v. 16, no. 3
Dental Press Journal of Orthodontics – ISSN 2176-9451
Dental Press J. Orthod.
v. 16, no. 3
May / June
Planning is necessary; running risks is not necessary
Along the many years dealing with topics in the frontiers of orthodontic possibilities, I have often answered questions about treatment risks. It started with the first lectures about skeletal anchorage about fifteen years ago, when concerned eyes paid ? and still pay ? attention to new treatment forms. Such concern should be expected, as responsible professionals fear that expected results may not be achieved when new treatments are used. This is especially true when dealing with complex treatments that involve new steps or additional knowledge. But do these treatments actually pose greater risks?
Maybe, let?s admit it, but not always. To give a better answer to this question, however, it is important to make it clear that there is a great difference between ?exposing to danger? and ?running risks?. This difference is called planning. Planning comprises identifying the problem clearly, understanding its progression and the consequences of not solving it, establishing different resolution scenarios and choosing one consciously, and, at last, recording step by step the actions that will be taken. In the Second World War, the greater commander of the Allied Forces, General Dwight Eisenhower, once said: ?Plans are useless, but planning is indispensable.?
There are endless new resources for planning, and I have recently witnessed an excellent example of that. In a Conference, I attended a lecture that is definitely one of the best that I have ever seen. It dealt with a new perspective for the diagnosis of anterior open bites, which leads to treatment planning that is actually focused on the etiology of the problem. The lecturer, Dr. Flávia Artese, described the work conducted by her father, Professor Alderico Artese, while we, the audience, were enchanted by the extraordinary revelations of her paper. It is incredible that, in the era of fantastic imaging diagnoses and highly sophisticate examinations, a new form of diagnosis, particularly one for such an old problem, should be brought to light by means of critical observation and sharp intelligence.
Their work has been summarized and published in the Special Article section of this issue. They argue that the lack of consensus about the etiology of anterior open bites has given rise to several treatment variations, which might explain the high degree of posttreatment instability in this type of malocclusion. In addition, their study provides criteria for the diagnosis and treatment of open bites based on different tongue postures. That is such a clear finding that it is amazing that nobody noticed it before.
]Again: Plans are nothing, but planning is everything. But how can we plan if we do not even understand the cause of the problem? I strongly suggest the reading of this article, which will be a landmark in the literature about an anomaly whose correction is one of the most difficult.
Enjoy your reading!
What´s new in Dentistry
Cephalometry is an important predictor of sleep-related breathing disorders in children
Sleep-related breathing disorders (SBD) have been studied and treated for a long time in adults, but little attention has been given to children, for whom SBD may be as serious as for adults. Parents, guardians and healthcare personnel should pay close attention to these problems, which may be treated during childhood. Their effects on everyday life, such as hyperactivity and poor school achievement, may have a severe impact on the development of an individual and may clearly affect health.
The relevance of this problem has motivated authors to evaluate the cephalometric characteristics of children with SBD.1 Cephalometry is an important facial morphometry tool available practically all over the world. This study sample included 70 children (34 boys; mean age = 7.3±1.72 years) who usually snored and had symptoms of sleep-related obstructive breathing disorders for over 6 months. Nocturnal polysomnography was used to divide children into 3 groups: 26 children with a diagnosis of obstructive sleep apnea (OSA); 17 with signs of upper airway resistance syndrome (UARS), and 27 snorers. The control group had 70 children with no breathing obstructions paired for age and sex. Lateral head radiographs were obtained, and cephalograms were traced and measured. [...]
Indirect bone resorption in orthodontic movement: when does periodontal reorganization begin and how does it occur?
Tooth movement induced by orthodontic appliances is one of the most frequent therapeutic procedures in clinical dental practice. The search for esthetics and functionality, both oral and dental, demands orthodontic treatments, which are often associated with root resorptions that may, in extreme cases, lead to tooth loss, periodontal damage, or both.
The knowledge of induced tooth movement biology, based on tissue, cell and molecular phenomena that take place on each day during movement progression, enable us to act safely and consciously when using drugs, procedures and interventions to optimize orthodontic treatment and patient comfort, to reduce or avoid root resorptions and to treat systemically compromised patients.
An interview with James A. McNamara Jr.
? Degree in Dentistry and Orthodontics, University of California, San Francisco.
? PhD in Anatomy from the University of Michigan.
? Professor of Thomas M. and Doris Graber Chair, Department of Orthodontics
and Pediatric Dentistry - University of Michigan.
? Professor of Cell Biology and Development - University of Michigan.
? Research Professor at the Center for Human Growth and Development at the
University of Michigan.
? Author of the book ?Orthodontics and Dentofacial Orthopedics.?
? Milo Hellman Research Award (AAO - 1973).
? Lecturer Sheldon E. Friel (European Society of Orthodontics -1979).
? Award Jacob A. Salzmann (AAO - 1994).
? Award James E. Brophy (AAO - 2001).
? Lecturer Valentine Mershon (AAO - 2002).
? Award Albert H. Ketcham (AAO - 2008).
? Graduate of the American Board of Orthodontics - ABO.
? Fellow of the American College of Dentists.
? Former President of Edward H. Angle Society of Orthodontists - Midwest.
? Editor of series ?Craniofacial Growth Monograph? - published by University of Michigan.
? Over 250 published articles.
? Wrote, edited or contributed to more than 68 books.
? Taught courses and conferences in 37 countries.
Imaging from temporomandibular joint during orthodontic treatment: a systematic review
Introduction: The evolution of imaging in dentistry has provided several advantages for the diagnosis and development of treatment plans in various dental specialties. Examinations as nuclear magnetic resonance, computed tomography and cone beam volumetric tomography, as well as 3D reconstruction methods, have enabled a precise analysis of orofacial structures. Allied to this fact, the effects of orthodontic treatment on temporomandibular joint (TMJ) could be evaluated with the accomplishment of clinical studies with appropriate designs and methodologies.
Objective: This study, a systematic literature review, had the objective of analyzing the interrelation between orthodontic treatment and TMJ, verifying if orthodontic treatment causes changes in the internal structures of TMJ.
Methods: Survey in research bases MEDLINE, Cochrane, EMBASE, Pubmed, Lilacs and BBO, between the years of 1966 and 2009, with focus in randomized clinical trials, longitudinal prospective nonrandomized studies, systematic reviews and meta-analysis.
Results: After application of the inclusion criteria 14 articles were selected, 2 were randomized clinical trials and 12 longitudinal nonrandomized studies.
Conclusions: According to the literature analysis, the data concludes that orthodontic treatment does not occur at the expense of unphysiological disc-condyle position. Some orthodontic mechanics may cause remodeling of articular bone components.
Cytotoxicity of electric spot welding: an in vitro study
Objective: The welding process involves metal ions capable of causing cell lysis. In view of this fact, the aim of this study was to test the hypothesis that cytotoxicity is present in different types of alloys (CrNi, TMA, NiTi) commonly used in orthodontic practice when these alloys are subjected to electric spot welding.
Methods: Three types of alloys were evaluated in this study. Thirty-six test specimens were fabricated, 6 for each wire combination, and divided into 6 groups: Group SS (stainless steel), Group ST (steel with TMA), Group SN (steel with NiTi), Group TT (TMA with TMA), Group TN group (TMA with NiTi) and Group NN (NiTi with NiTi). All groups were subjected to spot welding and assessed in terms of their potential cytotoxicity to oral tissues. The specimens were first cleaned with isopropyl alcohol and sterilized with ultraviolet light (UV). A cytotoxicity assay was performed using cultured cells (strain L929, mouse fibroblast cells), which were tested for viable cells in neutral red dye-uptake over 24 hours. Analysis of variance and multiple comparison (ANOVA), as well as Tukey test were employed (p<0.05).
Results: The results showed no statistically significant difference between experimental groups (P>0.05). Cell viability was higher in the TT group, followed by groups ST, TN, SS, NS and NN.
Conclusions: It became evident that the welding of NiTi alloy wires caused a greater amount of cell lysis. Electric spot welding was found to cause little cell lysis.
In vitro study of shear bond strength in direct bonding of orthodontic molar tubes
Objective: Although direct bonding takes up less clinical time and ensures increased preservation of gingival health, the banding of molar teeth is still widespread nowadays. It would therefore be convenient to devise methods capable of increasing the efficiency of this procedure, notably for teeth subjected to substantial masticatory impact, such as molars. This study was conducted with the purpose of evaluating whether direct bonding would benefit from the application of an additional layer of resin to the occlusal surfaces of the tube/tooth interface.
Methods: A sample of 40 mandibular third molars was selected and randomly divided into two groups: Group 1 - Conventional direct bonding, followed by the application of a layer of resin to the occlusal surfaces of the tube/tooth interface, and Group 2 - Conventional direct bonding. Shear bond strength was tested 24 hours after bonding with the aid of a universal testing machine operating at a speed of 0.5mm/min. The results were analyzed using the independent t-test.
Results: The shear bond strength tests yielded the following mean values: 17.08 MPa for Group 1 and 12.60 MPa for Group 2. Group 1 showed higher statistically significant shear bond strength than Group 2.
Conclusions: The application of an additional layer of resin to the occlusal surfaces of the tube/tooth interface was found to enhance bond strength quality of orthodontic buccal tubes bonded directly to molar teeth.
Evaluation of the bone age in 9-12 years old children in Manaus-AM city
Objective: This study evaluated bone age using the Greulich & Pyle method (1959) and pubertal growth according to the study conducted by Martins (1979).
Methods: Hand and wrist radiographs of 201 children (103 boys) aged 9 to 12 years living in the state of Amazonas (Brazil) were analyzed. A chi-square test was used for statistical analysis at a level of significance of 5% (p<0.05).
Results and Conclusions: Girls were at more advanced stages in all phases of skeletal growth than boys for the ages under study; 50% of the girls had reached pubertal growth peak, whereas only 11.6% of the boys were in the same stage. The beginning and the peak of the pubertal growth spurt occurred earlier among girls (10.1 ± 0.7 and 11.1 ± 0.8 years) than among boys (11.4 ± 0.7 and 12.3 ± 0.4 years). Early maturation was more frequent among girls than among boys (41.8% vs. 5.8%), and late maturation was more prevalent among boys (38.8% vs. 11.2%). Mean bone age in the group of boys was 10.4 ± 1.7 years, and in the group of girls, 11.7 ± 1.8 years.
Treatment effects on Class II division 1 high angle patients treated according to the Bioprogressive therapy (cervical headgear and lower utility arch), with emphasis on vertical control
Extraoral cervical traction appliances. Cephalometry. Orthodontics. Vertical control. Malocclusion. Class II, division 1.
Objective: This study investigated vertical control and the effects of orthodontic treatment on dolicofacial patients, using cervical headgear (CHG) and lower utility arch.
Methods: Cephalometric assessment of 26 dolicofacial patients with Class II, division 1, and mean age of 114 months. Orthodontic treatment involved the use of cervical headgear (CHG) in the maxillary arch, lower utility arch in the mandibular arch until normal occlusion of the molars was obtained and finished in accordance with Bioprogressive Therapy, with a mean duration of 56 months. The values of FMA, SN.GoGn, ANB, Fg-S, S-FPm, maxillary length, mandibular length, posterior facial height (PFH), anterior facial height (AFH), facial height index (FHI), occlusal plane angle (OPA), palatal plane angle (PPA), total chin (TC), upper lip (UL) and Z angle were evaluated.
Results: The results showed that treatment promoted stability of the mandibular, occlusal and palatal planes. Anteroposterior correction of the apical bases occurred, verified by the significant reduction in the variable ANB. The maxilla presented slight anterior displacement and increase in the anteroposterior dimension. The mandible presented improvement in its position in relation to the cranial base and its anteroposterior dimension increased significantly. The posterior and anterior facial heights remained in equilibrium, with no significant alteration in FHI. The tegumental profile presented significant improvement.
Conclusion: The treatment performed produced correction of the apical basis with control of the horizontal planes and facial heights, and was effective for vertical control.
Analysis of the correlation between mesiodistal angulation of canines and labiolingual inclination of incisors
Malocclusion. Canines, angulation. Incisors, inclination.
Objective: To assess the degree of correlation between canine angulation and incisor inclination.
Methods: Mesiodistal angulation of canines and labiolingual inclination of incisors were obtained by means of digital graphics software (ImageTool®) from standardized photographs of the casts of 60 patients. Incisor inclination was also assessed by lateral cephalometric radiographs.
Results: Random error showed a variation of around 2° in measurements made on the casts (1.8-2.5), while systematic error, measured by the intraclass correlation test, displayed excellent reproducibility for both methods used in this study (p<0.001, r=0.84-0.96). Linear correlation tests revealed a significant positive correlation between canine angulation and incisor inclination in the maxillary arch (r=0.3, p<0.05) and even more significantly in the mandibular arch (r=0.46 to 0.51, p<0.001), when both were measured on the casts. When incisor inclination was examined by cephalometrics, correlation level was statistically insignificant for maxillary incisors (r=0.06 to 0.21, p>0.05) and varied widely in the mandibular arch (r=0.14 to 0.50).
Conclusions: The introduction of changes in the angulation of canines with the aim of monitoring compensations observed in incisor inclination is warranted, especially in the lower arch.
Evaluation of shear strength of lingual brackets bonded to ceramic surfaces
Objectives: The aim of this study was to evaluate the shear strength of lingual metal brackets (American Orthodontics) bonded to ceramic veneers.
Methods: A total of 40 specimens were divided into four groups of 10, according to bonding material and ceramics preparation: Group I - Sondhi Rapid-Set resin and hydrofluoric acid, Group II - Sondhi Rapid-Set resin and aluminum oxide, Group III - Transbond XT resin and hydrofluoric acid, and Group IV - Transbond XT resin and aluminum oxide. Prior to bonding, the brackets were prepared with heavy-duty resin base (Z-250) and the ceramic veneers were treated with silane. The shear test was conducted with a Kratos testing machine at a speed of 0.5 mm/min.
Results: The results were statistically analyzed by the Tukey test (p<0.05) and showed a statistically significant difference between groups I (2.77 MPa) and IV (6.00 MPa), and between groups III (3.33 MPa) and IV.
Conclusions: In conclusion, the bonding of lingual brackets to ceramic surfaces exhibited greater shear strength when aluminum oxide was used in association with the two resins utilized in this study, although Transbond XT showed greater shear strength than Sondhi Rapid-Set.
Education and motivation in oral health ? preventing disease and promoting health in patients undergoing orthodontic treatment
Introduction: It is incumbent upon dentists to prevent disease, minimize risks and promote health. Patients also need to be made aware of their role in oral health care. Patients undergoing orthodontic treatment find it particularly difficult to maintain satisfactory oral hygiene owing to the presence of bands, wires and ligatures. It is therefore crucial to establish preventive motivation and guidance methods to ensure mechanical control of dental plaque.
Objectives: This study investigated the effects of educational, preventive and motivational actions on the oral health of patients undergoing fixed orthodontic treatment.
Methods: Participants received free toothpaste and toothbrushes throughout the study and instructions on oral hygiene were provided and reinforced throughout the six months of research. Physical examination was performed at baseline and after 6, 12 and 24 weeks for verification of plaque, gingival and bleeding indices.
Results: Initially, the oral hygiene of participants was inadequate. During the study, significant improvement in oral health occurred in all indices. Preventive, educational and motivational actions undertaken in this study were statistically effective in improving the oral health of orthodontic patients.
Conclusion: Health promotion and disease prevention should be part and parcel of the care provided by orthodontists directly to their patients whereas oral health care guidance and motivation should be provided before and during treatment.
Microbiological analysis of orthodontic pliers
Objective: To evaluate bacterial contamination of orthodontic pliers used in an academic setting.
Methods: Thirty-four pliers were selected ? 17 band remover pliers and 17 bird beak pliers. The control group was composed of 3 previously autoclaved pliers of each model. After use, the pliers in the experimental group were immersed in 10 ml of brain-heart infusion (BHI) culture medium for 2 minutes, incubated at 37º C for 24 to 48 h and seeded in duplicates in different agar-based solid culture media to detect and identify microbial agents.
Results: Microbiological analyses revealed that there was contamination in both types of orthodontic pliers. Several bacteria were detected, predominantly staphylococcus and isolated Gram-positive (G+) cocci. The band remover pliers had a greater contamination rate and mean values of 2.83 x 109 and 6.25 x 109 CFU/ml, with variations according to the type of culture medium. The 139 pliers also had all types of bacteria from the oral microbiota at values that ranged from 1.33 x 108 to 6.93 x 109 CFU/ml. The highest mean value was found in the medium to grow staphylococci, which confirmed, in certain cases, the presence of Staphylococcus aureus, which are not part of the normal oral microbiota but are usually found in the nasal cavity and on the skin.
Conclusion: Orthodontic pliers were contaminated as any other dental instrument after use in clinical situations. Therefore, they should undergo sterilization after each use in patients.
Cephalometric evaluation of the effects of the joint use of a mandibular protraction appliance (MPA) and a fixed orthodontic appliance on the skeletal structures of patients with Angle Class II, division 1 malocclusion
Objective: This study aimed to perform a cephalometric evaluation of the skeletal responses triggered by the joint use of a mandibular protraction appliance (MPA) and a fixed orthodontic appliance for correction of Class II, division 1 malocclusion in young Brazilian patients.
Methods: The sample consisted of 56 lateral cephalograms of 28 patients (16 women and 12 men). The initial mean age was 13.06 years and mean duration of therapy with MPA was 14.43 months. The lateral radiographs were obtained before and after treatment and were compared by two calibrated examiners to identify the skeletal changes induced by the MPA using 16 linear and angular cephalometric measures. Some independent variables (patient age, sex, facial pattern, MPA model, total use time, archwire and technique used during therapy with MPA) were considered and related to those measures in order to demonstrate the influence of these variables on them. Responses to treatment were analyzed and compared by the Wilcoxon Signed Ranks test and Mann-Whitney test at a significance level of 5%.
Results: The results showed restricted anterior displacement of the maxilla, increased mandibular protrusion, improved anteroposterior relationship of the basal bones and stability of the mandibular plane relative to the cranial base. The influence of variables age, facial pattern and MPA type was also noted.
Conclusions: MPA proved an effective alternative in the treatment of Class II, division 1 malocclusion, inducing changes in the skeletal component with satisfactory clinical results.
BBO Case Report
Angle Class II, division 2 malocclusion treated with extraction of permanent teeth*
Criteria for diagnosing and treating anterior open bite with stability
Introduction: Anterior open bite is considered a malocclusion that still defies correction, especially in terms of stability. The literature reports numerous studies on the subject but with controversial and conflicting information. Disagreement revolves around the definition of open bite, its etiological factors and available treatments. It is probably due to a lack of consensus over the etiology of anterior open bite that a wide range of treatments has emerged, which may explain the high rate of instability following the treatment of this malocclusion.
Objective: Review the concepts of etiology, treatment and stability of anterior open bite and present criteria for diagnosing and treating this malocclusion based on its etiology, and provide examples of treated cases that have remained stable in the long term.