Publications by authors named "Lincoln Issamu Nojima"

39 Publications

Reasons influencing the preferences of prospective patients and orthodontists for different orthodontic appliances.

Korean J Orthod 2021 Mar;51(2):115-125

Department of Pediatric Dentistry and Orthodontics, School of Dentistry, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.

Objective: To evaluate the reasons influencing the preferences for a certain type of orthodontic appliance over another among prospective patients (PP) and orthodontists.

Methods: A total of 49 PP and 51 orthodontists were asked about their preferences for the following appliances: clear aligners (CA), lingual metallic brackets (LMB), polycrystalline and monocrystalline ceramic brackets, and buccal metallic brackets (BMB). The participants rated the importance of 17 potential reasons that would explain their choices. The reasons that contributed most to these preferences were identified. Non-parametric tests (Fisher's exact, χ and Mann-Whitney tests) and multivariate analyses (regression and discriminant analysis) were used to assess the data (α = 0.05).

Results: CA and BMB were the most chosen appliances by PP and orthodontists, respectively. LMB was the most rejected option among both groups of participants ( < 0.001). Rates of the importance of pain/discomfort, smile esthetics, finishing details, and feeding/speech impairment showed the highest differences between PP and orthodontists ( < 0.0005). Discriminant analyses showed that individuals who considered treatment time and smile esthetics as more important were more likely to prefer CA, while those who prioritized finishing details and cost were more likely to choose BMB ( < 0.05).

Conclusions: Reasons related to comfort and quality of life during use were considered as more important by PP, while those related to the results and clinical performance of the appliances were considered as more relevant by orthodontists.
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http://dx.doi.org/10.4041/kjod.2021.51.2.115DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7940807PMC
March 2021

Mandibular buccal shelf and infrazygomatic crest thicknesses in patients with different vertical facial heights.

Am J Orthod Dentofacial Orthop 2020 Sep;158(3):349-356

Department of Orthodontics, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil. Electronic address:

Introduction: The purpose of this study was to use cone-beam computed tomography (CBCT) to determine bone thickness in the mandibular buccal shelf (MBS) and the infrazygomatic crest (IC) in individuals with different vertical facial heights for ultimate placement of miniscrews.

Methods: The sample consisted of 100 individuals aged at least 16 years, of whom 58 were women, and 42 were men. The mean age was 19.18 years (± 5.5 standard deviation). The patients' facial height was determined by the gonial angle. Cross-sectional slices of the MBS and IC were obtained with CBCT to evaluate bone thickness for the insertion of miniscrews in these extra-alveolar sites. Spearman's nonparametric test was used to correlate the gonial angle with MBS and IC thickness. The level of significance was 5%.

Results: The gonial angle ranged from 102.4° to 143.2°. Bone thickness in the MBS increased posteriorly, whereas bone thickness in the IC decreased posteriorly. There was an inversely proportional correlation between the gonial angle and the MBS. There was no correlation between the IC and the gonial angle.

Conclusions: Short-faced individuals had higher bone thickness values in the MBS than long-faced ones. There was no correlation between the patients' vertical face height and the bone width in the IC. The best site to install miniscrews in the MBS is buccal to the second molar distal root, whereas in the IC, it is buccal to the first molar mesiobuccal root. CBCT may be necessary to install extra-alveolar miniscrews correctly, especially in the IC.
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http://dx.doi.org/10.1016/j.ajodo.2019.08.016DOI Listing
September 2020

The influence of cigarette smoke on colour stability and friction property of aesthetic orthodontic wires-In vitro study.

Int Orthod 2020 Sep 10;18(3):555-560. Epub 2020 Jun 10.

Universidade Federal do Rio de Janeiro, School of Dentistry, Department of Pedodontics and Orthodontics, Rio de Janeiro, Brazil. Electronic address:

Objective: To evaluate the colour stability and friction property of aesthetic orthodontic wires when exposed to cigarette smoke.

Materials And Methods: Forty-eight samples of aesthetic orthodontic wires (0.019″×0.025″) were allocated to three experimental groups according to their brand (n=8): GAD (Aditek™); GTP (TP Orthodontics™); GRM (Rocky Mountain™) and their respective control groups (GC) (n=8). Samples were exposed to 2 cycles of smoke in a hermetic chamber while GCs were stored in artificial saliva at 37°C. Colour analysis (CIEL*a*b* colour space and NBS units) was performed on 5mm wire segments with the Vita Easyshade Compact spectrophotometer. The friction analysis was performed in a universal test machine, in segments of 5cm wires tied to ceramic brackets with maximum values recorded in N/cm. The comparison between groups was performed with the ANOVA/Tukey test (a=0.05) and the effect of the time evaluated with ANOVA-MR with Bonferroni correction (a=0.016).

Results: GTP and GRM did not show significant colour and friction property variations and did not differ from GC during the study (P>0.05). However, GAD was significantly sensitive to colour changes (T1-T0-L*: -4.09±1.06; a*: 2.25±0.39; b*: 1.70±0, (T2-T0-L* 0.66±0.92; a*: 2.76±0.35) and friction (T2-T0: 2.07±1.00N/cm) (P<0.016).

Conclusion: Exposure to cigarette smoke may alter the mechanical and optical properties of aesthetic orthodontic wires.
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http://dx.doi.org/10.1016/j.ortho.2020.05.005DOI Listing
September 2020

Influence of orthodontic loading on biomarkers levels around miniscrews.

Arch Oral Biol 2020 Apr 27;112:104668. Epub 2020 Jan 27.

Department of Orthodontics, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.

Objective: The aim of this study was to evaluate the levels of Interleukin-1α (IL-1α), Interleukin-1β (IL-1β), Interleukin-1 receptor antagonist (IL-1Ra), Interleukin-10 (IL-10), Interleukin-13 (IL-13), Vascular endothelial growth factor (VEGF), Granulocyte-colony stimulating factor (G-CSF), and Growth related oncogene (GRO) in the peri-miniscrew implant crevicular fluid (MICF) under orthodontic loading.

Design: The study sample comprised 14 miniscrews immediately loaded and 17 unloaded ones. A load of 200gF was immediately applied to the miniscrews in the loaded group after the placement surgery. Peri-miniscrew implant crevicular fluid was collected at baseline, at day 7, and at day 21. The levels of the biomarkers were measured using a multiplexed bead immunoassay. Intergroup comparisons were made using Mann-Whitney test. Friedman and Dunn's multiple comparison tests were used to evaluate intragroup differences over time.

Results: Although no statistical differences were observed between the groups at any time point for any of the 8 biomarkers evaluated, there was a statistically significant increase (p < 0.02) in the levels of all the biomarkers over time on both groups.

Conclusions: An immediate loading of 200gF does not alter the balance in the inflammatory response in peri-miniscrew tissues.
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http://dx.doi.org/10.1016/j.archoralbio.2020.104668DOI Listing
April 2020

Macroscopic and microscopic evaluation of flapless alveolar perforations on experimental tooth movement.

Dental Press J Orthod 2018 Nov-Dec;23(6):73-79

Universidade Federal do Rio de Janeiro, Faculdade de Odontologia, Departamento de Ortodontia e Odontopediatria (Rio de Janeiro/RJ, Brazil).

Objective: The aim of this study was to evaluate a flapless surgical technique as an alternative to traditional alveolar corticotomy used to accelerate orthodontic tooth movement (OTM).

Methods: To induce OTM in Wistar rats, 40 cN of orthodontic force were applied to the maxillary left first molars. Forty rats were distributed into control groups (CG1, CG3, CG7 and CG14) and experimental groups (n= 5), in which alveolar perforations were made using a spear-shaped guide bur (EG1, EG3, EG7, EG14). Euthanasia dates were set at 1, 3, 7 and 14 days, respectively, after tooth movement began. The amount of OTM was measured with a caliper, and osteoclasts present in the periodontal ligament of the mesial root of the moved tooth were counted by means of histological evaluation (tartrate-resistant acid phosphatase staining, TRAP).

Results: Although there was no difference in the amount of OTM within subgroups of corresponding experimental periods (p> 0.05), when EG14 and CG14 were compared, a larger number of osteoclasts was counted in the experimental group (p< 0.00).

Conclusion: The authors concluded that flapless cortical alveolar perforations led to more intense osteoclastic activity on the fourteenth day; nevertheless, no evidence of accelerated OTM could be noted.
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http://dx.doi.org/10.1590/2177-6709.23.6.073-079.oarDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6340197PMC
June 2019

Mini-implant selection protocol applied to MARPE.

Dental Press J Orthod 2018 Sep-Oct;23(5):93-101

Universidade Federal do Rio de Janeiro, Department of Pediatric Dentistry and Orthodontics (Rio de Janeiro/RJ, Brazil).

Introduction: Rapid maxillary expansion (RME) is the therapy of choice to correct skeletal transverse dimension in children and adolescents, associating orthopedic and dental effects. In an attempt to prevent the undesirable dentoalveolar effects and optimize the potential of skeletal expansion in individuals in advanced stages of skeletal maturation, the miniscrew-assisted rapid palatal expander (MARPE) was proposed by Lee et al. in 2010.

Objective: This paper presents a systematized protocol for selection of miniscrews indicated for MARPE, by the evaluation of cone-beam computed tomographies (CBCT). Variables related with the bone and soft tissue thicknesses at the palatal regions of interest, as well as in relation to the fixation rings of miniscrews of the palatal expander are analyzed and discussed to provide better performance in the clinical practice.
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http://dx.doi.org/10.1590/2177-6709.23.5.093-101.sarDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6266324PMC
March 2019

Effects of different primers on indirect orthodontic bonding: Shear bond strength, color change, and enamel roughness.

Korean J Orthod 2018 Jul 6;48(4):245-252. Epub 2018 Jul 6.

Department of Orthodontics, School of Dentistry, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.

Objective: We aimed to perform evaluation to compare 1) shear bond strength (SBS), adhesive remnant index (ARI), and color change between self-etched and acid-etched primers; 2) the SBS, ARI and color change between direct and indirect bonding; and 3) the enamel roughness (ER) between 12-blade bur and aluminum oxide polisher debonding methods.

Methods: Seventy bovine incisors were distributed in seven groups: control (no bonding), direct (DTBX), and 5 indirect bonding (ITBX, IZ350, ISONDHI, ISEP, and ITBXp). Transbond XT Primer was used in the DTBX, ITBX, and ITBXp groups, flow resin Z350 in the IZ350 group, Sondhi in the ISONDHI group, and SEP primer in the ISEP group. SBS, ARI, and ER were evaluated. The adhesive remnant was removed using a low-speed tungsten bur in all groups except the ITBXp, in which an aluminum oxide polisher was used. After coffee staining, color evaluations were performed using a spectrophotometer immediately after staining and prior to bonding.

Results: ISONDHI and ISEP showed significantly lower SBS ( < 0.01). DTBX had a greater number of teeth with all the adhesive on the enamel (70%), compared with the indirect bonding groups (0-30%). The ER in the ITBX and ITBXp groups was found to be greater because of both clean-up techniques used.

Conclusions: Direct and indirect bonding have similar results and all the primers used show satisfactory adhesion strength. Use of burs and polishers increases the ER, but polishers ensure greater integrity of the initial roughness. Resin tags do not change the color of the teeth.
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http://dx.doi.org/10.4041/kjod.2018.48.4.245DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6041458PMC
July 2018

High-intensity laser application in Orthodontics.

Dental Press J Orthod 2017 Nov-Dec;22(6):99-109

Universidade Federal de Santa Maria, Departamento de Estomatologia, Disciplina de Ortodontia (Santa Maria/RS, Brazil).​.

Introduction: In dental practice, low-level laser therapy (LLLT) and high-intensity laser therapy (HILT) are mainly used for dental surgery and biostimulation therapy. Within the Orthodontic specialty, while LLLT has been widely used to treat pain associated with orthodontic movement, accelerate bone regeneration after rapid maxillary expansion, and enhance orthodontic tooth movement, HILT, in turn, has been seen as an alternative for addressing soft tissue complications associated to orthodontic treatment.

Objective: The aim of this study is to discuss HILT applications in orthodontic treatment.

Methods: This study describes the use of HILT in surgical treatments such as gingivectomy, ulotomy, ulectomy, fiberotomy, labial and lingual frenectomies, as well as hard tissue and other dental restorative materials applications.

Conclusion: Despite the many applications for lasers in Orthodontics, they are still underused by Brazilian practitioners. However, it is quite likely that this demand will increase over the next years - following the trend in the USA, where laser therapies are more widely used.
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http://dx.doi.org/10.1590/2177-6709.22.6.099-109.sarDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5784822PMC
August 2018

An interview with Kee-Joon Lee.

Dental Press J Orthod 2017 Jul-Aug;22(4):28-33

» DDS, Universidade Federal do Rio de Janeiro/RJ. » MSc and PhD in Orthodontics, Universidade Federal do Rio de Janeiro/RJ. » Post-doctoral stage at Case Western Reserve University/OH. » Associate Professor, Department of Orthodontics, Universidade Federal do Rio de Janeiro/RJ. » Visiting Associate Professor, Department of Orthodontics, Case Western Reserve University/OH.

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http://dx.doi.org/10.1590/2177-6709.22.4.028-033.intDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5573007PMC
November 2018

Miniscrew-assisted rapid palatal expansion for managing arch perimeter in an adult patient.

Dental Press J Orthod 2017 May-Jun;22(3):97-108

Yonsei University,Department of Orthodontics, Seoul, Korea.

Introduction:: Etiology of dental crowding may be related to arch constriction in diverse dimensions, and an appropriate manipulation of arch perimeter by intervening in basal bone discrepancies cases, may be a key for crowding relief, especially when incisors movement is limited due to underlying pathology, periodontal issues or restrictions related to soft tissue profile.

Objectives: : This case report illustrates a 24-year old woman, with maxillary transverse deficiency, upper and lower arches crowding, Class II, division 1, subdivision right relationship, previous upper incisors traumatic episode and straight profile. A non-surgical and non-extraction treatment approach was feasible due to the miniscrew-assisted rapid palatal expansion technique (MARPE).

Methods: : The MARPE appliance consisted of a conventional Hyrax expander supported by four orthodontic miniscrews. A slow expansion protocol was adopted, with an overall of 40 days of activation and a 3-month retention period. Intrusive traction miniscrew-anchored mechanics were used for correcting the Class II subdivision relationship, managing lower arch perimeter and midline deviation before including the upper central incisors.

Results: : Post-treatment records show an intermolar width increase of 5 mm, bilateral Class I molar and canine relationships, upper and lower crowding resolution, coincident dental midlines and proper intercuspation.

Conclusions: : The MARPE is an effective treatment approach for managing arch-perimeter deficiencies related to maxillary transverse discrepancies in adult patients.
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http://dx.doi.org/10.1590/2177-6709.22.3.097-108.oarDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5525451PMC
May 2018

Four chemical methods of porcelain conditioning and their influence over bond strength and surface integrity.

Dental Press J Orthod 2015 Jul-Aug;20(4):51-6

Department of Pediatric Dentistry and Orthodontics, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, BR.

Objective: To assess four different chemical surface conditioning methods for ceramic material before bracket bonding, and their impact on shear bond strength and surface integrity at debonding.

Methods: Four experimental groups (n = 13) were set up according to the ceramic conditioning method: G1 = 37% phosphoric acid etching followed by silane application; G2 = 37% liquid phosphoric acid etching, no rinsing, followed by silane application; G3 = 10% hydrofluoric acid etching alone; and G4 = 10% hydrofluoric acid etching followed by silane application. After surface conditioning, metal brackets were bonded to porcelain by means of the Transbond XP system (3M Unitek). Samples were submitted to shear bond strength tests in a universal testing machine and the surfaces were later assessed with a microscope under 8 X magnification. ANOVA/Tukey tests were performed to establish the difference between groups (α= 5%).

Results: The highest shear bond strength values were found in groups G3 and G4 (22.01 ± 2.15 MPa and 22.83 ± 3.32 Mpa, respectively), followed by G1 (16.42 ± 3.61 MPa) and G2 (9.29 ± 1.95 MPa). As regards surface evaluation after bracket debonding, the use of liquid phosphoric acid followed by silane application (G2) produced the least damage to porcelain. When hydrofluoric acid and silane were applied, the risk of ceramic fracture increased.

Conclusions: Acceptable levels of bond strength for clinical use were reached by all methods tested; however, liquid phosphoric acid etching followed by silane application (G2) resulted in the least damage to the ceramic surface.
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http://dx.doi.org/10.1590/2176-9451.20.4.051-056.oarDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4593530PMC
January 2017

Indirect orthodontic bonding--a modified technique for improved efficiency and precision.

Dental Press J Orthod 2015 May-Jun;20(3):109-17

Universidade Federal do Rio de Janeiro, Brazil.

Introduction: The indirect bonding technique optimizes fixed appliance installation at the orthodontic office, ensuring precise bracket positioning, among other advantages. In this laboratory clinical phase, material and methods employed in creating the transfer tray are decisive to accuracy.

Objective: This article describes a simple, efficient and reproducible indirect bonding technique that allows the procedure to be carried out successfully. Variables influencing the orthodontic bonding are analyzed and discussed in order to aid professionals wishing to adopt the indirect bonding technique routinely in their clinical practice.
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http://dx.doi.org/10.1590/2176-9451.20.3.109-117.sarDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4520146PMC
December 2016

Authors' response.

Am J Orthod Dentofacial Orthop 2015 Jul;148(1):10

Rio de Janeiro, Rio de Janeiro, Brazil.

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http://dx.doi.org/10.1016/j.ajodo.2015.04.016DOI Listing
July 2015

Rapid maxillary expansion effects: an alternative assessment method by means of cone-beam tomography.

Dental Press J Orthod 2014 Sep-Oct;19(5):88-96

Federal University of Rio de Janeiro.

Introduction: This study aims to develop a method to assess the changes in palatal and lingual cross-sectional areas in patients submitted to rapid maxillary expansion (RME).

Methods: The sample comprised 31 Class I malocclusion individuals submitted to RME and divided into two groups treated with Haas (17 patients) and Hyrax (14 patients) expanders. Cone-beam computed tomography scans were acquired at T0 (before expansion ) and T1 (six months after screw stabilization). Maxillary and mandibular cross-sectional areas were assessed at first permanent molars and first premolars regions and compared at T0 and T1. Mandibular occlusal area was also analyzed.

Results: Maxillary cross-sectional areas increased in 56.18 mm2 and 44.32 mm2 for the posterior and anterior regions. These values were smaller for the mandible, representing augmentation of 40.32 mm2 and 39.91 mm2 for posterior and anterior sections. No differences were found when comparing both expanders. Mandibular occlusal area increased 43.99mm2 and mandibular incisors proclined. Increments of 1.74 mm and 1.7 mm occurred in mandibular intermolar and interpremolar distances. These same distances presented increments of 5.5 mm and 5.57 mm for the maxillary arch.

Conclusion: Occlusal and cross-sectional areas increased significantly after RME. The method described seems to be reliable and precise to assess intraoral area changes.
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http://dx.doi.org/10.1590/2176-9451.19.5.088-096.oarDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4296661PMC
May 2016

Transverse effects on the nasomaxillary complex one year after rapid maxillary expansion as the only intervention: a controlled study.

Dental Press J Orthod 2014 Sep-Oct;19(5):79-87

Fluminense Federal University.

The aim of this study was to assess by means of cone-beam computed tomography (CBCT) scans the transverse effects on the nasomaxillary complex in patients submitted to rapid maxillary expansion (RME) using Haas expander in comparison to untreated individuals. This prospective controlled clinical study assessed 30 subjects (18 boys and 12 girls) with mixed dentition and during pubertal growth. The treated group was submitted to RME with Haas expander, retention for six months and a six-month follow-up after removal. The control group matched the treated group in terms of age and sex distribution. CBCT scans were taken at treatment onset and one year after the expander was activated. Maxillary first molars (U6) width, right and left U6 angulation, maxillary alveolar width, maxillary basal width, palatal alveolar width, palatal base width, right and left alveolar angulation, palatal area, nasal base width, nasal cavity width and inferior nasal cavity area on the posterior, middle and anterior coronal slices were measured with Dolphin Imaging Software(r) 11.5, except for the first two variables which were performed only on the posterior slice. All transverse dimensions increased significantly (P < 0.05) in the treated group in comparison to the control, except for alveolar angulation and inferior nasal cavity area (P > 0.05). Results suggest that increase of molar, maxillary, palatal and nasal transverse dimensions was stable in comparison to the control group one year after treatment with RME.
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http://dx.doi.org/10.1590/2176-9451.19.5.079-087.oarDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4296650PMC
May 2016

Mechanical influence of thread pitch on orthodontic mini-implant stability.

Braz Oral Res 2015 16;29. Epub 2015 Feb 16.

Department of Orthodontics, School of Dentistry, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil.

The aim of this study was to evaluate the effect of pitch distance on the primary stability (PS) of orthodontic mini-implants (MIs) in artificial bone. Twenty experimental MIs were allocated to two groups, according to their geometric design: G1 (30o X 0.6 mm) and G2 (45o X 0.8 mm), and inserted into artificial bone of different densities: D1 (0.32 g/cm3) and D2 (0.64 g/cm3). The maximum insertion torque (IT) and removal torque (RT) values were recorded in N.cm. Loss of torque (LT) values were obtained by calculating the difference between the IT and RT. MI mobility was measured by means of a Periotest assessment. Normality and homogeneity were determined by means of the Kolmogorov-Smirnov and Shapiro-Wilk tests, respectively. A two-way ANOVA was used to detect differences between the mini-implant design and density factors. The ANOVA/Tukey tests were used to determine the intergroup difference. Higher IT values were observed for G2 (p ≤ 0.05) in D2. No statistical difference for RT was observed between the groups, whereas G2 presented higher values only for LT (p ≤ 0.05). The Periotest values (PTV) were higher for G1, in comparison with G2, in D1. G1 presented better PS in D2 (IT, RT and LT), whereas G2 was found to be more stable in D1, after evaluation with Periotest.
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http://dx.doi.org/10.1590/1807-3107BOR-2015.vol29.0042DOI Listing
May 2015

Influence of bone architecture on the primary stability of different mini-implant designs.

Am J Orthod Dentofacial Orthop 2015 Jan;147(1):45-51

Professor, Department of Pedodontics and Orthodontics, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil. Electronic address:

Introduction: Mechanical interlocking between a mini-implant (MI) and the bone substrate reflects directly on the primary stability achieved. The purposes of this study were to evaluate MI design performance in distinct bone substrates and correlate geometric characteristics with insertion site quality.

Methods: Two types of self-drilling MIs (1.6 × 8 mm) were allocated to 2 groups according to their geometric designs: Tomas system (Dentaurum, Ispringen, Germany) and Dual-Top (Rocky Mountain Orthodontics, Denver, Colo). Forty sections (8 × 10 mm) were taken from bovine pelvic ilium and pubic bone. Geometric design characteristics were evaluated using scanning electron microscope imaging and Image-Pro Insight software (Media Cybernetics, Rockville, Md). Bone quality parameters were assessed with a microcomputed tomography system, and primary stability was evaluated by insertion torque and pull-out strength. Intergroup comparisons were performed with analysis of variance and Tukey tests, and the Pearson correlation test was carried out (P <0.05).

Results: No significant difference was observed in the comparisons of the groups (Tomas: insertion torque, 12.87 N·cm; pull-out strength, 181 N; and Dual-Top: insertion torque, 9.95 N·cm; pull-out strength, 172.5 N) in the ilium. However, the Tomas group had a marked increase in insertion torque (25.08 N·cm; P <0.05) in the pubic bone.

Conclusions: MI mechanical performance differed according to bone quality parameters, indicating that certain geometric parameters may be set depending on the insertion substrate.
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http://dx.doi.org/10.1016/j.ajodo.2014.09.011DOI Listing
January 2015

Immediate changes in condylar position after rapid maxillary expansion.

Am J Orthod Dentofacial Orthop 2014 Jun;145(6):771-9

Orienting professor, Department of Orthodontics, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil. Electronic address:

Introduction: Although the dentoalveolar and skeletal effects of rapid maxillary expansion are well documented, the condylar response to this procedure is not well understood. The purpose of this study was to test the following null hypothesis: rapid maxillary expansion promotes immediate changes of the position of the condyles in patients with Class I malocclusion.

Methods: Thirty-four subjects with Class I malocclusion underwent rapid maxillary expansion. Cone-beam computed tomography images were collected before activation of the expander and 3 weeks later, after screw stabilization. Using specific software functions, it was possible to determine and reproduce head positioning and landmarks during the different times of the study.

Results: The axial, coronal, and sagittal planes were examined, and no asymmetries in condylar positions were found at either time. However, statistically significant anterior and inferior displacements of these structures occurred, with respective average values of 0.52 and 0.49 mm. Lateral inclinations of both condyles were observed and confirmed by the coronal condylar angles.

Conclusions: The null hypothesis was rejected. Statistically significant anterior and inferior displacements of the condyles occurred. Lateral inclination of the condyles was observed.
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http://dx.doi.org/10.1016/j.ajodo.2014.01.024DOI Listing
June 2014

Colonization of Streptococcus mutans on esthetic brackets: self-ligating vs conventional.

Am J Orthod Dentofacial Orthop 2013 Apr;143(4 Suppl):S72-7

Department of Orthodontics, School of Dentistry, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.

Introduction: Self-ligating orthodontic brackets rely on clips, rather than ligatures, to hold the archwire in place. It is unknown whether replacing ligatures with clips affects the adherence of Streptococcus mutans. The aim of this research was to evaluate whether self-ligating brackets have an advantage over conventional brackets as determined by the adherence of S mutans.

Methods: The sample consisted of 50 esthetic brackets, divided into 3 experimental groups and 2 control groups of 10 brackets each. Two experimental groups were active self-ligating brackets (QuicKlear; Forestadent, Pforzheim, Germany; and In-Ovation C; Dentsply GAC, Bohemia, NY); the other was a passive self-ligating bracket (Damon 3; Ormco, Glendora, Calif). The 2 control groups were conventional brackets (Mystique; Dentsply GAC; and Clarity; 3M Unitek, Monrovia, Calif). The brackets were randomly bonded to the canines, first and second premolars, and first and second molars in the mandibular left hemiarch of 10 male participants. Biofilm was collected from the tooth surfaces before bonding and from the brackets on day 21 and placed in Petri dishes containing Mitis salivarius agar. The brackets were removed on day 28 and examined by using scanning electron microscopy. Statistical analysis, analysis of variance, and the Tukey correction with a P value of 0.05 were used.

Results: The greatest numbers of colonies were found in an active self-ligating bracket group (In-Ovation C), and the fewest colonies were in a conventional bracket group (Clarity). The largest colonies formed on active self-ligating brackets. In the slot, the greatest formation was in a control group (Mystique).

Conclusions: Self-ligating esthetic brackets do not promote greater or lesser S mutans colonization when compared with conventional brackets. Differences were found to be related to the material composition of the bracket.
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http://dx.doi.org/10.1016/j.ajodo.2012.07.017DOI Listing
April 2013

Laser versus ultrasound on bone density recuperation after distraction osteogenesis-a cone-beam computer tomographic analysis.

J Oral Maxillofac Surg 2013 May 23;71(5):921-8. Epub 2013 Jan 23.

Department of Orthodontics, School of Dentistry, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.

Purpose: To assess the effects of low-level laser versus ultrasound irradiation on bone mineral density after distraction osteogenesis using cone-beam computed tomographic analysis in an experimental study.

Materials And Methods: Distraction osteogenesis was performed with rapid maxillary expansion devices (Hyrax-Morelli, Sorocaba-São Paulo-Brazil). After a 2-day latency period, the distraction devices were activated for 10 days at a rate of 1 mm/day. Four groups of 6 animals were distributed as follows: 1) control, 2) laser irradiation on the right side, 3) ultrasound irradiation on the right side, and 4) laser irradiation on the right side and ultrasound on the left side. Cone-beam computed tomography was used to determine bone mineral density by measuring the recovery (percentage). Analysis of variance and the Tukey test (P = .05) were used for statistical analyses.

Results: The influences of low-intensity laser and ultrasound irradiation on bone mineral density were statistically significant. The analyses showed greater bone mineral density recuperation in the mandibular side with the ultrasound application.

Conclusions: The results of this study suggest an acceleration of bone mineral density after laser and ultrasound irradiation. Ultrasound irradiation showed the greatest effects and the laser power positively influenced the recuperation of the bone density on the side opposite its application, causing a cross reaction or even exacerbating the inherent action of ultrasound irradiation.
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http://dx.doi.org/10.1016/j.joms.2012.11.010DOI Listing
May 2013

Influence of low-intensity laser therapy on the stability of orthodontic mini-implants: a study in rabbits.

Oral Surg Oral Med Oral Pathol Oral Radiol 2013 Feb 22;115(2):e26-30. Epub 2012 May 22.

Federal University of Rio de Janeiro, UFRJ, Rio de Janeiro, Brazil.

Objective: The objective of this study was to assess stability of different orthodontic mini-implants in the tibia of rabbits after low-intensity laser therapy.

Material And Methods: Thirty-two mini-implants were assessed, 16 were self-threading (Titanium Fix) and 16 self-perforating (INP). These were inserted into the tibia of rabbits and immediately loaded with a horizontal force of 200g uniting 2 mini-implants in each tibia. Then they were submitted to low-intensity laser therapy for 21 days. Sixteen male New Zealand breed rabbits were used, and divided into 2 groups of 8 animals each as follows: Groups INP and TF. In both groups, mini-implants were submitted to low-intensity laser therapy (right tibia) and their respective controls (left tibia) did not undergo laser therapy. After the animals were killed, blocks of bone tissue containing the mini-implants were removed so as to perform mechanical pull-out tests.

Results: There was a statistically significant difference only between Group TF submitted to laser and all the other groups (P < .05).

Conclusions: Low-intensity laser was capable of increasing stability of self-threading orthodontic mini-implants.
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http://dx.doi.org/10.1016/j.oooo.2011.09.036DOI Listing
February 2013

Microbial colonization in orthodontic mini-implants.

Braz Dent J 2012 ;23(4):422-7

Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil.

Peri-implant inflammation contributes for loss of secondary stability of orthodontic mini-implants. The investigation of microbial colonization in this area would benefit its control, and consequently favor the long-term success of mini-implants. Therefore, the aim of this study was to determine the establishment and the evolution of microbial colonization process in orthodontic mini-implants for 3 months, since the time of their installation. One-hundred and fifty samples collected from 15 mini-implants were investigated from baseline up to 3 months. The biological material was obtained from peri-implant area using paper points. Nonspecific, Streptococcus spp, Lactobacillus casei and Candida spp colonizations were analyzed by cell growth methods. Porphyromonas gingivalis colonization was observed by 16S rDNA-directed polymerase chain reaction. Data from cell growth were submitted to the Wilcoxon sign rank test and results from molecular analysis were presented in a descriptive way. There was no significant difference in the microbial colonization among the examined time intervals, except for Streptococcus spp, between baseline and 24 h, which characterized the initial colonization in this time interval. Lactobacillus casei and Candida spp colonizations were insignificant. No Porphyromonas gingivalis was detected among the analyzed samples. The microbial colonization of mini-implants did not significantly change during the study. However, it should be monitored by orthodontists, since it is an important factor for mini-implants success.
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http://dx.doi.org/10.1590/s0103-64402012000400019DOI Listing
December 2013

In situ evaluation of orthodontic elastomeric chains.

Braz Dent J 2012 ;23(4):394-8

Department of Orthodontics, Dental School, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil.

The hypothesis tested in this study was that intraoral exposure of elastomeric chains alters their tensile strength. For such purpose, it was evaluated the in situ behavior of different elastomeric chains stretched for 3 weeks. Three kinds of elastomeric chains, Plastic chain (PC), Memory chain (MC) and Super slick chain (SSC), were randomly placed in 3 quadrants of 13 patient in a fixed distance of 16 mm and mean initial force of 180 g. Tensile testing was performed in an universal testing machine at different intervals: initial, 1 h, 24 h, 1 week, 2 weeks and 3 weeks. A two-way ANOVA test was performed to identify the influence of both material and time on the force decrease. A subsequent one-way ANOVAtest with the Tukey's post hoc test was used to identify statistically significant intragroup and intergroup remaining force (g and %) differences at 5% significance level. The effect of both the material and the time factors were significant. All groups showed significant force decrease after the 1-h period (23% for PC and 14% for MC and SSC). At the end of the 3-week period, the remaining force was 57% (96 g), 67% (129 g) and 71% (125 g) for PC, MC and SSC, respectively. In conclusion, intraoral exposure of elastomeric chains altered their tensile strength. In general, the greater force decrease occurred within the first hour. The remaining force of the enhanced chains measured at each time interval was greater than the conventional one (PC). After 3 weeks, only the enhanced chains maintained the force applied over 100 g.
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http://dx.doi.org/10.1590/s0103-64402012000400014DOI Listing
December 2013

Surgical prediction of skeletal and soft tissue changes in treatment of Class II.

J Craniomaxillofac Surg 2013 Apr 30;41(3):198-203. Epub 2012 Nov 30.

Department of Orthodontics, Faculty of Dentistry, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.

Introduction: The purpose of this study was to study the treatment outcomes and the accuracy of digital prediction and the actual postoperative outcome with Dolphin program on subjects presenting Class II malocclusions.

Methods: Forty patients underwent surgical mandibular advancement (Group 1) and 40 underwent combined surgery of mandibular advancement and maxillary impaction (Group 2). The available pre surgical (t₁) and a minimum of 12 months post surgical (t₂) cephalometric radiographs were digitized. Predictive cephalograms (t₃) for both groups were traced.

Results: At all times evaluated, Group 1 displayed a shorter mandibular length and Group 2 had a longer lower face. In both groups the surgical interventions (t₂) were greater than initially predicted. There was no significant difference between groups with regards to overjet, overbite and soft tissue measurements.

Conclusions: In both groups surgeries were more extensive than planned. Facial convexity and the distance of the lips to cranial base presented similar values between t₂ (post surgical) and t₃ (predicted).
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http://dx.doi.org/10.1016/j.jcms.2012.07.009DOI Listing
April 2013

Long-term skeletal and profile stability after surgical-orthodontic treatment of Class II and Class III malocclusion.

J Craniomaxillofac Surg 2013 Jun 26;41(4):296-302. Epub 2012 Nov 26.

Department of Orthodontics, Faculty of Dentistry, Federal University of Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil.

Objective: The purpose of this perspective research was to study the long-term stability of skeletal, dentoalveolar and soft tissue after orthognathic surgery in subjects presenting with Class II and Class III malocclusions.

Methods: The available digitized cephalometric radiographs, including pretreatment (t0), presurgery (t1), a minimum of 12 months postsurgery (t2) and at least 3 years after the orthosurgery treatment (t3) were taken between 1998 and 2010. In Group 1 mandibular advancement and in Group 2 mandibular advancement and maxillary impaction surgery were performed for correction of Class II. In Group 3 maxillary advancement and in Group 4 surgical maxillary advancement with mandibular setback, for correction of Class III.

Results: In all the phases mandibular length was shorter in Group 1, and the inferior third of the face was longer in Group 2. Before the surgery there was greater maxillary deficiency in Group 3 than Group 4 and mandibular length was longer in Group 4.

Conclusion: In Groups 1 and 2, at retention phase, relapse occurred due to the increase in mandibular plane, whereas the surgeries performed in Groups 3 and 4 remained stable.
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http://dx.doi.org/10.1016/j.jcms.2012.10.001DOI Listing
June 2013

The importance of the diagnostic setup in the orthodontic treatment plan.

Int J Orthod Milwaukee 2012 ;23(2):35-9

Department of Orthodontics, Federal University of Rio de Janeiro.

The aim of this study was to address the importance of the diagnostic setup by examining two cases where diagnostic setups were made in order to determine the treatment plan. The diagnostic setup is a fundamental aid and should be used when there are doubts in the orthodontic planning.
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August 2012

Primary stability of orthodontic mini-implants inserted into maxilla and mandible of swine.

Oral Surg Oral Med Oral Pathol Oral Radiol 2012 Jun 2;113(6):748-54. Epub 2012 Jan 2.

Southwest Bahia University, UESB, Bahia, Brazil.

Objective: The objective of this study was to assess the primary stability of different orthodontic mini-implants inserted into different maxillary and mandibular regions of swine.

Material And Methods: One hundred eighty orthodontic mini-implants produced by 5 different manufacturers, all presenting several shapes, were divided into 5 groups: Mondeal (M), Neodent (N), SIN (S), INP, and Titanium Fix (T). Fifteen pigs (Sus scrofa piau) were used for study and 12 mini-implants were inserted into 3 mandibular and maxillary regions. After insertion, the animals were killed and osseous blocks containing the mini-implants were obtained for mechanical pullout tests to be performed by a universal test machine at cross-head speed of 0.5 mm/s. Maximum force values (N/cm) for insertion were recorded and submitted to both analysis of variance and Tukey's test.

Results: The primary stability provided by cylindrical mini-implants (groups M and I) was statistically significantly superior to that of conical mini-implants (groups N and S). On the other hand, screw-type mini-implants were shown to be statistically inferior compared with the others (P < .05). Statistical differences between pullout forces at different oral cavity regions were also found (P < .05). The mini-implants inserted into palatal suture had lesser stability, whereas those inserted into upper molar and premolar regions were shown to be more stable.

Conclusions: The shape of mini-implants, in association with location of insertion, is directly related to primary stability.
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http://dx.doi.org/10.1016/j.tripleo.2011.06.021DOI Listing
June 2012

Surgical prediction of skeletal and soft tissue changes in Class III treatment.

J Oral Maxillofac Surg 2012 Apr;70(4):e290-7

Department of Orthodontics, Faculty of Dentistry, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.

Purpose: The purpose of this study was to study the treatment outcomes and accuracy of the digital prediction using Dolphin Imaging Software and the actual postoperative outcome in subjects presenting Class III malocclusions.

Materials And Methods: Maxillary advancement surgery was performed in group 1, and maxillary advancement was combined with mandibular setback surgery in group 2. Predictive cephalometric tracings were made using Dolphin Imaging Software.

Results: Before surgery, the maxillary deficiency was significantly greater in group 1 than in group 2, and the mandibular length was significantly greater in group 2. Surgical reductions in mandibular length and angle were significantly greater 12 months after surgery than indicated by the predictive cephalometric tracings.

Conclusion: In groups 1 and 2, maxillary advancement surgery was performed in accordance with the Dolphin Imaging Software. The mandibular setback surgery performed was beyond the established plan, but without clinical implications. Mandibular dentoskeletal measurements showed a greater correlation with the profile than the maxillary measurements.
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http://dx.doi.org/10.1016/j.joms.2012.01.001DOI Listing
April 2012

Does the contact time of alginate with plaster cast influence its properties?

Braz Oral Res 2012 May-Jun;26(3):197-201. Epub 2012 Mar 20.

Department of Pedodontics and Orthodontics, School of Dentistry, Universidade Federal do Rio de Janeiro, Brazil.

The aim of this study was to verify the influence of the time of contact between alginate and gypsum after the modeling procedure on the properties of the plaster cast, such as surface detail, dimensional stability and microhardness. Thirty cylindrical specimens of orthodontic gypsum Type III were made by means of impressions of a stainless steel master model which had five reference lines in the upper surface. The samples were divided into two groups: Group 1 (G1) - with time of contact of 1 hour; and Group 2 (G2) - 12 hours of contact. All the specimens were stored up to 48 hours until they underwent laboratory testing. Surface detail and dimensional stability were tested by one calibrated examiner using a visual analysis and a profilometer (Profile Projector Nikon model 6C, Nikon Corporation, Tokyo, Japan), respectively, to evaluate the quality of reproduction of the lines and the distances between them. The microhardness was determined for each sample by making six indentations with a Vickers diamond pyramid indenter (Buehler, Lake Bluff, USA) under a load of 100 gF for 15 s. The results showed significant difference (P ≤ 0.05) between groups in two of the three properties examined: surface detail and microhardness, which decreased as the time of contact rose. The 12-hour time of contact between alginate and the plaster cast is not recommended because it influences the quality of the plaster cast.
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http://dx.doi.org/10.1590/s1806-83242012005000005DOI Listing
October 2012

Tomographic mapping of the hard palate and overlying mucosa.

Braz Oral Res 2012 Jan-Feb;26(1):36-42

Department of Pedodontics and Orthodontics, Federal University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil.

The aim of this study was to measure the thickness of the hard palate and its overlying mucosa using cone-beam computed tomography (CBCT), for purposes of miniscrew placement. The sample comprised 36 CBCT scans of patients aged 12 to 52 years from a database of the Orthodontics Department of the Federal University of Rio de Janeiro. Paracoronal views of the palatal region were reconstructed at 4, 8, 16 and 24 mm posterior to the incisive foramen. In each reconstruction measurements were taken at the suture, 3 mm and 6 mm bilaterally to it. Wilcoxon's test verified the differences between the selected regions. Total bone height decreased from the anterior to the posterior region. In cross sections 4, 16 and 24, bone height decreased from the suture laterally to the 3 mm region and then increased in the 6 mm region. The cortical thickness does not seem to be a concern because it presented a mean thickness of at least 1 mm at all sites evaluated. The measurements of the mucosa thickness decreased from lateral to median and from anterior to posterior regions. The most suitable areas for miniscrew placement in the palate are located 4 mm posterior to the incisive foramen, in the median or paramedian regions 3 mm adjacent to the suture.
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http://dx.doi.org/10.1590/s1806-83242012000100007DOI Listing
August 2012