v. 19, no. 2
Dental Press Journal of Orthodontics – ISSN 2176-9451
Dental Press J. Orthod.
v. 19, no. 2
March / April
The Brazilian dental science
“Men stand out for what they do; women, for what they induce men to do”.
(Carlos Drummond de Andrade, Brazilian poet from Minas Gerais state)
Three years ago, a sublime editorial praised the audacious growth of Brazilian dental scientific production. At that time, our former editor dared to foresee the position Brazil would occupy in 2015: the most productive country in terms of dental scientific knowledge. The author was based on data from Scopus which, at that point, did not include Dental Press Journal of Orthodontics (DPJO). This database currently provides data as far as 2012, with DPJO having the highest number of scientific publications in Brazilian Dentistry.
In the current scenario, as far as 2012, Brazil still occupies the second position in world scientific production. However, we have begun to peep, as a lynx, the fact that we have come nearer the United States, the most productive country in terms of scientific production. We are growing like a giant. In 2009, for instance, the American dental scientific production was 66% greater than the Brazilian production. Nevertheless, this difference narrowed down to 20% in 2012. We should not be surprised if Brazilian scientific production reaches the first position yet in 2014, thus, corresponding to what had been wisely foreseen.1 Moreover, we are certain that indexing DPJO into Scopus has contributed to accelerate such progress.
A reasonable amount of self-contemplation would reveal even more flaring indicators. Twelve years ago, in 2002, Scopus registered only 171 articles published by Brazilian authors within the field of Dentistry. In 2012, there were 1,533. Our h-index — an index that measures the impact of the scientific knowledge produced by a country, university or author — has increased exponentially. Brazil currently occupies the eighth position in the Dentistry field, which is something for Brazilian scientific production, although still young, to be proud of. Despite any criticism, improvements in this index are strongly related to government policies of closely following the scientific production of Brazilian postgraduate courses. In other words, it all resembles a conductor who perfectly leads the drum section of a samba school playing in a constant rhythm.
Furthermore, made-in-Brazil journals have significantly contributed to highlight the notorious development of Brazilian postgraduate intellectual production. Brazil currently has seven journals indexed in Scopus: In 2012, these scientific journals published 675 articles (whereas there were only two journals in 2002, with 96 articles published). At this point, you may have squinted towards a major criticism: it is only numbers. But no. Given the substantial increase in Brazilian h-index and the healthy improvements in postgraduate scientific production, this editorial is not able to list all techniques that could be employed to correct such ‘strabismus’.
In this context, Orthodontics has a lot to celebrate. In 2012, Brazil was the most productive country in terms of orthodontic publications, with DPJO — a journal indexed in the most important databases in the world — playing a major role. The h-index for Brazilian Orthodontics is the third in the world. We are certain that indexation of DPJO in PubMed/MEDLINE in 2013 will greatly contribute to future achievements.
Brazilian dental science is still simmering and, in a mathematical counterpoint, challenges the regression towards the mean. The position it has reached is a consequence of an action that involves an immeasurable number of researchers from the most secluded places of Brazil — who work overnight with passion and dedication; insane people who believe they can produce state-of-the-art scientific knowledge. Believing is a prime virtue, and that explains all the euphoria.
We have been conducted through this path by a beautiful and powerful leadership (as of a maestra): with indefatigable dedication and exhilarating inspiration — as a contagious samba that spreads itself among carnival revelers due to its sagacity. Only Drummond, in his sensibility, could perfectly describe the women of his homestate.
Reasons for mini-implants failure: choosing installation site should be valued!
Mini-implants. Absolute anchorage. Micro-screws. Temporary anchorage devices.
Mini-implant loss is often associated with physical and mechanical aspects that result from choosing an inappropriate placement site. It is worth highlighting that:
- a) Interdental alveolar bone crests are flexible and deformable. For this reason, they may not offer the ideal absolute anchorage. The more cervical the structures, the more delicate they are, thus offering less physical support for mini-implant placement;
- b) Alveolar bone crests of triangular shape are more deformable, whereas those of rectangular shape are more flexible;
- c) The bases of the alveolar processes of the maxilla and the mandible are not flexible, for this reason, they are more likely to receive mini-implants;
- d) The more cervical a mini-implant is placed, the higher the risk of loss; the more apical a mini-implant is placed, the better its prognosis will be;
- e) 3D evaluations play a major role in planning the use of mini-implants.
Based on the aforementioned considerations, the hypotheses about mini-implant loss are as follows:
- 1) Deflection of maxillary and mandibular alveolar processes when mini-implants are more cervically placed;
- 2) Mini-implants placed too near the periodontal ligament, with normal intra-alveolar tooth movement;
- 3) Low bone density, low thickness and low alveolar bone volume;
- 4) Low alveolar cortical bone thickness;
- 5) Excessive pressure inducing trabecular bone microfracture;
- 6) Sites of higher anatomical weakness in the mandible and the maxilla;
- 7) Thicker gingival tissue not considered when choosing the mini-implant.
Error of the method: what is it for?
The aim of this paper is to demonstrate the importance of evaluating the error of the method in Orthodontic scientific studies. Special emphasis will be given to the scientific importance and the different types of the error of the method (systematic and casual), the statistical tests most commonly used to quantify these errors and the clinical meaning of the error of the method for the interpretation of results obtained from orthodontic treatment. [...]
An interview with Marissa C. Keesler
Dr. Marissa Keesler attended dental school at Creighton University in Omaha, Nebraska and in 1987 received her Doctor of Dental Surgery degree with high honors. In 1989, she graduated from Marquette University with a Certificate and Master of Science degree in Orthodontics. Dr. Keesler has been an Adjunct Professor in the Marquette Graduate Orthodontic Department since 1990 and has been a guest speaker at several universities and orthodontic groups nationally and internationally. She has contributed to the development of several orthodontic textbooks in topics related to multidisciplinary treatment and the indirect bonding technique. Dr. Keesler is a member of the American Association of Orthodontists and many other local and national dental and orthodontic societies such as the Edward H. Angle Society of Orthodontists and the Pierre Fauchard Academy. She also has Diplomate status with the American Board of Orthodontics and is a graduate of the AEO Roth/Williams Center. Dr. Keesler has been in specialty practice since 1989 and has had a full-time private practice in Neenah since 1992. In 2000, she was joined by her husband, Dr. Jeffrey T. Keesler, who has a dual specialty in Prosthodontics and Orthodontics.
Dr. Roberto Lima Filho
Transverse effect of Haas and Hyrax appliances on the upper dental arch in patients with unilateral complete cleft lip and palate: A comparative study
Palatine expansion technique. Cleft palate. Dental arch.
Objective: The aim of the present study was to evaluate the transverse effect of rapid maxillary expansion in patients with unilateral complete cleft lip and palate while comparing the Haas and Hyrax appliances.
Methods: The sample consisted of 48 patients divided into two groups: Group I – 25 patients treated with modified Haas appliance (mean age: 10 years 8 months); and Group II – 23 patients treated with Hyrax appliance (mean age: 10 years 6 months). Casts were taken during pre-expansion and after removal of the appliance at the end of the retention period. The models were scanned with the aid of the 3 Shape R700 3D scanner. Initial and final transverse distances were measured at cusp tips and cervical-palatal points of maxillary teeth by using the Ortho Analyzer™ 3D software.
Results: The mean expansion obtained between cusp tips and cervical-palatal points for inter-canine width was 4.80 mm and 4.35 mm with the Haas appliance and 5.91 mm and 5.91 mm with the Hyrax appliance. As for first premolars or first deciduous molars, the values obtained were 6.46 mm and 5.90 mm in the Haas group and 7.11 mm and 6.65 mm in the Hyrax group. With regard to first molars, values were 6.11 mm and 5.24 mm in the Haas group and 7.55 mm and 6.31 mm in the Hyrax group.
Conclusion: Rapid maxillary expansion significantly increased the transverse dimensions of the upper dental arch in patients with cleft palate, with no significant differences between the Hass and Hyrax expanders.
The influence of orthodontic fixed appliances on the oral microbiota: A systematic review
Orthodontic appliances. Periodontics. Attachment sites. Microbiological. Microbiological analysis.
Objective: To investigate whether there is scientific evidence to support the hypothesis that the presence of orthodontic fixed appliances influences the oral microbiota.
Methods: The search for articles was conducted in PubMed; ISI Web of Knowledge and Ovid databases, including articles published in English until May 17th, 2012. They should report human observational studies presenting the following keywords: “fixed orthodontic appliance” AND “microbiological colonization”; OR “periodontal pathogens”; OR “Streptococcus”; OR “Lactobacillus”; OR “Candida”; OR “Tannerella forsythia”; OR “Treponema denticola”; OR “Fusobacterium nucleatum”; OR “Actimomyces actinomycetemcomitans”; OR “Prevotella intermedia”, OR “Prevotella nigrescens”; OR “Porphyromonas gingivalis”. Articles were previously selected by title and abstract. Articles that met the inclusion criteria were analyzed and classified as having low, moderate or high methodology quality. A new detailed checklist for quality assessment was developed based on the information required for applicable data extraction for reviews. The study design, sample, follow-up period, collection and microbial analysis methods, statistical treatment, results and discussion were assessed.
Results: The initial search retrieved 305 articles of which 33 articles were selected by title and abstract. After full-text reading, 8 articles met the inclusion criteria, out of which 4 articles were classified as having low and 4 as moderate methodological quality. The moderate methodological quality studies were included in the systematic review.
Conclusions: The literature revealed moderate evidence that the presence of fixed appliances influences the quantity and quality of oral microbiota.
Bibliometric analysis of scientific articles published in Brazilian and international orthodontic journals over a 10-year period
Bibliometrics. Dental research. Orthodontics. Study characteristics.
Objective: This study aimed at describing the profiles of Brazilian and international studies published in orthodontic journals.
Methods: The sample comprised 635 articles selected from two scientific journals, i.e., Dental Press Journal of Orthodontics and American Journal of Orthodontics and Dentofacial Orthopedics, which were analyzed at three different intervals over a 10-year period (1999 – 2004 – 2009). Articles were described in terms of knowledge domain, study design, and country of origin (or state of origin for Brazilian papers).
Results: The most frequent study designs adopted in international studies were cohort (23.9%) and cross-sectional (21.7%) designs. Among Brazilian papers, cross-sectional studies (28.9%) and literature reviews (24.6%) showed greater frequency. The topics most often investigated were dental materials (17%) and treatment devices (12.4%) in international articles, with the latter topic being addressed by 16% of the Brazilian publications, followed by malocclusion, with 12.6%. In all cases, the most frequent countries of origin coincided with the countries of origin of each journal.
Conclusions: The majority of the studies analyzed featured a low level of scientific evidence. Moreover, the findings showed that journals tend to publish studies produced in their own country of origin, and that there are marked discrepancies in the number of papers published by different Brazilian states.
Photometric analysis of esthetically pleasant and unpleasant facial profile
Esthetics. Photography. Orthodontics.
Objective: To identify which linear, angular and proportionality measures could influence a profile to be considered esthetically pleasant or unpleasant, and to assess sexual dimorphism.
Methods: 150 standardized facial profile photographs of dental students of both sexes were obtained and printed on photographic paper. Ten plastic surgeons, ten orthodontists and ten layperson answered a questionnaire characterizing each profile as pleasant, acceptable or unpleasant. With the use of a score system, the 15 most pleasant and unpleasant profiles of each sex were selected. The photographs were scanned into AutoCAD computer software. Linear, angular and proportion measurements were obtained using the software tools. The average values between groups were compared by the Student’s t-test and the Mann-Whitney test at 5%.
Results: The linear measures LL-S, LL-H, LL-E, LL-B and Pn-H showed statistically significant differences (p < 0.05). Statistical differences were also found in the angular measures G’.Pn.Pg’, G’.Sn.Pg’ and Sn.Me’.C and in the proportions G’-Sn:Sn-Me’ and Sn-Gn’:Gn’-C (p < 0.05). Differences between sexes were found for the linear measure Ala-Pn, angles G’-Pg’.N-Pn, Sn.Me’.C, and proportions Gn’-Sn:Sn-Me’ and Ala-Pn:N’-Sn. (p < 0.05).
Conclusion: The anteroposterior position of the lower lip, the amount of nose that influences the profile, facial convexity, total vertical proportion and lip-chin proportion appear to influence pleasantness of facial profile. Sexual dimorphism was identified in nasal length, nasofacial and lower third of the face angles, total vertical and nasal height/length proportions.
Comparison of topical and infiltration anesthesia for orthodontic mini-implant placement
Anesthetics. Orthodontics. Dental implants. Orthodontic anchorage procedures.
Objective: To compare the acceptability and effectiveness of topical and infiltration anesthesia for placement of mini-implants used as temporary anchorage devices.
Methods: The sample comprised 40 patients, 17 males and 23 females, whose mean age was 26 years old and who were all undergoing orthodontic treatment and in need for anchorage reinforcement. Mini-implants were bilaterally placed in the maxilla of all individuals, with infiltration anesthesia on one side and topical anesthesia on the other. These 40 patients completed two questionnaires, one before and another after mini-implant placement and pain was measured through a visual analog scale (VAS). The data collected were analyzed using descriptive statistics and the measurements of pain were compared by means of the non-parametric test of Mann-Whitney.
Results: It was found that 60% of patients felt more comfortable with the use of topical anesthesia for mini-implant placement; 72.5% of patients described the occurrence of pressure during placement of the anchorage device as the most unpleasant sensation of the entire process; 62.5% of patients felt more pain with the use of topical anesthesia.
Conclusion: It was concluded that patients had less pain with the use of infiltration anesthesia, and also preferred this type of anesthetic.
Evaluation of a photographic method to measure dental angulation
Dental crown. Dental photography. Evaluation.
Objective: To analyze the reliability and reproducibility of a simplified method for analysis of dental angulation using digital photos of plaster dental casts.
Methods: Digital and standardized photographs of plaster casts were performed and posteriorly imported to an angle reading graphic program in order to have measurements obtained. Such procedures were repeated to evaluate the random error and to analyze reproducibility through intraclass correlation. The sample consisted of 12 individuals (six male and six female) with full permanent dentition orthodontically untreated. The analyses were bilaterally carried out, and generated 24 measurements.
Results: The random error showed variation of 0.77 to 2.55 degrees for teeth angulation. The statistical analysis revealed that the method presents excellent reproducibility (p < 0.0001) for all teeth, except for the upper premolars. In spite of that, it is still considered statistically significant (p < 0.001).
Conclusion: The proposed method presents enough reliability that justifies its use in the development of scientific research as well as in clinical practice.
Reliability of CBCT in the diagnosis of dental asymmetry
Cone-beam computed tomography. Imaging. Three-dimensional diagnosis. Dental arch.
Objective: The aim of this study was to validate a method used to assess dental asymmetry, in relation to the skeletal midline, by means of CBCT.
Methods: Ten patients who had CBCT scans taken were randomly selected for this study. Five different observers repeated 10 landmarks (x, y and z variables for each) and 12 linear measurements within 10 days. Measurements were taken in both arches to evaluate symmetry of first molars, canines and dental midline in relation to the skeletal midline. Intraclass correlation coefficient (ICC) was carried out to assess intra- and interobserver reliability for landmarks and distances. Average mean difference was also assessed to check measurement errors between observers.
Results: ICC landmarks was ≥ 0.9 for 27 (90%) and 25 (83%) variables for intra- and interobserver, respectively. ICC for distances was ≥ 0.9 for 7 (58%) and 5 (42%), respectively. All ICC landmarks for distances were >0.75 for both intra- and interobserver. The mean difference between observers was ≤ 0.6 mm for all the distances.
Conclusion: The method used to assess dental asymmetry by means of CBCT is valid. Measurements of molars, canines and dental midline symmetry with the skeletal midline are reproducible and reliable when taken by means of CBCT and by different operators.
Nicotine effect on bone remodeling during orthodontic tooth movement: Histological study in rats
Tooth movement. Bone resorption. Bone formation. Blood vessels. Nicotine.
Introduction: Nicotine is harmful to angiogenesis, osteogenesis and synthesis of collagen.
Objective: The aim of this study was to investigate the effect of nicotine on bone remodeling during orthodontic movement in rats.
Methods: Eighty male Wistar rats were randomly divided into three groups: Group C (control), group CM (with orthodontic movement) and group NM (nicotine with orthodontic movement) groups. The animals comprising groups C and CM received 0.9% saline solution while group NM received nicotine solution (2 mg/kg). A nickel-titanium closed-coil spring was used to induce tooth movement. The animals were euthanized and tissue specimens were processed histologically. We quantified blood vessels, Howship’s lacunae and osteoclast-like cells present in the tension and compression areas of periodontal ligaments. The extent of bone formation was evaluated under polarized light to determine the percentage of immature/mature collagen.
Results: We observed lower blood vessel densities in the NM group in comparison to the CM group, three (p < 0.001) and seven (p < 0.05) days after force application. Osteoclast-like cells and Howship’s lacunae in the NM group presented lower levels of expression in comparison to the CM group, with significant differences on day 7 (p < 0.05 for both variables) and day 14 (p < 0.05 for osteoclast-like cells and p < 0.01 for Howship’s lacunae). The percentage of immature collagen increased in the NM group in comparison to the CM group with a statistically significant difference on day 3 (p < 0.05), day 7 (p < 0.001), day 14 (p < 0.001) and day 21 (p < 0.001).
Conclusions: Nicotine affects bone remodeling during orthodontic movement, reducing angiogenesis, osteoclast-like cells and Howship’s lacunae, thereby delaying the collagen maturation process in developed bone matrix.
Corrosion behavior of self-ligating and conventional metal brackets
Corrosion. Orthodontic brackets. Metal.
Objective: To test the null hypothesis that the aging process in self-ligating brackets is not higher than in conventional brackets.
Methods: Twenty-five conventional (GN-3M/Unitek; GE-GAC; VE-Aditek) and 25 self-ligating (SCs-3M/Unitek; INs-GAC; ECs-Aditek) metal brackets from three manufacturers (n = 150) were submitted to aging process in 0.9% NaCl solution at a constant temperature of 37 ± 1°C for 21 days. The content of nickel, chromium and iron ions in the solution collected at intervals of 7, 14 and 21 days was quantified by atomic absorption spectrophotometry. After the aging process, the brackets were analyzed by scanning electron microscopy (SEM) under 22X and 1,000X magnifications.
Results: Comparison of metal release in self-ligating and conventional brackets from the same manufacturer proved that the SCs group released more nickel (p < 0.05) than the GN group after 7 and 14 days, but less chromium (p < 0.05) after 14 days and less iron (p < 0.05) at the three experimental time intervals. The INs group released less iron (p < 0.05) than the GE group after 7 days and less nickel, chromium and iron (p < 0.05) after 14 and 21 days. The ECs group released more nickel, chromium and iron (p < 0.05) than the VE group after 14 days, but released less nickel and chromium (p <L; 0.05) after 7 days and less chromium and iron (p < 0.05) after 21 days. The SEM analysis revealed alterations on surface topography of conventional and self-ligating brackets.
Conclusions: The aging process in self-ligating brackets was not greater than in conventional brackets from the same manufacturer. The null hypothesis was accepted.
BBO Case Report
Class I malocclusion with anterior crossbite and severe crowding
Severe discrepancy. Crossbite. Corrective Orthodontics.
Segmented arch or continuous arch technique? A rational approach
Orthodontics. Corrective Orthodontics. Biomechanics.