVE:: The aim of this study was to evaluate the skeletal and dental effects of rapid maxillary expansion (RME) in cleft patients using two types of expanders. METHODS:: Twenty unilateral cleft lip and palate patients were randomly divided into two groups, according to the type of expander used: (I) modified Hyrax and (II) inverted Mini-Hyrax. A pretreatment cone-beam computed tomographic image (T0) was taken as part of the initial orthodontic records and three months after RME, for bone graft planning (T1). RESULTS:: In general, there was no significant difference among groups (p > 0.05). Both showed a significant transverse maxillary expansion (p < 0.05) and no significant forward and/or downward movement of the maxilla (p > 0.05). There was greater dental crown than apical expansion. Maxillary posterior expansion tended to be larger than anterior opening (p < 0.05). Cleft and non-cleft sides were symmetrically expanded and there was no difference in dental tipping between both sides (p > 0.05). CONCLUSIONS:: The appliances tested are effective in the transverse expansion of the maxilla. However, these appliances should be better indicated to cleft cases also presenting posterior transverse discrepancy, since there was greater expansion in the posterior maxillary region than in the anterior one.
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Fisura del Paladar/terapia , Aparatos Ortodóncicos , Técnica de Expansión Palatina/instrumentación , Niño , Fisura del Paladar/diagnóstico por imagen , Tomografía Computarizada de Haz Cónico , Femenino , Humanos , Masculino , Hueso Paladar/diagnóstico por imagenRESUMEN
INTRODUCTION: Drugs that block the renin-angiotensin system (RAS) are widely used for treating hypertension, heart and kidney failure, and the harmful effects of diabetes. Components of the RAS have been identified in various organs, but little is known of their effects on bone remodeling. The aim of this study was to evaluate whether the blockage of the RAS influences strain-induced bone remodeling in a model of orthodontic tooth movement. METHODS: An orthodontic appliance was placed in C57BL6/J mice that were randomly divided into 2 groups: vehicle-treated mice (VH) and mice treated with losartan (an angiotensin II receptor blocker). Orthodontic tooth movement and the number of tartrate-resistant acid phosphatase-positive cells were determined by histopathologic analysis. The expression of mediators involved in bone remodeling was evaluated by quantitative real-time polymerase chain reaction. Blood pressure was measured before and during the experimental period. RESULTS: Orthodontic tooth movement and tartrate-resistant acid phosphatase-positive cells were significantly reduced in the losartan group compared with the VH group. mRNA levels of osteoclast markers (RANK, RANKL, cathepsin K, and metalloproteinase 13) were lower in the losartan mice than in the VH group, whereas the expressions of osteoblast markers and negative regulators of bone resorption (periostin, dentin matrix protein, alkaline phosphatase, collagen 1A1, semaphorin 3A3, metalloproteinase 2, and osteoprotegerin) were higher in the VH group. CONCLUSIONS: Blockage of the RAS system decreases osteoclast differentiation and activity and, consequently, results in decreased strain-induced bone remodeling in orthodontic tooth movement.
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Antagonistas de Receptores de Angiotensina/farmacología , Remodelación Ósea/efectos de los fármacos , Losartán/farmacología , Maxilar/efectos de los fármacos , Técnicas de Movimiento Dental/métodos , Fosfatasa Ácida/análisis , Fosfatasa Alcalina/análisis , Animales , Presión Sanguínea/efectos de los fármacos , Catepsina K/análisis , Moléculas de Adhesión Celular/análisis , Colágeno Tipo I/análisis , Cadena alfa 1 del Colágeno Tipo I , Proteínas de la Matriz Extracelular/análisis , Isoenzimas/análisis , Masculino , Metaloproteinasa 13 de la Matriz/análisis , Metaloproteinasa 2 de la Matriz/análisis , Ratones , Ratones Endogámicos C57BL , Modelos Animales , Osteoblastos/efectos de los fármacos , Osteoclastos/efectos de los fármacos , Osteoprotegerina/análisis , Ligando RANK/análisis , Distribución Aleatoria , Receptor Activador del Factor Nuclear kappa-B/análisis , Semaforina-3A/análisis , Fosfatasa Ácida Tartratorresistente , Técnicas de Movimiento Dental/instrumentaciónRESUMEN
OBJECTIVE: To evaluate the anterior and posterior maxillary width, the nasal passage volume, the oropharyngeal minimum axial area, and volume changes in unilateral cleft lip and palate patients treated with one of the following four expanders: Hyrax, Fan-Type, inverted mini-hyrax supported on the first permanent molars (iMini-M), or inverted mini-hyrax supported on the first premolars (iMini-B). MATERIALS AND METHODS: A total of 40 patients with transverse maxillary deficiency who were submitted for rapid maxillary expansion were divided in four groups according to type of expander used. Cone-beam computed tomography images were taken before and 3 months after expansion. One-way analysis of variance was used to analyze the differences among the groups, and paired t-tests were used to evaluate the changes in each group. RESULTS: All groups showed a significant increase in the anterior maxillary width, with no intergroup differences. The iMini-B was the only group that did not show a significant increase in the posterior maxillary width. The intergroup comparison demonstrated differences among all groups except between Hyrax and iMini-M, which showed the greatest posterior expansions. The intragroup analysis showed a significant increase in the nasal passage volume in hyrax and inverted mini-hyrax on the molar groups, but the intergroup comparison revealed a significant difference only between Fan-Type and inverted mini-hyrax on the molars. None of the expanders caused significant changes in the oropharyngeal measurements. CONCLUSIONS: Only the Hyrax and inverted mini-hyrax on the molar expanders effectively increased the nasal passage volume, and none of the expanders evaluated in this study modified the oropharyngeal airway.
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Labio Leporino/terapia , Maxilar/anatomía & histología , Técnica de Expansión Palatina , Adolescente , Niño , Tomografía Computarizada de Haz Cónico , Femenino , Humanos , Masculino , NarizRESUMEN
Cleft lip and palate patients commonly present maxillary constriction, particularly in the anterior region. The aim of this case report was to describe an alternative clinical approach that used a smaller Hyrax screw unconventionally positioned to achieve greater anterior than posterior expansion in patients with complete unilateral cleft lip and palate. The idea presented here is to take advantage of a reduced dimension screw to position it anteriorly. When only anterior expansion was needed (patient 1), the appliance was soldered to the first premolar bands and associated to a transpalatal arch cemented to the first molars. However, when overall expansion was required (patient 2), the screw was positioned anteriorly, but soldered to the first molar bands. Intercanine, premolar, and first molar widths were measured on dental casts with a digital caliper. Pre-expansion and postexpansion radiographs and tomographies were also evaluated. A significant anterior expansion and no intermolar width increase were registered in the first patient. Although patient 2 also presented a greater anterior than posterior expansion, a noteworthy expansion occurred at the molar region. The alternative approach to expand the maxilla in cleft patients reported here caused greater anterior than posterior expansion when the Mini-Hyrax was associated to a transpalatal arch, and its reduced dimension also minimized discomfort and facilitated hygiene.