v. 15, no. 1
Dental Press Journal of Orthodontics – ISSN 2176-9451
Dental Press J. Orthod.
v. 15, no. 1
January / February
Adversities stimulating advances
The economic crisis is over. At least thatÂs what we observe when analyzing different indexes, that is, industry, Bovespa activity, and unemployment. The course and submission of the crisis have instilled a feeling that we would only sporadically experience: we have really been living in a great country. And at this time it is not the country of the future, but the present one. We have found that several of our recognized weaknesses, were, in fact, our greatest force. This is what this editorial refers to: how adversities stimulate advances.
We have been facing a banking system vaccinated through the years of hyperinflation and other economic problems. There has been a need for several regulations in order to control social problems caused by the uncontrolled rise of prices. It was precisely this high immunity, considered by many as a disproportional and damaging intervention of the State on economy, which had prevented us from the bank negative exposure that other countries had faced during the world economic crisis.
What´s new in Dentistry
Three-dimensional face morphometry
Facial anthropometry plays a key role in clinical assessments, providing an accurate diagnosis for different syndromes. Clinicians working with the head and face (maxillo-facial, plastic and aesthetic surgeons; orthodontists and prosthodontists) are the mostly interested in this three-dimensional information, being able to estimate the normal and abnormal growth, planning and evaluating surgical or orthodontic treatment, plastic surgeries and anthropometric studies.1,6
Currently, classic direct anthropometry is being replaced with various three-dimensional image (3D) analyzers, and the knowledge and application of this technology is essential for clinicians to analyze the information for planning and evaluating medical procedures and treatments.
Facial landmarks (previously marked on the face of the subject) represent the link between conventional and digital anthropometry7: conventional anthropometry identifies soft-tissue landmarks, and places some instrument (calipers, protractors) over them. Fundamentally, digital anthropometry collects a set of digital landmarks from the soft-tissue surface, and uses their spatial x, y, z coordinates as end-points for calculations based on Euclidean geometry: linear distances and angles. Together with these classic measurements, mathematics and geometrics allow the assessment of more complex characteristics from the same set of landmarks used by conventional anthropometry: estimations of volumes and surfaces, analyses of symmetry, and detailed assessments of shape.2-5,8[...]
Sources of controversies over analgesics prescribed after activation of orthodontic appliances Acetylsalicylic acid or acetaminophen?
The wide range of available drugs raises questions about the desirable and undesirable effects on orthodontic movement. Could medications such as non-steroidal anti-inflammatory drugs (NSAIDs)ASA, acetaminophen, diclofenac, ibuprofen, indomethacin and celecoxib, corticosteroids and bisphosphonates have any impact on bone metabolism to the extent of interfering with orthodontic movement?3,18
When administered to control pain and discomfort after activation of the orthodontic appliance, what would be the influence of ASA and acetaminophen on tooth movement and the root resorption associated with it? To help in clarifying this question, Maldonado34 and his team set out to quantitatively determine the influence of ASA and acetaminophen on induced tooth movement and on root resorption by means of optical microscopy. In another study they described the history and action mechanisms of these two medications.14
However, when analyzing the literature on the subject, it appears that no work repeated the same experimental model of any other work. The appliance used to move a tooth, the force applied, the dosage and duration of drug use, route of administration, the experimental animal, the teeth that were moved, the types of tissue section and tooth movement assessment as well as many other details differ from study to study, thus precluding comparisons. Without comparisons and without relevant discussions grounded and based on relevant literature it becomes difficult to draw inferences for clinical applications.[...]
James Leonard Vaden
It was with great honor and pleasure that I accepted the invitation to coordinate this interview with Dr. Vaden, for whom I have a deep admiration, especially for his work as a clinician and educator. His clinic life started in 1972 in his office in Cookeville, TN, where, he has been attending children and adults. Over the years, he has been trying to pass his orthodontic experience through more than 120 articles published, as either an author or co-author of 10 chapters of textbooks, in addition to more than 200 lectures carried out in several countries, including Brazil, where he has been five times. He is married to Dr. Beverly Hedgepeth and has a daughter, Meg, a lawyer in New York. He and Beverly live in a farm in the area of Buck Mountain, Vanderbilt, TN, where he raises Angus cattle. In his spare time, he works the land with a John Deere tractor that he had repaired by himself.
Along with well known professors we could prepare questions that express the brilliant opinions of our interviewer on several topics related to contemporary Orthodontics. Have a nice reading![...]
Assessment of mandibular advancement surgery with 3D CBCT models superimposition
Cone-Beam Computed Tomography. Image processing. Computer-assisted surgery. Computer simulation. Orthodontics. Oral surgery.
Objectives: To assess surgery and short-term post-surgery changes in the position of the condyles, rami and chin after mandibular advancement.
Methods: Pre-surgery (T1), 1 week postsurgery (T2), and 6 weeks post-surgery (T3) CBCT scans were acquired for 20 retrognathic patients with short or normal face height. Three-dimensional models were built and superimposed through a fully automated voxel-wise method using the cranial base of the pre-surgery scan as reference. Anatomic regions of interest were selected and analyzed separately. Withinsubject surface distances between T1-T2, T2-T3, T1-T3 were computed. Color-coded maps and semi-transparent display of overlaid structures allowed the evaluation of displacement directions.
Results: After an antero-inferior chin displacement with surgery in all cases (>4 mm in 87.5%), 25% of the patients showed some kind of posterior movement (<3 mm), and 69% showed an antero-superior movement after splint removal. Comparing T1-T3, an anteroinferior (87.5% of the cases) or only inferior (12.5%) displacement was observed (>4 mm in 80%). Considering all directions of displacement, the surface distance differences for the condyles and rami were small: 77.5% of the condyles moved <2 mm with surgery (T1-T2), and 90% moved <2 mm in the short-term (T2-T3) and in the total evaluation (T1-T3), while the rami showed a <3 mm change with surgery in 72.5% of the cases, and a <2 mm change in 87.5% (T2-T3) and in 82% (T1-T3).
Conclusions: Expected displacements with surgery were observed and post-surgery changes suggested a short-term adaptive response toward recovery of condyle and ramus displacements. The changes on the chin following splint removal suggested an acceptable adaptation, but with considerable individual variability.
Standardization of a method for measuring buccal and lingual bone plates using Cone Beam Computed Tomography
Tomography. Spiral Cone Beam Computed Tomography. Diagnosis. Alveolar process.
Introduction: The thickness of the buccal and lingual bone plates constitutes one of the limiting factors of the orthodontic movement. The imaging technology has permitted the evaluation of this anatomical region, by means of cone beam computed tomography.
Objectives: To detailed describe and standardize a method for measuring the buccal and lingual bone plate thickness in CBCT images.
Methods: Digital standardization of face image should constitute the first step before the selection of CBCT slices. Two axial sections of each jaw were used for measuring the thickness of buccal and lingual bone plates. The cemento-enamel junction of the first permanent molars was used as a reference, both in the upper and lower arches.
Results: Axial sections parallel to the palatine plane were recommended for quantitative evaluation of the alveolar bone plate in the maxilla. In the mandibular arch, the axial sections should be parallel to the functional occlusal plane. Conclusion: The method described shows reproducibility for evaluating the periodontal effects of tooth movement for clinical or research purposes, permitting the comparison between pre and posttreatment images.
Laboratorial study of the cuspids retraction timing and tipping effects during space closure, using the segmented arch technique
Orthodontics. Segmented arch. Orthodontic space closure.
Objective: Evaluate the cuspids retraction time and tipping effects, after submitting it to three different orthodontic retraction loops: the T loop, the boot loop, and the tear drop loop.
Methods: It was used the following orthodontic wires: Morelli 0.019 x 0.025-in stainless steel, 3M Unitek 0.019 x 0.025-in stainless steel and Ormco 0.019 x 0.025-in beta-titanium (TMA). The resulting sample from the combination of these variables was submitted to a test developed on a typodont simulator used specifically for this purpose.
Results: As the closure timing concerns, it was verified that a slower closure and therefore, a smaller releasing force system was achieved by the T loop design and by employing the beta-titanium alloy on its construction. As to the tipping effects generated by the retraction device, the tear drop loop caused greater tipping effects than the other loops evaluated. The T loop, on the other hand, showed itself statistically related to the lowest tipping numerical values. However, when the 3M Unitek stainless steel wire was used to produce the device, all of the types of loops evaluated were considered statistically similar.
Conclusion: Regardless of the loop design, the ones built out of beta-titanium alloy kept them statistically related to the lowest tipping numerical values observed for the retracted dental element.
Reproducibility of natural head position in profile photographs of children aged 8 to 12 years with and without the aid of a cephalostat
Natural head position. True vertical line. Orthodontics. Children.
Objectives: The present study assessed the reproducibility of the natural head position (NHP) in children.
Methods: Twenty-five children (12 females and 13 males) aged 8 to 12 years (patients at the School of Dentistry of the Universidade Estadual de Maringá PR, Brazil) were photographed. Photographs were taken in the NHP using a digital camera with and without the aid of a cephalostat. A vertical line (VL) was used as reference for the measurements. The photographs were taken again after a 15-day interval using the same protocol. Reproducibility of the NHP between both photograph sessions was evaluated using an angular measurement between the reference vertical line and a profile line passing through the soft pogonion and the upper lip point.
Results and Conclusion: Although positional variations have suggested that patients in this age group should receive additional orientation on NHP photographs, there were no significant differences in the NHP within a 15-day interval with or without the aid of a cephalostat. The NHP proved to be a method with good reproducibility in children.
Analysis of skeletal maturation in patients aged 13 to 20 years by means of hand wrist radiographs
Maturity. Tooth movement. Dental implant.
Objectives: Evaluate an alternative and simplified radiographic method that will enable implantologists and orthodontists to keep track of bone growth completion as well as differences between genders in a sample of individuals from 13 to 20 years of age.
Methods: A hand wrist radiograph was acquired with the use of occlusal radiographic film to assess the maturation of the radius bone. One hundred and sixty patients of both genders were divided into groups of 10 individuals. The radiographs were examined by five raters using applicable rating standards, all specialists in orthodontics.
Results: The results showed that there was a positive correlation between the chronological age of the patients and their biological age, whereas female bone maturation occurs earlier than in males.
Conclusion: This method can determine the stage of maturation of the radius bone, allowing an affordable means of diagnosis and rapid determination of bone age for correct installation of an implant and/or orthodontic appliance.
The influence of the methodological variables on the shear bond strength
Methodological variables. Investigation protocol. Bracket bonding. Shear bond strength.
Objectives: Evaluate the influence of several methodological variables on the shear bondstrength of in vitro studies.
Methods: 105 bovine incisors were sectioned at the cervical level.The coronary portion was included in PVC rings, fulfilled with auto polymerized acrylic resin,with its labial surfaces positioned upward. All the samples were prepared for bonding, cleanedand acid etched on the central area of the crowns. In this area, central incisors Morellibrackets were bonded with Concise (3M/Unitek). Three testing groups were established,according to the studied variable: Group 1storage previous to bonding (a- thymol 0.1%;b- distilled water; c- freezing); Group 2crosshead speed of the universal testing machine(a- 0.5 mm/min; b- 1.0 mm/min; c- 2.00 mm/min) and Group 3commercial brand of 37%phosphoric acid (a- 3M/Unitek; b- Acid Gel; c- Attack Tek). The shear bond strength test wasperformed at the Emic DL2000 universal testing machine. Data was analyzed through theStudents t test for independent samples.
Results: In Group 1, the freezing group showed thehigher values of shear bond strength when compared to the others, although no statisticaldifference was observed (p > 0.05). For Group 2, the higher the crosshead speed, the lowerthe shear bond strength, with no statistical difference. In Group 3, the 3M/Unitek brandshowed the highest average of shear bond strength in MPa, but also no statistical differencewas shown.
Conclusions: The variable analyzed in this research had not presented enoughinfluence to determine significant differences between the results.
Comparison of the occlusal outcomes and treatment time of Class II malocclusion with the Pendulum appliance and with two maxillary premolar extractions
Class II. Pendulum. Extractions. Distalization.
Objectives: The purpose of this study was to compare the occlusal outcomes and the treatment time of Class II malocclusion with the Pendulum appliance and with two maxillary premolar extractions.
Methods: For this, 48 Class II malocclusion patients were selected and divided into two groups according to the treatment protocol: group 1 consisted of dental study casts and initial cephalograms of 22 patients treated with the Pendulum appliance, with an initial mean age of 14.44 years and group 2, comprised of dental study casts and initial cephalograms of 26 patients treated with two maxillary premolar extractions and a initial mean age of 13.66 years. The occlusal outcomes were evaluated on dental casts with the PAR occlusal index and the treatment time of each group was calculated by the clinical records. The variables were compared by the t tests.
Results and conclusions: The results demonstrated that the occlusal outcomes were similar between the groups, however, the two maxillary premolar extractions protocol provided occlusal outcomes in a shorter treatment time than the Pendulum treatment.
A PowerPoint-based guide to assist in choosing the suitable statistical test*
Biostatistics (Public Health). Health statistics. Statistics. Statistical databases. Interactive tutorial.
Selecting appropriate methods for statistical analysis may be difficult, especially for the students and others in the early phases of the research career. On the other hand, PowerPoint presentation is a very common tool to researchers and dental students, so a statistical guide based on PowerPoint could narrow the gap between orthodontist and the Biostatistics. This guide provides objective and useful information about several statistical methods using examples related to the dental field. A Power-Point presentation is employed to assist the user to find answers to common questions regarding biostatistics, such as the most appropriate statistical test to compare groups, to make correlations and regressions or to look for casual and systematic errors for a specific method. Assistance to check normal distribution and to choose the most suitable graphics is also presented. This guide* could be even used by reviewers in a quick assessment to check the appropriated statistical methodology into a specific study.
Clinical and polysomnographic assessment of the BRD Appliance in the treatment of Obstructive Sleep Apnea Syndrome
Obstructive Sleep Apnea. Polysomnography. Respiratory protection devices. Snoring.
Objectives: This research was designed to perform a clinical and polysomnographic evaluation of the effect of an oral appliance (OA) for the treatment of Obstructive Sleep Apnea Syndrome (OSAS), developed and tested by two Brazilian federal universities.
Methods: The sample consisted of 50 patients (aged between 18 and 65 years, 33 men and 17 women) with initial polysomnographic diagnoses of mild to moderate OSAS. All patients underwent a new polysomnographic assessment during an entire night (using the OA) approximately six months after the first evaluation. Based on the reduction of apnea and hypopnea index (AHI) obtained with the use of the OA, the patients were divided into good responders (reduction of 50% or more of the AHI, remaining below 10 events/hour) and poor responders (AHI remained greater than or equal to 10 events/hour).
Results and Conclusions: In 54% of the sample, the AHI decreased to less than five events/hour with the use of the OA; in 38% the reduction in AHI was greater than 50% but remained above the five events/hour; and in 6% of the sample the AHI decreased less than 50%. The good responders accounted for 86% of the studied sample, while the other 14% were poor responders. There were significant improvements in the sleepiness scale, the AHI, the micro-arousals and the minimum oxyhemoglobin saturation with the utilized therapy. A high Body Mass Index seemed to negatively interfere in the performance of the device under study.
Aesthetics in Orthodontics: Six horizontal smile lines
Orthodontics. Aesthetics in Orthodontics. Dental aesthetics. Mouth aesthetics. Smile.
Introduction: Smile analysis is an important stage for the diagnosis, planning, treatment and prognosis of any dental treatment involving aesthetic objectives. The evaluation of the intrinsic characteristics of the smile is a necessary procedure to achieve consistent form in orthodontic treatments, which in turn makes it necessary to recognize the components and factors that affect these characteristics.
Objective: The objective of this work is to present six horizontal smile lines and their importance in obtaining the desired results in orthodontic treatments.
Conclusion: The analysis of the six horizontal smile lines facilitates the understanding of the intrinsic characteristics that interfere in the aesthetics of the mouth. Moreover, a harmonization of these lines gives each professional a higher possibility of success in their treatments that include aesthetic objectives.
BBO Case Report
Angle Class II, Division 2, malocclusion with deep overbite
Angle Class II malocclusion. Corrective Orthodontics. Deep overbite.
This case report describes the orthodontic treatment of an adult patient, who presented a Angle Class II, Division 2, malocclusion, with overbite, severe curve of Spee, right maxillary lateral incisor proclined and gengival recessions. The patient was treated with extraction of the first premolars and maximum anchorage control. This case was presented to the Brazilian Board of Orthodontics and Dentofacial Orthopedics (BBO) representing the category 6, deep overbite malocclusion, as part of the requirements for obtaining the title of Diplomate by BBO.
Anticipated Benefit: a new protocol for orthognathic surgery treatment that eliminates the need for conventional orthodontic preparation
Orthognathic surgery. Dentofacial deformities. Orthodontic preparation.
Introduction: Conventional orthodontic-surgical treatment for the correction of dentofacial deformities takes up a lengthy period of time preparing the patient orthodontically, which sometimes causes a temporary deterioration in the patients appearance. This fact has set the stage for the development of a new treatment technique aimed at addressing these issues.
Objectives: To introduce a new protocolnamed Anticipated Benefitand to illustrate it with a clinical case.
Methods: The planning stages are presented and then illustrated by treating a patient with a Class III deformity. According to this method, after some careful planning the orthodontic appliance is fixed and subsequently orthognathic surgery is performed.
Conclusion: Although both the traditional and the Anticipated Benefit techniques provide excellent functional and aesthetic results, the new protocol achieves significant improvements soon after the start of treatment. The new method has proved very convenient, particularly for the patient.