Renésio Armindo Grehs

Histologic evaluation of human pulp tissue after orthodontic intrusion.

INTRODUCTION The forces applied during orthodontic treatment bring about effects on the teeth and surrounding tissues. The aim of this study was to evaluate the possible changes in the human pulpal tissue resulting from orthodontic intrusion in a 21-day period using histologic examination. METHODS The sample consisted of 17 young individuals of both sexes between the ages of 12 and 19 years. A total of 34 premolars were evaluated with orthodontic indication of extraction. Because it is a split-mouth study, in each patient, intrusion force of 60 g was applied randomly on 1 of the dental elements experimental group for 21 days. The counterpart control group received no force. After extractions, these dental elements were fixed in 10% formaldehyde, processed automatically, submitted to histotechnical preparation, and stained with hematoxylin-eosin for analysis under optical microscope. RESULTS The paired Fisher exact test (P ≤ .05) showed a significant increase of fibrous tissue in the experimental group. The nonparametric paired Wilcoxon test (P ≤ .05) showed a significant increase in the number of pulpal nodules in the elements of the experimental group and showed no difference in the number of blood vessels between the groups. Large-caliber vessels and congested elements were observed in 8 of the experimental group elements. CONCLUSIONS The orthodontic intrusion force, in these conditions, caused vascular changes in the pulpal tissue and also increased the presence of fibrosis and the number of pulp calcifications in the experimental elements.

Síndrome do incisivo central superior solitário: relato de caso

INTRODUCTION: The presence of a single median maxillary central incisor is an uncommon event in the population. The prevalence of the Solitary Median Maxillary Central Incisor (SMMCI) syndrome is about 1:50,000 live births, occurring more in women. This alteration in the development of the dental occlusion is characterized by structural malformations, over all in midline region of the patient. The early diagnosis and the adequate treatment of this syndrome are of great importance, therefore this condition can be an indication that the patient can present other severe congenital malformations, not having to consider the SMMCI a simple dental anomaly. The orthodontic procedures, in these cases, vary depending on the degree of involvement of bone structures of the maxilla, the occlusion in itself, and mainly of the midpalatal suture. OBJECTIVES: To discuss, based on scientific evidence, important aspects related to the SMMCI and present a clinical case of female patient with SMMCI, which was submitted to orthodontic treatment in the Childrens Dental Integrated Clinic of the Federal University of Santa Maria - RS/Brazil. CONCLUSION: According to the critical analysis of literature, it is very important to correctly early diagnose this condition, since there is the possibility of this syndrome to be associated with other problems of development. Moreover, the patients affected by SMMCI should be attended by a multidisciplinary health team in order to optimize the clinical results and recover the quality of life of these patients.

Imaginologia da articulação temporomandibular durante o tratamento ortodôntico: uma revisão sistemática

INTRODUCTION: The evolution of imaging in dentistry has provided several advantages for the diagnosis and development of treatment plans in various dental specialties. Examinations as nuclear magnetic resonance, computed tomography and Cone Beam volumetric tomography, as well as 3D reconstruction methods, have enabled a precise analysis of orofacial structures. Allied to this fact, the effects of orthodontic treatment on temporomandibular joint (TMJ) could be evaluated with the accomplishment of clinical studies with appropriate designs and methodologies. OBJECTIVE: This study, a systematic literature review, had the objective of analyzing the interrelation between orthodontic treatment and TMJ, verifying if orthodontic treatment causes changes in the internal structures of TMJ. METHODS: Survey in research bases MEDLINE, Cochrane, EMBASE, Pubmed, Lilacs and BBO, between the years of 1966 and 2009, with focus in randomized clinical trials, longitudinal prospective nonrandomized studies, systematic reviews and metaanalysis. RESULTS: After application of the inclusion criteria 14 articles were selected, 2 were randomized clinical trials and 12 longitudinal nonrandomized studies. CONCLUSIONS: According to the literature analysis, the data concludes that orthodontic treatment does not occur at the expense of unphysiological disc-condyle position. Some orthodontic mechanics may cause remodeling of articular bone components.

Ortodontia como fator de risco para disfunções temporomandibulares: uma revisão sistemática

INTRODUCTION: The interrelationship between Orthodontics and temporomandibular disorders (TMD) has attracted an increasing interest in Dentistry in the last years, becoming subject of discussion and controversy. In a recent past, occlusion was considered the main etiological factor of TMD and orthodontic treatment a primary therapeutical measure for a physiological reestablishment of the stomatognathic system. Thus, the role of Orthodontics in the prevention, development and treatment of TMD started to be investigated. With the accomplishment of scientific studies with more rigorous and precise methodology, the relationship between orthodontic treatment and TMD could be evaluated and questioned in a context based on scientific evidences. OBJECTIVES: This study, through a systematic literature review had the purpose of analyzing the interrelationship between Orthodontics and TMD, verifying if the orthodontic treatment is a contributing factor for TMD development. METHODS: It was conducted a survey in research bases (MED-LINE, Cochrane, EMBASE, Pubmed, Lilacs and BBO) between the years of 1966 and 2009, with focus in randomized clinical trials, longitudinal prospective non-randomized studies, systematic reviews and meta-analysis. RESULTS: After application of the inclusion criteria 18 articles were used, which were 12 longitudinal prospective non-randomized studies, 4 systematic reviews, 1 randomized clinical trial and 1 meta-analysis, which evaluated the relationship between orthodontic treatment and TMD. CONCLUSIONS: According to the literature, the data concludes that orthodontic treatment cannot be considered a contributing factor for the development of temporomandibular disorders.

Enamel Roughness Changes after Removal of Orthodontic Adhesive

The aim of this study was to evaluate enamel roughness, quality of the enamel surfaces and time duration comparing different orthodontic adhesive removal protocols. Premolars were used to test three adhesive removal methods (n = 20): five-blade carbide bur, 30-blade carbide bur, and ultrasonic diamond bur. Bracket was bonded using TransbondTM XT adhesive. Roughness with different parameters was measured before bracket bonding and after adhesive remnants removal. Micromorphological analysis of enamel surface (n = 5) was performed by SEM images and categorized in enamel damage index—“perfect”; “satisfying”; “imperfect”; and “unacceptable”. Time was measured in seconds. All removal methods caused increased roughness in relation to Ra, Rq, and Rz parameters (X axis) comparing to healthy enamel surface. Enamel surface resulted from removal using five-blade burs was scored as satisfactory. Carbide bur groups decreased the roughness values of Ra, Rq, and Rz parameters on the Y axis and enamel surface was considered unacceptable. The 30-blade group increased symmetry (Rsk) and flattening (Rku) parameters of roughness and surface was scored as unsatisfactory. Diamond bur removed adhesive in 54.8 s, faster than five-blade carbide bur. The five-blade bur group resulted in less enamel roughness than the 30-blade and diamond groups.

Dimensional changes in plaster cast models due to the position of the impression tray during setting

Introduction: The objective of this study was to assess whether the positioning of the impression tray could cause distortion to plaster casts during gypsum setting time.Materials and Methods: Fifteen pairs of master models were cast with alginate impression material and immediately filled with gypsum. Impressions were allowed to set with the tray in the noninverted position (Group A) or in the inverted position (Group B). The plaster models were digitized using a laser scanner (3Shape R-700, 3Shape A/S, Copenhagen, Denmark). Measurements of tooth size and distance were obtained using O3d software (Widialabs, Brazil) measurement tools. Data were analyzed by paired t-test and linear regression with 5% significance.Results and Conclusion: Most of the measurements from both groups were similar, except forthe lower intermolar distance. It was not possible to corroborate the presence of distortions due to the position of the impression tray during gypsum setting time.

Orthodontics as a therapeutic option for temporomandibular disorders: a systematic review

OBJECTIVE: Orthodontics as an option for treatment and prevention of Temporomandibular Disorders (TMD) is a topic that has generated discussion over time. While an occlusion current defends Orthodontics as an alternative to treatment, another current defends more conservative and reversible treatments. The objective of this study, through a systematic literature review, was to analyze the relationship between Orthodontics and TMD, checking the effects of orthodontic therapy in treatment and prevention of TMD. METHODS: Survey in research bases: MEDLINE, Cochrane, EMBASE, Pubmed, Lilacs and BBO, between the years of 1966 and May 2009, with focus in randomized clinical trials, non-randomized prospective longitudinal studies, systematic reviews and meta-analysis was performed. RESULTS: After application of the inclusion criteria 11 articles were selected, 9 which were non-randomized prospective longitudinal studies, 1 randomized clinical trial and 1 systematic review. CONCLUSIONS: According to the literature, there is a lack of specific studies that evaluated Orthodontics as an option for treatment and prevention of TMD. Thus the data conclude that there is no significant scientific evidences that orthodontic treatment treats or prevents TMD.