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Sotos syndrome is a genetic disorder characterized by overgrowth in childhood, specific facial manifestations, advanced bone age, and mental retardation. The purpose of this article is to describe the nonsurgical orthodontic treatment of a 10-year-old boy with a skeletal mandibular protrusion, unilateral posterior crossbite, and Sotos syndrome. After maxillary lateral expansion, the skeletal Class III relationship with an anterior crossbite improved because of mandibular clockwise rotation, whereas the facemask had a marginal effect. After growth at 16 years, he had a skeletal Class I relationship, and thus, conventional orthodontic treatment with preadjusted edgewise appliances was initiated. After 41 months of multibracket treatment, acceptable occlusion with a functional Class I relationship was obtained. One year postretention, few changes in occlusion and facial features were observed. Our results demonstrate that considering the maxillofacial vertical growth during the peripubertal period associated with Sotos syndrome, more attention should be paid to the early orthopedic treatment with the facemask and/or chincap.
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Má Oclusão Classe III de Angle , Má Oclusão , Síndrome de Sotos , Masculino , Humanos , Criança , Má Oclusão Classe III de Angle/terapia , Cefalometria , Mandíbula , Técnica de Expansão Palatina , Aparelhos de Tração Extrabucal , MaxilaRESUMO
INTRODUCTION: The purpose of this research was to compare insertion techniques and effects on mechanical and clinical parameters between 2 types of miniscrews. METHODS: Forty-four consecutive patients whose orthodontic treatment involved the use of miniscrews (miniscrew A [MA] and miniscrew B [MB]) for anchorage were included in this study. Miniscrews were placed with predrilling or self-drilling; peak maximum insertion torque (MIT) and Periotest values were measured. Cone-beam computed tomography was performed after the insertion of miniscrews and root proximity determination; cortical bone thickness was also analyzed. Periotest values were measured after the application of orthodontic force. RESULTS: Self-drilling produced higher Periotest values (P <0.01) for MA and higher MIT (P <0.01) for MB with closer root proximity (P <0.05). MB had higher MIT and Periotest values with drilling compared with MA (P <0.05); MB also showed closer root proximity (P <0.05). Successful miniscrews had lower MIT (P <0.05) for MB and lower Periotest values (P <0.01) for both MA and MB, with significantly more distant root proximity (P <0.01). Self-drilling produced higher Periotest values at the time of placement (P <0.01) and after 4 weeks (P <0.05) in MA. Drilling produced higher Periotest values for MB at the time of placement (P <0.05). MIT had positive correlations with Periotest values for MB with self-drilling (P <0.01) and with root proximity for MA with drilling (P <0.01). Periotest values had negative correlations with root proximity for MA and the MB group with drilling (P <0.01). CONCLUSIONS: For miniscrews with larger diameters, higher MIT may result in more mobility (higher Periotest values). Drilling can avoid root contact and enhance primary stability, thus producing lower Periotest values.
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Procedimentos de Ancoragem Ortodôntica , Parafusos Ósseos , Tomografia Computadorizada de Feixe Cônico , Humanos , Procedimentos de Ancoragem Ortodôntica/métodos , Desenho de Aparelho Ortodôntico , TorqueRESUMO
AIM AND OBJECTIVE: To present an Apert syndrome patient with midfacial growth deficiency treated with Le Fort III distraction osteogenesis and subsequent two-jaw surgery. BACKGROUND: Apert syndrome is expressed as a severe and irregular craniosynostosis, midfacial hypoplasia, and symmetric syndactyly in the fingers and toes. For craniosynostosis syndromes, treatment planning is complex due to the disharmony between facial profile and occlusion. CASE DESCRIPTION: A 4-year-and-5-month-old boy, diagnosed with Apert syndrome, showed a concave profile accompanied with midfacial hypoplasia, moderate exorbitism, a reversed occlusion of -10.0 mm, an anterior open bite of -5.0 mm, and skeletal class III jaw-base relationship. The patient, aged 15 years and 4 months, underwent a Le Fort III osteotomy, and subsequent osteodistraction was performed via a rigid external distraction (RED) device. His midfacial bone was advanced by approximately 7.0 mm. One year after the distraction, preoperative treatment with 0.018-in preadjusted edgewise appliances was initiated. Two-jaw surgery with a Le Fort I osteotomy and bilateral sagittal split ramus osteotomy was performed after 42 months of preoperative orthodontic treatment. At the age of 20 years and 9 months, his facial profile dramatically changed to a straight profile, and an acceptable occlusion with an adequate interincisal relationship was obtained. A functional occlusion with an excellent facial profile was maintained throughout the 2-year retention period, although the upper dental arch width was slightly decreased, resulting in the recurrence of the left posterior crossbite. CONCLUSION: Our report indicates the necessity of long-term follow-up in patients with craniosynostosis because of syndrome-specific growth and methodologically induced relapse. CLINICAL SIGNIFICANCE: The two-stage operation combining early distraction osteogenesis and postgrowth orthognathic surgery proves to be an effective therapy for correcting midfacial hypoplasia and skeletal mandibular protrusion caused by Apert syndrome.
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Acrocefalossindactilia , Mordida Aberta , Osteogênese por Distração , Acrocefalossindactilia/complicações , Acrocefalossindactilia/cirurgia , Adolescente , Adulto , Cefalometria/métodos , Humanos , Lactente , Masculino , Mordida Aberta/etiologia , Osteogênese por Distração/efeitos adversos , Osteogênese por Distração/métodos , Osteotomia de Le Fort/métodos , Adulto JovemRESUMO
BACKGROUND/OBJECTIVES: Primary stability is required for successful use of microscrew. This study investigated correlations among biomechanical, morphological, and clinical values in relationship to root contact and different placement locations. MATERIALS/METHODS: Thirty-three microscrews were placed between the molars (n = 18) or in the body of the mandible (n = 15) in three pigs. Insertion torque, Periotest, resonance frequency analysis (RFA), and static and dynamic stiffness were measured. Cone beam computed tomography was performed before and after the insertion of microscrews. Interproximal microscrews were divided into root contacted microscrews (n = 9) and non-root contact microscrews (n = 9). Factorial analysis of variance was conducted, with significance set at P < 0.05. RESULTS: A significant difference was observed between bodily and root contacted microscrews in Periotest, RFA, static and dynamic stiffness, Tanδ, and bone density (RFA, P = 0.045; all others, P < 0.001). A significant difference was observed between bodily and non-root contact microscrews in Periotest, RFA, and bone density (RFA, P = 0.025; all others, P < 0.001). A significant difference was observed in static (P = 0.01) and dynamic (P = 0.038) stiffness between microscrews with and without contact. Dynamic stiffness (P = 0.02) and Tanδ (P = 0.03) showed significant correlations with Periotest results only in bodily microscrews. LIMITATIONS: Since a pig bone was used, some differences in the quality and quantity of the bone might be observed between humans. CONCLUSIONS/IMPLICATIONS: Stiffness values distinguished between microscrews with and without contact. Periotest and RFA results indicated that bodily microscrews were more stable than interproximal microscrews. Periotest and RFA may be useful with large, microscrews and/or in thick cortical bone, but further investigation is required to determine the stability of interproximal microscrews.
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Implantes Dentários , Animais , Densidade Óssea , Osso Cortical/diagnóstico por imagem , Implantação Dentária Endóssea , Humanos , Mandíbula/diagnóstico por imagem , Mandíbula/cirurgia , Osseointegração , Suínos , TorqueRESUMO
AIM AND OBJECTIVE: To present a growing patient with unilateral mandibular hypoplasia and microtia involved in the first and second branchial arch syndrome (FSBAS) treated with functional appliance. BACKGROUND: The FSBAS comprises several developmental facial hypoplasia in ear and maxillofacial bones, resulting in hemifacial microsomia. Treatment for hemifacial microsomia varies greatly depending on the grade of mandibular deformities. Functional appliance treatment during growth period is available for mild to moderate mandibular deformities. However, there are few reports of hemifacial microsomia treated with functional appliance. CASE DESCRIPTION: The patient, an 8-year-and-5-month-old girl, had a chief complaint of mandibular deviation. She had been diagnosed with the FSBAS at birth. Her facial profile was straight and panoramic radiograph indicated that the mandibular ramal height of the affected side was about 60.4% compared to the unaffected side. The occlusal cant was 6°, and the right maxilla and mandible showed severe growth deficiency. At the age of 10 years, functional appliance with expander was used; for 2 years 6 months, the maxillomandibular growth was controlled and from panoramic radiograph, the ramus height of the affected side was increased to 65.0% compared to the unaffected left mandibular ramus. At the age of 12 years and 8 months, multibracket treatment was initiated. After 32 months of active treatment, proper occlusion with functional Class I canine and molar relationships was obtained, although facial asymmetry associated with the difference of ramus heights still existed. The resulting occlusion was stable during 1.5-year retention period. CONCLUSION: Our results indicated the importance of orthopedic treatment during growth period in the patient with hemifacial microsomia involving the FSBAS. CLINICAL SIGNIFICANCE: This report proposes an efficacy of conventional orthodontic treatment for growing patients with hemifacial microsomia involved in the FSBAS.
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Síndrome de Goldenhar , Criança , Oclusão Dentária , Assimetria Facial/diagnóstico por imagem , Assimetria Facial/terapia , Feminino , Síndrome de Goldenhar/diagnóstico por imagem , Humanos , Lactente , Mandíbula/diagnóstico por imagem , MaxilaRESUMO
OBJECTIVE: To understand the actual condition of orthodontic treatment in team care for patients with syndromic craniosynostosis (SCS) in Japan. DESIGN: A nationwide collaborative survey. SETTING: Twenty-four orthodontic clinics in Japan. PATIENTS: A total of 246 patients with SCS. MAIN OUTCOME MEASURE: Treatment history was examined based on orthodontic records using common survey sheets. RESULTS: Most patients first visited the orthodontic clinic in the deciduous or mixed dentition phase. Midface advancement was performed without visiting the orthodontic clinic in about a quarter of the patients, and more than a half of the patients underwent "surgery-first" midface advancement. First-phase orthodontic treatment was carried out in about a half of the patients, and maxillary expansion and protraction were performed. Tooth extraction was required in about two-thirds of patients, and the extraction of maxillary teeth was required in most patients. Tooth abnormalities were found in 37.8% of patients, and abnormalities of maxillary molars were frequently (58.3%) found in patients who had undergone midface surgery below the age of 6 years. CONCLUSIONS: Many patients underwent "surgery-first" midface advancement, and visiting the orthodontic clinic at least before advancement was considered desirable. First-phase orthodontic treatment should be performed considering the burden of care. Midface advancement below the age of 6 years had a high risk of injury to the maxillary molars. This survey is considered useful for improving orthodontic treatment in team care of patients with SCS.
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Craniossinostoses/terapia , Ortodontia Corretiva/métodos , Procedimentos Cirúrgicos Ortognáticos/métodos , Adolescente , Criança , Pré-Escolar , Terapia Combinada , Feminino , Humanos , Lactente , Recém-Nascido , Japão , Masculino , Técnica de Expansão Palatina , Equipe de Assistência ao Paciente , Inquéritos e Questionários , Extração Dentária , Resultado do Tratamento , Adulto JovemRESUMO
In this study, we present the development of a fine structural human phantom designed specifically for applications in dentistry. This research focused on assessing the viability of applying medical computer vision techniques to the task of segmenting individual teeth within a phantom. Using a virtual cone-beam computed tomography (CBCT) system, we generated over 170,000 training datasets. These datasets were produced by varying the elemental densities and tooth sizes within the human phantom, as well as varying the X-ray spectrum, noise intensity, and projection cutoff intensity in the virtual CBCT system. The deep-learning (DL) based tooth segmentation model was trained using the generated datasets. The results demonstrate an agreement with manual contouring when applied to clinical CBCT data. Specifically, the Dice similarity coefficient exceeded 0.87, indicating the robust performance of the developed segmentation model even when virtual imaging was used. The present results show the practical utility of virtual imaging techniques in dentistry and highlight the potential of medical computer vision for enhancing precision and efficiency in dental imaging processes.
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Tomografia Computadorizada de Feixe Cônico , Imagens de Fantasmas , Dente , Humanos , Dente/diagnóstico por imagem , Dente/anatomia & histologia , Tomografia Computadorizada de Feixe Cônico/métodos , Odontologia/métodos , Processamento de Imagem Assistida por Computador/métodos , Aprendizado ProfundoRESUMO
PATIENTS: This case report presents a minimally invasive approach to replace a missing mandibular lateral incisor using a dual-injection molding technique with flowable composite resins. Integrated with a comprehensive digital workflow, this method achieves a structurally and esthetically biomimetic, bi-layered prosthetic solution. A 34-year-old woman with congenital absence of a mandibular lateral incisor was successfully rehabilitated using a direct composite resin-bonded fixed partial denture (RBFPD). DISCUSSION: Two specialized three-dimensional (3D)-printed flexible indices stabilized by a custom-designed 3D-printed rigid holder were employed to ensure the meticulous injection molding of flowable composite resins formulated to emulate the inherent chromatic gradations between dentin and enamel. The inherent flexibility of the indices, combined with the holder, facilitated accurate and seamless adaptation to the complex morphological features of the dental arch, thereby mitigating the challenges commonly associated with rigid 3D-printed resin indices. CONCLUSIONS: The bilayered direct composite RBFPD using 3D printed flexible indices prepared with a full digital workflow has several advantages over other dental prosthetic solutions, including noninvasiveness, cost-effectiveness, biomimetic esthetics, repairability, and shortened treatment times. Although the initial results are promising, further longitudinal studies with larger patient cohorts are required to confirm the long-term efficacy of this approach.
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PURPOSE: This case report presents a direct composite inverse injection technique using a bi-layer clear mini-index fabricated with a digital workflow to restore extensive posterior occlusal cavities in a 13-year-old patient. MATERIALS AND METHODS: After a root canal treatment in the right mandibular first molar and step-wise excavation of deep caries in the left mandibular first molar, the extensive occlusal restorations were digitally designed using CAD software, upon which digital wax-ups were 3D-printed. Bi-layer clear mini-indices consisting of a hard outer plastic layer and an elastic inner silicone layer were prepared from the 3D-printed cast. The bonding surfaces were deproteinized using a 6% sodium hypochlorite solution, and an antioxidant (Clearfil DC Activator; Kuraray Noritake) was utilized to improve the dentin bonding durability of a 2-step self-etch adhesive (Clearfil SE Bond 2; Kuraray Noritake). Subsequently, a highly filled universal-shade flowable resin composite (RC) was incrementally placed into the cavities. To create the final occlusal morphology, the same RC was inversely injected through the opening of the bi-layer indices. RESULTS: The workflow was feasible, and the occlusal cavities were efficiently restored using the injection technique. Occlusal carving and adjustments of the morphology were not necessary, leading to less chair time. At the 1-year follow-up, the clinical outcome was excellent. CONCLUSION: The injection technique with a bi-layer clear mini-index accurately translated the digital wax-ups into large, final restorations. Precise morphology and shortened chair time enhanced patient satisfaction, but at the expense of multiple visits.
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Suscetibilidade à Cárie Dentária , Cimentos Dentários , Humanos , Criança , Adolescente , Cimentos Dentários/química , Resinas Compostas/química , Cimentos de Resina/química , Antioxidantes , Restauração Dentária Permanente , Adesivos Dentinários/químicaRESUMO
In this article, we report successful orthodontic treatment combined with segmental distraction osteogenesis after a modified LeFort II osteotomy in a patient with craniosynostosis. An 8-year-old boy diagnosed with craniosynostosis had a dished-in face, an anterior crossbite, and a skeletal Class III jaw relationship because of midfacial hypoplasia. At the age of 13 years 6 months, the maxillary second and mandibular first premolars were extracted, and leveling and alignment of both arches was started with preadjusted edgewise appliances. At age 14 years 11 months, the patient had a modified LeFort II osteotomy, and the maxillary segment was advanced 7 mm and fixed to the zygomatic bone. At the same time, segmental distraction osteogenesis was started with a rigid external distraction system, and the nasal segment was advanced for 20 days at a rate of 1.0 mm per day. The total active treatment period was 40 months. As a result of the modified segmental distraction osteogenesis, significant improvement of his severe midfacial hypoplasia was achieved without excessive advancement of the maxillary dentition. Both the facial profile and the occlusion were stable after 1 year of retention. However, the nasal segment relapsed 1.4 mm during the 1.5 years after the segmental distraction osteogenesis. Evaluation of the stability and retention suggests that some overcorrection in midfacial advancement is recommended.
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Craniossinostoses/cirurgia , Má Oclusão Classe III de Angle/cirurgia , Maxila/cirurgia , Osteogênese por Distração/métodos , Osteotomia de Le Fort/métodos , Retrognatismo/cirurgia , Cefalometria , Criança , Craniossinostoses/complicações , Humanos , Masculino , Má Oclusão Classe III de Angle/etiologia , Má Oclusão Classe III de Angle/terapia , Ortodontia Corretiva/métodos , Retrognatismo/etiologia , Extração DentáriaRESUMO
INTRODUCTION: In this study, we investigated the association between the severity of alveolar clefts in infants and the succeeding maxillofacial growth in patients affected by complete unilateral cleft lip and palate. METHODS: The subjects were 35 nonsyndromic patients affected by unilateral cleft lip and palate (n = 27) or bilateral cleft lip and palate (n = 8). Plaster models and lateral cephalograms taken at 6 years of age were analyzed and compared with the Japanese norms. In the unilateral cleft lip and palate patients, the relationship between the width of the alveolar cleft before palatoplasty and the skeletal characteristics was also explored. RESULTS: Significant deficiencies of the posterior maxilla and steep palatal planes were noted in both the unilateral and bilateral cleft lip and palate patients. However, they were not clearly observed in the unilateral cleft lip and palate patients born with a small alveolar cleft and were correlated with the severity of alveolar cleft in infancy. Neither cleft type nor the severity of the alveolar cleft was implicated in the maxillary arch form in childhood, but the growth of the alveolar height on the cleft side was less in the unilateral cleft lip and palate patients born with a large alveolar cleft. CONCLUSIONS: The severity of the alveolar cleft before palatoplasty affects the succeeding vertical maxillofacial growth in patients affected by unilateral cleft lip and palate; this suggests the necessity of a different diagnosis and treatment in unilateral cleft lip and palate patients according to the severity of the alveolar cleft in infancy.
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Fissura Palatina/patologia , Fissura Palatina/fisiopatologia , Desenvolvimento Maxilofacial , Dimensão Vertical , Processo Alveolar/crescimento & desenvolvimento , Processo Alveolar/patologia , Análise de Variância , Estudos de Casos e Controles , Cefalometria , Criança , Pré-Escolar , Fenda Labial/patologia , Arco Dental/patologia , Feminino , Humanos , Imageamento Tridimensional , Masculino , Maxila/crescimento & desenvolvimento , Maxila/patologia , Modelos Anatômicos , Modelos Dentários , Palato Duro/crescimento & desenvolvimento , Palato Duro/patologia , Valores de Referência , Índice de Gravidade de Doença , Estatísticas não ParamétricasRESUMO
One-third of postmenopausal women experience at least one osteoporotic bone fracture in their lifetime that occurs spontaneously or from low-impact events. However, osteoporosis-associated jaw bone fractures are extremely rare. It was also observed that jaw bone marrow stem cells (BMSCs) have a higher capacity to form mineralized tissues than limb BMSCs. At present, the underlying causes and mechanisms of variations between jaw bone and limb bone during postmenopause are largely unknown. Thus, the objective of the current study was to examine the site-specific effects of estrogen deficiency using comprehensive analysis of bone quantity and quality, and its association with characterization of cellular components of bone. Nine rats (female, 6 months old) for each bilateral sham and ovariectomy (OVX) surgery were obtained and maintained for 2 months after surgery. A hemi-mandible and a femur from each rat were characterized for parameters of volume, mineral density, cortical and trabecular morphology, and static and dynamic mechanical analysis. Another set of 5 rats (female, 9 months old) was obtained for assays of BMSCs. Following cytometry to identify BMSCs, bioassays for proliferation, and osteogenic, adipogenic, chondrogenic differentiation, and cell mitochondrial stress tests were performed. In addition, mRNA expression of BMSCs was analyzed. OVX decreased bone quantity and quality (mineral content, morphology, and energy dissipation) of femur while those of mandible were not influenced. Cellular assays demonstrated that mandible BMSCs showed greater differentiation than femur BMSCs. Gene ontology pathway analysis indicated that the mandibular BMSCs showed most significant differential expression of genes in the regulatory pathways of osteoblast differentiation, SMAD signaling, cartilage development, and glucose transmembrane transporter activity. These findings suggested that active mandibular BMSCs maintain bone formation and mineralization by balancing the rapid bone resorption caused by estrogen deficiency. These characteristics likely help reduce the risk of osteoporotic fracture in postmenopausal jawbone.
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Células-Tronco Mesenquimais , Animais , Densidade Óssea , Osso e Ossos , Diferenciação Celular , Estrogênios , Feminino , Humanos , Osteogênese , Ovariectomia , Ratos , Células-TroncoRESUMO
Cortical bone thickness is assumed to be a major factor regulating miniscrew stability. We investigated stress distribution in two miniscrews with different thread shapes (type A and B) and in cortical bone of three different thicknesses using three-dimensional (3D) finite element (FE) models. More specifically, 3D FE models of two different miniscrews were created and placed obliquely or vertically into a cylindrical bone model representing different cortical bone thicknesses. When force was applied to the miniscrew, the stress distribution on the screw surface and in the peri-implant bone was assessed using FE methodology. Miniscrew safety was evaluated using a modified Soderberg safety factor. Screw head displacement increased with a decrease in cortical bone thickness, irrespective of screw type. The smallest minimum principal stresses on the screw surfaces remained constant in type A miniscrews on changes in cortical bone thickness. Minimum principal stresses also appeared on the cortical bone surface. Lower absolute values of minimum principal stresses were seen in type A miniscrews when placed vertically and with upward traction in obliquely placed type B miniscrews. Both miniscrews had acceptable safety factor values. Taken together, orthodontists should select and use the suitable miniscrew for each patient in consideration of bone properties.
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Procedimentos de Ancoragem Ortodôntica , Osso Cortical , Análise de Elementos Finitos , Humanos , Procedimentos de Ancoragem Ortodôntica/métodos , Desenho de Aparelho Ortodôntico , Estresse Mecânico , TitânioRESUMO
BACKGROUND: The purpose of this study was to assess the effectiveness of training residents in an orthodontic program in the placement of miniscrews by using cone beam computed tomography (CBCT) images. A total of 90 miniscrews were placed in 15 pig mandibles over a 3-year period by 15 first-year orthodontic residents. Miniscrews were divided into three groups (Control group: no radiographs; 2D group: placement with 2D radiographs; CBCT group: placement with CBCT). Proximity of the miniscrew to the neighboring root was measured. The miniscrew success rate was examined in the graduate clinic from 2015 to 2021. RESULTS: The percentage of root contact for each group was: 36.7% (11/30), 20.0% (6/30), 0% (0/30), for the Control, 2D, and CBCT groups, respectively. The CBCT group was significantly different from the Control and 2D groups (p < 0.05). For root proximity, the miniscrews were significantly closer to the roots in the Control (p < 0.001) and 2D (p < 0.001) groups compared with the CBCT group. No significant difference was observed between the Control and 2D groups (p = 0.80). There was no significant difference among the years in the miniscrew success rate. CONCLUSIONS: Training the residents in an orthodontic graduate program using CBCT may be helpful to avoid root damage and to decrease the miniscrew failure rate.
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Procedimentos de Ancoragem Ortodôntica , Animais , Parafusos Ósseos , Tomografia Computadorizada de Feixe Cônico/métodos , Mandíbula/cirurgia , SuínosRESUMO
OBJECTIVES: To determine the accuracy of three-dimensional (3D) printed models fabricated from cone-beam computed tomography (CBCT) scans of human mandibular dry skulls in comparison with models derived from intraoral scanner (IOS) data. MATERIALS AND METHODS: Six human mandibular dry skulls were scanned by IOS and CBCT. Digital models (DMs) constructed from the IOS and CBCT data were fabricated physically using a 3D printer. The width and thickness of individual teeth and intercanine and molar widths were measured using a digital caliper. The accuracy of the DMs was compared between IOS and CBCT. Paired t-tests were used for intergroup comparisons. RESULTS: All intraclass correlation coefficient values for the three measurements (mesial-distal, buccal-lingual, width) exceeded 0.9. For the mandibular teeth, there were significant discrepancies in model accuracy between the IOS (average discrepancies of 0.18 ± 0.08 mm and 0.16 ± 0.12 mm for width and thickness, respectively) and CBCT (0.28 ± 0.07 mm for width, 0.37 ± 0.2 mm for thickness; P < .01). Intercanine (P = .38) and molar widths (P = .41) showed no significant difference between groups. CONCLUSIONS: There was a statistically significant difference in the accuracy of DMs obtained from CBCT and IOS; however, this did not seem to result in any important clinical difference. CBCT could be routinely used as an orthodontic diagnostic tool and for appliance construction.
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Imageamento Tridimensional , Dente , Humanos , Imageamento Tridimensional/métodos , Tomografia Computadorizada de Feixe Cônico/métodos , Mandíbula/diagnóstico por imagem , Dente/diagnóstico por imagem , CrânioRESUMO
Background/purpose: Primary stability of orthodontic miniscrew system is of great importance in maintaining stable anchorage during a treatment period. Thus, this study aimed to examine whether the thread shape of orthodontic miniscrew had an effect on its mechanical stability in bone. Materials and methods: Three different types of miniscrews (type A and B with a regular thread shape; type C with a novel thread shape) were placed in artificial bone block with different artificial cortical bone thickness of 1.5, 2.0 and 3.0 mm. Values of maximum insertion torque (MIT), removal torque (RT), torque ratio (TR), screw mobility, static stiffness (K), dynamic stiffness (K∗) and energy dissipation (tan δ) ability were assessed for each miniscrew system. Results: The MIT, RT, TR and K of type C miniscrew were significantly greater than those of type A and B miniscrews when the miniscrews were placed in the thinner artificial bone. Furthermore, the TR value of type C miniscrew was more than 1, indicating the MRT value was larger than the MIT value in the novel miniscrew. The values of K∗ and tan δ were almost similar among the three types of miniscrews. Conclusion: The miniscrew with a novel thread shape showed a higher initial stability compared to those with a regular thread shape. Thus, in order to obtain a sufficient initial stability, it is important to select the type of screw thread that is appropriate for the thickness of the cortical bone.
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A 6-year-old boy, diagnosed with Crouzon syndrome, had moderate exorbitism, a concave profile, an anterior crossbite of -4.0 mm, and a skeletal Class III jaw-base relationship caused by midfacial hypoplasia. At age 8 years 9 months, a LeFort III osteotomy was performed, and distraction osteogenesis was immediately started with the rigid external distractor system. The midface was advanced approximately 10.0 mm for 6 days, including overcorrection. After the distraction, a reverse headgear was used for 6 years to prevent relapse and to accelerate expected growth. At age 16 years 5 months, after extraction of the maxillary first premolars and mandibular third molars, 0.022-in preadjusted edgewise brackets were placed to treat the edge-to-edge incisor relationship and minor crowding. After 13 months of treatment, the facial profile was significantly improved, and an acceptable occlusion was achieved. During the 9-year observation period after the distraction, acceptable facial growth occurred, and no relapse of the maxillary advancement was observed. However, syndrome-specific growth and methodologically induced relapse should be considered when planning a LeFort III distraction in children for the treatment of Crouzon syndrome.
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Disostose Craniofacial/cirurgia , Fixadores Externos , Osteogênese por Distração/métodos , Osteotomia de Le Fort/métodos , Dente Pré-Molar/cirurgia , Cefalometria/métodos , Criança , Aparelhos de Tração Extrabucal , Seguimentos , Humanos , Masculino , Má Oclusão Classe III de Angle/cirurgia , Má Oclusão Classe III de Angle/terapia , Maxila/cirurgia , Desenvolvimento Maxilofacial/fisiologia , Dente Serotino/cirurgia , Braquetes Ortodônticos , Osteogênese por Distração/instrumentação , Técnica de Expansão Palatina/instrumentação , Planejamento de Assistência ao Paciente , Extração Seriada , Técnicas de Movimentação Dentária/instrumentação , Resultado do TratamentoRESUMO
We aimed to elucidate stress distribution in miniscrews and the surrounding bone when miniscrews inserted at different depths were implanted vertically or obliquely. The distributions of the equivalent stress on the screw surface and the minimum principal stress in the surrounding bone were calculated using finite element models. When the miniscrews were inserted vertically and obliquely, screw head displacement, greatest equivalent stress on the miniscrew surface, and absolute value of minimum principal stresses in the surrounding bone decreased with increasing insertion depth. Stresses in the obliquely inserted miniscrew with upward traction were smaller than in other insertion conditions, irrespective of insertion depth. With the application of orthodontic force, stress distribution around the miniscrew and surrounding bone is closely related to the insertion depth and insertion angle, which mutually affect each other. In particular, the obliquely inserted miniscrew with upward traction might be the most secure against screw failure and fracture.
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Procedimentos de Ancoragem Ortodôntica , Parafusos Ósseos , Análise do Estresse Dentário , Análise de Elementos Finitos , Estresse MecânicoRESUMO
Postmenopausal osteoporosis causes severe loss of bone quantity and quality in limb bone but has a lesser effect on jaw bone. Thus, the objective of this study was to examine whether ovariectomy (OVX) and mastication alter the regional variation of jaw bone characteristics. Sprague-Dawley female rats (6 months) were given a bilateral OVX or a sham operation (SHAM) (n = 10 for each group). After 2 months post-OVX, the hemi-mandible from each rat was dissected. A micro-computed tomography based mean, standard deviation (SD), the lower and upper 5th percentile (Low5 and High5) values of tissue mineral density (TMD) histograms were assessed for whole bone (WB), alveolar bone (AB), cortical bone (CB), and trabecular bone (TB) regions. Morphology of TB and periodontal ligament (PDL) was also obtained. Layers of AB were segmented up to 400 µm from the PDL. Mechanical properties at the tissue level were measured by nanoindentation at the same site by a single loading-unloading cycle of indentation in hydration. The AB and TB regions had significantly lower TMD Mean, Low5, and High5 but higher SD than the CB region for both sham and OVX groups (p < 0.01). TMD parameters of the OVX group rapidly increased up to 60 µm away from the PDL and were significantly higher than those of the sham group starting at 280 µm and farther in the CB region (p < 0.05). All values of morphological and nanoindentation parameters were not significantly different between sham and OVX groups (p > 0.06). Estrogen deficiency induced by OVX did not deteriorate bone characteristics including mineral density, morphology, and nanoindentation parameters in rat mandibles. Masticatory loading had an effect on the TMD parameters at the limited region of AB. These results provide insight into why osteoporosis-associated jaw bone fractures are extremely rare.
Assuntos
Densidade Óssea , Mandíbula , Animais , Feminino , Humanos , Mandíbula/diagnóstico por imagem , Ovariectomia , Ratos , Ratos Sprague-Dawley , Microtomografia por Raio-XRESUMO
BACKGROUND: We successfully treated a 37-year-old male who had skeletal open bite with severe amelogenesis imperfecta (AI) with orthodontics, compression osteogenesis, and prosthodontics. CASE PRESENTATION: The patient was diagnosed with severe anterior open bite caused by severe AI. Corticotomy was performed on both buccal and palatal sides of the molar regions, and anchor plates were placed onto the bilateral zygomatic buttress and the center of the hard palate. After corticotomy, posterior maxillary segments were moved 3.5 mm superiorly to correct skeletal open bite with elastic chains. After 8-month, overbite had decreased by 2.0 mm. After further 5 months of prosthodontic preparation, orthodontic appliances were removed, and provisional crowns were set on all teeth. The anterior open bite was corrected, and ideal occlusion with a Class I molar relationship was achieved. The upper first molars were intruded 3.5 mm, resulting in 3.0o counter-clockwise rotation of the mandible. The total active treatment period was 16 months. Acceptable occlusion with a good facial profile was well maintained throughout the 8-year retention period. CONCLUSIONS: Our results indicate long-term stability after interdisciplinary treatment combining orthodontics, oral surgery, and prosthodontics in a patient with severe anterior open bite and AI.