Dental Press Journal of Orthodontics – ISSN 2176-9451
Dental Press J. Orthod.
v. 19, no. 3
May / June
Dental malocclusion at the navel of the Xingu river
“And whatever is now disclosed to the people,
Will surprise everyone not for being exotic,
but for having remained concealed
Until it was perceived as obvious.”
Caetano Veloso, song: “An indian”
The feeling of coexisting with and treating a highly prevalent disease of which origin is unknown is unsettling. It reminds us of when heavy drugs were used to treat cancer of which association with Genetics was still unknown — in fact, nothing was known about the fact that the origin of cancer was right there, in the nucleus of the cell, in the DNA. And this logically resulted in a waste of time and lives. However, when the time came for oncologists and geneticists — cloistered in their laboratories, traveling into the nucleus of the cell — to meet, science made a gold-medal jump and Oncogenetics, the new science, sat on the front chairs of Oncology conferences.
Although millions of people undergo orthodontic treatment, the causes of malocclusion have not yet been clearly determined. That certainly is a paradox for a contemporary world that strives to offer evidence of facts. What is even worse is to know that discussions on malocclusion, held in orthodontic events, raise significantly less interest than presentations about new material and new treatment techniques. Would we be walking towards the same abyss Medicine, a science that does not admit delays, has fallen into?
It all began with Begg2 who, in 1954, studied the skulls of Australian aborigines. He established that malocclusion is “a disease of modern civilization” caused by tooth wear. Understanding Begg’s findings means perceiving the brilliant history that influenced the origins of Orthodontics and provided the road that enabled extraction of permanent teeth for space opening in the dental arch so as to counterbalance the absence of interproximal wear. Nevertheless, Begg’s concepts went beyond technicality, which bothers a lot of people, as Omar Gabriel would say. A macro analysis reveals the remarkable influence of his theory over the hypothesis that malocclusion, especially dental crowding, is mainly of environmental etiology.
Begg’s theory is still controversial and has been discussed under four models of investigation: 1) experiments with animal models; 2) analysis of ancestors’ skulls gleaned by means of excavations, and epidemiological studies conducted with primitive/isolated populations; 4) studies conducted with human twins. Overall, the findings have given support to the hypothesis that malocclusion is basically of environmental etiology.
Nevertheless, the issue is not as simple as it may seem and, for this reason, must be brought to light. One should assume that a given malocclusion probably has different etiological factors in comparison to other occlusal alterations. The fact that the obvious may be concealed intrigues a whole generation of uneasy orthodontists who believe that if we repeat the same mistakes made by Oncology — restrain the micro look taken at the nucleus of the cell and the DNA — we may pay a high price for a torpid progress.
Following Begg’s line of reasoning, I decided to provoke the monolith of orthodontic architecture by trying to reproduce his finding under a micro look: the DNA. I chose to study the indigenous people from the Brazilian Amazon3,4 following the pattern established by Begg. I sailed down the profuse Xingu river, carrying Genetics in my saddlebag.
Initially, it is worth noting that it is common for the amerindian (American indigenous) to establish new settlements, whether by means of fission (division) or fusion (union). Thus, it is easy to understand that miscigenation contributes to increasing genetic variation among indigenous people, which counterbalances with low intratribal variation.5 Therefore, unlike what it is commonly believed, indigenous groups are genetically different from each other, even though the individuals comprising the same village are similar in appearance.
Would that be the perfect opportunity for me to answer my questions regarding the theme? I put on my indigenist boots and my researcher saddlebag and, just like Begg who is now disguised in the brazilianity of a Villas-Bôas, I steered my horse towards the Xingu river where I remained between 2009 and 2010. The area has several settlements consisted of indigenous people of nine different ethnic groups. It is, therefore, one of the most ethnically diverse human community in the world.
During our first trip, we established contact with two Arara villages. Thus, two genetically different settlements.
An anthropological study about the Arara people6 revealed that the individuals comprising the Arara of Iriri village come from the same family who descend from a couple who, according to historical reports, was expeled from the Arara of Laranjal village. The separation process supposedly occurred between 1925 and 1926 when the indigenous people lived isolated.
The expelled couple had seven children and the initial expansion of the Arara of Iriri village occurred through the mating of closely related people characterized as incestuous (brother-sister, father-daughter, mother-son). Afterwards, it was established as a result of marriage between close relatives (aunt-nephew, uncle-niece, first cousins).5 Inbreeding, however, was rare in the ancestral tribe.
A genetic study5 comparing Arara villages revealed the presence of one single haplotype DNAY and mitochondrial DNA, which corroborates the historical reports on the descendant group.The study also revealed a drastic case of linear fission (involving relatives) within an ancestral tribe.Furthermore, it revealed that the genetic distance and the molecular variance between the two Arara villages were so great that despite having the same origin, their populations significantly differ in terms of genotype.
These indigenous people keep the same traditional eating habits, which was proved by similar tooth wear (a direct evidence of what an individual ate in the past) found between different villages. Therefore, both populations have the same origin and live in similar environments, but they are significantly different in terms of genetics.That was an open door for answering my initial question, but now, with a genetic support.
In the study design, we obtained an epidemiological assessment of malocclusion prevalence, which revealed marked differences in the dentofacial characteristics of the tribes. Malocclusion was twice as prevalent in the descendent village (Arara of Iriri). Most individuals comprising the original villages had a normal occlusal relationship, whereas those comprising the descendent group often had Class III malocclusion. The condition affected one third of the population. Another spasmodic result was the absence of dental crowding in the descendent village, while the original group had one fourth of its population affected by this type of malocclusion. These results mitigate the influence of tooth wear on dentofacial development and highlight the predominance of heredity in the etiology of abnormal variation in dental occlusion .We went on the opposite direction of the river rapids imported by Begg’s findings.2
After my journey on the land of the Arara, I decided to steer my canoe even further. That was when we decided to visit the Assurini people in the Xingu river, and two Xicrin-Kaiapó villages in the Bacajá river. The results yielded by our investigation confirmed the marked difference in the occlusal pattern of these groups. We reached the same conclusion. No great news for Dr. Cléber Bidegain Pereira, a Brazilian orthodontist from Uruguaiana who visited the Yanomamis in the 70s. The Yanomamis lived in complete isolation from civilization. Notwithstanding this fact, the results yielded by Dr. Pereira revealed that 71% of the sample had some feature of malocclusion, similarly to what is found for the Brazilian urban population. Crowding was observed in 48% of the sample, even though the indigenous population kept their traditional eating habits. Adults had completely worn cusps. Our true Villas-Bôas of Orthodontics concluded that malocclusion is genetically determined and follows the morphological human evolution. Thus, it does not rely on an individual’s masticatory activity. We reached the same village half a century later.
Every science must accept the potential errors arising from its conclusions: that is a fact. Science must also establish a reasonable amount of self-contemplation, often examining its exposed navel — a common habit among indigenous people.There is a chance that we are mistaken. But black swans are real in the scientific community as well as in non-fiction works, as it is the case of the movie directed by Cao Hamburger — a moviemaker generated by scientists. Xingu: a confluence of water, people, science and conscience.
Protraction of the maxilla may be achieved with face mask without previous palatal expansion
Conventional and self-ligating brackets have similar tooth movement, anchorage loss and tooth tipping rates
Prematurity and low birth weight do not affect potential malocclusions
Vertical patients have thinner cortical bone
Tooth gel with melaleuca alternifolia proves effective in controlling carious biofilm in orthodontic patients
Mini-implants and miniplates generate sub-absolute and absolute anchorage
Miniplates. Mini-implants. Osteocytes. Mechanotransduction. Periosteum. Orthopedics.
The functional demand imposed on bone promotes changes in the spatial properties of osteocytes as well as in their extensions uniformly distributed throughout the mineralized surface. Once spatial deformation is established, osteocytes create the need for structural adaptations that result in bone formation and resorption that happen to meet the functional demands. The endosteum and the periosteum are the effectors responsible for stimulating adaptive osteocytes in the inner and outer surfaces.Changes in shape, volume and position of the jaws as a result of skeletal correction of the maxilla and mandible require anchorage to allow bone remodeling to redefine morphology, esthetics and function as a result of spatial deformation conducted by orthodontic appliances. Examining the degree of changes in shape, volume and structural relationship of areas where mini-implants and miniplates are placed allows us to classify mini-implants as devices of subabsolute anchorage and miniplates as devices of absolute anchorage.
Controlling false positive rates in research and its clinical implications
Statistical analysis is, in fact, an error analysis. A statistical test does not guarantee reliable results, it only quantifies the probability of error of a given conclusion.1 While reading the articles of this journal, you will find a p-value. For instance, the article by Garib et al2 describes the p-values for a given variable at two different moments: this p-value, also known as false-positive rate,1 demonstrates the probability of error when asserting that there is a difference before and after expansion. [...]
An interview with Mark G. Hans
It is a great honor to conduct an interview with Professor Mark G. Hans, after following his outstanding work ahead of the Bolton-Brush Growth Study Center and the Department of Orthodontics at the prestigious Case Western Reserve School of Dental Medicine(CWRU) in Cleveland, Ohio. Born in Berea, Ohio, Professor Mark Hans attended Yale University in New Haven, CT, and earned his Bachelor of Science Degree in Chemistry. Upon graduation, Dr. Hans received his DDS and Masters Degree of Science in Dentistry with specialty certification in Orthodontics at Case Western Reserve University. During his education, Dr. Hans’ Master’s Thesis won the Harry Sicher Award for Best Research by an Orthodontic Student and being granted a Presidential Teaching Fellowship. As one of the youngest doctors ever certified by the American Board of Orthodontics, Dr. Hans continues to maintain his board certification. He has worked through academics on a variety of research interests, that includes the demographics of orthodontic practice, digital radiographic data, dental and craniofacial genetics, as obstructive sleep apnea syndrome, with selected publications in these fields. One of his noteworthy contributions to the orthodontic literature came along with Dr. Donald Enlow on the pages of “Essentials of Facial Growth”, being reference on the study of craniofacial growth and development. Dr. Mark Hans’s academic career is linked to CWRU, recognized as the renowned birthplace of research on craniofacial growth and development, where the classic Bolton-Brush Growth Study was historically set. Today, Dr. Hans is the Director of The Bolton-Brush Growth Study Center, performing, with great skill and dedication, the handling of the larger longitudinal sample of bone growth study. He is Associate Dean for Graduate Studies, Professor and Chairman of the Department of Orthodontics, working in clinical and theoretical activities with students of the Undergraduate Course from the School of Dental Medicine and residents in the Department of Orthodontics at CWRU. Part of his clinical practice at the university is devoted to the treatment of craniofacial anomalies and to special needs patients. Prof. Mark Hans has been wisely conducting the Joint Cephalometric Experts Group (JCEG) since 2008, held at the School of Dental Medicine (CWRU). He coordinates a team composed of American, Asian, Brazilian and European researchers and clinicians, working on the transition from 2D cephalometrics to 3D cone beam imaging as well as 3D models for diagnosis, treatment planning and assessment of orthodontic outcomes. Dr. Hans travels to different countries to give lectures on his fields of interest. Besides, he still maintains a clinical orthodontic practice at his private office. In every respect, Dr. Hans coordinates all activities with particular skill and performance. Married to Susan, they have two sons, Thomas and Jack and one daughter, Sarah and he enjoys playing jazz guitar for family and friends.
Matilde da Cunha Gonçalves Nojima
Immediate periodontal bone plate changes induced by rapid maxillary expansion in the early mixed dentition: CT findings
Daniela Gamba Garib, Maria Helena Ocké Menezes, Omar Gabriel da Silva Filho, Patricia Bittencourt Dutra dos Santos
Objective: This study aimed at evaluating buccal and lingual bone plate changes caused by rapid maxillary expansion (RME) in the mixed dentition by means of computed tomography (CT).
Methods: The sample comprised spiral CT exams taken from 22 mixed dentition patients from 6 to 9 years of age (mean age of 8.1 years) presenting constricted maxillary arch treated with Haas-type expanders. Patients were submitted to spiral CT scan before expansion and after the screw activation period with a 30-day interval between T1 and T2. Multiplanar reconstruction was used to measure buccal and lingual bone plate thickness and buccal bone crest level of maxillary posterior deciduous and permanent teeth. Changes induced by expansion were evaluated using paired t test (p < 0.05).
Results: Thickness of buccal and lingual bone plates of posterior teeth remained unchanged during the expansion period, except for deciduous second molars which showed a slight reduction in bone thickness at the distal region of its buccal aspect. Buccal bone dehiscences were not observed in the supporting teeth after expansion.
Conclusion: RME performed in mixed dentition did not produce immediate undesirable effects on periodontal bone tissues.
Cephalometric effects of the Jones Jig appliance followed by fixed appliances in Class II malocclusion treatment
Malocclusion. Angle Class II. Corrective Orthodontics. Tooth movement.
Objective: The aim of this study was to cephalometrically assess the skeletal and dentoalveolar effects of Class II malocclusion treatment performed with the Jones Jig appliance followed by fixed appliances.
Methods: The sample comprised 25 patients with Class II malocclusion treated with the Jones Jig appliance followed by fixed appliances, at a mean initial age of 12.90 years old. The mean time of the entire orthodontic treatment was 3.89 years. The distalization phase lasted for 0.85 years, after which the fixed appliance was used for 3.04 years. Cephalograms were used at initial (T1), post-distalization (T2) and final phases of treatment (T3). For intragroup comparison of the three phases evaluated, dependent ANOVA and Tukey tests were used.
Results: Jones Jig appliance did not interfere in the maxillary and mandibular component and did not change maxillomandibular relationship. Jones Jig appliance promoted distalization of first molars with anchorage loss, mesialization and significant extrusion of first and second premolars, as well as a significant increase in anterior face height at the end of treatment. The majority of adverse effects that occur during intraoral distalization are subsequently corrected during corrective mechanics. Buccal inclination and protrusion of mandibular incisors were identified. By the end of treatment, correction of overjet and overbite was observed.
Conclusions: Jones Jig appliance promoted distalization of first molars with anchorage loss represented by significant mesial movement and extrusion of first and second premolars, in addition to a significant increase in anterior face height.
Mandibular asymmetry: A proposal of radiographic analysis with public domain software
Panoramic radiography. Imaging diagnosis. Mandible.
Objective: This preliminary study aimed to propose a new analysis of digital panoramic radiographs for a differential diagnosis between functional and morphological mandibular asymmetry in children with and without unilateral posterior crossbite.
Methods: Analysis is based on linear and angular measurements taken from nine anatomic points, demarcated in sequence directly on digital images. A specific plugin was developed as part of a larger public domain image processing software (ImageJ) to automate and facilitate measurements. Since panoramic radiographs are typically subject to magnification differences between the right and left sides, horizontal linear measurements were adjusted for greater accuracy in both sides by means of a Distortion Factor (DF). In order to provide a preliminary assessment of proposed analysis and the developed plugin, radiographs of ten patients (5 with unilateral posterior crossbite and 5 with normal occlusion) were analyzed.
Results: Considerable divergence was found between the right and left sides in the measurements of mandibular length and position of condyles in patients with unilateral posterior crossbite in comparison to individuals with normal occlusion.
Conclusion: Although there are more effective and accurate diagnostic methods, panoramic radiography is still widespread, especially in emerging countries. This study presented initial evidence that the proposed analysis can be an important resource for planning early orthodontic intervention and, thus, avoid progression of asymmetries and their consequences.
Association between gingivitis and anterior gingival enlargement in subjects undergoing fixed orthodontic treatment
Epidemiology. Orthodontics. Gingivitis. Gingival enlargement.
Objective: The aim of this study was to investigate the association among gingival enlargement (GE), periodontal conditions and socio-demographic characteristics in subjects undergoing fixed orthodontic treatment.
Methods: A sample of 330 patients undergoing fixed orthodontic treatment for at least 6 months were examined by a single calibrated examiner for plaque and gingival indexes, probing pocket depth, clinical attachment loss and gingival enlargement. Socio-economic background, orthodontic treatment duration and use of dental floss were assessed by oral interviews. Associations were assessed by means of unadjusted and adjusted Poisson’s regression models.
Results: The presence of gingival bleeding (RR 1.01; 95% CI 1.00-1.01) and excess resin around brackets (RR 1.02; 95% CI 1.02-1.03) were associated with an increase in GE. No associations were found between socio-demographic characteristics and GE.
Conclusion: Proximal anterior gingival bleeding and excess resin around brackets are associated with higher levels of anterior gingival enlargement in subjects under orthodontic treatment.
Immunolocalization of FGF-2 and VEGF in rat periodontal ligament during experimental tooth movement
Periodontal ligament. Orthodontics. Vascular endothelial growth factor A. Fibroblast growth factor 1.
Objective: This article aimed at identifying the expression of fibroblast growth factor-2 (FGF-2) and vascular endothelial growth factor (VEGF) in the tension and pressure areas of rat periodontal ligament, in different periods of experimental orthodontic tooth movement.
Methods: An orthodontic force of 0.5 N was applied to the upper right first molar of 18 male Wistar rats for periods of 3 (group I), 7 (group II) and 14 days (group III). The counter-side first molar was used as a control. The animals were euthanized at the aforementioned time periods, and their maxillary bone was removed and fixed. After demineralization, the specimens were histologically processed and embedded in paraffin. FGF-2 and VEGF expressions were studied through immunohistochemistry and morphological analysis.
Results: The experimental side showed a higher expression of both FGF-2 and VEGF in all groups, when compared with the control side (P < 0.05). Statistically significant differences were also found between the tension and pressure areas in the experimental side.
Conclusion: Both FGF-2 and VEGF are expressed in rat periodontal tissue. Additionally, these growth factors are upregulated when orthodontic forces are applied, thereby suggesting that they play an important role in changes that occur in periodontal tissue during orthodontic movement.
Changes in skeletal and dental relationship in Class II Division I malocclusion after rapid maxillary expansion: a prospective study
Palatal expansion technique. Angle Class II malocclusion. Clinical trial. Orthodontics.
Objective: To assess skeletal and dental changes immediately after rapid maxillary expansion (RME) in Class II Division 1 malocclusion patients and after a retention period, using cone beam computed tomography (CBCT) imaging.
Methods: Seventeen children with Class II, Division 1 malocclusion and maxillary skeletal transverse deficiency underwent RME following the Haas protocol. CBCT were taken before treatment (T1), at the end of the active expansion phase (T2) and after a retention period of 6 months (T3). The scanned images were measured anteroposteriorly (SNA, SNB, ANB, overjet and MR) and vertically (N-ANS, ANS-Me, N-Me and overbite).
Results: Significant differences were identified immediately after RME as the maxilla moved forward, the mandible moved downward, overjet increased and overbite decreased. During the retention period, the maxilla relapsed backwards and the mandible was displaced forward, leaving patients with an overall increase in anterior facial height.
Conclusion: RME treatment allowed more anterior than inferior positioning of the mandible during the retention period, thus significantly improving Class II dental relationship in 75% of the patients evaluated.
Comparative study of friction between metallic and conventional interactive self-ligating brackets in different alignment conditions
Sérgio Ricardo Jakob, Davison Matheus, Maria Cristina Jimenez-Pellegrin, Cecília Pedroso Turssi, Flávia Lucisano Botelho do Amaral
Objective: The aim of this study was to compare the friction between three bracket models: conventional stainless steel (Ovation, Dentsply GAC), self-ligating ceramic (In-Ovation, Denstply GAC) and self-ligating stainless steel brackets (In-Ovation R, Dentsply GAC).
Methods: Five brackets were used for each model. They were bonded to an aluminum prototype that allowed the simulation of four misalignment situations (n = 10). Three of these situations occured at the initial phase (in which a 0.016-in nickel-titanium wire was used): 1. horizontal; 2. vertical; and 3. simultaneous horizontal/vertical. One of the situations occurred at the final treatment phase: 4. no misalignment (in which a 0.019 x 0.025-inch stainless steel rectangular wire was used). The wires slipped through the brackets and friction was measured by a Universal Testing Machine.
Results: Analysis of variance followed by Tukey’s Test for multiple comparisons (α = 0.05) were applied to assess the results. Significant interaction (p < 0.01) among groups was found. For the tests that simulated initial alignment, Ovation® bracket produced the highest friction. The two self-ligating models resulted in lower and similar values, except for the horizontal situation, in which In-Ovation C® showed lower friction, which was similar to the In-Ovation R® metallic model. For the no misalignment situation, the same results were observed.
Conclusion: The self-ligating system was superior to the conventional one due to producing less friction. With regard to the material used for manufacturing the brackets, the In-Ovation C® ceramic model showed less friction than the metallic ones.
Insertion torque versus mechanical resistance of mini- implants inserted in different cortical thickness
Orthodontic anchorage procedures. Torque. Orthodontics.
Objective: This study aimed to measure insertion torque, tip mechanical resistance to fracture and transmucosal neck of mini-implants (MI) (Conexão Sistemas de PróteseT), as well as to analyze surface morphology.
Methods: Mechanical tests were carried out to measure the insertion torque of MIs in different cortical thicknesses, and tip mechanical resistance to fracture as well as transmucosal neck of MIs. Surface morphology was assessed by scanning electron microscopy (SEM) before and after the mechanical tests.
Results: Values of mechanical resistance to fracture (22.14 N.cm and 54.95 N.cm) were higher and statistically different (P < 0.05) from values of insertion torque for 1-mm (7.60 N.cm) and 2-mm (13.27 N.cm) cortical thicknesses. Insertion torque was statistically similar (P > 0.05) to torsional fracture in the tip of MI (22.14 N.cm) when 3 mm cortical thickness (16.11 N.cm) and dense bone (23.95 N.cm) were used. Torsional fracture of the transmucosal neck (54.95 N.cm) was higher and statistically different (P < 0.05) from insertion torsional strength in all tested situations. SEM analysis showed that the MIs had the same smooth surface when received from the manufacturer and after the mechanical tests were performed. Additionally, no significant marks resulting from the manufacturing process were observed.
Conclusion: All mini-implants tested presented adequate surface morphology. The resistance of mini-implants to fracture safely allows placement in 1 and 2-mm cortical thickness. However, in 3-mm cortical thickness and dense bones, pre-drilling with a bur is recommended before insertion.
Effect of 0.12% chlorhexidine in reducing microorganisms found in aerosol used for dental prophylaxis of pacients submitted to fixed orthodontic treatment
Aerosol propellant. Effects of air contamination. Chlorhexidine.
Objective: This study aimed at assessing, in vivo, whether the prior use of 0.12% chlorhexidine as mouthwash would decrease air contamination caused by aerosolized sodium bicarbonate during dental prophylaxis. The study was conducted with 23 patients aged between 10 and 40 years old who were randomly selected and undergoing fixed orthodontic treatment.
Methods: The study was divided into two phases (T1 and T2) with a 30-day interval in between. In both phases, dental prophylaxis was performed with aerosolized sodium bicarbonate jetted to the upper and lower arches for 4 minutes. In T1, 10 minutes before the prophylaxis procedure, the participants used distilled water as mouthwash for one minute; whereas in T2, mouthwash was performed with 0.12% chlorhexidine. Microbial samples were collected in BHI agar plates for microbiological analysis. Two dishes were positioned on the clinician (10 cm from the mouth) and a third one at 15 cm from the patient’s mouth. The samples were incubated for 48 hours at 37°C. Results were expressed in colony-forming units (CFU).
Results: Statistical analysis carried out by means of Student’s t test, as well as Wilconxon and Kruskal-Wallis tests revealed that the prior use of 0.12% chlorhexidine as mouthwash significantly reduced CFU in the three positions studied (P < 0.001).
Conclusion: The prior use of 0.12% chlorhexidine as mouthwash significantly reduced contamination caused by aerosolized sodium bicarbonate during dental prophylaxis in the orthodontic clinic.
Discomfort associated with fixed orthodontic appliances: determinant factors and influence on quality of life
Adolescent. Orthodontics. Quality of life.
Objective: To investigate the determinant factors of discomfort attributed to the use of fixed orthodontic appliance and the effect on the quality of life of adolescents.
Material and Methods: Two hundred and seventy-two individuals aged between 9 and 18 years old, enrolled in public and private schools and undergoing orthodontic treatment with fixed appliance participated in this cross-sectional study. The participants were randomly selected from a sample comprising 62,496 individuals of the same age group. Data was collected by means of questionnaires and an interview. Discomfort intensity and bio-psychosocial variables were assessed using the Oral Impact on Daily Performance questionnaire. Self-esteem was determined using the Global Negative Self-Evaluation questionnaire. Statistical analysis involved the chi-square test and both simple and multiple Poisson regression analyses.
Results: Although most individuals did not present discomfort, there was a prevalence of 15.9% of impact on individuals’ daily life exclusively due to the use of fixed orthodontic appliance . Age [PR: 3.2 (95% CI: 1.2-8.5)], speech impairment [PR: 2.2 (95% CI: 1.1-4.6)], poor oral hygiene [PR: 2.4 (95% CI: 1.2-4.8)] and tooth mobility [PR: 3.9 (95% CI: 1.8-8.1)] remained independently associated with a greater prevalence of discomfort (P ≤ 0.05).
Conclusions: Discomfort associated with the use of fixed orthodontic appliances exerted a negative influence on the quality of life of the adolescents comprising the present study. The determinants of this association were age, poor oral hygiene, speech impairment and tooth mobility.
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Relationship between facial morphology, anterior open bite and non-nutritive sucking habits during the primary dentition stage
Open bite. Face. Primary dentition.
Introduction: Non-nutritive sucking habits (NNSHs) can cause occlusal alterations, including anterior open bite (AOB). However, not all patients develop this malocclusion. Therefore, the emergence of AOB does not depend on deleterious habits, only.
Objective: Investigate a potential association between non-nutritive sucking habits (NNSHs), anterior open bite (AOB) and facial morphology (FM).
Methods: 176 children in the primary dentition stage were selected. Intra and extraoral clinical examinations were performed and the children’s legal guardians were asked to respond to a questionnaire comprising issues related to non-nutritive sucking habits (NNSHs).
Results: A statistically significant relationship was found between non-nutritive sucking habits (NNSHs) and anterior open bite (AOB). However, no association was found between these factors and children’s facial morphology (FM).
Conclusions: Non-nutritive sucking habits (NNSHs) during the primary dentition stage play a key role in determining anterior open bite (AOB) malocclusion regardless of patient’s morphological facial pattern (FM).
Comparison of frictional resistance between self-ligating and conventional brackets tied with elastomeric and metal ligature in orthodontic archwires
Dental brackets. Wires. Friction. Self-ligating.
Objective: To compare the frictional resistance between self-ligating and conventional brackets tied to different types of wire.
Material and Methods: Abzil Kirium Capelozza (Pattern I) and Easy Clip (Roth prescription) incisor brackets were used. An elastomeric ligature or a ligating wire 0.10-in was used to ligate the wire to the Abzil bracket. Three types of orthodontic archwire alloys were assessed: 0.016-in NiTi wire, 0.016 x 0.021-in NiTi wire and 0.019 x 0.025-in steel wire. Ten observations were carried out for each bracket-archwire angulation combination. Brackets were mounted in a special appliance, positioned at 90 degrees in relation to the wire and tested in two angulations. Frictional test was performed in a Universal Testing Machine at 5 mm/min and 10 mm of displacement. The means (MPa) were submitted to ANOVA and Tukey’s test set at 5% of significance. The surfaces of wires and brackets were observed at SEM.
Results: Steel-tied brackets (16.48 ± 8.31) showed higher means of frictional resistance than elastomeric-tied brackets (4.29 ± 2.16 ) and self-ligating brackets (1.66 ± 1.57) (P < 0.05), which also differed from each other (P < 0.05). As for the type of wire, 0.019 x 0.025-in steel wire (5.67 ± 3.97) showed lower means (P < 0.05) than 0.16-in NiTi wire (8.26 ± 10.92) and 0.016 x 0.021-in NiTi wire (8.51 ± 7.95), which did not differ from each other (P > 0.05). No statistical differences (P > 0.05) were found between zero (7.76 ± 8.46) and five-degree (7.19 ± 7.93) angulations.
Conclusions: Friction was influenced not only by the type of bracket, but also by the ligating systems. Different morphological aspects were observed for the brackets and wires studied
Dissatisfaction with dentofacial appearance and the normative need for orthodontic treatment: determinant factors
Malocclusion. Orthodontics. Quality of life.
Objective: This study aims at assessing the normative need for orthodontic treatment and the factors that determine the subjective impact of malocclusion on 12-year-old Brazilian school children.
Methods: A total of 451 subjects (215 males and 236 females) were randomly selected from private and public schools of Juiz de Fora, Brazil. The collected data included sociodemographic information and occlusal conditions. The esthetic subjective impact of malocclusion was assessed by means of the Orthodontic Aesthetic Subjective Impact Score – OASIS, whereas the malocclusion and the need for orthodontic treatment were assessed by means of the Dental Aesthetic Index (DAI) and the Index of Orthodontic Treatment Need-Aesthetic Component (IOTN-AC).
Results: Prevalence of normative need for orthodontic treatment was 65.6% (n = 155), and prevalence of orthodontic esthetic subjective impact was 14.9%. The following variables showed significant association with esthetic subjective impact of malocclusion: female (p = 0.042; OR = 0.5; CI = 0.2-0.9), public school student (p = 0.002; OR = 6.8; CI = 1.9-23.8), maxillary overjet ≥ 4 mm (p = 0.037; OR = 1.7; ICI = 1-3) and gingival smile ≥ 4 mm (p = 0.008; OR = 3.4; CI = 1.3-8.8).
Conclusion: The normative need for orthodontic treatment overestimated the perceived need. Occlusal and sociocultural factors influenced the dissatisfaction of schoolchildren with their dentofacial appearance.
BBO Case Reporte
Class I malocclusion with severe double protrusion treated with first premolars extraction*
*Clinical case report approved by the Brazilian Board of Orthodontics and Facial Orthopedics (BBO).
Angle Class I malocclusion. Orthodontic space closure. Orthodontic anchorage procedures.
Angle Class I malocclusion with bymaxillary protrusion is characterized by severe buccal tipping of incisors, which causes upper and lower lip protrusion. First premolars extraction is recommended to reduce facial convexity as a result of anterior teeth retraction, which keeps canines and first molars in key to occlusion. In order to yield orthodontic results that are compatible with ideal esthetic and cephalometric outcomes, the space closure phase needs to be carried out with overbite and incisors torque control. The majority of cases also requires maximum anchorage of posterior teeth. This case was presented to the Brazilian Board of Orthodontics and Facial Orthopedics (BBO) as a requirement for the title of certified by the BBO.
From conventional to self-ligating bracket systems: Is it possible to aggregate the experience with the former to the use of the latter?
Orthodontic brackets. Angle Class III malocclusion. Facial pattern.
Introduction: Orthodontics, just as any other science, has undergone advances in technology that aim at improving treatment efficacy with a view to reducing treatment time, providing patients with comfort, and achieving the expected, yet hardly attained long-term stability. The current advances in orthodontic technology seem to represent a period of transition between conventional brackets (with elastic modules) and self-ligating brackets systems. Scientific evidence does not always confirm the clear clinical advantages of the self-ligating system, particularly with regard to reduced time required for alignment and leveling (a relatively simple protocol), greater comfort for patients, and higher chances of performing treatment without extractions — even though the number of extractions is more closely related to patient’s facial morphological pattern, regardless of the technique of choice. Orthodontics has recently and brilliantly used bracket individualization in compensatory treatment with a view to improving treatment efficacy with lower biological costs and reduced treatment time.
Objective: This paper aims at presenting a well-defined protocol employed to produce a better treatment performance during this period of technological transition. It explores the advantages of each system, particularly with regards to reduced treatment time and increased compensatory tooth movement in adult patients. It particularly addresses compensable Class III malocclusions, comparing the system of self-ligating brackets, with which greater expansive and protrusive tooth movement (maxillary arch) is expected, with conventional brackets Capelozza Prescription III, with which maintaining the original form of the arch (mandibular arch) with as little changes as possible is key to yield the desired results.