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1.
Eur J Orthod ; 2020 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-33300988

RESUMO

OBJECTIVE: The primary objective of this study was to quantify the orthodontic tooth movement (OTM) and orthodontically induced root resorption (OIRR) with differential force system in conjunction with minimal surgical insult. MATERIAL AND METHODS: 15-week-old, 48 male Wistar rats were used in the research and were randomly divided into six groups: 1. Group 1 (8 Wistar rats): OTM for 14 days with 8-g force; 2. Group 2 (8 Wistar rats): OTM for 14 days with 25-g force; 3. Group 3 (8 Wistar rats): OTM for 14 days with 100-g force; 4. Group 4 (8 Wistar rats): OTM for 14 days with 8-g force and alveolar decortications (ADs); 5. Group 5 (8 Wistar rats): OTM for 14 days with 25-g force and ADs; 6. Group 6 (8 Wistar rats): OTM for 14 days with 100-g force and ADs. A nickel-titanium spring was used to protract the molar mesially using maxillary incisors as an anchorage. ADs (minimal surgical insult) were done using a hand piece and a round bur, adjacent to the left first maxillary molar on the palatal alveolar bone. After 14 days of OTM, Wistar rats were killed and microfocus computed tomography and histological analysis were performed. RESULTS: The 100-g group showed significant increase (P < 0.05) in OTM. However, with ADs, the OTM was significantly higher (P < 0.05) in 8 and 100 g. In addition, with ADs, there is significant increase (P < 0.05) in OIRR and significant decrease (P < 0.05) in bone volume fraction. Histological quantification of tartrate-resistant acid phosphatase indicated a significant increase (P < 0.05) in the number of osteoclasts with ADs when compared without ADs. CONCLUSIONS: Light force in conjunction with ADs are optimal to accelerate the OTM. Additionally, ADs increases the OIRR.

2.
Angle Orthod ; 90(4): 524-531, 2020 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-33378490

RESUMO

OBJECTIVE: To determine the effect of alveolar decortication on orthodontically induced root resorption. MATERIALS AND METHODS: A total of 24 male Wistar rats (14 week old) were used. The rats were randomly divided into one of the following three groups: group 1 (control group), orthodontic tooth movement (OTM) for 2 weeks; group 2, OTM for 2 weeks + two alveolar decortications (2AD); group 3, OTM for 2 weeks + four alveolar decortications (4AD). The first molar was moved mesially for 2 weeks. Micro computed tomography was used to analyze root volume. In addition, histological sections were stained with Tartrate Resistant Acid Phosphatase (TRAP) to quantify the osteoclast number. RESULTS: The buccal root volume in OTM + 4AD group was decreased by 8.92% and 6.11% when compared with the OTM-only group and OTM + 2AD group, respectively. Similarly, the other four root volumes in the OTM + 4AD group was decreased by 8.99% and 5.24% when compared with the OTM-only group and OTM + 2AD group, respectively. There was a decrease in buccal root density in the OTM + 4AD group by 4.66% and 3.56% when compared with the OTM-only group and the OTM + 2AD group, respectively. In addition, there was an increase in the number of osteoclasts by 195.73% and 98.74% in OTM + 4AD group in comparison with the OTM and OTM + 2AD group. CONCLUSIONS: The amount of orthodontically induced root resorption was positively correlated with the extent of surgical injury used to accelerate orthodontic tooth movement.


Assuntos
Reabsorção da Raiz , Animais , Masculino , Osteoclastos , Ratos , Ratos Wistar , Reabsorção da Raiz/diagnóstico por imagem , Reabsorção da Raiz/etiologia , Técnicas de Movimentação Dentária/efeitos adversos , Raiz Dentária/diagnóstico por imagem , Microtomografia por Raio-X
4.
Dental Press J Orthod ; 25(4): 44-50, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32965386

RESUMO

OBJECTIVE: To perform a numerical simulation using FEM to study the von Mises stresses on Mushroom archwires. METHODS: Mushroom archwires made of titanium-molybdenum alloy with 0.017 x 0.025-in cross-section were used in this study. A YS of 1240 MPa and a Young's modulus of 69 GPa were adopted. The archwire was modeled in Autodesk Inventor software and its behavior was simulated using the finite element code Ansys Workbench (Swanson Analysis Systems, Houston, Pennsylvania, USA). A large displacement simulation was used for non-linear analysis. The archwires were deformed in their extremities with 0° and 45°, and activated by their vertical extremities separated at 4.0 or 5.0 mm. RESULTS: Tensions revealed a maximum of 1158 MPa at the whole part of the loop at 5.0mm of activation, except in a very small area situated at the top of the loop, in which a maximum of 1324 Mpa was found. CONCLUSIONS: Mushroom loops are capable to produce tension levels in an elastic range and could be safely activated up to 5.0mm.


Assuntos
Agaricales , Incisivo , Fenômenos Biomecânicos , Módulo de Elasticidade , Análise de Elementos Finitos , Estresse Mecânico
5.
Prog Orthod ; 21(1): 23, 2020 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-32830306

RESUMO

OBJECTIVES: To evaluate the dental and skeletal effects that occur in the correction of anterior open bite with clear aligners. MATERIALS AND METHOD: In this single-center retrospective study, the mechanism of anterior open bite closure using clear aligners (Invisalign, Align Technology, Santa Clara, CA, USA) was evaluated by cephalometric superimposition based on records of patients consecutively treated by a single, experienced Invisalign provider. Inclusion criteria consisted of anterior open bite (overbite < 0.5 mm), adult patients (18+) at the beginning of treatment, consecutive records, and good quality pre- and post-treatment records, where the required landmarks were clearly visible. RESULTS: A total of 45 patients were included for data analysis with a mean age of 30.73 ± 8.0 years and initial open bite of - 1.21 ± 1.15 mm. During treatment, the upper incisors showed significant (p < 0.05) retraction [U1-SN'(°) = - 10.91 ± 6.95°], [U1-SN'perp(mm) = - 2.57 ± 1.75 mm] and extrusion [U1-SN'(mm) = 1.45 ± 0.89 mm]. The lower incisors also showed significant retraction [IMPA(°) = - 3.73 ± 4.91°), (ΔL1-MP'perp (mm) = - 1.08 ± 1.59] and extrusion (ΔL1-MP'(mm) = 0.53 ± 0.74). Regarding molar position, no significant changes were noted in the anteroposterior position of the upper [ΔU6-SN'perp(mm) = 0.01 ± 1.08 mm] and lower molar [ΔL6-MP'perp(mm) = 0.03 ± 0.87 mm]; however, there was a statistically significant intrusion of the upper [ΔU6-SN'(mm) = - 0.47 ± 0.59 mm] and lower molar [ΔL6-MP'(mm) = - 0.39 ± 0.76 mm]. CONCLUSION: Open bite closure with clear aligners occurred due to a combination of maxillary and mandibular incisor extrusion and maxillary and mandibular molar intrusion, with slight mandibular auto rotation. Significant retraction of maxillary and mandibular incisors was also observed with treatment. Clear aligners are effective in reducing/controlling the vertical dimension in open bite patients.


Assuntos
Má Oclusão de Angle Classe II , Mordida Aberta , Aparelhos Ortodônticos Removíveis , Adulto , Cefalometria , Humanos , Estudos Retrospectivos , Técnicas de Movimentação Dentária , Adulto Jovem
6.
Dental press j. orthod. (Impr.) ; 25(4): 44-50, July-Aug. 2020. tab, graf
Artigo em Inglês | LILACS-Express | LILACS, BBO - Odontologia | ID: biblio-1133679

RESUMO

ABSTRACT Objective: To perform a numerical simulation using FEM to study the von Mises stresses on Mushroom archwires. Methods: Mushroom archwires made of titanium-molybdenum alloy with 0.017 x 0.025-in cross-section were used in this study. A YS of 1240 MPa and a Young's modulus of 69 GPa were adopted. The archwire was modeled in Autodesk Inventor software and its behavior was simulated using the finite element code Ansys Workbench (Swanson Analysis Systems, Houston, Pennsylvania, USA). A large displacement simulation was used for non-linear analysis. The archwires were deformed in their extremities with 0° and 45°, and activated by their vertical extremities separated at 4.0 or 5.0 mm. Results: Tensions revealed a maximum of 1158 MPa at the whole part of the loop at 5.0mm of activation, except in a very small area situated at the top of the loop, in which a maximum of 1324 Mpa was found. Conclusions: Mushroom loops are capable to produce tension levels in an elastic range and could be safely activated up to 5.0mm.


RESUMO Objetivo: Realizar uma simulação numérica, por meio do Método dos Elementos Finitos (MEF), para obter as tensões de von Mises em arcos Mushroom. Métodos: Foram usados arcos com geometria Mushroom de titânio-molibdênio, com secção transversal 0,017" x 0,025". Adotou-se valores de tensão de escoamento (σesc) de 1.240 MPa e módulo de elasticidade (E) de 69 GPa. O arco foi modelado por meio do software Autodesk Inventor, e seu desempenho foi simulado utilizando-se o software de elementos finitos Ansys Workbench (Swanson Analysis System, Houston, Pennsylvania, EUA). Para a simulação, foi considerada a análise para grandes deslocamentos. O arco foi conformado em suas extremidades considerando-se planos de 0° e 45°, pré-ativado em 2,5mm e ativado por meio de suas extremidades verticais, separadas 4,0 mm ou 5,0 mm. Resultados: As tensões revelaram um valor máximo de 1.158 MPa na maior parte da alça, aos 5,0 mm de ativação, com exceção de uma área muito pequena, com valor de 1.324 MPa, situada no topo da alça. Conclusões: Os arcos Mushroom são capazes de produzir níveis de tensão situados dentro da região elástica e poderiam ser ativados com segurança até os 5,0 mm de ativação.

7.
Eur J Orthod ; 42(4): 378-386, 2020 09 11.
Artigo em Inglês | MEDLINE | ID: mdl-32572439

RESUMO

INTRODUCTION: The aim of this study was to investigate the effect of supplemental vibratory force on biomarkers of bone remodelling during orthodontic tooth movement, the rate of mandibular anterior alignment (RMAA), and compliance with a vibration device. DESIGN, SETTINGS, AND PARTICIPANTS: Forty patients between the ages 15-35 undergoing fixed appliance treatment that presented to a university orthodontic clinic were randomly allocated to supplemental use of an intraoral vibrational device (n = 20, AcceleDent®) or fixed appliance only (n = 20). Salivary multiplex assay was completed to analyse the concentration of selected biomarkers of bone remodelling before treatment (T0) and at three following time points (T1, T2, T3), 4-6 weeks apart. Irregularity of the mandibular anterior teeth and compliance was assessed at the same trial time points. Data were analysed blindly on an intention-to-treat basis with descriptive statistics, Mann-Whitney U-test, Wilcoxon signed-rank test, and linear mixed effects regression modelling. RESULTS: No difference in the changes in salivary biomarkers of bone remodelling and RMAA between groups at any time point over the trial duration was observed. No correlation was found between changes in irregularity and biomarker level from baseline to another time point. Lastly, there was no association between RMAA and compliance with the AcceleDent® device. CONCLUSIONS: Supplemental vibratory force during orthodontic treatment with fixed appliances does not affect biomarkers of bone remodelling or the RMAA. LIMITATIONS: The main limitation of the study was the small sample size and the large variability in the salivary biomarkers. HARMS: No harms were observed during the duration of the trial. PROTOCOL: The protocol was not published prior to trial commencement. REGISTRATION: The study was registered in Clinical Trials.gov (NCT02119455) first posted on April 2014.


Assuntos
Aparelhos Ortodônticos Fixos , Técnicas de Movimentação Dentária , Vibração , Adolescente , Adulto , Biomarcadores , Humanos , Aparelhos Ortodônticos , Projetos Piloto , Adulto Jovem
9.
Angle Orthod ; 2020 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-32134334

RESUMO

OBJECTIVE: To determine the effect of alveolar decortication on orthodontically induced root resorption. MATERIALS AND METHODS: A total of 24 male Wistar rats (14 week old) were used. The rats were randomly divided into one of the following three groups: group 1 (control group), orthodontic tooth movement (OTM) for 2 weeks; group 2, OTM for 2 weeks + two alveolar decortications (2AD); group 3, OTM for 2 weeks + four alveolar decortications (4AD). The first molar was moved mesially for 2 weeks. Micro computed tomography was used to analyze root volume. In addition, histological sections were stained with Tartrate Resistant Acid Phosphatase (TRAP) to quantify the osteoclast number. RESULTS: The buccal root volume in OTM + 4AD group was decreased by 8.92% and 6.11% when compared with the OTM-only group and OTM + 2AD group, respectively. Similarly, the other four root volumes in the OTM + 4AD group was decreased by 8.99% and 5.24% when compared with the OTM-only group and OTM + 2AD group, respectively. There was a decrease in buccal root density in the OTM + 4AD group by 4.66% and 3.56% when compared with the OTM-only group and the OTM + 2AD group, respectively. In addition, there was an increase in the number of osteoclasts by 195.73% and 98.74% in OTM + 4AD group in comparison with the OTM and OTM + 2AD group. CONCLUSIONS: The amount of orthodontically induced root resorption was positively correlated with the extent of surgical injury used to accelerate orthodontic tooth movement.

10.
Eur J Orthod ; 2020 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-32077935

RESUMO

OBJECTIVE: The aim of this study was to evaluate and compare the amount of external apical root resorption (EARR) observed during the orthodontic treatment with pre-adjusted edgewise appliance (PEA) or clear aligner therapy (CAT) and with 2D or 3D radiographic methods of measuring the root resorption. SEARCH STRATEGY AND SELECTION CRITERIA: A search of PubMed MEDLINE, Scopus, Cochrane Central Register of Controlled Trials, LILACS, Web of Science, Dissertations & Theses Global, ClinicalTrials.gov registry, and the ISRCTN Registry was performed. Studies that have evaluated the amount of root resorption in non-extraction cases using CAT or PEA were selected for the systematic review. A meta-analysis was performed for the amount of root resorption of permanent maxillary incisors using PEA or CAT treatment modalities by either 2D or cone-beam computed tomography radiographic examination. DATA COLLECTION AND ANALYSIS: Database research, elimination of duplicate studies, data extraction, and risk of bias were performed by authors independently and in duplication. A random-effect meta-analysis followed by subgroup comparisons were performed to evaluate EARR. RESULTS: A total of 16 studies (4 were prospective and 12 were retrospective) were identified for inclusion in the systematic review. The mean root resorption for the permanent maxillary incisors was in the range from 0.25 to 1.13 mm (overall: 0.49 mm; 95% confidence interval [CI] = 0.24 to 0.75 mm). The mean root resorption difference between CAT and PEA was statistically significant (P < 0.05) for 12 but not for 21, 11, or 22. LIMITATIONS: One of the drawbacks is a lack of good quality prospective studies, specifically randomized clinical trials in the literature. CONCLUSIONS AND IMPLICATIONS: Neither PEA or CAT technique leads to clinically significant root resorption (1 mm) of the maxillary incisors. The amount of EARR of maxillary incisors is not significant in comparing two treatment modalities (PEA and CAT), except for 12, where the PEA group has significantly more EARR when compared to CAT. REGISTRATION: The protocol for this systematic review was based on the Cochrane Handbook for Systematic Reviews of Interventions 5.1.0 and was registered at PROSPERO database (https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42018113051). This systematic review is reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement.

11.
Am J Orthod Dentofacial Orthop ; 157(2): 228-239, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32005475

RESUMO

INTRODUCTION: The objective of this study was to assess the reproducibility of cervical vertebral maturation (CVM) method based on the type of radiographic image and the level of experience and level of training of the evaluator. METHODS: Ten evaluators (5 orthodontic residents and 5 faculty members) were randomly divided into 2 groups: trained and untrained. All participants evaluated 80 radiographic images previously acquired in 4 different formats: (1) 2-dimensional (2D) digital (2D-digital), (2) 2D digitized hard copy from the Iowa Facial Growth Study (American Association of Orthodontists Foundation Craniofacial Growth Legacy Collection), (3) 2D digital reconstructed from a 3-dimensional (3D) radiograph (2D-from 3D), and (4) 3D cone-beam computerized tomographic (3D-CBCT) images. Agreement among evaluators on the morphology of the cervical vertebrae (CV) and the CVM stage of each radiographic image was assessed using Randolph's kappa statistic and Kendall's W coefficient of concordance. RESULTS: Interobserver agreement on the determination of a curvature on the inferior border of the CV was substantial to perfect, whereas agreement on shape was fair to moderate. Overall, the level training in all image types, except 3D-CBCTs, but not the level of experience affected the agreement for shape and curvature of the CVs. Interobserver agreement on CVM staging for all combined images was substantial at 0.72. Faculty had a higher level of agreement than residents except for 2D-digital and 3D-CBCT images, whereas trained evaluators had an overall higher level of agreement than untrained evaluators except for 3D-CBCT images. CONCLUSIONS: Interobserver agreement in determining CVM stage was substantial for all images evaluated; experience and training resulted in higher level of agreement for some image types. The 3D-CBCT images did not provide increased interobserver agreement over current 2D-digital lateral cephalograms in determining CVM staging or shape of the CV. The highest agreement in CVM staging was obtained on 2D-digital lateral cephalograms with training.


Assuntos
Cefalometria , Vértebras Cervicais , Tomografia Computadorizada de Feixe Cônico , Ortodontia/educação , Vértebras Cervicais/diagnóstico por imagem , Competência Clínica , Humanos , Imageamento Tridimensional , Iowa , Variações Dependentes do Observador , Reprodutibilidade dos Testes
12.
Eur J Orthod ; 42(4): 371-377, 2020 09 11.
Artigo em Inglês | MEDLINE | ID: mdl-32065225

RESUMO

BACKGROUND AND OBJECTIVES: Orthodontic relapse is a physiologic process that involves remodelling of the alveolar bone and principle periodontal ligament fibres. Raloxifene is an Food and Drug Administration (FDA)-approved selective oestrogen receptor modulator that inhibits systemic bone loss. In our study, we examined the effects of Raloxifene on alveolar bone modelling and orthodontic relapse in a rodent model. MATERIALS AND METHODS: The efficacy of raloxifene was evaluated in 15-week-old male Wistar rats, 8 in each group (Control, Raloxifene, Raloxifene + 7-day relapse, Raloxifene + 14-day relapse) for a total of 42 days. All animals had 14 days of orthodontic tooth movement with a closed nickel-titanium coil spring tied from incisors to right first molar applying 5-8 gm of force. On the day of appliance removal, impression was taken with silicon material and the distance between first molar and second molar was filled with light-cured adhesive resin cement for retention phase. Raloxifene Retention, Raloxifene Retention + 7D, Raloxifene Retention + 14D groups received 14 daily doses of raloxifene (2.0 mg/kg/day) subcutaneously after orthodontic tooth movement during retention. After 14 days of retention, the retainer was removed and right first molar was allowed to relapse for a period of 14 days. Raloxifene injection continued for the Raloxifene + 14-day relapse group during relapse phase too. Control group received saline injections during retention. Animals were euthanized by CO2 inhalation. The outcome measure included percentage of relapse, bone volume fraction, tissue density, and histology analysis using tartrate-resistant acid phosphatase staining and determining receptor activator of nuclear factor-кB-ligand (RANKL) and osteoprotegerin expression. RESULTS: Raloxifene Retention + 14D group had significantly less (P < 0.05) orthodontic relapse when compared with other groups. There was a significant increase (P < 0.05) in bone volume fraction and tissue density in the Raloxifene Retention + 14D group when compared with other groups. Similarly, there was significant decrease in number of osteoclasts and RANKL expression in Raloxifene Retention + 14D group when compared with Raloxifene Retention + 7D group (P < 0.05). CONCLUSION: Raloxifene could decrease post-orthodontic treatment relapse by decreasing bone resorption and indirectly enhancing bone formation.


Assuntos
Cloridrato de Raloxifeno/farmacologia , Técnicas de Movimentação Dentária , Animais , Remodelação Óssea , Masculino , Dente Molar , Osteoclastos , Ratos , Ratos Wistar , Recidiva
13.
Eur J Orthod ; 42(3): 317-325, 2020 06 23.
Artigo em Inglês | MEDLINE | ID: mdl-31147678

RESUMO

BACKGROUND: Accelerating orthodontic tooth movement (OTM) through biologically effective methods, such as increasing osteoclast-mediated alveolar resorption, could effectively shorten treatment time. OBJECTIVE: To evaluate an injectable formulation containing receptor activator of nuclear factor kappa-B ligand (RANKL) on the OTM. MATERIALS AND METHODS: We fabricated a RANKL formulation from 100 µl of 100 µg/ml RANKL adsorbed on 10 mg of poly(lactic acid-co-glycolic acid) microspheres embedded in a 10 wt% aqueous hydroxyethyl cellulose carrier gel. We characterized these formulations for the rate of RANKL release, and then tested for bioactivity using in vitro cell culture. In vivo OTM studies were conducted using 15 week old male Wistar rats for 14 days. We injected the RANKL formulations palatal to the left maxillary first molar and accomplished OTM with a nickel-titanium (NiTi) coil spring applying 5-8 g force. Control groups involved the application of NiTi coil spring with and without placebo formulation. The outcome measure included the distance of tooth movement, bone volume fraction, tissue density, and root volume determined with micro-computed tomography. We determined the amount of osteoclast activity using tartrate-resistant acid phosphatase (TRAP) staining. RESULTS: These formulations were able to sustain the release of RANKL for more than 30 days, and the released RANKL showed a positive effect on mice osteoclast precursor cells (RAW 264.7). Reported injectable RANKL formulations were effective in accelerating OTM compared with other control groups, with 129.2 per cent more tooth movement than no formulation and 71.8 per cent more than placebo formulation, corresponding with a significant increase in the amount of TRAP activity. We did not observe any significant differences in root resorption between the groups. CONCLUSION: Our study shows a significant increase in OTM with injectable formulations containing RANKL.


Assuntos
Osteoclastos , Técnicas de Movimentação Dentária , Animais , Preparações de Ação Retardada , Masculino , Camundongos , Ratos , Ratos Wistar , Microtomografia por Raio-X
14.
Am J Orthod Dentofacial Orthop ; 156(5): 675-684, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31677676

RESUMO

Orthognathic surgery is necessary when a patient's major complaints include skeletal discrepancies that cannot be corrected with orthodontic treatment alone. Currently, orthognathic surgery can be performed through conventional and surgery-first approaches. Some advantages are attributed to the surgery-first approach, such as shortened treatment time and immediate esthetic improvement. The aim of this case report is to present the retreatment of a patient presenting with a skeletal Class III malocclusion, with maxillary retrusion and mandibular protrusion, who was successfully treated with the surgery-first approach and customized lingual appliances, combined with miniplate anchorage in the postoperative orthodontic treatment. The total orthodontic treatment time was 8 months.


Assuntos
Procedimentos de Ancoragem Ortodôntica , Cirurgia Ortognática , Procedimentos Cirúrgicos Ortognáticos , Cefalometria , Estética Dentária , Humanos , Aparelhos Ortodônticos , Retratamento , Língua
16.
Eur J Orthod ; 41(6): 601-608, 2019 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-30828725

RESUMO

OBJECTIVE: The primary objective of this study was to investigate how the extent of surgical insult affects the orthodontic tooth movement (OTM) and the alveolar bone modelling and remodelling in a rodent model. MATERIAL AND METHODS: 15-week-old male Wistar rats were used in the research and they were randomly divided into three treatment groups: (1) OTM only (N = 8); (2) OTM + 2 alveolar decortication (AD) (less surgical insult) (N = 8); and (3) OTM + 4 AD (more surgical insult) (N = 8). A nickel-titanium spring delivering 5-8 g of force was used to protract the molar mesially using maxillary incisors as an anchorage. AD was done using a hand piece and a round bur, adjacent to the left first maxillary molar on the palatal alveolar bone. After 14 days of OTM Wistar rats were killed and microfocus computed tomography and histological analysis were performed. RESULTS: The OTM + 4AD group presented with a significant increase (P < 0.05) in the rate of tooth movement when compared to OTM + 2AD group and OTM only group. In addition, the OTM + 4AD group had a significant decrease in bone volume and tissue density (P < 0.05) and a significant increase (P < 0.05) in the trabecular spacing and trabecular thickness when compared to OTM only. Histological quantification of tartrate-resistant acid phosphatase indicated a significant percent increase (P < 0.05) in OTM + 4AD group, when compared to OTM + 2AD and OTM only group. RESULTS: Increased surgical insult increases the rate of OTM. Additionally, increased surgical insult decreases the bone volume and the tissue density.


Assuntos
Remodelação Óssea , Técnicas de Movimentação Dentária/efeitos adversos , Animais , Masculino , Dente Molar/cirurgia , Osteoclastos , Ratos , Ratos Wistar , Fosfatase Ácida Resistente a Tartarato
17.
Eur J Orthod ; 41(5): 513-518, 2019 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-30715310

RESUMO

OBJECTIVE: To investigate the factors associated with the change in alveolar bone level of mandibular second and third molars after second molar protraction into the space of the missing first molar (L6) or second premolar (LE). METHODS: Fifty-one patients in whom space of the missing L6 or LE was treated with second molar protraction (13 males, 38 females, mean age 19.6 ± 4.7 years) from 2003 to 2015 were included. The alveolar bone level and position and angulation of the mandibular second and third molars were measured in panoramic radiographs at pre-treatment (T1), and after the alignment of the third molars following second molar protraction (T2). Factors associated with alveolar bone loss on the distal aspect of the mandibular second molars were assessed using linear regression analysis. RESULTS: Age at T1 (P < 0.001) and third molar angulation at T1 (P = 0.002) were significant factors for the prediction of alveolar bone level distal to the second molars. LIMITATION: This study used two-dimensional panoramic radiographs, and we could observe only the interproximal bone level. CONCLUSIONS: After second molar protraction into the missing first molar or second premolar space, mandibular second molars may exhibit alveolar bone resorption in the distal root in older patients and in those with mesially tilted third molars before treatment.


Assuntos
Dente Serotino/diagnóstico por imagem , Dente Molar/diagnóstico por imagem , Adolescente , Adulto , Idoso , Dente Pré-Molar/cirurgia , Feminino , Humanos , Masculino , Mandíbula/diagnóstico por imagem , Radiografia Panorâmica , Adulto Jovem
19.
Orthod Craniofac Res ; 22(1): 32-37, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30451366

RESUMO

OBJECTIVES: To evaluate the amount of external apical root resorption (EARR) secondary to orthodontic treatment in patients with Short Root Anomaly (SRA) compared to patients with average root lengths using Cone Beam Computed Tomography (CBCT). SETTINGS AND SAMPLE POPULATION: Cone beam computed tomography scans of 23 SRA and 26 control patients were selected from 232 pretreatment scans from a single private practice. MATERIALS AND METHODS: Cone beam computed tomography scans before (T1) and after orthodontic treatment (T2) were evaluated for differences in the change in tooth and root length of the maxillary incisors between both groups. Gender, treatment duration and age were examined as covariates. RESULTS: The mean values for root and tooth length of the maxillary incisors decreased by a range of 0.6 to 1.3 mm after orthodontic treatment. There was no significant difference between the groups for the majority of the measurements although there was a trend for less EARR in the SRA group. The maxillary left central incisor had significantly less proportional and non-proportional loss in tooth length in the SRA group. Age, gender and treatment duration were not associated with change in the proportional and non-proportional lengths for both groups. CONCLUSION: Patients with SRA did not exhibit a significant difference in the proportional and non-proportional change of length after orthodontic treatment when compared to the controls for most measurements. Only tooth length for the maxillary left central incisor had significantly less reduction after orthodontic treatment for both the proportional and non-proportional measurements in the SRA group compared to the control group.


Assuntos
Reabsorção da Raiz/etiologia , Ápice Dentário/anormalidades , Técnicas de Movimentação Dentária/efeitos adversos , Estudos de Casos e Controles , Tomografia Computadorizada de Feixe Cônico , Feminino , Humanos , Masculino , Estudos Retrospectivos , Fatores de Risco , Reabsorção da Raiz/diagnóstico por imagem , Ápice Dentário/diagnóstico por imagem , Adulto Jovem
20.
Prog Orthod ; 19(1): 43, 2018 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-30393829

RESUMO

BACKGROUND: The objective was to compare the palatal bone thickness (PBT) and palatal bone density (PBD) in the anterior, middle, and posterior part of the palate in males and females. METHODS: This retrospective study reviewed cone beam computed tomography scans of 359 patients. The scans were divided into 99 growing males, 105 growing females, 74 non-growing males, and 81 non-growing females. The measurements of PBT and PBD were made in between the canine and first premolar, the first premolar and second premolar, the second premolar and first molar, and the first molar and second molar. The measurements were made in the center of the palate and 4 mm away from the center. ANOVA was used to analyze the PBT and PBD in different areas between four different groups. RESULTS: The PBT was lower (P <  0.0001) as we moved from the anterior to the posterior palate. The PBT was more (P <  0.001) in the center of the palate than 4 mm away from the center, except in between the canine and first premolar. The growing male and non-growing male had higher (P <  0.0001) PBT than the growing female and non-growing female in between the canine and first premolar and the first premolar and second premolar both in the center and 4 mm away from it. The PBD was higher (P <  0.05) in between the canine and first premolar area at the center of the palate and between the second premolar and first molar 4 mm away from the center in all the experimental groups. CONCLUSIONS: There exists a definite gender and growth variation in the PBT and PBD in different parts of the palate. Palatal bone thickness between the males and females revealed that the males had significantly higher PBT than the females.


Assuntos
Implantes Dentários , Palato Duro/anatomia & histologia , Palato Duro/crescimento & desenvolvimento , Adolescente , Adulto , Criança , Tomografia Computadorizada de Feixe Cônico/métodos , Feminino , Humanos , Imageamento Tridimensional , Masculino , Palato Duro/diagnóstico por imagem , Estudos Retrospectivos , Fatores Sexuais , Adulto Jovem
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