Rívea Inês Ferreira

Breastfeeding and non-nutritive sucking patterns related to the prevalence of anterior open bite in primary dentition

Objective Nutritional, immunological and psychological benefits of exclusive breastfeeding for the first 6 months of life are unequivocally recognized. However, mothers should also be aware of the importance of breastfeeding for promoting adequate oral development. This study evaluated the association between breastfeeding and non-nutritive sucking patterns and the prevalence of anterior open bite in primary dentition. Material and Methods Infant feeding and non-nutritive sucking were investigated in a 3-6 year-old sample of 1,377 children, from São Paulo city, Brazil. Children were grouped according to breastfeeding duration: G1 – non-breastfed, G2 – shorter than 6 months, G3 – interruption between 6 and 12 months, and G4 – longer than 12 months. Three calibrated dentists performed clinical examinations and classified overbite into 3 categories: normal, anterior open bite and deep bite. Chi-square tests (p<0.05) with odds ratio (OR) calculation were used for intergroup comparisons. The impact of breastfeeding and non-nutritive sucking on the prevalence of anterior open bite was analyzed using binary logistic regression. Results The prevalence estimates of anterior open bite were: 31.9% (G1), 26.1% (G2), 22.1% (G3), and 6.2% (G4). G1 would have significantly more chances of having anterior open bite compared with G4; in the total sample (OR=7.1) and in the subgroup without history of non-nutritive sucking (OR=9.3). Prolonging breastfeeding for 12 months was associated with a 3.7 times lower chance of having anterior open bite. In each year of persistence with non-nutritive sucking habits, the chance of developing this malocclusion increased in 2.38 times. Conclusion Breastfeeding and non-nutritive sucking durations demonstrated opposite effects on the prediction of anterior open bite. Non-breastfed children presented significantly greater chances of having anterior open bite compared with those who were breastfed for periods longer than 12 months, demonstrating the beneficial influence of breastfeeding on dental occlusion.

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

INTRODUCTIONnThis cross-sectional retrospective epidemiologic study assessed the relationship between exclusive breastfeeding duration and the prevalence of posterior crossbite in the deciduous dentition.nnnMETHODSnClinical 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.nnnRESULTSnThe 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.nnnCONCLUSIONSnChildren 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.

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.

Detection of vertical root fractures by cone-beam computerized tomography in endodontically treated teeth with fiber-resin and titanium posts: an in vitro study.

OBJECTIVEnThe aim of this study was to assess the performance of 2 cone-beam computerized tomography (CBCT) systems for detecting vertical fractures in root-filled teeth with fiber-resin or titanium posts.nnnSTUDY DESIGNnCBCT images acquired with the use of Scanora 3D and i-CAT of roots with fiber-resin (n = 30) or titanium (n = 29) posts, before and after the induction of fractures, were assessed by 6 radiologists using Ondemand 3D software. Interobserver agreement was analyzed using kappa statistics. Sensitivity, specificity, accuracy, and positive and negative predictive values were compared with analysis of variance/Student-Newman-Keuls test.nnnRESULTSnInterobserver agreement for fiber-resin posts ranged from 0.5 to 0.7 (Scanora 3D) and 0.35-0.76 (i-CAT). For titanium posts, ranged from 0.42 to 0.80 (Scanora 3D) and 0.31-0.73 (i-CAT). Higher sensitivity (0.85; P < .05) and negative predictive values (0.88; P < .001) were observed for i-CAT in roots with fiber-resin posts than with other combinations.nnnCONCLUSIONSnThe diagnostic performance for detecting vertical fractures was higher for roots with fiber-resin than with titanium posts.

Effect of breast- and bottle-feeding duration on the age of pacifier use persistence

This study evaluated the effect of breast- and bottle-feeding duration on the age of pacifier use persistence. Questionnaires (n = 723) with information on nutritive and nonnutritive sucking habits of children aged 3-6 years were assessed. The sample was divided according to breastfeeding duration: G1 - non-breastfed, G2 - up to 3 months, G3 - discontinued between 4 and 6 months, G4 - discontinued between 7 and 12 months, and G5 - longer than 12 months. The children were also assigned to 4 groups by age of pacifier use persistence, as well as by age of bottle-feeding persistence: no habits, up to 2 years, 3-4 years and 5-6 years. Associations between nutritive sucking habits and pacifier use were analyzed using logistic regression. The larger breastfeeding groups were G2 (37.9%) and G4 (19.4%). Many children discontinued pacifier use and bottle-feeding at 3-4 years of age (24.9% and 40.1%, respectively). Chances of non-breastfed children (G1) with prolonged pacifier-sucking habits, in the three age ranges, were progressively higher in comparison with group G4 (OR: 4.0-7.5, p < 0.01). When comparing bottle-fed with non bottle-fed children, the age range at which bottle-feeding had been discontinued was significantly associated with that of pacifier use cessation: up to 2 years (OR = 6.2), 3-4 years (OR = 7.6) and 5-6 years (OR = 27.0), p < 0.01. It may be suggested that breastfeeding duration has an inversely proportional effect on the age of pacifier use persistence. Bottle-fed children who use pacifiers tend to discontinue these habits at the same period.

Bottle feeding, increased overjet and Class 2 primary canine relationship: is there any association?

The aim of this study was to investigate the association between bottle feeding and prevalence rates of increased overjet and Class 2 primary canine relationship. The sample consisted of 911 children (461 boys, 450 girls) aged 3 (13.9%), 4 (40.8%), 5 (34%) and 6 (11.3%) years, with complete primary dentition. Information about nutritive and nonnutritive (pacifier and/or digit) sucking habits was collected through questionnaires. Three calibrated dentists (κ: 0.9-1.0 and Rs > 0.90) performed the clinical assessments. The children were divided into four groups: G1 - not bottle-fed; G2 - exclusively bottle-fed; G3 - breast- and bottle-fed, bottle feeding ceased before 3 years of age; and G4 - breast- and bottle-fed, bottle feeding ceased between 3 and 4 years of age. Associations between nutritive and nonnutritive sucking behaviors and the malocclusions studied were analyzed by multiple binary logistic regression (α= 0.05). The frequencies of increased overjet were: 25.3% (G1), 38.8% (G2), 39.2% (G3) and 47.8% (G4). The percentages of Class 2 canine relationship were: 27.9% (G1), 48.8% (G2), 43.4% (G3) and 43% (G4). No significant effect of bottle feeding was found. The chances of diagnosing increased overjet (O.R. = 4.42, p < 0.001) and Class 2 canine relationship (O.R. = 4.02, p < 0.001) were greater for children with pacifier and/or digit-sucking habits, compared to those without a history of nonnutritive sucking behavior. It may be suggested that bottle feeding alone is not directly associated with higher prevalence rates of increased overjet and Class 2 canine relationship in the primary dentition.

Comparative study of dental arch width in plaster models, photocopies and digitized images

The aim of this study was to comparatively assess dental arch width, in the canine and molar regions, by means of direct measurements from plaster models, photocopies and digitized images of the models. The sample consisted of 130 pairs of plaster models, photocopies and digitized images of the models of white patients (n = 65), both genders, with Class I and Class II Division 1 malocclusions, treated by standard Edgewise mechanics and extraction of the four first premolars. Maxillary and mandibular intercanine and intermolar widths were measured by a calibrated examiner, prior to and after orthodontic treatment, using the three modes of reproduction of the dental arches. Dispersion of the data relative to pre- and posttreatment intra-arch linear measurements (mm) was represented as box plots. The three measuring methods were compared by one-way ANOVA for repeated measurements (alpha = 0.05). Initial / final mean values varied as follows: 33.94 to 34.29 mm / 34.49 to 34.66 mm (maxillary intercanine width); 26.23 to 26.26 mm / 26.77 to 26.84 mm (mandibular intercanine width); 49.55 to 49.66 mm / 47.28 to 47.45 mm (maxillary intermolar width) and 43.28 to 43.41 mm / 40.29 to 40.46 mm (mandibular intermolar width). There were no statistically significant differences between mean dental arch widths estimated by the three studied methods, prior to and after orthodontic treatment. It may be concluded that photocopies and digitized images of the plaster models provided reliable reproductions of the dental arches for obtaining transversal intra-arch measurements.

Mesiodistal width and proximal enamel thickness of maxillary first bicuspids

This study aimed at evaluating measurements relative to the mesiodistal crown width and enamel thickness of maxillary first bicuspids. The sample consisted of 40 extracted sound bicuspids (20 right and 20 left), selected from white patients (mean age: 23.7 +/- 4.2 years), who were treated orthodontically with tooth extraction at a private clinic in São Paulo, SP, Brazil. All teeth were embedded in acrylic resin and cut along their long axis through the proximal surfaces, parallel to the buccal side, to obtain 0.6-mm central sections. The mesiodistal crown width and proximal enamel thickness were measured using a stereoscopic microscope connected to a computer. Measurements for right and left teeth, as well as the mesial and distal enamel thicknesses in the total sample, were compared by the Wilcoxon test (alpha = 0.05). The mesiodistal crown width mean values found were 7.51 mm (+/- 0.54) on the right side and 7.53 mm (+/- 0.35) on the left side. The mean enamel thickness on the distal surfaces for both sides was 1.29 mm (right: s.d. = 0.12 and left: s.d. = 0.18). The mean values for the mesial surfaces were 1.08 mm (+/- 0.14) and 1.19 mm (+/- 0.25), on the right and the left sides, respectively. No significant differences were found between the crown measurements and enamel thicknesses on the left and right sides. However, enamel thickness was significantly greater on the distal surfaces. Reliable measurements of enamel thickness are useful to guide stripping, which may be an attractive alternative to tooth extraction because it allows the transverse arch dimension to be maintained.

In vitro induction of enamel subsurface demineralization for evaluation of diagnostic imaging methods

The aim of this study was to investigate a model of inducing enamel subsurface demineralization for evaluating diagnostic imaging methods. Fifty sound teeth had their crowns coated with acid-resistant varnish, leaving a 7 mm2 circular window of exposed enamel in one of the proximal surfaces. The specimens were assigned to 5 groups (4 experimental and the control) and were kept immersed in a buffer solution at pH 4.8, 50% saturated in relation to enamel, for 60, 75, 90 and 120 days, or were not exposed to the solution. Digital radiographs were taken, prior to and after each immersion period, and interpreted by a radiologist. For validation, the enamel was submitted to microhardness profiling. In addition, the solutions were analyzed for phosphorus (Pi) and calcium (Ca) concentrations. Microhardness data were evaluated using two-way ANOVA (p<0.05) and Tukeys test. Pi and Ca concentrations were compared using one-way ANOVA (α = 0.05). The performance of radiography was assessed by ROC analysis. The microhardness values for the control group ranged from 405 to 432 KHN. Of the 4 experimental groups, the 60-day group demonstrated the highest values (179-379 KHN) and the 120-day group, the lowest values (103-277 KHN). The lowest total concentrations of Pi and Ca (1.74 mM and 2.63 mM, respectively) were found in the solutions of the 60- day group, indicating the lowest rate of mineral loss, however, there was no significant difference among the other experimental groups. The performance for detecting images consistent with caries lesions was high (Az = 0.89). Therefore, this in vitro model of inducing demineralization may be considered suitable for research intended to evaluate imaging methods for the diagnosis of proximal caries lesions.

Crown dimensions and proximal enamel thickness of mandibular second bicuspids

To achieve proper recontouring of anterior and posterior teeth, to obtain optimal morphology during enamel stripping, it is important to be aware of dental anatomy. This study aimed at evaluating crown dimensions and proximal enamel thickness in a sample of 40 extracted sound, human, mandibular, second bicuspids (20 right and 20 left). Mesiodistal, cervico-occlusal and buccolingual crown dimensions were measured using a digital caliper, accurate to 0.01 mm. Teeth were embedded in acrylic resin and cut along their long axes through the proximal surfaces to obtain 0.7 mm-thick central sections. Enamel thickness on the cut sections was measured using a perfilometer. Comparative analyses were carried out using the Students-t test (α= 5%). The mean mesiodistal crown widths for right and left teeth were 7.79 mm (± 0.47) and 7.70 mm (± 0.51), respectively. Mean cervico-occlusal heights ranged from 8.31 mm (± 0.75) on the right to 8.38 mm (± 0.85) on the left teeth. The mean values for the buccolingual dimension were 8.67 mm (± 0.70) on the right and 8.65 mm (± 0.54) on the left teeth. The mean enamel thickness on the mesial surfaces ranged from 1.35 mm (± 0.22) to 1.40 mm (± 0.17), on the left and right sides, respectively. On the distal surfaces, the corresponding values were 1.44 mm (± 0.21) and 1.46 mm (± 0.12). No significant differences were found between measurements for right and left teeth. However, enamel thickness was significantly greater on the distal surfaces, compared with the mesial surfaces.