Jucienne Salgado Ribeiro

Transverse craniofacial dimensions in Angle Class II, Division 1 malocclusion according to breathing mode

The aim of this longitudinal study was to assess the relation between the transverse craniofacial dimensions of subjects with Class II, Division 1 malocclusion and the breathing mode presented by them. Forty Angle Class II, Division 1 malocclusion subjects of both genders participated in the study, 23 of which were predominantly nose breathers and 17 were predominantly mouth breathers. The mean age ranged from 10 years and 9 months to 14 years--Age range 1; and from 13 years and 4 months to 16 years and 6 months--Age range 2. Measurements of six transverse craniofacial dimensions were performed in P-A teleradiographs: Total Sphenoid, Total Zygomatic, Total Nasal Cavity, Total Maxilla, Total Mastoid and Total Antegonion. The transversal craniofacial dimensions were measured and compared in both groups at age ranges 1 and 2. The longitudinal assessment of age ranges 1 and 2 showed that there was no statistically significant influence of the breathing mode on the craniofacial dimensions evaluated, or on the alteration of these dimensions. Breathing mode had no influence on craniofacial development in the sample studied.

Princípios biomecânicos do aparelho extrabucal

The use of the headgear appliance for the treatment of Angle Class II malocclusion demands that the biomechanic principles are understood and applied so that the clinic case is conducted in a way that the side effects are minimized and the benefits maximized. Therefore, the orthodontist must be able to predict the effects of the inclination of the line of traction and its relation to the teeth and maxillary centers of resistance. Any rotation movement, inclination or translation of the teeth and maxillary and mandibular rotation clockwise or counter clockwise can be predict and planned when the orthodontist knows the mechanism that cause them, as well as the effects that the different types of traction produce in subjects with dolichofacial, mesofacial or brachyfacial types. Thus, the aim of this work is to present predominant and indispensable factors for the utilization of the headgear appliance for the treatment of Angle Class II malocclusion.

Evaluation of transverse changes in the dental arches according to growth pattern: a longitudinal study

OBJECTIVE: To evaluate changes in intercanine (LICW and UICW) and intermolar (LIMW and UIMW) widths on the dental arches of subjects with normal occlusion and Angle Class I malocclusion during the transition to permanent dentition, and evaluate whether or not facial pattern influences on the normal development of the dentition and occlusion. METHODS: Nineteen Caucasian Brazilian children were selected, with ages ranging from 6 to 8.6 years at T1 and from 10.10 to 14.2 years at T2. Their second records consisted of study dental casts and a lateral cephalometric radiograph. To obtain intermolar and intercanine widths a three-dimensional scanner unit (digitizer MicroScribe 3DX) was used connected to a microcomputer. To analyze changes at T1 and T2 Students paired t-test was applied, whereas Spearmans correlation analysis was used to assess the relationship between measurements obtained at T1 and T2 and the facial pattern, both at 95% level of confidence. RESULTS: The mean values found on each assessment time (T1 and T2) were statistically different (p=0.000 for LICW, p=0.001 for UICW, p=0.000 for UIMW, and p=0.046 for LIMW), regardless of the facial pattern. The anterior dimensions, UICW and LICW, increased by 3.21 mm and 1.52 mm, respectively. And the posterior dimensions, UIMW and LIMW, increased by 2.16 mm and 0.50 mm, respectively. Only UIMW showed a significant correlation with the facial pattern (p<0.01). CONCLUSION: There was an increase in dental arch width during the transition period from primary or mixed dentition to permanent dentition irrespective of facial pattern. Only the changes observed in the maxillary intermolar width were associated with the facial pattern.

Calcium, amylase, glucose, total protein concentrations, flow rate, pH and buffering capacity of saliva in patients undergoing orthodontic treatment with fixed appliances

Methods: Salivary samples were collected from 50 individuals divided in two groups: Experimental Group - pa- tients with fixed orthodontic appliances (n=25); and Control Group - subjects with no orthodontic appliances (n=25). Salivary flow rate, pH, buffering capacity, amylase activity, concentrations of total proteins, calcium and glucose were measured in all salivary samples. Results: There was a reduction in salivary pH and buffering capacity and an increase in the concentration of cal- cium ions in the experimental group (p<0.05); there was also an increase in glucose, amylase and protein concen- trations in the saliva of the Experimental Group, but the differences were insignificant. There was insignificant correlation between calcium ion concentration and salivary flow or between buffering capacity and salivary flow. Conclusion: The saliva of individuals with fixed orthodontic appliances had lower pH, buffering capacity and cal- cium concentration than that of individuals without any type of orthodontic appliance. These oral changes are enough to cause tooth demineralization. Patients with orthodontic appliances should adopt additional oral hy- giene procedures.

Resistência adesiva após colagem e recolagem de bráquetes: um estudo in vitro

Introducao: A busca por um material adesivo para recolagem de braquetes com adesao adequada desperta interesse ao ortodontista. A resina fotopolimerizavel ReBond® foi introduzida na Ortodontia com esta fi¬nalidade. Objetivos: Avaliar e comparar o desempenho in vitro do ReBond® com a resina Transbond XT® na recolagem de braquetes metalicos. Materiais e Metodos: Noventa incisivos inferiores bovinos foram divididos em 3 grupos (n=30): Grupo I: braquetes colados com resina Transbond® e colagem de novos braquetes com resina Transbond®; Grupo II: braquetes colados com resina Transbond® e recolados com resina Rebond®; Grupo III: braquetes colados e recolados com resina Transbond®. Os corpos de prova foram submetidos ao teste de cisalhamento na maquina de ensaio universal DL 500 (EMIC). Os valores obtidos foram analisados estatisticamente e apresentaram distribuicao normal (ANOVA e TUKEY-HSD). Resultados: Os resultados evidenciaram existir diferenca estatisticamente significante entre grupos e en¬tre colagem/recolagem dos braquetes. A forca de colagem inicial demonstrou ser sempre superior a forca de recolagem, em todos os grupos experimentais. Conclusoes: A forca de recolagem dos braquetes com Rebond® e Transbond® apresentaram forcas de adesao adequadas ao uso clinico.