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1.
Angle Orthod ; 94(3): 303-312, 2024 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-38639455

RESUMEN

OBJECTIVES: To compare skeletodental changes between early and late treatment groups using modified C-palatal plates (MCPP) and long-term retention outcomes in hyperdivergent Class II adolescents. MATERIALS AND METHODS: Seventy-one hyperdivergent Class II patients were divided into four groups according to treatment modality and treatment timing: group 1, early treatment with MCPP (n = 16; 9.9 ± 0.9 years); group 2, late treatment with MCPP (n = 19; 12.3 ± 0.8 years); group 3, early treatment with headgear (HG; n = 18; 9.6 ± 0.8 years); and group 4, late treatment with HG (n = 18; 12.1 ± 1.2 years). Lateral cephalograms were taken and skeletal and dental variables were measured. For statistical analysis, paired t-tests, independent t-tests, and multiple regression were performed. RESULTS: The early MCPP group showed a more significant decrease in mandibular plane angle than the late MCPP group did, and vertical control was more efficient in the early group than in the late group. In the MCPP groups, both FMA and SN-GoGn were increased with late treatment but decreased with early treatment, and the difference was statistically significant (P < .01). The early-treatment MCPP group had a significant decrease in SN-GoGn of 0.6° compared with an increase of 1.7° in the early treatment HG group (P < .01). Posttreatment stability of both the early and late MCPP groups was maintained in long-term retention. CONCLUSIONS: Early MCPP showed more significant vertical control than late MCPP. However, there was no difference in long-term stability between early and late groups.


Asunto(s)
Maloclusión Clase II de Angle , Paladar (Hueso) , Humanos , Adolescente , Cefalometría , Análisis Multivariante , Aparatos de Tracción Extraoral , Diente Molar , Maloclusión Clase II de Angle/diagnóstico por imagen , Maloclusión Clase II de Angle/terapia , Mandíbula
2.
J Nanobiotechnology ; 22(1): 149, 2024 Apr 04.
Artículo en Inglés | MEDLINE | ID: mdl-38570846

RESUMEN

BACKGROUND: Myocardial infarction (MI), a representative form of ischemic heart disease, remains a huge burden worldwide. This study aimed to explore whether extracellular vesicles (EVs) secreted from hyaluronic acid (HA)-primed induced mesenchymal stem cells (HA-iMSC-EVs) could enhance the cardiac repair after MI. RESULTS: HA-iMSC-EVs showed typical characteristics for EVs such as morphology, size, and marker proteins expression. Compared with iMSC-EVs, HA-iMSC-EVs showed enhanced tube formation and survival against oxidative stress in endothelial cells, while reduced reactive oxygen species (ROS) generation in cardiomyocytes. In THP-1 macrophages, both types of EVs markedly reduced the expression of pro-inflammatory signaling players, whereas HA-iMSC-EVs were more potent in augmenting anti-inflammatory markers. A significant decrease of inflammasome proteins was observed in HA-iMSC-EV-treated THP-1. Further, phospho-SMAD2 as well as fibrosis markers in TGF-ß1-stimulated cardiomyocytes were reduced in HA-iMSC-EVs treatment. Proteomic data showed that HA-iMSC-EVs were enriched with multiple pathways including immunity, extracellular matrix organization, angiogenesis, and cell cycle. The localization of HA-iMSC-EVs in myocardium was confirmed after delivery by either intravenous or intramyocardial route, with the latter increased intensity. Echocardiography revealed that intramyocardial HA-iMSC-EVs injections improved cardiac function and reduced adverse cardiac remodeling and necrotic size in MI heart. Histologically, MI hearts receiving HA-iMSC-EVs had increased capillary density and viable myocardium, while showed reduced fibrosis. CONCLUSIONS: Our results suggest that HA-iMSC-EVs improve cardiac function by augmenting vessel growth, while reducing ROS generation, inflammation, and fibrosis in MI heart.


Asunto(s)
Células Madre Mesenquimatosas , Infarto del Miocardio , Humanos , Ácido Hialurónico/farmacología , Células Endoteliales/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Proteómica , Infarto del Miocardio/terapia , Infarto del Miocardio/patología , Miocitos Cardíacos/metabolismo , Células Madre Mesenquimatosas/metabolismo , Fibrosis
3.
J World Fed Orthod ; 2024 Apr 22.
Artículo en Inglés | MEDLINE | ID: mdl-38653656

RESUMEN

Orthodontic uprighting or traction of an impacted mandibular second molar often necessitates invasive interventions. This report aims to illustrate the utilization of nickel-titanium wire segments inserted into small, simple tubes for uprighting mesially impacted mandibular second molars and also for scissor bite correction. The term "simple tube" refers to a tube without a bonding base attached to a tooth surface by covering it with flowable composite resin. Due to the absence of a bonding base, the simple tube is characterized by its diminutive size and minimal profile height, facilitating placement on partially exposed second molars and unconventional positioning to adjust the force geometry. In this case study, mesially-impacted mandibular second molars with scissor bite were uprighted in a 21-year-old male utilizing simple tubes. Simple tubes can be used for molar uprighting and scissor bite correction buccally and lingually.

5.
Nat Commun ; 15(1): 2564, 2024 Mar 22.
Artículo en Inglés | MEDLINE | ID: mdl-38519491

RESUMEN

Engineered human cardiac tissues have been utilized for various biomedical applications, including drug testing, disease modeling, and regenerative medicine. However, the applications of cardiac tissues derived from human pluripotent stem cells are often limited due to their immaturity and lack of functionality. Therefore, in this study, we establish a perfusable culture system based on in vivo-like heart microenvironments to improve human cardiac tissue fabrication. The integrated culture platform of a microfluidic chip and a three-dimensional heart extracellular matrix enhances human cardiac tissue development and their structural and functional maturation. These tissues are comprised of cardiovascular lineage cells, including cardiomyocytes and cardiac fibroblasts derived from human induced pluripotent stem cells, as well as vascular endothelial cells. The resultant macroscale human cardiac tissues exhibit improved efficacy in drug testing (small molecules with various levels of arrhythmia risk), disease modeling (Long QT Syndrome and cardiac fibrosis), and regenerative therapy (myocardial infarction treatment). Therefore, our culture system can serve as a highly effective tissue-engineering platform to provide human cardiac tissues for versatile biomedical applications.


Asunto(s)
Células Endoteliales , Células Madre Pluripotentes Inducidas , Humanos , Diferenciación Celular , Miocitos Cardíacos , Ingeniería de Tejidos/métodos
6.
J Vis Exp ; (204)2024 Feb 23.
Artículo en Inglés | MEDLINE | ID: mdl-38465926

RESUMEN

This study aimed to introduce cone-beam computed tomography (CBCT) digitization and integration of digital dental images (DDI) based on artificial intelligence (AI)-based registration (ABR) and to evaluate the reliability and reproducibility using this method compared with those of surface-based registration (SBR). This retrospective study consisted of CBCT images and DDI of 17 patients who had undergone computer-aided bimaxillary orthognathic surgery. The digitization of CBCT images and their integration with DDI were repeated using an AI-based program. CBCT images and DDI were integrated using a point-to-point registration. In contrast, with the SBR method, the three landmarks were identified manually on the CBCT and DDI, which were integrated with the iterative closest points method. After two repeated integrations of each method, the three-dimensional coordinate values of the first maxillary molars and central incisors and their differences were obtained. Intraclass coefficient (ICC) testing was performed to evaluate intra-observer reliability with each method's coordinates and compare their reliability between the ABR and SBR. The intra-observer reliability showed significant and almost perfect ICC in each method. There was no significance in the mean difference between the first and second registrations in each ABR and SBR and between both methods; however, their ranges were narrower with ABR than with the SBR method. This study shows that AI-based digitization and integration are reliable and reproducible.


Asunto(s)
Procesamiento de Imagen Asistido por Computador , Imagenología Tridimensional , Humanos , Reproducibilidad de los Resultados , Procesamiento de Imagen Asistido por Computador/métodos , Imagenología Tridimensional/métodos , Inteligencia Artificial , Estudios Retrospectivos , Tomografía Computarizada de Haz Cónico/métodos
7.
Clin Orthop Surg ; 16(1): 16-22, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38304220

RESUMEN

Background: The purposes of this study were to determine the accuracy of our cup positioning method and to evaluate the dislocation rate after total hip arthroplasty (THA). Methods: After positioning the patient in the lateral decubitus position on the operation table, an anteroposterior view of the hip was taken. The pelvic pitch was measured on the X-ray. A positive pitch was defined as the caudal rotation of the upper hemipelvis. Our target abduction of the cup was 43°. We used the cup holder to guesstimate the cup abduction. In a preliminary study, we found that the weight of the cup holder increased the pelvic pitch by 5°. Thus, the target abduction of the cup holder was calculated by a formula: 43° - pelvic pitch - 5°. During the cup insertion, the cup holder was anteverted to the calculated target according to the concept of combined anteversion. We evaluated 478 THAs (429 patients), which were done with the use of the method. Results: The mean cup abduction was 43.9° (range, 32.0°-53.0°) and the mean error of cup abduction was 2.4° (standard deviation [SD], 2.0°; range, 0.0°-11.0°). The mean cup anteversion was 28.5° (range, 10.0°-42.0°) and the mean error of cup anteversion was 6.7° (SD, 5.2°; range, 0.0°-27.6°). Of all, 82.4% of the cups (394 / 478) were within the safe zone: 30°-50° abduction and 10°-35° anteversion. During 2- to 5-year follow-up, no hip dislocated. Conclusions: Our adjusting method according to the pelvic pitch can be a reliable option for optimizing the cup abduction in THA.


Asunto(s)
Artroplastia de Reemplazo de Cadera , Prótesis de Cadera , Luxaciones Articulares , Humanos , Acetábulo/cirugía , Artroplastia de Reemplazo de Cadera/métodos , Radiografía , Movimiento , Luxaciones Articulares/cirugía
8.
Vasc Specialist Int ; 40: 3, 2024 Feb 02.
Artículo en Inglés | MEDLINE | ID: mdl-38303149

RESUMEN

Aortic pseudoaneurysms (PA) vary in size and may remain asymptomatic. PAs may be caused by vascular injury, such as trauma or surgery, or other non-traumatic causes, such as Bechet disease, infection, or penetrating atherosclerotic ulcers. The diagnosis of PAs may have been delayed for decades. We present a case of a PA detected incidentally in a male patient who experienced traumatic bowel perforation due to blunt abdominal trauma 30 years before presentation. Computed tomography (CT) displayed a 9.2 cm mass in the pelvis, initially considered a neoplasm of small bowel origin. Further analysis of the CT images suggested a thrombosed PA at the aortic bifurcation, which was confirmed via surgical exploration. Graft interposition was performed using a Dacron 16-8 mm graft and the patient recovered without any complications. This case highlights the importance of a high index of suspicion for the diagnosis of a thrombosed aortic PA.

9.
Am J Orthod Dentofacial Orthop ; 165(4): 383-384, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38402482

RESUMEN

As a specialty board, the American Board of Orthodontics (ABO) serves to protect the public and the orthodontic specialty by certifying orthodontists. The demonstration of commitment to lifelong learning and self-improvement is critical to achieving the highest level of patient care. The ABO completed a practice analysis study in 2023 to ensure all examinations represent current assessments of proficiency in orthodontics at a level of quality that satisfies professional expectations. The practice analysis is essential to providing a demonstrable relationship between the examination content and orthodontic practice and provides a critical foundation for ABO's examination programs.


Asunto(s)
Ortodoncia , Humanos , Estados Unidos , Consejos de Especialidades , Ortodoncistas , Atención Odontológica
10.
Korean J Ophthalmol ; 38(2): 105-112, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38351485

RESUMEN

PURPOSE: To evaluate the refractive outcomes after ultrathin Descemet stripping automated endothelial keratoplasty (UT-DSAEK) combined with phacoemulsification and intraocular lens implantation (triple procedure) in the South Korean population. METHODS: This retrospective observational study included 37 eyes of 36 patients who underwent the UT-DSAEK triple procedure between 2012 and 2021 in a single tertiary hospital. Preoperative and postoperative refractive outcomes and endothelial parameters at 1, 3, 6, and 12 months were observed. RESULTS: At the final postoperative 12-month period, the average best-corrected visual acuity was 0.4 ± 0.5 in logarithm of the minimum angle of resolution. The mean endothelial cell density at 12 months was 1,841.92 ± 731.24 cells/mm2, indicating no significant endothelial cell loss compared to the baseline (p = 0.128). The mean postoperative central corneal thickness at 12 months was 597.41 ± 86.26 µm. The postoperative mean absolute error at 12 months was 0.96 ± 0.89 diopters (D) and mean error was 0.89 ± 0.97 D. CONCLUSIONS: The results of our South Korean cohort study on UT-DSAEK triple surgery showed favorable and safe outcomes. Regardless of graft thickness, it should be noted that a hyperopic shift of 1.00 to 2.00 D needs to be considered in the case of UT-DSAEK triple surgery.


Asunto(s)
Catarata , Trasplante de Córnea , Queratoplastia Endotelial de la Lámina Limitante Posterior , Distrofia Endotelial de Fuchs , Humanos , Agudeza Visual , Estudios de Cohortes , Refracción Ocular , Estudios Retrospectivos , Queratoplastia Endotelial de la Lámina Limitante Posterior/métodos , Endotelio Corneal/trasplante , Distrofia Endotelial de Fuchs/cirugía
11.
J World Fed Orthod ; 13(1): 2-9, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38185583

RESUMEN

Anterior open bite can be effectively treated nonsurgically via molar intrusion. This technique, involving the intrusion of posterior teeth using temporary skeletal anchorage devices, prompts counterclockwise rotation of the mandible. This rotation not only corrects anterior open bite but also contributes to a decrease in anterior facial height, improvements in lip incompetency, and forward movement of the chin. For successful outcomes, temporary skeletal anchorage devices, installed on both the buccal and palatal sides, must deliver equivalent intrusion force to the maxillary teeth. Treatment planning should consider factors such as skeletal discrepancies, vertical excess, incisor exposure, and configuration of the occlusal plane. Clinicians are advised to closely monitor periodontal changes and consider overcorrection to ensure lasting stability and maintenance of incisal overlap post-treatment.


Asunto(s)
Mordida Abierta , Métodos de Anclaje en Ortodoncia , Humanos , Mordida Abierta/etiología , Mordida Abierta/terapia , Métodos de Anclaje en Ortodoncia/efectos adversos , Técnicas de Movimiento Dental , Cefalometría/métodos , Diente Molar
12.
Nat Struct Mol Biol ; 31(3): 447-454, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38233573

RESUMEN

Hepatitis B virus (HBV), a leading cause of developing hepatocellular carcinoma affecting more than 290 million people worldwide, is an enveloped DNA virus specifically infecting hepatocytes. Myristoylated preS1 domain of the HBV large surface protein binds to the host receptor sodium-taurocholate cotransporting polypeptide (NTCP), a hepatocellular bile acid transporter, to initiate viral entry. Here, we report the cryogenic-electron microscopy structure of the myristoylated preS1 (residues 2-48) peptide bound to human NTCP. The unexpectedly folded N-terminal half of the peptide embeds deeply into the outward-facing tunnel of NTCP, whereas the C-terminal half formed extensive contacts on the extracellular surface. Our findings reveal an unprecedented induced-fit mechanism for establishing high-affinity virus-host attachment and provide a blueprint for the rational design of anti-HBV drugs targeting virus entry.


Asunto(s)
Virus de la Hepatitis B , Simportadores , Humanos , Virus de la Hepatitis B/genética , Hepatocitos/metabolismo , Unión Proteica , Acoplamiento Viral , Péptidos/metabolismo , Simportadores/metabolismo , Internalización del Virus
13.
J World Fed Orthod ; 13(1): 18-24, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38171974

RESUMEN

This article examines the characteristics of hypodivergent craniofacial patterns and explores treatment modalities in response to these features. It discusses the impact of robust masticatory muscles, which produce heavy occlusal forces. In addition, it examines the use of Botox or splints to reduce gonial angles in individuals with a square face. A nonextraction treatment approach supported by temporary skeletal anchorage devices is recommended; however, if anatomical limitations persist, extraction may be necessary when arch expansion, molar distalization, incisor proclination, or interproximal reduction cannot create the necessary space. In hypodivergent cases where a nonextraction approach is impractical, a single-arch extraction strategy may be considered to prevent a reduction in the vertical dimension. Emphasizing esthetics, particularly maxillary incisor display, a protocol of total arch extrusion of the maxillary dentition assisted with temporary skeletal anchorage device, bite raisers, and interarch elastics is suggested.


Asunto(s)
Maloclusión Clase II de Angle , Mandíbula , Humanos , Maloclusión Clase II de Angle/terapia , Técnicas de Movimiento Dental , Estética Dental , Diente Molar
14.
J World Fed Orthod ; 13(1): 10-17, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38176981

RESUMEN

Deep bite is usually treated by intrusion of the anterior teeth, extrusion of the posterior teeth, or a combination thereof. Various traditional methods have been used to correct deep bites, but they can cause negative side effects. Recently, temporary skeletal anchorage devices (TSADs) have been used to intrude the anterior teeth simply and efficiently without side effects. The amount of incisal exposure at rest should be considered as the first factor in determining which tooth segment should be intruded to correct a deep bite. The center of resistance of the anterior teeth should be considered to achieve the proper biomechanics when intruding them. The location of TSADs should be determined to ensure sufficient interradicular bone to achieve the desired tooth movement. Therefore, clinicians should understand the biomechanical and clinical considerations to correct a deep bite using TSADs.


Asunto(s)
Mordida Abierta , Métodos de Anclaje en Ortodoncia , Sobremordida , Humanos , Mordida Abierta/terapia , Técnicas de Movimiento Dental , Tornillos Óseos
15.
J Craniofac Surg ; 2024 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-38227626

RESUMEN

OBJECTIVE: To investigate the etiology and preventive measures of posttransplant kinky or curly hair growth after female hairline correction surgery. BACKGROUND: Hair transplant surgery can be accompanied by various adverse effects, one of which is severely kinky or curly hair after surgery. Posttransplant kinky or curly hair is not well-understood for its cause or prevention. METHODS: The study was targeted at a total of 980 patients who were confirmed whether they developed kinky or curly hair after female hairline correction surgery. Incidence, surgical method, degree of curliness, predisposed location, characteristics, hair caliber (thin, medium, and thick), and left-right differences were examined. RESULTS: Among the total 980 patients, posttransplant curly hair (PTCH) was manifested in 38(3.9%) patients. None of the patients who underwent surgery at the present clinic developed posttransplant kinky hair; all 38 patients showed PTCH growth. In 36 cases, transplanted hair started to grow in curly patterns around 4 months after surgery. However, the remaining 2 cases showed no curly growth pattern when the transplanted hair was short at postoperative 4 months, but started to grow curly starting at 6 to 8 months after surgery as the hair growth direction was obstructed or compressed by the existing hair. CONCLUSION: Familiarity with the cause, prevention, and management of posttransplant kinky hair and PTCH will be of great help to hair surgeons.

16.
Angle Orthod ; 94(2): 159-167, 2024 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-38195065

RESUMEN

OBJECTIVES: To compare posttreatment stability in skeletal Class III patients between those treated by total mandibular arch distalization (TMAD) with buccal mini-implants and those by mandibular setback surgery (MSS). MATERIALS AND METHODS: The samples included 40 Class III adults, 20 treated by TMAD using buccal interradicular mini-implants and 20 treated with MSS. Lateral cephalograms were taken at pretreatment, posttreatment, and at least 1-year follow-up, and 24 variables were compared using statistical analysis. RESULTS: Mandibular first molars moved distally 1.9 mm with intrusion of 1.1 mm after treatment in the TMAD group. The mandibular incisors moved distally by 2.3 mm. The MSS group exhibited a significant skeletal change of the mandible, whereas the TMAD group did not. During retention, there were no skeletal or dental changes other than 0.6 mm labial movement of the mandibular incisors (P < .05) in the MSS group. There was 1.4° of mesial tipping (P < .01) and 0.4 mm of mesial movement of the mandibular molars and 1.9° of labial tipping (P < .001) and 0.8 mm of mesial movement of the mandibular incisors in the TMAD group. These dental changes were not significantly different between the two groups. CONCLUSIONS: The TMAD group showed a slightly decreased overjet with labial tipping of the mandibular incisors and mesial tipping of the first molars during retention. Posttreatment stability of the mandibular dentition was not significantly different between the groups. It can be useful to plan camouflage treatment by TMAD with mini-implants in mild-to-moderate Class III patients.


Asunto(s)
Maxilar , Sobremordida , Adulto , Humanos , Técnicas de Movimiento Dental , Cefalometría , Mandíbula/cirugía
17.
Facial Plast Surg ; 40(1): 1-8, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-36731512

RESUMEN

The most important factor that distinguishes a youthful appearance from an aged one is the shape of the lower face. This study aimed to examine the outcome of volume reduction of the lower face using laser-assisted liposuction (SmartLipo) at the time of rhytidectomy in Asians. There were 20 patients (Group 1) for whom only extended deep-plane rhytidectomy were performed, while extended deep-plane rhytidectomy with laser-assisted liposuction was performed on 42 patients (Group 2). This study was performed retrospectively. The FACE-Q questionnaire was given to evaluate the subjective result of the patient. Efficacy was evaluated by measuring the fat quantity at the midpoint and anterior border of the masseter muscle on each side by using an ultrasound scan in Group 2. Then, the correlation between the change in the quantity of fat and the FACE-Q was investigated. The overall satisfaction, and satisfaction for the lower face, jawline, and the area under the chin were significantly higher for Group 2 for which the procedure was concurrently performed in comparison to Group 1. In Group 2, change in the fat was reduced by 21.2% (Rt.) and 22.5% (Lt.) at the mid-point and 24.5% (Rt.) and 26.4% (Lt.) at the anterior border of the masseter muscle. Changes in the fat quantity and lower face satisfaction displayed a significant correlation. With a greater reduction in fat quantity, the score of lower face satisfaction was higher. In addition, with a higher level of satisfaction for the lower face and jawline, the overall satisfaction score displayed a higher positive correlation. Laser-assisted liposuction was useful for the additive procedure at the time of rhytidectomy and improved patient's satisfaction after surgery.


Asunto(s)
Lipectomía , Ritidoplastia , Humanos , Ritidoplastia/métodos , Estudios Retrospectivos , Mentón , Rayos Láser , Satisfacción del Paciente
18.
Orthod Craniofac Res ; 27(2): 303-312, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-37955169

RESUMEN

OBJECTIVE: To compare changes in the maxillary posterior structure as seen in cone-beam computed tomography (CBCT) images resulting from facemask therapy using skeletal (miniplate/FM) anchorage versus tooth-borne anchorage (RME/FM). MATERIALS AND METHODS: A retrospective study was conducted on 20 patients divided into the miniplate/FM group (nine patients aged 9.5 ± 1.4 years) and the RME/FM group (11 patients aged 9.2 ± 1.4 years). CBCT images before and after facemask therapy were evaluated to assess changes in the maxillary posterior structure. RESULTS: The miniplate/FM group had greater advancement of the maxilla and midface compared to the RME/FM group (p < .05). Specifically, there was about three times more advancement of the pterygomaxillary suture in the miniplate/FM group than in the RME/FM group (p < .05). Moreover, the advancement of the pterygomaxillary suture was about half the advancement of A point in the miniplate/FM group, while only about 25% in the RME/FM group. Finally, the miniplate/FM group showed an increase in the transverse dimension of the posterior and superior parts of the maxilla (p < .05). CONCLUSION: There was greater forward movement of the pterygomaxillary suture with facemask therapy using the skeletal anchorage compared to tooth-borne anchorage, leading to a more significant advancement of the maxilla and midface.


Asunto(s)
Maloclusión de Angle Clase III , Humanos , Maloclusión de Angle Clase III/terapia , Estudios Retrospectivos , Maxilar/diagnóstico por imagen , Maxilar/cirugía , Máscaras , Técnica de Expansión Palatina , Aparatos de Tracción Extraoral , Cefalometría/métodos
19.
Angle Orthod ; 94(2): 247-257, 2024 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-37963549

RESUMEN

Inadequate maxillary incisor display can negatively impact facial esthetics. Various treatment options exist depending on the underlying cause and severity of the condition. Skeletal anchorage was used to extrude the maxillary dentition and rotate the mandible backward, enhancing visibility of the maxillary incisors. An extrusion assembly was introduced to achieve orthodontic extrusion. Use of bite raisers and interarch elastics was also discussed. Treatment results demonstrated successful achievement of the treatment goals. In addition to optimal occlusion, the patient's facial profile improved with increased lip fullness. There was an increase in vertical facial height, and maxillary incisor display was significantly improved, resulting in a more pleasant smile. Two-year postretention records evidenced the stability of total arch extrusion to improve maxillary incisor display.


Asunto(s)
Incisivo , Métodos de Anclaje en Ortodoncia , Humanos , Técnicas de Movimiento Dental/métodos , Diente Molar , Métodos de Anclaje en Ortodoncia/métodos , Mandíbula , Maxilar , Cefalometría/métodos
20.
Orthod Craniofac Res ; 27(1): 102-109, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37496461

RESUMEN

OBJECTIVE: This finite element analysis (FEA) aimed to assess the stress distribution in the mandible and fixation system with various directions of the intermaxillary fixation (IMF) using mini-implants (MIs) and elastics following mandibular advancement with a bilateral sagittal split ramus osteotomy (BSSRO). MATERIALS AND METHODS: A total of nine mandibular advancement models were set according to the position of the MIs (1.6 mm in diameter, 8 mm in length) and direction of the IMF elastics (1/4 inch, 5 oz). Major and minor principal stresses in the cortical and cancellous bones, von Mises stresses in the fixation system (miniplate and monocortical screws), and bending angles of the miniplate were analysed. RESULTS: Compressive and tensile stress distributions in the mandible and von Mises stress distributions in the fixation system were greater in models with a Class III IMF elastic direction and a higher IMF elastic force than in models with a Class II IMF elastic direction and a lower IMF elastic force. The bending angle of the miniplate was negligible. CONCLUSIONS: Stress distributions in the bone and fixation system varied depending on the direction, amount of force, and position of IMF elastics and MIs. Conclusively, IMF elastics in the Class II direction with minimal load in the area close to the osteotomy site should be recommended.


Asunto(s)
Implantes Dentales , Avance Mandibular , Métodos de Anclaje en Ortodoncia , Osteotomía Sagital de Rama Mandibular , Análisis de Elementos Finitos , Placas Óseas , Tornillos Óseos , Estrés Mecánico , Mandíbula/cirugía
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