v. 15, no. 2
Dental Press Journal of Orthodontics – ISSN 2176-9451
Dental Press J. Orthod.
v. 15, no. 2
March / April
Orthodontics of the future: From fiction to reality
Renowned science fiction author Isaac Asimov once asserted that whoever writes science fiction cannot help making predictionsnot of what will happen but of what may happen. In fact, since researchers are often required to scan the present in order to shed light on the future, we could modestly compare ourselves to science fiction writers. This is the outlook I intend to adopt from now on in this editorial. I will try to answer a question someone recently posed to me.
What will orthodontics be like in 30 years?
In 30 years, the World Federation of Orthodontists (WFO) will have established guidelines for the course content of graduate orthodontic programs around the world. The number of courses comprising only a handful of credit hours in educationally developed countries will have fallen dramatically. In these countries courses will tend to last 2 to 3 years full time. Organizations such as the Brazilian Board of Orthodontics and the American Board of Orthodontics will be crucial in the process of professional quality assessment. The orthodontic community will become more globalized. Students worldwide will be able to simultaneously attend interactive classes.
Increased Information Technology skills will prove essential in daily practice. Study models will be digital, not only to speed up preparation and analysis but also because the cost of storing plaster models will become unreasonably high in major cities around the world. Three-dimensional printers will be used whenever physical models are needed. But there will be other reasons behind the need for increased Information Technology capability.
Three-dimensional image superimposition methods will be commonplace. Students of Orthodontics will have access to better designed studies and evidence-based practice will be a routine. As a consequence, we will rationalize the use of X-rays in imaging exams.
Technological advances will enable convenient custom-designed treatments and thus we will be able to see more patients in less time and with a high level of excellence. This will mean greater access to treatment by the population. It will also demand some obvious adjustments. Countries such as Brazil, which already has more dentists than required to meet its populations oral health needs will see the size of its dental educational system shrink.
Orthodontic practice will undergo changes as well. Information Technology will bolster patient care by assisting the work flow. Tooth movement control systems will alert orthodontists whenever they divert from the treatment goals or delay in taking the necessary therapeutic measures. Patients, in turn, will interact more with the treatment, making even more informed decisions about what the treatment plan has in store for them.
All issues discussed here will lead to a single outcome, i.e., the quality of orthodontic services will rise as well as their beneficial impact on the global population.
Many of you may be wondering now what the relationship is between this fiction and todays orthodontics. The answer is that they are deeply entwined. Obviously, I only described one among many possible future scenarios. However, my vision is already materializing as you read this editorial and the fact that many young professionals are not aware of it should give us reason for concern.
Digital models are now a tangible reality at affordable prices. Furthermore, professionals are incorporating them into clinical practice, making set-ups and increasing the quality of their presentations for both patients and dentists. Methods like the one presented by Motta et al in this issue of the Journalfor superimposing tomographic imagesare part of a technology available to all interested parties.
The movement in search of evidence-based dentistry is irreversible and so is the need for a solid education capable of producing qualified professionals. Young dentists, newly undergraduated from schools of dentistry, should apply for a graduate course with an extensive workload that can endow them with the skills needed to enter the market with their heads held high. These truths can be found in the content of the interview featured in this issue. Our interviewee, Dr. Turpin, editor-in-chief of the American Journal of Orthodontics and Dentofacial Orthopedics, also underscored the relevance of the Boards of Orthodontics for public recognition of orthodontists as successful professionals.
Thus, in line with Asimov, the predictions I made may not be what will happen, but what is likely to happen. Whatever the future may bring, preparing for it entails proper training and adequate continuing education.
Young dentists, brace yourselves for the future by attaining excellence in your training for you are the lead characters of my fiction.
What´s new in Dentistry
Whats new in digital photography?
Digital photography has become ubiquitous in modern society and its importance in dentistry is unquestionable.3,4,5,9 This assertion is confirmed by the fact that the 2009 Nobel Prize in Physics was awarded to the inventors of the charge coupled device (CCD).10
Although this technology dates back to the 1970s and the first digital camera was launched in the market in the 1990s, the clinical use of this tool in dental offices has become a reality in the early 21st century.5,11 CCD allows users to view photographs on the spot, eliminating film and film development costs while systematic image management can be performed in the clinic. These features have combined to make this novel digital system extremely attractive.3,6 Another advantage lies in CCDs image manipulation and editing capabilities, which streamline interpersonal communication, ensuring successful results. 2,8 Figures 1 and 2 show examples of digital manipulation assisting in outcome prediction and clinical procedure planning, respectively.
Although historically the introduction of this resource in dental practice is a recent phenomenon, digital cameras have become commonplace in most orthodontic offices. However, increasing market pressures to sell modern cameras with higher resolutions pose some important questions: Whats new in digital photography?
Are the latest cameras that boast more and more megapixels (MP) our best choice? Whats the best suited resolution for orthodontic photography?
Due to the lack of literature in this area, it might prove convenient to provide some clarification so that orthodontists can learn about the technical and scientific reasons for taking advantage, as much as possible, of the benefits of digital photography.[...]
ERM functions, EGF and orthodontic movement or Why doesn't orthodontic movement cause alveolodental ankylosis?
Can orthodontic movement induce alveolodental ankylosis? This question is often asked and the answer involves further questioning: Why dont the teeth naturally evolve to alveolodental ankylosis if they are separated from the bone by only 0.2 to 0.4 mm (the minimum and maximum thickness of the periodontal ligament)?
The periodontal ligament is richly cellularized and vascularized, featuring numerous elastic and reticular collagen fibers, typical of connective tissues (Figs 1, 2 and 3). In between these structures it has a gel, namely, the extracellular matrix. Among the fibers, fibroblasts, vessels and nerves of the periodontal ligament there is a network of epithelial cords and islands that continuously release mediators, especially EGF, i.e., Epithelial or Epidermal Growth Factor (Fig 2). Areas on the surface of the bone tissue that contain EGF stimulate bone resorption, hindering the formation of new layers. This epithelium network interposed between bone and tooth in the ligament tissue is known as Epithelial Rests of Malassez (ERM), derived from apoptosis in Hertwigs Epithelial Root Sheath (HERS). Malassez original drawings (Fig 4) depicted these epithelial cords and islands in the same manner as we analyze them microscopically today.
It was long believed that ERM comprised latent or quiescent cells devoid of structure and function, often associated with the genesis of cysts and tumors. However, these epithelial periodontal components are active, produce mediators and fulfill key functions in maintaining periodontal health and root integrity even during orthodontic movement. In this paper we will discuss these wonderful structures and their functions to assist us in understanding the relevant responses to the two questions posed above.
An interview with David L. Turpin (editor-in-chief of the AJO-DO)
Dr. Turpin attended dental school at the University of Iowa located in the Midwest, then gained entrance as a resident in orthodontics to the University of Washington in Seattle. His primary goal was to study under the guidance of Alton W. Moore, then Chair in Seattle. Upon graduation in 1966, he started a private practice, returning to the University of Washington 4 years later to teach part time in the clinic. He has been married to Judith Clark Turpin for 48 years. They have three children and three grandchildren, ages 8 to 19. He has spent most of his spare time traveling widely during the past 10 years, so that may qualify as a current hobby. At the moment he is reading a book named, The Tipping Point by Malcolm Gladwell and plan to start Dan Browns The Lost Symbol shortly.
Dr. Turpin has worked on orthodontic journals for over 30 yearsfrom his early days on the Bulletin of the Pacific Coast Society of Orthodontists, to The Angle Orthodontist, and finally the American Journal of Orthodontics and Dentofacial Orthopedics. He will retire as editor-in-chief of the AJO-DO at the end of 2010 when Dr. Vincent G. Kokich will become the new editor.[...]
Superimposition of 3D cone-beam CT models in orthognathic surgery
Cone Beam Computed Tomography. Three-dimensional image. Surgery, computer assisted. Computer simulation. Orthodontics. Surgery. Oral.
Introduction: Limitations of 2D quantitative and qualitative evaluation of surgical displacements can be overcome by CBCT and three-dimensional imaging tools.
Objectives: The method described in this study allows the assessment of changes in the condyles, rami, chin, maxilla and dentition by the comparison of CBCT scans before and after orthognathic surgery.
Methods: 3D models are built and superimposed through a fully automated voxel-wise method using the pre-surgery cranial base as reference. It identifies and compares the grayscale of both three-dimensional structures, avoiding observer landmark identification. The distances between the anatomical surfaces pre and post-surgery are then computed for each pair of models in the same subject. The evaluation of displacement directions is visually done through color maps and semi-transparencies of the superimposed models.
Conclusions: It can be concluded that this method, which uses free softwares and is mostly automated, shows advantages in the long-term evaluation of orthognathic patients when compared to conventional 2D methods. Accurate measurements can be acquired by images in real size and without anatomical superimpositions, and great 3D information is provided to clinicians and researchers.
A comparative study of manual vs. computerized cephalometric analysis
Radiography. Cephalometrics. Craniometry.
Objective: To conduct a comparative analysis between manual and computerized tracings using specific software, in order to define inter- and intraobserver results.
Methods: A sample was used consisting of 50 standardized lateral cephalometric radiographs, of male and female patients of various age groups. The radiographs were analyzed by two observers, who each performed the manual and computerized tracings of all 50 radiographs. Angular and linear measurements were obtained, which were later submitted to the Mann-Whitney test in order to compare the inter- and intraobserver results between the two types of tracings.
Results and Conclusions: the study concluded that confidence can be increased in tracings obtained from computer-assisted cephalometric analysis, as the discrepancies found between inter- and intraobserver tracings, both manual and computerized, were mostly not statistically significant.
Change in the gingival fluid volume during maxillary canine retraction
Gingival sulcus. Orthodontic movement. Inflammation.
Introduction: In the analysis of the pressure-tension theory of tooth movement, the application of an orthodontic force causes gradual displacement of fluids of the periodontal ligament, followed by distortion of the cells and extracellular matrix.
Objectives: This study evaluated the gingival fluid volume on the mesial and distal aspects of the maxillary canines of 14 patients (3 males and 11 females) submitted to orthodontic movement.
Methods: The fluid was collected using standard absorbent paper strips (PeriopaperTM) and the fluid volume was determined using the instrument Periotron at seven different periods (day -7, day 0, 1 hour, 24 hours, 14 days, 21 days, 80 days). The Friedman test was applied to compare the data achieved (p < 0.01 and p < 0.05).
Results: The results revealed a significant change in the gingival fluid volume with time on both the pressure side (p < 0.001) and the tension side (p < 0.01). On the pressure side, the gingival fluid volume was significantly lower at the periods 0 (p < 0.01) and 24hs (p < 0.001) compared to the period 80 days.
Relationship between mandibular growth and skeletal maturation in young melanodermic Brazilian women*
Skeletal maturation. Melanodermic subjects. Hand and wrist radiographs. Mandibular growth. Frontal sinus.
Objective: To assess the degree of correlation between mandibular growth and skeletal maturation in young melanodermic Brazilian women.
Methods: The authors examined 140 lateral cephalometric radiographs and an additional 140 radiographs of hands and wrists of young female Brazilian melanodermic subjects aged 8 to 14 years with normal occlusion or Angle Class I malocclusion, who had not been subjected to previous orthodontic treatment. Using the hand and wrist radiographs, the authors evaluated the development of ossification centers in the proximal phalanx of the 3rd finger and the distal epiphysis of the radius bone, by tracing according to the method described by Eklof and Ringertz. The lateral cephalometric radiographs enabled an analysis of frontal sinus pneumatization according to the method described by Ruf and Pancherz, and of the cephalometric measurements representative of mandibular growth, namely, Co-Go, Co-Gn, Go-Gn, Fg-Pg. The data were statistically analyzed using Pearsons Correlation to determine the degree of relationship between variables.
Results and Conclusions: A highly significant correlation was found between ossification centers observed on the hand and wrist radiographs and cephalometric measurements representative of the mandibular growth (r = 0.777). Although statistically significant, there was a low correlation between frontal sinus pneumatization and the progression of skeletal maturity (r = 0.306), as well as a relationship between frontal sinus pneumatization and the cephalometric measurements representative of mandibular growth (r = 0.218).
Breastfeeding, deleterious oral habits and malocclusion in 5-year-old children in São Pedro, SP, Brazil
Breastfeeding. Malocclusion. Children.
Objective: To estimate the frequency of malocclusion and their associations with the type and period of breastfeeding, deleterious oral habits, and information received by mothers during the pre-natal period, in 5-year-old children attending municipal daycare centers.
Methods: The sample consisted of 162 children resident in the municipality of Sao Pedro, SP, Brazil. In an interview with each of the mothers, information was collected about the time and form of breastfeeding, presence of deleterious habits, and information the mother received during the pre-natal period. The epidemiological exam was performed at the daycare center facilities by a single, previously calibrated examiner, under direct lighting. The following variables were evaluated: presence and severity of malocclusion [slight overcrowding and spacing (OS)], open occlusal relationship (open bite) (OPB), vertical overlap (over bite) (OVB), uni- or bilateral crossbite (CB), positive overjet (OV) and the primary second molar terminal plane relationship (TPR)]. Data analysis consisted of univariate analysis (chi-square test) and multiple logistic regressions.
Results: The prevalence of malocclusions was 95.7% (OS = 22.8%; OPB = 24.7%; OVB = 20.4%; CB = 14.8%; and OV = 13.0%). In TPR the straight terminal plane was predominant (85.0%). Among the deleterious oral habits, the use of a pacifier was the only risk indicator (OR = 5.25; p = 0.001) for open occlusal relationship (open bite) in children that used it for over three years, detected in the logistic regressions.
Conclusion: The prevalence of malocclusions and deleterious oral habits in the studied sample was high. Children that used a pacifier for over three years showed greater probability of presenting with open occlusal relationship (open bite).
Frictional forces in stainless steel and plastic brackets using four types of wire ligation*
Friction. Orthodontic ligation. Metal bracket. Plastic bracket.
Objective: This in vitro study evaluated and compared the frictional resistance of stainless steel and polycarbonate (PC) composite brackets tied with metal wire and elastomeric ligation.
Methods: Four stainless steel and four polycarbonate composite brackets for premolars were placed in a universal testing machine for the traction of a piece of 0.019 x 0.025-in wire at 0.5 mm/min and total displacement of 8 mm. Ligations were performed according to the following alternatives: metal ligation with Steiner tying pliers; metal ligation using Mathieu tying pliers; Morelli elastomeric ligation; and TP Orthodontics elastomeric ligation.
Results and Conclusions: Elastomeric modules generated more friction than the metal ligations, and the ligation with the Mathieu tying pliers caused less friction than all the other conditions under study. PC brackets generated less friction than metal brackets, but the choice of material to be used in clinical conditions should take into consideration other variables, such as resistance to shearing and to fractures, as well as color stability and microorganism adherence.
Influence of mandibular sagittal position on facial esthetics
Facial profile. Orthodontics. Orthognathic surgery.
Objectives: To analyze the influence of mandibular sagittal position in the determination of facial attractiveness.
Methods: Facial profile photographs were taken of an Afro-descendant man and a Caucasian man, as well as an Afro-descendant woman and a Caucasian woman. These photos were manipulated on the computer using Adobe Photoshop CS2 to produce from each original facea straight profile, three simulating retrusion and three protrusion mandibular discrepancies. In all, 28 photographs were evaluated by orthodontists (n = 20), oral maxillofacial surgeons (n = 20), plastic artists (n = 20) and laypersons (n = 20). The descriptive analysis was performed by calculating the mean and standard deviation for each group.
Results: The straight facial profile was met with greater acceptance by Afro-descendant male faces and female faces. Caucasian males found a lightly concave facial profile with a more prominent mandible to be the most pleasant. After an analysis of skeletal discrepancies simulations, Caucasian males also showed a preference for mandibular protrusion versus retrusion. Females, however, preferred convex over concave profiles.
Conclusion: The results showed agreement between groups of evaluators in selecting the most attractive profiles. Regarding male faces, a straight profile with a slightly concave face seemed more attractive and a straight facial profile was also greatly valued.
The relationship between bruxism, occlusal factors and oral habits
Bruxism. Sleep. Malocclusion. Oral habits.
Objective: Evaluating the relationship between bruxism, occlusal factors and oral habits in children and adolescent subjects, students from public schools in Brasilia-Federal District city.
Methods: A group of 680 students, of both genders, average age 4 - 16 years, were randomly selected. Data was collected by clinical evaluation and questionnaires replied by the responsible for the students. The occlusion morphological aspects were evaluated according to Angle classification and following a criteria created for the deciduous dentition, according to Foster and Hamilton (1969). Uni or bilateral posterior and anterior crossbites were evaluated. The chi-square test, the Odds Ratio and the SPSS software were used for the statistic analysis.
Results and Conclusion: 592 questionnaires were fulfilled completely. Bruxism had a prevalence of 43%, whilst 57% presented malocclusion. Oral habits were observed in 53%. The prevalence of a malocclusion increased from 42.6% in the deciduous dentition to 74.4% in the permanent dentition. The evaluation of the results showed that there was no statistically significant relationship between bruxism and the studied occlusal factors (p > 0.05). Differences were not found between genders in both variables. Onicofagy was the most frequent habit (35%), mainly in the female subjects. There was a statistically significant relationship between bruxism and oral habits. Evaluating the specific types of habits, just pacifier sucking showed to be related to the bruxism. Additional studies will be necessary for a better understanding of the local origin of bruxism.
The profile of orthodontists in relation to the legal aspects of dental records
Civil liability. Orthodontics. Forensic dentistry.
Objective: The purpose of this study was to acquire knowledge about the key legal aspects of orthodontic practice, which may be used as important defense tools in the event of ethical and/ or legal actions.
Methods: A cross-sectional study was conducted with dentists in Belo Horizonte, Minas Gerais State, Brazil, by means of a specific instrument (questionnaire) addressing the ethical and legal disputes that involve the orthodontic specialty. Participants were asked to fill out the following questionnaire fields: personal identification, academic background, orthodontic accessories, oral hygiene, treatment plan, service provision, orthodontic documentation, drug prescription and forms of communication with patients, among others.
Results: A total of 237 orthodontists, all members of the Regional Council of Dentistry, Minas Gerais State (CRO-MG) and living in Belo Horizonte, were given the data collection instrument. Out of this total, 69 (29.11%) answered and returned the questionnaires. Of the 69 respondents, 57.97% were male and 42.03% female. It was found that 52.17% of these professionals graduated from Higher Education Institutions (ISEs). It was observed that 34.78% of these orthodontists completed specialization between 5 and 10 years after graduation. Most professionals (94.2%) enter into their medical records information about any damage caused to the orthodontic accessories used by their patients and 53.62% of the orthodontists keep their patients orthodontic documentation on file throughout their active professional life.
Conclusions: This study revealed that some analysis parameters were very satisfactory, such as: the availability of service provision contract models, communication with patients and/or their lawful guardians in case of abandonment of treatment, orthodontic documentation files and the entering into the dental records of information concerning the breakage of and damage to orthodontic accessories. However, some practices have yet to be adopted, such as: patient signature should be collected in the event of damage to orthodontic accessories and copies of drug prescriptions and certificates should be kept on file.
Analysis of mandibular dimensions growth at different fetal ages
Growth. Mandible. Fetus.
Objective:To investigate growth asymmetry between the left and right hemimandibles (HMs) during the 2nd and early 3rd trimester of pregnancy.
Methods: Sixty eight hemimandibles (34 mandibles) of fetuses were used20 female and 14 malepreserved in 10% formalin solution, and the following measurements were performed: Condyle-Coronoid Process (Co-CP), Gonion-Coronoid Process (Go-CP), Gonion-Gnathion (Go-Gn), Condyle-Gnathion (Co-Gn), Symphyseal Height (SH), Mandibular Angle (MA). The data were collected, tabulated and analyzed with the aid of SPSS software, version 11.0, 2005. One-way ANOVA test was performed to compare the mean values of anatomical measurements of the right and left HMs. Gestational ages were divided into second trimester (Period 1: 13-18 weeks and Period 2: 18-24 weeks), and early third trimester (Period 3: 24-30 weeks) of pregnancy.
Results: We noted a slight growth rate asymmetry in Go-Gn, Co-CP, Co-Gn, Go-CP and SH, comparing the left and right mandibular halves, between the 2nd and early 3rd trimester of pregnancy, although not statistically significant (p > 0.05). It was also found that the mandibular angle decreased and showed a slightthough statistically significant (p < 0.05)asymmetry in the same prenatal period.
Conclusion: The authors concluded that there was a slight asymmetry in the growth rate of measurements Go-Gn, Co-CP, Co-Gn, Go-CP and SH, comparing the left with the right hemimandible between the 2nd and early 3rd trimester of gestation.
BBO Case Report
Angle Class III malocclusion with severe anteroposterior discrepancy
Angle Class III malocclusion. Maxillofacial surgery. Corrective Orthodontics.
This case report describes the treatment of a 36-year-old patient who presented a skeletal and dental Class III malocclusion and missing upper canines. The patient was treated with orthosurgical maxillary advancement (Le Fort 1) and occlusal adjustment of the first premolars, which replaced the canines. This case was presented to the Brazilian Board of Orthodontics and Facial Orthopedics (BBO), as representative of Category 4, i.e., malocclusion with severe anteroposterior discrepancy, as part of the requirements for obtaining the BBO Diploma.
Associated dental anomalies: The orthodontist decoding the genetics which regulates the dental development disturbances
Genetics. Dental anomalies. Tooth agenesis. Etiology. Orthodontics.
This article aims to approach the diagnosis and orthodontic intervention of the dental anomalies, emphasizing the etiological aspects which define these developmental irregularities. A genetic interrelationship seems to exist determining some dental anomalies, considering the high frequency of associations. The same genetic defect may give rise to different phenotypes, including tooth agenesis, microdontia, ectopias and delayed dental development. The clinical implications of the associated dental anomalies are relevant, since early detection of a single dental anomaly may call the attention of professionals to the possible development of other associated anomalies in the same patient or in the family, allowing timely orthodontic intervention.