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Background In orthodontic treatment, the combination of an activator with a headgear is commonly used in treatment of the hyperdivergent Class II malocclusion. However, the distribution of stresses transmitted to the maxilla by these appliances has been little studied. This study aimed to compare the biomechanical effects of stresses transmitted to the maxilla and teeth by a Teuscher activator (TA) for different lines of action of extraoral force, using finite element analysis. Material and Methods A tridimensional finite element model of the maxilla and teeth was created based on the true geometry of a human skull. The (TA) and the face bow were designed in 3D computer-aided design and fixed in the maxilla model. To study the effects of mechanical stress transmitted to the maxilla in the treatment of hyperdivergent Class II malocclusion with (TA) combined with extraoral forces, five different finite element models were used, considering the centers of resistance of the maxilla and dentition. Results The results showed that stresses increased progressively when the force line of action moved in posteroanterior direction. Von Mises equivalent stress was lower in Model 1 (0°) than in Model 5 (60°). In Models 1 (0°) and 2 (15°), molars suffered greater distal displacement and incisors showed extrusion. In Model 3 (30°), the force line of action promoted a distal displacement of molars and incisors. In Models 4 (45°) and 5 (60°), the whole maxillary anterior sector showed counterclockwise displacement. Conclusions Different force lines of action influence the intensity and distribution of orthodontic and orthopedic forces in the maxilla. The extraoral force’s line of action used in Model 3 (30°) is the most compatible with the objectives of the hyperdivergent Class II malocclusion treatment in growing patients. Key words:Class II, Headgear, Early treatment, FEA.

Background In recent times the deontology of the dental profession has acquired special relevance as a result of problems that dentists have had to face to resolve ethical conflicts. Material and methods Information on deontology in the dental profession has been compiled in publications of health sciences in general and specific codes for dentistry, while expressing opinions about the experience of the authors themselves who, from a humanistic and health overview are concentrated in the dental area. Results This article presents our point of view of how the dentist-patient relationship should be in the face of current demands from patients and society, with a focus on the crucial role of ethical issues not only in undergraduate studies but also in the consideration of ethical questions in the specialization and in the usual practice. The dental profession has a special trust in the community, and the best dentist-patient relationship should be based on that trust, honesty, providing high-quality and appropriate treatment, and keeping the patient safe and healthy. Conclusions The patient has the right to be fully and adequately informed, as well as to participate in decisions about treatment. The dentist has a duty to put the patient first and treat her with her wishes in mind as long as these expectations are within the limits of accepted treatment. The dentist must provide dental care without discrimination or prejudice. Key words:Preemptive analgesia, dental extraction, cyclooxygenases, real-time polymerase chain reaction.

Maintaining good oral hygiene in patients wearing fixed appliances is a challenge for orthodontics. Conventional education has been demonstrated to be insufficient for the promotion of good oral habits, while motivational interviewing has the potential to facilitate health behavior change. The present randomized controlled trial with 130 patients aimed to evaluate the effectiveness of a single session of motivational interviewing in enhancing oral hygiene in orthodontic patients compared with conventional education alone. Results revealed an immediate improvement in oral hygiene which remained stable throughout the 6-month follow-up.

Background Little is known about the effect of non-nutritive sucking habits (pacifier and digital sucking) in the prevalence of molar Class in mixed dentition. The aim of this study was determinate the relation between non-nutritive sucking habits, and Angle´s molar Class, in the horizontal plane, and it´s relation with gender. A convenience sample of 326 children with ages between 6 and 12 years was selected from three schools of Oporto. Material and methods To collect the epidemiologic data, was used a method recommended by the WHO. An indirect questionnaire about the medical history, dental habits, was used. It was adapted from Sanchez-Molins and validated by Clinical Dental III of Integrated Dental University Institute Health Sciences, Gandra, Portugal. Results In this study, 326 infants were examined in order to determine the prevalence of non-nutritive sucking habits. Only 45 observed children did not mentioned any kind of non-nutritive sucking habit; the remaining 281 children mentioned at least one potential bad habit. Children with non-nutritive sucking habits show a higher molar Class II percentage in females, while molar Class III is more frequent among males compared with children with no sucking habits. Conclusions Children with non-nutritive sucking habits, presented a higher-Class II prevalence with statistically significance. It was detected a direct relationship between Angle´s molar Class and gender. Key words:Finger sucking, pacifier sucking, Angle Class malocclusion.

Background This study aimed to explore the association between feeding habits, non-nutritive sucking habits, and malocclusions in deciduous dentition. Methods A cross-sectional observational survey was carried out in 275 children aged 3 to 6 years and included clinical evaluations of malocclusions and structured interviews. Statistical significance for the association between feeding habits and the development of malocclusion was determined using chi-square and Fisher’s exact tests. In addition, odds ratio (OR) calculations were used for intergroup comparisons. Controlling for confounders was adjusted by excluding children with non-nutritive sucking habits. Results The results indicated that there were no significant relationships between exclusive breastfeeding or bottlefeeding and the presence of any type of malocclusion (p > 0.05). There was also no significant association between breastfeeding or bottlefeeding duration and malocclusion (p > 0.05). In addition, it was observed that exclusive breastfeeding had a protective effect and diminished the risk of acquiring non-nutritive sucking habits (p = 0.001). Conclusions There was no association between feeding habits and malocclusions in the deciduous dentition in this sample of children. Exclusive breastfeeding reduced the risk of acquiring non-nutritive sucking habits.

Objective: This review attempts to organize the existing published literature regarding tooth movement in orthodontic treatment when low-level laser therapy (LLLT) is applied. Background data: The literature discusses different methods that have been developed to motivate the remodeling and decrease the duration of orthodontic treatment. The application of LLLT has been introduced to favor the biomechanics of tooth movements. However there is disagreement between authors as to whether LLLT reduces orthodontic treatment time, and the parameters that are used vary. Materials and methods: Studies in humans and animals in which LLLT was applied to increase the dental movement were reviewed. Three reviewers selected the articles. The resulting studies were analyzed according to the parameters used in the application of laser and existing changes clinically and histopathologically. Results: Out of 84 studies, 5 human studies were selected in which canine traction had been performed after removing a premolar, and 11 studies in rats were selected in which first premolar traction was realized. There were statistically significant changes in four human studies and eight animal studies. Conclusions: Varying the wavelength with a reasonable dose in the target zone leads to obtaining the desired biological effect and achieving a reduction of the orthodontic treatment time, although there are studies that do not demonstrate any benefit according to their values.

We describe a female patient with a midline syndrome. The patient presents agenesis of the corpus callosum, encephalocele, iris coloboma, hypertelorism, submucosal cleft palate and dental anomalies. Despite being very characteristic, her phenotypical traits do not coincide exactly with those reported to date in the literature. The karyotype and the molecular cytogenetic study do not show mutations. We identify the presence of dental anomalies in the mother and other family members, not being identified MSX1 and PAX9 mutations that could the related with their etiology. Despite the fact that dental agenesis has been related to a large number of other malformation syndromes and congenital conditions, dental anomalies have only rarely been mentioned when reporting midline syndromes. These dental phenotypical traits, present in the patient and her family, could be considered part of the midline syndrome in carriers as well as in the patients.

Objectives: To evaluate the prevalence of dental agenesis and its possible association with other developmental dental anomalies and systemic entities. Setting and Sample Population: Descriptive transversal study, for which 1518 clinical records, of patients visited by the Odontological Service of the Primary Health Centre of Cassà de la Selva (Girona-Spain) between December 2002 and February 2006 were reviewed. The data were recorded in relation to the oral and dental anomalies and the associated systemic entities, between the ones referred as concomitant in literature. Results: Values of 9.48% (7.25% excluding the third molars) for dental agenesis and 0.39% for oligodontia were obtained. The presence of dental agenesis concomitant with some other forms of oral and dental anomalies was observed. Attention must be drawn to the fact that a greater number of concomitant systemic entities were observed in those patients that presented a severe phenotypical pattern of dental agenesis. Conclusions: The results of the present study do not differ from the ones reported in studies of similar characteristics among Occidental and Spanish populations. The relationship observed between certain systemic entities and developmental dental anomalies suggest a possible common genetic etiology.