Relationship between breastfeeding duration and prevalence of posterior crossbite in the deciduous dentition.

INTRODUCTION: This cross-sectional retrospective epidemiologic study assessed the relationship between exclusive breastfeeding duration and the prevalence of posterior crossbite in the deciduous dentition. METHODS: Clinical examinations were performed in 1377 Brazilian children (690 boys, 687 girls), 3 to 6 years old, from 11 public schools in São Paulo, Brazil. Based on questionnaires answered by the parents, the children were classified into 4 groups according to the duration of exclusive breastfeeding: G1, never (119 subjects); G2, less than 6 months (720 subjects); G3, 6 to 12 months (312 subjects); and G4, more than 12 months (226 subjects). The statistical analyses included the chi-square test (P <0.05) and the odds ratio. RESULTS: The posterior crossbite was observed in 31.1%, 22.4%, 8.3%, and 2.2% of the children, in groups G1, G2, G3, and G4, respectively. The results showed a statistically significant relationship between exclusive breastfeeding duration and the prevalence of posterior crossbite. CONCLUSIONS: Children who were breastfed for more than 12 months had a 20-fold lower risk for the development of posterior crossbite compared with children who were never breastfed and a 5-fold lower risk compared with those breastfed between 6 and 12 months.

Soft tissue profile in white Brazilian adults with normal occlusions and well-balanced faces.

OBJECTIVE: To analyze anteroposterior soft tissue facial parameters for a sample of white Brazilian adults and to compare these measurements with the values proposed for white North American adults. MATERIALS AND METHODS: Facial profile photographs were taken of 59 white Brazilians (30 men and 29 women) with normal occlusions and balanced faces with ages ranging from 18 to 30 years. The independent Student's t-test (P < .05) was used to compare the soft tissue parameters of the Brazilians with those of the North Americans. RESULTS: White Brazilian women presented a less protruded face compared with white American women except for the glabella region. White Brazilian women showed a smaller nasal projection, less protruded upper and lower lips, a more obtuse nasolabial angle, and a smaller projection of the B' point and chin than white American women. Conversely, the two male groups demonstrated less evident soft tissue profile differences, with the exception of the nose projection, which was smaller in white Brazilian men than in white American men. CONCLUSIONS: A universal standard of facial esthetic is not applicable to diverse white populations. Differences regarding the soft tissue profile features were found between white Brazilians and white Americans. These differences should be considered in the orthodontic/orthognathic surgery diagnosis and treatment plan for white Brazilians together with the patient's individual opinion and perception of beauty.

Prevalence of posterior crossbite among pacifier users: a study in the deciduous dentition.

The aim of this study was to evaluate the prevalence of posterior crossbite among children whose pacifier-sucking habit persisted until different ages. Children aged 3 to 6 years were randomly selected from public preschools in São Paulo, SP, Brazil. Their mothers were asked to complete a questionnaire on non-nutritive sucking behaviors. The sample consisted of 366 children assigned to 2 groups: control (n = 96) and pacifier users (n = 270). Pacifier users were further assigned to 3 subgroups, according to the age of habit persistence: P1 - until 2 years of age; P2 - between 2 and 4 years of age; and P3 - between 4 and 6 years of age. One dentist assessed the children for occlusal relationships through clinical examination. Associations between the age interval of habit discontinuation and the prevalence of posterior crossbite were analyzed using the chi-square test (p < 0.05). The prevalence of posterior crossbite was significantly higher among pacifier users (20.4%), compared to control children (5.2%), p < 0.01. Unilateral posterior crossbite was more prevalent than bilateral crossbite among pacifier users (9.8% versus 3.6%). Functional posterior crossbites were diagnosed in 3.1% of the control children and 7% of the pacifier users. The frequencies of posterior crossbite were notably high for children in the 3 pacifier subgroups, P1, P2, and P3, corresponding to 17.2%, 16.9%, and 27.3%, respectively. The high prevalence of posterior crossbite may be associated with pacifier-sucking habits that persisted after 2 years of age.

Facial profile evaluation in Japanese-Brazilian adults with normal occlusions and well-balanced faces.

INTRODUCTION: The purpose of this study was to establish the norms of soft-tissue profile analysis for a sample of Japanese-Brazilian adults. METHODS: Facial-profile photographs were taken of 60 Japanese-Brazilians (30 men, 30 women) with normal occlusions and balanced faces, ranging in age from 18 to 30 years. The facial-profile variables were measured by computerized means and compared with white norms by using the independent t test. RESULTS: Statistically significant differences were found in the Japanese-Brazilian sample compared with the white norms. Japanese-Brazilian women had more anteriorly positioned glabellae, smaller nasal projections, and more opened nasolabial angles than white American women. Japanese-Brazilian men had more anteriorly positioned glabellae, smaller noses, larger protrusions of the upper and lower lips, less projected B'-points, and more obtuse nasolabial angles than white American men. CONCLUSIONS: A single norm for facial-profile esthetics does not apply to all ethnic groups. The normative data for the Japanese population should be used as a guide for comparison during diagnosis, and the orthodontist and the maxillofacial surgeon should also consider each patient's perception of beauty, to establish an individualized treatment plan.