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1.
Int Orthod ; 2021 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-33516650

RESUMO

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 This was supplemented with search in 6 additional resources for published, unpublished and ongoing trials up.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

2.
Angle Orthod ; 90(6): 794-800, 2020 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-33378521

RESUMO

OBJECTIVES: To determine whether there was a correlation between patients' bone thickness and time spent in orthodontic treatment. The secondary aim was to study the influence of Angle classification, extraction treatment, and age on overall treatment duration. MATERIALS AND METHODS: In this retrospective study, records of 971 orthodontic patients from two centers were reviewed and 500 subjects were included after imposing inclusion/exclusion criteria. The Mental Index was used to determine patients' bone density. For the Mental Index, a line perpendicular to the inferior border of the mandible was drawn on a panoramic radiograph so that it intersected the inferior border of the mental foramen. The mandibular cortical thickness was measured along this line. Two-sample t-test or a chi-square test, followed by multiple linear regression, were used to identify the factors affecting treatment duration. RESULTS: Mandibular cortical thickness was negatively associated with treatment time for all subjects (P < .05). After adjusting for covariables, it remained significant for center-1, but non-significant for center-2 subjects. Angle Class II and Class III malocclusion, extraction therapy, and age had significant positive correlations with treatment duration (P < .05). CONCLUSIONS: There is a negative correlation between the mandibular cortical thickness and orthodontic treatment duration. An extraction treatment plan and treatment of Angle Class II and Class III malocclusions significantly increase the duration of orthodontic treatment. Additionally, patients over 12 years of age have shorter treatment times compared to patients under 12 years of age.


Assuntos
Má Oclusão de Angle Classe II , Mandíbula , Cefalometria , Criança , Osso Cortical/diagnóstico por imagem , Humanos , Má Oclusão de Angle Classe II/diagnóstico por imagem , Má Oclusão de Angle Classe II/terapia , Mandíbula/diagnóstico por imagem , Radiografia Panorâmica , Estudos Retrospectivos
3.
Artigo em Inglês | MEDLINE | ID: mdl-33221093

RESUMO

INTRODUCTION: The primary objective of the study was to quantitatively analyze the width and height of the mandibular buccal shelf area (MBS) at 3 different potential locations for mini-implant placement. In addition, we aimed to compare and contrast the bone parameters of the MBS to study the correlation between different growth status (growing or nongrowing), facial types (hypodivergent, normodivergent, and hyperdivergent), and sex differences (male or female). METHODS: In this retrospective cone-beam computed tomography study, 678 subjects were included. They were divided into groups according to growth status, facial type, and sex. Scans were imported into the reconstruction program and were aligned in 3 different steps. Measurements were made at 6 different coronal sections: mandibular first molar distal root, second molar mesial root, and second molar distal root (bilaterally). The roots of mandibular molars were used as a reference to measure the width and the roof of the inferior alveolar canal to measure the height of the buccal shelf area. Intraobserver reliability was assessed by measuring the width and height of MBS in 20 randomly selected subjects. RESULTS: No significant difference (P > 0.05) was found in the width of MBS between males and females. MBS width increased, and height decreased (P < 0.0001) as moved distally from the first molar distal root to the second molar distal root in all 3 facial types irrespective of age or sex. The hypodivergent facial type had significantly greater bone width than the hyperdivergent facial type at all the 3 locations in both males and females. The hypodivergent facial type had significantly less (P < 0.0001) bone height than the hyperdivergent group at all the 3 locations irrespective of age or sex. CONCLUSIONS: The optimal site for MBS mini-implant is the buccal region of the distal root of mandibular second molars. Hypodivergent patients have more width and less height of MBS compared with hyperdivergent patients. MBS mini-implants are not advised for growing patients because of proximity to developing roots.

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.
Bioengineering (Basel) ; 7(2)2020 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-32545428

RESUMO

Extraction of teeth is an important treatment decision in orthodontic practice. An expert system that is able to arrive at suitable treatment decisions can be valuable to clinicians for verifying treatment plans, minimizing human error, training orthodontists, and improving reliability. In this work, we train a number of machine learning models for this prediction task using data for 287 patients, evaluated independently by five different orthodontists. We demonstrate why ensemble methods are particularly suited for this task. We evaluate the performance of the machine learning models and interpret the training behavior. We show that the results for our model are close to the level of agreement between different orthodontists.

7.
Clin Anat ; 2020 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-32427363

RESUMO

INTRODUCTION: The objective of this study was to classify median palatine suture (MPS) maturation type in young and adult patients. Additionally, we compared MPS maturity type and density based on sex and growth status. MATERIALS AND METHODS: In this retrospective cone beam computed tomography study, we included a total of 221 subjects, grouped based on sex and growth status. Once scans were aligned and oriented in the sagittal view, we conducted our evaluations on the axial sections. Based on interdigitation and shape, the MPS were categorized into Maturation Types A through E. Additionally, MPS density was measured as Hounsfield unit equivalent pixel intensity value scale for anterior and posterior sutural regions. RESULTS: The majority of male (39%) and female (42%) subjects had MPS Maturation Type C. A maximum number of growing (42%) patients had Type C and nongrowing subjects (39%) had Type E sutures. The sex comparison showed significantly lower (p < .001) MPS density for both anterior and posterior regions in males when compared to females. Additionally, for the posterior region, nongrowing males had significantly lower (p < .001) MPS density when compared to nongrowing females. Subgroup comparisons of the MPS densities between growing and nongrowing males and growing and nongrowing females showed a significant difference (p < .001). CONCLUSION: Classification of the MPS based on the maturation types provides a reliable predictor for orthodontic treatment planning. MPS density is significantly higher in females as compared to males. Similarly, nongrowing individuals have significantly higher MPS density compared to growing individuals for both anterior and posterior locations.

8.
J Vis Exp ; (158)2020 04 08.
Artigo em Inglês | MEDLINE | ID: mdl-32338652

RESUMO

The center of resistance (CRES) is regarded as the fundamental reference point for predictable tooth movement. The methods used to estimate the CRES of teeth range from traditional radiographic and physical measurements to in vitro analysis on models or cadaver specimens. Techniques involving finite element analysis of high-dose micro-CT scans of models and single teeth have shown a lot of promise, but little has been done with newer, low-dose, and low resolution cone beam computed tomography (CBCT) images. Also, the CRES for only a few select teeth (i.e., maxillary central incisor, canine, and first molar) have been described; the rest have been largely ignored. There is also a need to describe the methodology of determining the CRES in detail, so that it becomes easy to replicate and build upon. This study used routine CBCT patient images for developing tools and a workflow to obtain finite element models for locating the CRES of maxillary teeth. The CBCT volume images were manipulated to extract three-dimensional (3D) biological structures relevant in determining the CRES of the maxillary teeth by segmentation. The segmented objects were cleaned and converted into a virtual mesh made up tetrahedral (tet4) triangles having a maximum edge length of 1 mm with 3matic software. The models were further converted into a solid volumetric mesh of tetrahedrons with a maximum edge length of 1 mm for use in finite element analysis. The engineering software, Abaqus, was used to preprocess the models to create an assembly and set material properties, interaction conditions, boundary conditions, and load applications. The loads, when analyzed, simulated the stresses and strains on the system, aiding in locating the CRES. This study is the first step in accurate prediction of tooth movement.


Assuntos
Análise de Elementos Finitos , Imageamento Tridimensional/métodos , Dente/fisiologia , Tomografia Computadorizada de Feixe Cônico , Modelos Dentários , Humanos , Maxila/diagnóstico por imagem , Software , Dente/diagnóstico por imagem , Técnicas de Movimentação Dentária/instrumentação
9.
Korean J Orthod ; 50(2): 108-119, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32257936

RESUMO

Objective: The primary objective of this study was to quantitatively analyze the bone parameters (thickness and density) at four different interdental areas from the distal region of the canine to the mesial region of the second molar in the maxilla and the mandible. The secondary aim was to compare and contrast the bone parameters at these specific locations in terms of sex, growth status, and facial type. Methods: This retrospective cone-beam computed tomography (CBCT) study reviewed 290 CBCT images of patients seeking orthodontic treatment. Cortical bone thickness in millimeters (mm) and density in pixel intensity value were measured for the regions (1) between the canine and first premolar, (2) between the first and second premolars, (3) between the second premolar and first molar, and (4) between the first and second molars. At each location, the bone thickness and density were measured at distances of 2, 6, and 10 mm from the alveolar crest. Results: The sex comparison (male vs. female) in cortical bone thickness showed no significant difference (p > 0.001). The bone density in growing subjects was significantly (p < 0.001) lower than that in non-growing subjects for most locations. There was no significant difference (p > 0.001) in bone parameters in relation to facial pattern in the maxilla and mandible for most sites. Conclusions: There was no significant sex-related difference in cortical bone thickness. The buccal cortical bone density was higher in females than in males. Bone parameters were similar for subjects with hyperdivergent, hypodivergent, and normodivergent facial patterns.

10.
Turk J Orthod ; 32(3): 182-189, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31565695

RESUMO

Protraction of posterior teeth to close the spaces in patients with congenitally missing maxillary lateral incisors is challenging. Mini-implants are a reliable source of anchorage for this purpose. This case report demonstrates the application of a T-bar protraction appliance with a palatal mini-implant for en masse protraction of posterior teeth into the lateral incisor space in an adolescent patient. The patient's occlusion and esthetics were significantly improved, and ideal overjet and overbite were obtained after 30 months of treatment. Follow-up records six months after the completion of the treatment displayed stable results.

11.
Am J Orthod Dentofacial Orthop ; 155(3): 421-431, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30826045

RESUMO

Short root anomaly (SRA) is a rare familial dental condition that is often misdiagnosed. Orthodontic treatment of patients with SRA is challenging because it is difficult to diagnose, it may be accompanied by other dental anomalies, and it has been reported to contribute to additional susceptibility to root resorption during orthodontic treatment. In this article, we describe a methodical and evidence-based means of diagnosing and orthodontically managing a patient with SRA. The patient had additional challenges, including impacted and ectopic teeth. An individualized treatment plan that incorporated efficient and effective mechanics led to a well seated occlusion and an esthetic smile.


Assuntos
Extrusão Ortodôntica/métodos , Ortodontia Corretiva/métodos , Erupção Ectópica de Dente/diagnóstico por imagem , Erupção Ectópica de Dente/terapia , Raiz Dentária/anormalidades , Raiz Dentária/diagnóstico por imagem , Dente Impactado/terapia , Adolescente , Cefalometria , Tomografia Computadorizada de Feixe Cônico , Estética Dentária , Feminino , Humanos , Radiografia Panorâmica , Sorriso , Dente Impactado/diagnóstico por imagem
12.
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
13.
J Vis Exp ; (137)2018 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-30102279

RESUMO

A proper understanding of the force system created by various orthodontic appliances can make treatment of patients efficient and predictable. Reducing the complicated multi-bracket appliances to a simple two-bracket system for the purpose of force system evaluation will be the first step in this direction. However, much of the orthodontic biomechanics in this regard is confined to 2D experimental studies, computer modeling/analysis or theoretical extrapolation of existing models. The objective of this protocol is to design, construct and validate an in vitro 3D model capable of measuring the forces and moments generated by an archwire with a V-bend placed between two brackets. Additional objectives are to compare the force system generated by different types of archwires among themselves and to previous models. For this purpose, a 2 x 4 appliance representing a molar and an incisor has been simulated. An orthodontic wire tester (OWT) is constructed consisting of two multi-axis force transducers or load cells (nanosensors) to which the orthodontic brackets are attached. The load cells are capable of measuring the force system in all the three planes of space. Two types of archwires, stainless-steel and beta-titanium of three different sizes (0.016 x 0.022 inch, 0.017 x 0.025 inch and 0.019 x 0.025 inch), are tested. Each wire receives a single vertical V-bend systematically placed at a specific position with a predefined angle. Similar V-bends are replicated on different archwires at 11 different locations between the molar and incisor attachments. This is the first time an attempt has been made in vitro to simulate an orthodontic appliance utilizing V-bends on different archwires.


Assuntos
Teste de Materiais/métodos , Desenho de Aparelho Ortodôntico/métodos , Fios Ortodônticos/estatística & dados numéricos , Humanos , Propriedades de Superfície
14.
Am J Orthod Dentofacial Orthop ; 154(2): 156-157, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-30075914
15.
Am J Orthod Dentofacial Orthop ; 153(2): 175-183, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29407494

RESUMO

INTRODUCTION: Clear aligners and to a lesser extent self-ligated brackets are considered to facilitate better oral hygiene than traditional fixed orthodontic appliances. This 3-arm parallel-group prospective randomized clinical trial compared the long-term and short-term effects of clear aligners, self-ligated brackets, and conventional (elastomeric-ligated) brackets on patients' oral hygiene during active orthodontic treatment. METHODS: Seventy-one participants (41 boys, 30 girls; mean age, 15.6 years) undergoing orthodontic treatment were randomly allocated through a computer-generated randomization schedule to one of the groups based on the choice of intervention: Clear Aligners (CLA) (Align Technology, San Jose, Calif) (n = 27), preadjusted edgewise fixed appliance with self-ligated brackets (SLB) (Carriere, Carlsbad, Calif (n = 22), or preadjusted edgewise fixed appliance with elastomeric ligated brackets (ELB) (Ortho Organizers Inc., Carlsbad, CA) (n = 22). For each participant, the primary outcome, plaque index (PI), and secondary outcomes, gingival Index (GI) and periodontal bleeding index (PBI), were measured at baseline (T0), after 9 months of treatment (T1), and after 18 months of treatment (T2). Blinding of the clinicians and the patients to the intervention was impossible. It was only done for outcome assessment and for the statistician. Ten participants did not receive the allocated intervention for various reasons. RESULTS: The means and standard deviations of PI at T0 (CLA, 0.50 ± 0.51; SLB, 0.65 ± 0.49; ELB, 0.70 ± 0.73), T1 (CLA, 0.83 ± 0.48; SLB, 1.38 ± 0.72; ELB, 1.32 ± 0.67), and T2 (CLA, 0.92 ± 0.58; SLB, 1.07 ± 0.59; ELB, 1.32 ± 0.67) were similar. The odds ratio (OR) for plaque index (0 or ≥1) comparing SLB or CLA to ELB was not significant. OR for SLB vs ELB = 1.54 at T0 (95% CI, 0.39-6.27), 0.88 at T1 (95% CI, 0.03-24.69), and 0.83 at T2 (95% CI, 0.02-27.70); OR for CLA vs ELB = 1.07 at T0 (95% CI, 0.30-3.88), 0.24 at T1 (95% CI, 0.01-1.98), and 0.17 at T2 (95% CI, 0.01-1.71). However, the odds ratios comparing CLA with ELB for GI (OR = 0.14; P = 0.015) and PBI (OR = 0.10; P = 0.012) were statistically significant at T1. CONCLUSIONS: In this prospective randomized clinical trial, we found no evidence of differences in oral hygiene levels among clear aligners, self-ligated brackets, and conventional elastomeric ligated brackets after 18 months of active orthodontic treatment. REGISTRATION: The trial is registered at ClinicalTrials.gov (NCT02745626). PROTOCOL: The protocol was not published before trial commencement.


Assuntos
Higiene Bucal , Aparelhos Ortodônticos , Ortodontia Corretiva/instrumentação , Adolescente , Índice de Placa Dentária , Feminino , Humanos , Masculino , Aparelhos Ortodônticos/efeitos adversos , Braquetes Ortodônticos/efeitos adversos , Contenções Ortodônticas/efeitos adversos , Ortodontia Corretiva/efeitos adversos , Índice Periodontal , Fatores de Tempo
16.
Eur J Orthod ; 39(2): 202-208, 2017 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-27287313

RESUMO

Background: Our previous understanding of V-bend mechanics is primarily from two-dimensional (2D) analysis of archwire bracket interactions in the second order. These analyses do not take into consideration the three-dimensional (3D) nature of orthodontic appliances involving the third order. Objective: To quantify the force system generated in a 3D two bracket set up involving the molar and incisors with vertical V-bends. Materials and methods: Maxillary molar and incisor brackets were arranged in a dental arch form and attached to load cells capable of measuring forces and moments in all three planes (x, y, and z) of space. Symmetrical V-bends (right and left sides) were placed at 11 different locations along rectangular beta-titanium archwires of various sizes at an angle of 150degrees. Each wire was evaluated for the 11 bend positions. Specifically, the vertical forces (Fz) and anterio-posterior moments (Mx) were analysed. Descriptive statistics were used to interpret the results. Results: With increasing archwire size, Fz and Mx increased at the two brackets (P < 0.05). The vertical forces were linear and symmetric in nature, increasing in magnitude as the bends moved closer to either bracket. The Mx curves were asymmetric and non-linear displaying higher magnitudes for molar bracket. As the bends were moved closer to either bracket a distinct flattening of the incisor Mx curve was noted, implying no change in its magnitude. Conclusions: This article provides critical information on V-bend mechanics involving second order and third order archwire-bracket interactions. A model for determining this force system is described that might allow for easier translation to actual clinical practice.


Assuntos
Desenho de Aparelho Ortodôntico , Fios Ortodônticos , Ligas Dentárias , Análise do Estresse Dentário/métodos , Humanos , Incisivo/fisiologia , Dente Molar/fisiologia , Aparelhos Ortodônticos , Braquetes Ortodônticos , Aço Inoxidável , Estresse Mecânico , Titânio
17.
Am J Orthod Dentofacial Orthop ; 150(5): 864-875, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27871713

RESUMO

Protraction of mandibular posterior teeth requiring absolute anchorage has always been a challenge, especially when the space is located in the anterior region, since more teeth must be protracted. Traditionally, skeletal anchorage devices have been used for anchorage reinforcement during protraction. However, drawbacks such as requirement of a surgical step, inability to tolerate heavy forces, and patient willingness to undergo such surgical procedures can be limiting factors. Additionally, the mechanics involved can sometimes create undesirable side effects, thereby limiting their application in such situations. This report describes the use of a fixed functional appliance as an anchorage-reinforcement device for en-masse protraction of mandibular posterior teeth into a missing lateral incisor space.


Assuntos
Fechamento de Espaço Ortodôntico/métodos , Fios Ortodônticos , Técnicas de Movimentação Dentária/métodos , Adolescente , Cefalometria , Humanos , Masculino , Má Oclusão de Angle Classe II/complicações , Má Oclusão de Angle Classe II/terapia , Mandíbula , Procedimentos de Ancoragem Ortodôntica/instrumentação , Procedimentos de Ancoragem Ortodôntica/métodos , Fechamento de Espaço Ortodôntico/instrumentação , Perda de Dente/complicações , Perda de Dente/terapia , Técnicas de Movimentação Dentária/instrumentação
19.
Angle Orthod ; 86(1): 32-8, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25978684

RESUMO

OBJECTIVE: To quantify the effects of tip-back mechanics on the maxillary first molars and incisors. MATERIALS AND METHODS: Sixteen subjects with Class II end-on malocclusion were treated with an intrusion arch to achieve distalization of the maxillary molar through tip-back mechanics. Lateral cephalograms were taken prior to molar tip-back (T1), after molar tip-back (T2), and after molar root uprighting (T3). Data were analyzed using the Friedman's and Wilcoxon signed rank tests to evaluate differences in time points (P ≤ .016). RESULTS: The maxillary first molar distalized 1.53 mm (P = .001) with 6.65° (P = .001) of distal tipping and 0.86 mm (P = .001) of extrusion at T2. Minor relapse of the first molar (mesial direction) was seen at T3. The maxillary incisors flared labially 0.4 mm, and the incisor root apex moved palatally 1.19 mm (P = .005) at T2. At T3, the incisor root apex moved palatally 1.5 mm (P = .003) from T1. An angular change from T1 of 3.31° (P = .008) and 3.53° (P = .014) was seen at T2 and T3, respectively, as a result of palatal root movement of the maxillary incisors. CONCLUSIONS: A significant amount of distalization of maxillary molars was attained at the crown level with tip-back mechanics. Palatal root angulation change was significant in the incisors with minimal anteroposterior movement of the incisal edge.


Assuntos
Dentição , Má Oclusão de Angle Classe II/terapia , Técnicas de Movimentação Dentária , Cefalometria , Humanos , Incisivo , Maxila , Dente Molar , Estudos Prospectivos
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