Scielo RSS <![CDATA[Dental Press Journal of Orthodontics]]> http://www.scielo.br/rss.php?pid=2176-945120120001&lang=en vol. 17 num. 1 lang. en <![CDATA[SciELO Logo]]> http://www.scielo.br/img/en/fbpelogp.gif http://www.scielo.br <![CDATA[<b>A journey, I mean, a journal...</b>]]> http://www.scielo.br/scielo.php?script=sci_arttext&pid=S2176-94512012000100001&lng=en&nrm=iso&tlng=en <![CDATA[<b>The impact of orthodontic treatment on periodontal support loss</b>]]> http://www.scielo.br/scielo.php?script=sci_arttext&pid=S2176-94512012000100002&lng=en&nrm=iso&tlng=en <![CDATA[<b>Cementum, apical morphology and hypercementosis</b>: <b>a probable adaptive response of the periodontal support tissues and potential orthodontic implications</b>]]> http://www.scielo.br/scielo.php?script=sci_arttext&pid=S2176-94512012000100003&lng=en&nrm=iso&tlng=en Information about orthodontic movement of teeth with hypercementosis is scarce. As cementum deposition continues to occur, cementum is expected to change the shape of the root and apex over time, but this has not yet been demonstrated. Nor has it ever been established whether it increases or decreases the prevalence of root resorption during orthodontic treatment. The unique biological function of the interconnected network of cementocytes may play a role in orthodontic movement and its associated root resorptions, but no research has ever been conducted on the topic. Unlike cementum thickness and hypercementosis, root and apex shape has not yet been related to patient age. A study of the precise difference between increased cementum thickness and hypercementosis is warranted. Hypercementosis refers to excessive cementum formation above and beyond the extent necessary to fulfill its normal functions, resulting in abnormal thickening with macroscopic changes in the tooth root, which may require the delivery of forces that are different from conventional mechanics in their intensity, direction and distribution. What are the unique features and specificities involved in moving teeth that present with hypercementosis? Bodily movements would be expected to occur, since inclination might prove difficult to achieve, but would the root resorption index be higher or lower? <![CDATA[<b>An interview with Jorge Faber</b>]]> http://www.scielo.br/scielo.php?script=sci_arttext&pid=S2176-94512012000100004&lng=en&nrm=iso&tlng=en Information about orthodontic movement of teeth with hypercementosis is scarce. As cementum deposition continues to occur, cementum is expected to change the shape of the root and apex over time, but this has not yet been demonstrated. Nor has it ever been established whether it increases or decreases the prevalence of root resorption during orthodontic treatment. The unique biological function of the interconnected network of cementocytes may play a role in orthodontic movement and its associated root resorptions, but no research has ever been conducted on the topic. Unlike cementum thickness and hypercementosis, root and apex shape has not yet been related to patient age. A study of the precise difference between increased cementum thickness and hypercementosis is warranted. Hypercementosis refers to excessive cementum formation above and beyond the extent necessary to fulfill its normal functions, resulting in abnormal thickening with macroscopic changes in the tooth root, which may require the delivery of forces that are different from conventional mechanics in their intensity, direction and distribution. What are the unique features and specificities involved in moving teeth that present with hypercementosis? Bodily movements would be expected to occur, since inclination might prove difficult to achieve, but would the root resorption index be higher or lower? <![CDATA[<b>Influence of the banded Herbst appliance on dental changes in mixed dentition</b>]]> http://www.scielo.br/scielo.php?script=sci_arttext&pid=S2176-94512012000100005&lng=en&nrm=iso&tlng=en OBJECTIVE: This prospective clinical study was conducted with the purpose of evaluating the influence of the banded Herbst appliance on dental changes during the early treatment of Class II malocclusion. METHOD: The sample consisted of 15 prepubertal subjects (12 boys and 3 girls, initial age: 9 years and 6 months) who were treated with the Herbst appliance. Treatment effects were compared with those of a Class II Division 1 group of 15 subjects (8 boys and 7 girls, mean initial age 9 years and 1 month), not treated orthodontically. Statistical analysis was performed using Student t-test with 5% significance level. RESULTS: The results showed that treatment with the banded Herbst appliance in the mixed dentition stage tended to upright maxillary incisors (mean: 4.14°). The maxillary molars were distalized and intruded significantly (mean 2.65 mm and 1.24 mm, respectively), the lower incisors slightly protruded anteriorly (mean 1.64 mm) and the molars showed no significant changes in the horizontal and vertical directions. Furthermore, significant improvements were noted in overbite (1.26 mm), overjet (4.8 mm) and molar relationship (12.08 mm). CONCLUSIONS: Changes in the upper dental arch were found to be greater than changes in the lower arch. Furthermore, mandibular anchorage loss was reduced due to the anchorage system used in the study. <![CDATA[<b>Study of tension in the periodontal ligament using the finite elements method</b>]]> http://www.scielo.br/scielo.php?script=sci_arttext&pid=S2176-94512012000100006&lng=en&nrm=iso&tlng=en Orthodontic movement is process of transformation of a physical stimulation into a force applied to a tooth, with a biological response identified as bone remodelling. Although it is possible to measure the force applied on a tooth, its distribution around the root is irregular forming areas of higher concentration of tensions, which do not correspond to the force initially applied. To evaluate the behavior of the periodontal ligament after the application of an external action and to prove which would be the areas of higher tension generated in the periodontium, the Finite Elements Method (FEM) was used in comparison to the results obtained in vivo on experimental models in rat. To test the error susceptibility of the technique used in the experimental model, the force application was simulated in three different heights on the mesial surface of the molar. The resulting histological analysis was compared with the result obtained for the computational code and disclosed that the greater focus of osteoclasts in activity had coincided with the compressed areas of the periodontal ligament. The alteration of points of force application generated areas of more extensive deformations in the periodontal ligament, as the point of application was more distant of the initial point, the horizontal force vector became bigger. These results demonstrate that the FEM is an adequate tool to study the distribution of orthodontic forces. The sensitivity of the experimental model used was also observed in relation to the installation of the dental movement device, which should be considered depending on the objective of the research. <![CDATA[<b>The influence of asthma onset and severity on malocclusion prevalence in children and adolescents</b>]]> http://www.scielo.br/scielo.php?script=sci_arttext&pid=S2176-94512012000100007&lng=en&nrm=iso&tlng=en OBJECTIVE: The influence of asthma, its severity levels and onset time on malocclusion occurrence were investigated. METHODS: The sample was composed by 176 children/adolescents, of both genders, aged 3 to 15 years, that were divided in two groups. The asthma group (AG) enrolled 88 children/adolescents that were seen at the Breathe Londrina Program. The asthma-free group (AFG) enrolled 88 preschool and school children recruited in 2 public schools. Malocclusion diagnosis was made according to WHO criteria (OMS, 1999). RESULTS: A higher prevalence in malocclusions in asthmatic patients in mixed dentition was observed when compared to controls (p<0.05). On the other hand, these results were not observed for deciduous (p&gt;0.05) and permanent dentition (p&gt;0.05). A significant association was seen between asthma onset time and marked maxillary overjet (p<0.05), and open bite (p<0.05) in the mixed dentition, being both conditions more common among those that have presented the symptoms of asthma prior to 12 months of age. CONCLUSION: The results of this study indicate that the early manifestation of asthma at first year of life can cause dentofacial changes. Therefore, the prompt diagnostic of the illness, as well as the establishment of a proper therapy could improve the symptoms and chronic complications of asthma and also reduce its impact on craniofacial development. <![CDATA[<b>Assessment of the orthodontic knowledge demonstrated by dental school undergraduates</b>: <b>recognizing the key features of Angle Class II, Division 1 malocclusion</b>]]> http://www.scielo.br/scielo.php?script=sci_arttext&pid=S2176-94512012000100008&lng=en&nrm=iso&tlng=en OBJECTIVE: To investigate the ability of undergraduate students in diagnosing Angle Class II malocclusion and evaluate the clinical approach of these students toward a patient displaying this condition. METHODS: The sample consisted of 138 students attending the last semester of 10 dental schools in the State of Rio de Janeiro/Brazil assessed by questionnaires with closed questions. They were presented with photographs and dental casts of a patient in the mixed dentition, with Angle Class II malocclusion, increased overjet and overbite, deviated dental midlines and anterior diastemas in the upper arch. RESULTS: It was found that students easily identified increased overjet (92% of students), followed by the presence of diastemas (89%), midline deviation (84.7%) and increased overbite (77.3%). Conversely, approximately half the sample (n=70 or 51% of the students) were able to identify bilateral Angle Class II malocclusion. Nearly all agreed on the need for treatment and that it should be provided by a specialist (n=131 or 95%), but found it difficult to determine the ideal moment to start orthodontic treatment: 48.9% of the sample would begin treatment at the end of the mixed dentition, 41.7% would indicate treatment during deciduous dentition and 7.9% during permanent dentition. CONCLUSIONS: On completion of their undergraduate courses, students encounter difficulties in diagnosing Class II and even find it hard to articulate ideas about a basic treatment protocol to correct this malocclusion. <![CDATA[<b>Assessment of soft profile characteristics in Amazonian youngsters with normal occlusion</b>]]> http://www.scielo.br/scielo.php?script=sci_arttext&pid=S2176-94512012000100009&lng=en&nrm=iso&tlng=en OBJECTIVE: The present study aimed to determine from a sample of Amazonian youngsters, with normal occlusion, the mean values for soft profile characteristics using cephalometric radiographs obtained in lateral norm. METHODS: The cephalometric radiographs of the 30 youngsters, being 15 males and 15 females, with mean age of 21.6 years old, were assessed. For statistical analysis, central tendencies and dispersion measurements (mean and standard deviation) were used and, for both the comparison of the mean values of males and females and the correlations between the measurements of the soft profile and bony profile, the unpaired Student's t-test was applied. RESULTS AND CONCLUSION: After obtaining statistical data, parameters were set based on the cephalometric norms regarding the specialized literature, revealing that all variables presented a normal distribution pattern. There was sexual dimorphism for the following measurements: ANB, NAP, ANS-Me, N-ANS, Sn'-Me', and N'-SN'. Norms were determined for all the assessed measurements. Statistical differences were observed between the norm found in the present study and those found in the specialized literature. <![CDATA[<b>Evaluation of transverse changes in the dental arches according to growth pattern</b>: <b>a longitudinal study</b>]]> http://www.scielo.br/scielo.php?script=sci_arttext&pid=S2176-94512012000100010&lng=en&nrm=iso&tlng=en OBJECTIVE: To evaluate changes in intercanine (LICW and UICW) and intermolar (LIMW and UIMW) widths on the dental arches of subjects with normal occlusion and Angle Class I malocclusion during the transition to permanent dentition, and evaluate whether or not facial pattern influences on the normal development of the dentition and occlusion. METHODS: Nineteen Caucasian Brazilian children were selected, with ages ranging from 6 to 8.6 years at T1 and from 10.10 to 14.2 years at T2. Their second records consisted of study dental casts and a lateral cephalometric radiograph. To obtain intermolar and intercanine widths a three-dimensional scanner unit (digitizer MicroScribe 3DX) was used connected to a microcomputer. To analyze changes at T1 and T2 Student's paired t-test was applied, whereas Spearman's correlation analysis was used to assess the relationship between measurements obtained at T1 and T2 and the facial pattern, both at 95% level of confidence. RESULTS: The mean values found on each assessment time (T1 and T2) were statistically different (p=0.000 for LICW, p=0.001 for UICW, p=0.000 for UIMW, and p=0.046 for LIMW), regardless of the facial pattern. The anterior dimensions, UICW and LICW, increased by 3.21 mm and 1.52 mm, respectively. And the posterior dimensions, UIMW and LIMW, increased by 2.16 mm and 0.50 mm, respectively. Only UIMW showed a significant correlation with the facial pattern (p<0.01). CONCLUSION: There was an increase in dental arch width during the transition period from primary or mixed dentition to permanent dentition irrespective of facial pattern. Only the changes observed in the maxillary intermolar width were associated with the facial pattern. <![CDATA[<b>Cephalometric deviations present in children and adolescents with temporomandibular joint disorders</b>]]> http://www.scielo.br/scielo.php?script=sci_arttext&pid=S2176-94512012000100011&lng=en&nrm=iso&tlng=en INTRODUCTION: Temporomandibular disorders (TMD) have proved to be a risk factor for developing hyperdivergent facial growth patterns. OBJECTIVE: The aims of this study were: (1) Assess differences between the cephalometric measurements in children with articular TMD and a control group, before and after mandibular growth peak according to cervical vertebral maturation; and (2) Identify a predictive model capable of differentiating patients with TMD and control group patients based on early cephalometric characteristics. METHOD: The study included children and adolescents with maximum age of 17 years, divided into experimental group (n=30) diagnosed with articular TMD-according to the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) for children and adolescents-subdivided according to growth stage, called pre-peak (n=17) and post-peak (n=13) and control group (n = 30), matched by gender, skeletal maturity stage of the cervical vertebrae and classification of malocclusion. Lateral cephalometric and craniofacial structures were traced and their relations divided into: Cranial base, maxilla, mandible, intermaxillary relations, vertical skeletal relations and dental relations. Differences between the means for each variable were evaluated by applying the statistical Student t test for independent samples. RESULTS: The means of the variables analyzed in the pre-peak showed no statistically significant differences. However, analysis of post-peak showed that the experimental group displayed decreased SNA and SNB and increased SN.Gn and 1.NB (p<0.05). CONCLUSION: It was possible to identify a predictive model able to differentiate patients with TMD and asymptomatic controls from early cephalometric characteristics. <![CDATA[<b>Dental age as indicator of adolescence</b>]]> http://www.scielo.br/scielo.php?script=sci_arttext&pid=S2176-94512012000100012&lng=en&nrm=iso&tlng=en AIM: The purpose of the present study was to analyze the relationship between root formation of the first premolars and skeletal maturation stages identified in hand-wrist radiographs. METHODS: A cross-sectional study was carried out involving the panoramic and hand-wrist radiographs obtained on the same date of 232 patients, 123 boys and 109 girls aged 4 years and 5 months to 17 years and 12 months. Root formation stages of the first premolars were related to the ossification stages of the sesamoid bone, epiphyseal stages of the phalanx of the thumb and epiphyseal stages of the radius. RESULTS: The studied variables demonstrated statistically significant correlations. CONCLUSION: Roots of the lower first premolars do not reach 2/3 of their complete length before adolescence. <![CDATA[<b>Vertical growth control during maxillary expansion using a bonded Hyrax appliance</b>]]> http://www.scielo.br/scielo.php?script=sci_arttext&pid=S2176-94512012000100013&lng=en&nrm=iso&tlng=en INTRODUCTION: Rapid maxillary expansion (RME) for the treatment of maxillary deficiency and posterior crossbite may induce changes in the vertical dimension. Expanders with occlusal splints have been developed to minimize unwanted vertical effects. OBJECTIVE: This preliminary study used cephalometri radiographs to evaluate the vertical effects of RME using a Hyrax appliance in children with maxillary deficiency. METHOD: Twenty-six patients (11 boys; mean age = 8 years and 5 months) with maxillary deficiency and posterior crossbite were treated using a Hyrax appliance with an acrylic occlusal splint. Radiographs and cephalometric studies were performed before the beginning of the treatment (T1) and after RME active time (T2), at a mean interval of 7 months. Results were compared with normative values. RESULTS AND CONCLUSIONS: At the end of treatment, there were no statistically significant changes, and measurements were similar to the normative values. Data showed that there were no significant effects on vertical growth, which suggests that appliances with occlusal splints may be used to correct transverse deficiencies regardless of the patient's growth pattern. <![CDATA[<b>Association between nonnutritive sucking habits and anterior open bite in the deciduous dentition of Japanese-Brazilians</b>]]> http://www.scielo.br/scielo.php?script=sci_arttext&pid=S2176-94512012000100014&lng=en&nrm=iso&tlng=en OBJECTIVE: Assess the association between nonnutritive sucking habits and anterior open bite in the deciduous dentition of Japanese-Brazilian children. METHODS: 410 children of Japanese origin were assessed, 206 boys and 204 girls, between 2 and 6 years of age, in schools in São Paulo State, Brazil. Questionnaires concerning their nonnutritive sucking habits were sent to their legal guardians. Chi-square tests (p<0.05) were applied to assess the association between nonnutritive sucking habits and anterior open bite, and the logistic regression test to obtain the relative risk. RESULTS: The prevalence of sucking habits found in the sample was of 44.6% and for the anterior open bite, 4.4%. There was a statistically significant association between anterior open bite and sucking habits (O.R.=10.77), persistence of sucking habits from 2 to 4 years old (O.R.=22.06), and the persistence of sucking habits from 4 to 6 years old (O.R.=17.31). As for the interruption period of the habit, the group that had interrupted the habit for a period equal or inferior to six months showed an increased prevalence of open bite compared to the group without this habit or in which the habit was interrupted for more than six months. CONCLUSION: Japanese-Brazilian children that had sucking habits have greater chance of acquiring anterior open bite in the deciduous dentition. <![CDATA[<b>Dahlberg formula</b>: a novel approach for its evaluation]]> http://www.scielo.br/scielo.php?script=sci_arttext&pid=S2176-94512012000100015&lng=en&nrm=iso&tlng=en INTRODUCTION: The accurate evaluation of error of measurement (EM) is extremely important as in growth studies as in clinical research, since there are usually quantitatively small changes. In any study it is important to evaluate the EM to validate the results and, consequently, the conclusions. Because of its extreme simplicity, the Dahlberg formula is largely used worldwide, mainly in cephalometric studies. OBJECTIVES: (I) To elucidate the formula proposed by Dahlberg in 1940, evaluating it by comparison with linear regression analysis; (II) To propose a simple methodology to analyze the results, which provides statistical elements to assist researchers in obtaining a consistent evaluation of the EM. METHODS: We applied linear regression analysis, hypothesis tests on its parameters and a formula involving the standard deviation of error of measurement and the measured values. RESULTS AND CONCLUSION: we introduced an error coefficient, which is a proportion related to the scale of observed values. This provides new parameters to facilitate the evaluation of the impact of random errors in the research final results. <![CDATA[<b>Evaluation of the dental arch asymmetry in natural normal occlusion and Class II malocclusion individuals</b>]]> http://www.scielo.br/scielo.php?script=sci_arttext&pid=S2176-94512012000100016&lng=en&nrm=iso&tlng=en OBJECTIVE: To verify the presence and degree of asymmetry of dental arches in Brazilian individuals with natural normal occlusion and Class II, Divisions 1 and 2 malocclusions. METHODS: The study evaluated the symmetry of the maxillary and mandibular dental arches of 180 pairs of dental casts, divided into: Group I = 60 pairs of natural normal occlusion individuals; Group II = 60 pairs of Class II, Division 1 malocclusion individuals; and Group III = 60 pairs of Class II, Division 2 malocclusion individuals. A device was used to measure dental midline deviation and the canine tip in the dental arches (in degrees). It was also verified the distance of the upper canines from the palatal suture, intercanine distance, and anteroposterior upper and lower first molar position. RESULTS: Dental arches of individuals from all groups presented asymmetry, regardless of the presence of malocclusion. Group I showed a lower asymmetry degree in relation to Groups II and III. The asymmetry in Groups II and III was similar. CONCLUSION: The dental arches of individuals with natural normal occlusion and with Class II, Division 1 and Division 2 malocclusions showed asymmetry. The asymmetry degree was higher in the mandibular dental arches than in the maxillary dental arches in all 3 evaluated groups. <![CDATA[<b>Study of the number of occlusal contacts in maximum intercuspation before orthodontic treatment in subjects with Angle Class I and Class II Division 1 malocclusion </b>]]> http://www.scielo.br/scielo.php?script=sci_arttext&pid=S2176-94512012000100017&lng=en&nrm=iso&tlng=en OBJECTIVE: Define and compare numbers and types of occlusal contacts in maximum intercuspation. METHODS: The study consisted of clinical and photographic analysis of occlusal contacts in maximum intercuspation. Twenty-six Caucasian Brazilian subjects were selected before orthodontic treatment, 20 males and 6 females, with ages ranging between 12 and 18 years. The subjects were diagnosed and grouped as follows: 13 with Angle Class I malocclusion and 13 with Angle Class II Division 1 malocclusion. After analysis, the occlusal contacts were classified according to the established criteria as: tripodism, bipodism, monopodism (respectively, three, two or one contact point with the slope of the fossa); cuspid to a marginal ridge; cuspid to two marginal ridges; cuspid tip to opposite inclined plane; surface to surface; and edge to edge. RESULTS: The mean number of occlusal contacts per subject in Class I malocclusion was 43.38 and for Class II Division 1 malocclusion it was 44.38, this difference was not statistically significant (p>0.05). CONCLUSIONS: There is a variety of factors that influence the number of occlusal contacts between a Class I and a Class II, Division 1 malocclusion. There is no standardization of occlusal contact type according to the studied malocclusions. A proper selection of occlusal contact types such as cuspid to fossa or cuspid to marginal ridge and its location in the teeth should be individually defined according to the demands of each case. The existence of an adequate occlusal contact leads to a correct distribution of forces, promoting periodontal health. <![CDATA[<b>Transverse malocclusion, posterior crossbite and severe discrepancy</b>]]> http://www.scielo.br/scielo.php?script=sci_arttext&pid=S2176-94512012000100018&lng=en&nrm=iso&tlng=en This article reports the orthodontic treatment of a 14 years and 2 months old female patient, presenting both anterior and posterior unilateral left crossbite, related to a transverse atrophy of the maxilla and a severe negative tooth-arch discrepancy in the upper arch. A maxillary expansion with a modified Haas appliance was the first therapeutic attempt. Then, fixed appliances were used in both arches, and the second left premolar was extracted. The space for the upper left lateral incisor was achieved with compressed springs and tooth movement was accomplished with double archwires. The final result showed a good intercuspation, considering that the left molar relation remained as a Class II, which demanded special occlusal adjustments. This case was presented to the Brazilian Board of Orthodontics and Facial Orthopedics, representing category 5, as a partial requirement for the BBO certificate. <![CDATA[<b>Orthosurgical treatment of patients in the growth period</b>: <b>at what cost?</b>]]> http://www.scielo.br/scielo.php?script=sci_arttext&pid=S2176-94512012000100019&lng=en&nrm=iso&tlng=en Awaiting growth to end prior to starting orthosurgical treatment is sometimes extremely difficult for patients suffering from severe facial deformities. In cases of substantial skeletal disharmonies surgery may be indicated during active growth phase when the patient is psychosocially, aesthetically and/or functionally compromised. To indicate this therapy, orthodontic criteria, such as mild intramaxillary discrepancy and the possibility of preoperative preparation without major dental repositioning, must be met. A second orthosurgical treatment will probably prove necessary after growth has ended. This treatment should not be considered as routine, but rather as a therapeutic option in carefully selected cases.