Cátia Cardoso Abdo Quintão

A systematic review of etiological and risk factors associated with bruxism

Objective The aim of the present work was to systematically review the literature and identify all peer-reviewed papers dealing with etiological and risk factors associated with bruxism. Data sources Data extraction was carried out according to the standard Cochrane systematic review methodology. The following databases were searched for randomized clinical trials (RCT), controlled clinical trials (CCT) or cohort studies: Cochrane Library, Medline, and Embase from 1980 to 2011. Unpublished literature was searched electronically using ClinicalTrials.gov. Data selection The primary outcome was bruxism etiology. Studies should have a standardized method to assess bruxism. Data extraction Screening of eligible studies, assessment of the methodological quality and data extraction were conducted independently and in duplicate. Two reviewers inspected the references using the same search strategy and then applied the same inclusion criteria to the selected studies. They used criteria for methodological quality that was previously described in the Cochrane Handbook. Among the 1247 related articles that were critically assessed, one randomized clinical trial, one controlled clinical trial and seven longitudinal studies were included in the critical appraisal. Of these studies, five were selected, but reported different outcomes. Data synthesis There is convincing evidence that (sleep-related) bruxism can be induced by esophageal acidification and also that it has an important relationship with smoking in a dose-dependent manner. Disturbances in the central dopaminergic system are also implicated in the etiology of bruxism.

Relationship between dental size and normal occlusion in Brazilian patients

The present study was performed on dental casts and lateral cephalometric films of 30 Caucasian Brazilian individuals (15 males and 15 females) aged 18 to 27 years and 4 months, all presenting normal occlusion and satisfactory facial profile. The aims were to investigate the existence of dental discrepancies according to Boltons criteria, to obtain mean values for overbite, overjet, curve of Spee and interincisal angle, and to demonstrate any correlation among these parameters. A single calibrated operator measured each variable characteristics and the process was recorded twice with an accurate modified digital caliper. It was observed that the sample of normal occlusion did not present any dental discrepancy among the 12 teeth of opposite arches. The overall ratio (91.46) and anterior ratio (77.83) were in accordance with those proposed by Bolton. The mean values for normal occlusion in this Brazilian sample were defined as: 2.45 mm for overbite; 1.92 mm for overjet; 1.01 mm for curve of Spee and 129.57 degrees for interincisal angle. A statistically significant correlation was found between overjet and overbite.

Long-Term 3-Dimensional Stability of Mandibular Advancement Surgery

PURPOSE To evaluate 3-dimensional changes in the position of the condyles, rami, and chin from 1 to 3 years after mandibular advancement surgery. MATERIALS AND METHODS This prospective observational study used pre- and postoperative cone-beam computed tomograms of 27 subjects with skeletal Class II jaw relation and normal or deep overbite. An automatic technique of cranial base superimposition was used to assess positional and bone remodeling changes that were visually displayed and quantified using 3-dimensional color maps. Analysis of covariance with presence of genioplasty, age at time of surgery, and gender as explanatory variables was used to estimate and test adjusted mean changes for each region of interest. RESULTS The chin rotated downward and backward 1 to 3 years after surgery. Changes of at least 2 mm were observed in 17% of cases. Mandibular condyles presented with displacements or bone remodeling of at least 2 mm on the anterior surface (21% of cases on the left side and 13% on the right), superior surface (8% on right and left sides), and lateral poles (17% on left side and 4% on right). Posterior borders of the rami exhibited symmetric lateral or rotational displacements in 4% of cases. CONCLUSION In the hierarchy of surgical stability, mandibular advancement surgery is considered one of the most stable surgical procedures. However, 1 to 3 years after surgery, approximately 20% of patients had 2- to 4-mm changes in horizontal and vertical chin positions or changes in condylar position and adaptive bone remodeling.

Dental crowding The role of genetics and tooth wear

OBJECTIVE To evaluate the role of genetics and tooth wear in the etiology of dental crowding through the analysis of a split indigenous Amazon population. MATERIALS AND METHODS Dental crowding prevalence (n  =  117), tooth wear (n  =  117), and inbreeding coefficient (n  =  288) were compared for both villages. A biometric investigation was performed by dental cast analysis of 55 individuals with no tooth loss. Mann-Whitney statistics, independent t-tests, and Fisher exact tests were used at P < .05. RESULTS A high coefficient of inbreeding was confirmed in the resultant village (F  =  0.25, P < .001). Tooth wear was not significantly different (P  =  .99), while a significantly higher prevalence of dental crowding was confirmed in the original village (PR  =  6.67, P  =  0.02). Forty dental arches (n  =  20) were examined in the new group, and only one (2.5%) had a dental crowding ≥ 5 mm. In the original villages, we found 20 arches (28.6%) with dental crowding. No difference was observed for tooth size, while larger dental arch dimensions explained a lower level of dental crowding in the resultant village. CONCLUSIONS Our findings downplay the widespread influence of tooth wear, a direct evidence of what an individual ate in the past, on dental crowding and emphasize the role of heredity, exacerbated through inbreeding, in the etiology of this malocclusion.

Dental Occlusion in a Split Amazon Indigenous Population: Genetics Prevails over Environment

Background Studies examining human and nonhuman primates have supported the hypothesis that the recent increase in the occurrence of misalignment of teeth and/or incorrect relation of dental arches, named dental malocclusion, is mainly attributed to the availability of a more processed diet and the reduced need for powerful masticatory action. For the first time on live human populations, genetic and tooth wear influences on occlusal variation were examined in a split indigenous population. The Arara-Iriri people are descendants of a single couple expelled from a larger village. In the resultant village, expansion occurred through the mating of close relatives, resulting in marked genetic cohesion with substantial genetic differences. Methodology/Principal Findings Dental malocclusion, tooth wear and inbreeding coefficient were evaluated. The sample examined was composed of 176 individuals from both villages. Prevalence Ratio and descriptive differences in the outcomes frequency for each developmental stage of the dentition were considered. Statistical differences between the villages were examined using the chi-square test or Fishers exact statistic. Tooth wear and the inbreeding coefficient (F) between the villages was tested with Mann-Whitney statistics. All the statistics were performed using two-tailed distribution at p≤0.05. The coefficient inbreeding (F) confirmed the frequent incestuous unions among the Arara-Iriri indigenous group. Despite the tooth wear similarities, we found a striking difference in occlusal patterns between the two Arara villages. In the original village, dental malocclusion was present in about one third of the population; whilst in the resultant village, the occurrence was almost doubled. Furthermore, the morphological characteristics of malocclusion were strongly different between the groups. Conclusions/Significance Our findings downplay the widespread influence of tooth wear, a direct evidence of what an individual ate in the past, on occlusal variation of living human populations. They also suggest that genetics plays the most important role on dental malocclusion etiology.

Factors associated with orthodontic treatment seeking by 12-15-year-old children at a state university-funded clinic.

Objectives To investigate the interrelationships between factors involved in orthodontic treatment seeking by children aged 12–15 years. Setting State funded orthodontic clinic at the Faculty of Dentistry of the Rio de Janeiro State University (UERJ), Rio de Janeiro, Brazil, and a nearby public school. Subjects and methods One hundred and ninety‐four adolescents aged 12–15 years took part in the study; 92 had sought orthodontic treatment at UERJ (orthodontic group) and 102 were from a nearby public school and had never undergone or sought orthodontic treatment (comparison group). Each participant underwent a comprehensive oral examination, and both parent and child were questioned about who had initiated the orthodontic referral. Outcomes Normative need assessed with IOTN DHC; clinician and self‐perceived aesthetic perception assessed with IOTN AC, previous caries experience was determined using the decayed, missing and filled teeth index (DMFT) and WHO diagnostic criteria. The ‘Brazil Economic Classification Criteria’ was used to classify the socioeconomic status. Intra‐examiner repeatability and inter‐examiner agreement were assessed with kappa statistics. Univariate and multiple logistic regression analyses were used to investigate the association between orthodontic treatment seeking (dependent variable) and the independent variables (i.e. aesthetic impairment, malocclusion severity, socioeconomic status, gender, age and DMFT). Results Univariate analyses showed that self‐perceived aesthetics (P<0·001), examiner‐assessed aesthetics (P = 0·01) and treatment need (P<0·001), socioeconomic status (P<0·001) were significantly associated with orthodontic treatment seeking, but gender (P = 0·22) and DMFT (P = 0·41) were not. Multiple logistic regression analyses showed that poor self‐perceived aesthetics (OR = 16·7; 95% CI: 4·17–61·9), more severe malocclusion (OR = 3·4; 95% CI 1·64–7·14) and better socioeconomic position (OR = 39·1; 95% CI: 5·47–280·54) significantly influenced the decision to seek orthodontic treatment. Conclusions Concern about dental appearance and the desire for treatment, together with normative orthodontic need, should be carefully assessed by dentists before referring patients to specialized orthodontic care in publicly‐funded clinics. In a publicly‐funded oral health care system, self‐perceived orthodontic treatment need is the key to establishing treatment priority.

A escolha do teste estatístico - um tutorial em forma de apresentação em PowerPoint

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 systematic error for a specific method. Assistance to check normality distribution and to choose the most suitable graphics is also presented. This guide (downloadable in www.dentalpress.com.br) could be even used by reviewers in a quick assessment to check the appropriated statistical methodology into a specific study.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.

Análise do emprego do cálculo amostral e do erro do método em pesquisas científicas publicadas na literatura ortodôntica nacional e internacional

INTRODUCTION: Reliable sample size and an appropriate analysis of error are important steps to validate the data obtained in a scientific study, in addition to the ethical and economic issues. OBJECTIVE: To evaluate, quantitatively, how often the researchers of orthodontic science have used the calculation of sample size and evaluated the method error in studies published in Brazil and in the United States of America. METHODS: Two major journals, according to CAPES (Brazilian Federal Agency for Support and Evaluation of Graduate Education), were analyzed through a hand search: Revista Dental Press de Ortodontia e Ortopedia Facial and the American Journal of Orthodontics and Dentofacial Orthopedics (AJO-DO). Only papers published between 2005 and 2008 were examined. RESULTS: Most of surveys published in both journals employed some method of error analysis, when this methodology can be applied. On the other hand, only a very small number of articles published in these journals have any description of how sample size was calculated. This proportion was 21.1% for the journal published in the United States (AJO-DO), and was significantly lower (p= 0.008) for the journal of orthodontics published in Brazil (3.9%). CONCLUSION: Researchers and the editorial board of both journals should drive greater concern for the examination of errors inherent in the absence of such analyses in scientific research, particularly the errors related to the use of an inadequate sample size.

Soft tissue profile changes after rapid maxillary expansion with a bonded expander

The aim of this study was to evaluate the short- and long-term treatment effects of rapid maxillary expansion (RME) on the soft tissue facial profile of subjects treated with a modified acrylic-hyrax device. The sample comprised 10 males and 10 females in the mixed dentition. Their average age was 9.3 years ± 10 months pre-treatment (T1), with a narrow maxilla and posterior crossbite, treated with a modified fixed maxillary expander with an occlusal splint. Lateral cephalometric radiographs obtained at T1, immediately post-expansion (T2), and after retention (T3) were used to determine possible changes in the soft tissue facial profile. The means and standard deviations for linear and angular cephalometric measurements were analysed statistically using analysis of variance and Tukeys test (α = 0.05). The measurements at T2 differed significantly from those at T1 and T3. However, RME did not produce any statistically significant alteration (P > 0.05) in the soft tissue profile for any of the cephalometric landmarks evaluated when compared at T1 and T3. The use of a fixed expander associated with an occlusal splint did not cause significant alterations in the soft tissue facial profile at T3. This modified device is effective for preventing the adverse vertical effects of RME such as an increase anterior face height in patients with a crossbite.

Severe anterior open-bite malocclusion.

This case report describes the treatment of a severe anterior open bite, Class II malocclusion with a history of dummy sucking. The 9-year-old girl presented with a significant anteroposterior and vertical discrepancy. Her face was convex with procumbent lips. She had an anterior open bite of 9 mm, an overjet of 8 mm, and a transverse maxillary deficiency. In consultation with the parents and patient, a nonsurgical therapy was elected, with the goals of reducing protrusion and closing the anterior open bite.