Vanda Urzal

The prevalence of anterior open bite in Portuguese children during deciduous and mixed dentition – Correlations for a prevention strategy

INTRODUCTION Anterior open bite (AOB) is a vertical malocclusion that requires thorough diagnosis to ensure long-term stability. The aim of this study was to determine the prevalence of AOB in Portuguese children during deciduous and mixed dentition in order to assess the need for orthodontic treatment and to determine its relation to other associated features. MATERIAL AND METHODS A group of 1264 children aged between 3 and 12 from Porto in Portugal were observed. The statistical methodology included the independent Chi(2) test, Fishers exact test and binary logistic regression. RESULTS The prevalence of AOB was 16.9% with 95% CI (11.9%, 24.5%) for primary dentition and 11.3% with 95% CI (8.4%, 15.1%) for mixed dentition. Pacifier sucking, thumb sucking, tongue thrust and oral breathing are major risk factors for AOB in primary dentition, ranked in descending order. In mixed dentition, the factors are ranked as follows: pacifier sucking, lip sucking, tongue thrust and oral breathing. CONCLUSION Due to the close connection between the prevalence of AOB and dysfunctional problems, prevention strategies should be integrated into a national public health program. The habits mentioned above should be eliminated early by using the appropriate protocols in order to reduce the risk factors of malocclusion.

Relationships between teeth and adjacent structures: How to achieve more esthetic results

Nowadays, the demand for esthetic dental treatment is fundamental and is conditioned by gender, age and level of education. The color and appearance of teeth and crowding in the anterior segment feature among the main factors governing the choice of treatment. The aim of this article is to check six basic parameters needed to obtain an esthetic result.

European College of Orthodontics: Commission of affiliation and titularisation

Date of birth: 12/01/1992; sex: male. A. PRETREATMENT RECORDS 25/05/2005; 13 years 4 months. DIAGNOSIS Angle Class I; Teeth missing prior to treatment: third molars. TREATMENT PLAN Appliances and devices: Hyrax appliance, multibracket straight-wire appliances, 0.022×0.028″, Roth technique; start of treatment: 13 years 6 months; 06/07/2005. B. POSTTREATMENT RECORDS 06/12/2007; 15 years 11 months. DURATION OF ACTIVE TREATMENT 2 years 5 months. RETENTION Hawley maxillary retainer;12/12/08; bonded lingual mandibular wire from 33 to 43; 12/12/08. C. POSTRETENTION RECORDS: (1 year minimum): Duration of retention: Maxilla: 1 year; mandible: permanent.

Diagnostic model of anterior open bite--a new way to predict skeletal type: a cross-sectional study.

INTRODUCTION The aim of this study was to determine a differential diagnostic model for anterior open bite (AOB) in children in order to predict evolution with growth in cases of skeletal or dysfunctional dysplasia. MATERIAL AND METHODS The sample was composed of 128 subjects divided into 2 groups according to overbite values: a control group with normal occlusion and 2.5 ± 1mm overbite, and an AOB group with a negative overbite. Measurements of hyoid bone position, gonial angle, SN/Go-Gn, FMA, height of alveolar processes, upper lip height, height of the anterior nasal spine to stomion superior, upper incisor and menton, antegonial notch, symphysis anatomy, condyle anatomy, convexity, facial axis, lower oropharyngeal area and curve of Spee were obtained for all subjects, based on lateral cephalometric radiographs and lateral photos. All data were analyzed, and multivariate logistic regression was applied. The area under the receiver operating characteristic (ROC) curve was calculated for the models obtained by logistic regression, in order to evaluate them. Statistical analysis was performed in IBM(®) SPSS(®) Statistics version 21.0. RESULTS The results demonstrated that the AOB model was capable of predicting skeletal anterior open bite with an accuracy of 93%. The seven variables selected were: lower face height (LFH), height of mandibular alveolar process, antegonial notch, symphysis direction, symphysis thickness, gonial angle and facial axis. CONCLUSIONS Measurements of facial morphology made it possible to construct a model able to differentiate, with a small margin of error, between the two distinct forms of AOB: skeletal and dysfunctional.

Orthodontics diagnostic based on multinomial logistic regression model

The main objective of this study is evaluate the influence of several covariates in the occurrence of two types of vertical jaw dysplasia (open bite and deepbite) in orthodontics field. The study of vertical jaw dysplasia is of great interest to the community of orthodontists, to ensure long-term stability of treatment, as this envolves complex etiological factors. In this work we propose to build a multinomial logistic regression model that could assess the probability of an individual have open bite or deepbite taking into account some cephalometric measures of hyoid bone (HB) and some individual characteristics. The study was conducted in a retrospective evaluation and consisted of 191 individuals random selected from a clinic in the Northern region of Portugal. We evaluated multiple factors in the construction of multinomial logistic regression model with 2 logit functions. The technique used to select variables to be included in the model, was the stepwise technique by choosing the smallest p value for the variable entering in the model. Of the modeling process through multinomial logistic regression have resulted five position of the hyoid bone that have statistical significance and that can contribute as an auxiliary for the diagnosis of vertical jaw dysplasia.