Aim: To evaluate the effect of the cranial base on the nasomaxillary complex in class II division 1 malocclusion. Materials and Methods: The study was carried out on a sample of 104 Iraqi subjects in Mosul City aged 18-24 years 53 females and 51 males having class II division 1 malocclusion. Lateral and posteroanterior radiographs were taken for each subject and twenty three measurements were used (Nine angular and fourteen linear). Results of the analysis were the median (NSBa), lateral cranial base (NSCo) and saddle angle (NSAr) showed a significant effect on the inclination of the Frankfort plane from the anterior and posterior cranial base in same direction, For the saddle angle significantly affect the inclination of the Frankfort plane but in the opposite direction while on anteroposterior position of alveolar process of the premaxilla (SNPr) in the same direction. The anterior part (SN), second lateral posterior part (SCo) and depth of cranial base (NBa) significantly affect the maxillary length (ApMax-PNS), upper anterior (N-ANS) and posterior facial height (S-PNS). For the median posterior part (SBa) and first lateral posterior part (SAr) no significant effect on (upper anterior facial height). The anterior cranial base width (GL-GL) showed a significant affect [facial (Zy-Zy), maxillary (J-J) and upper intermolar width (U6-U6)]. While posterior cranial base width (Mas-Mas) was significantly affect [facial (Zy-Zy), maxillary (J-J) and nasal width (Nc-Nc)].Conclusion: The median, lateral cranial base and saddle angles showed correlation with the inclination of the Frankfort plane from the anterior and posterior cranial base. The observed impact of the cranial base widths on the nasomaxillary complex widths were for anterior cranial base width there was a significant effect on bizygomatic, bimaxillary and intermolar width
Aims: This study aimed to detect if there are a correlation between the maxillary sinus measurements ( height and depth) with the cranial and facial structures that probably could estimate a functional matrix rule of the maxillary sinus in the growth of these structure add to estimate the percent of increase from age group to another. Materials and Methods: A digital lateral cephalometric radiographs of 113 males with class I malocclusion from Mosul city were divided into three age groups: 14 patients Preadolescent (6-9 years), 70 patients adolescent (11-15 years) and 29 patients adult (17-42 years) with measurements taken involving the maxillary sinus height and depth, maxillary length, mandibular lengths, anterior facial height(upper and lower parts), posterior facial height (upper and lower part), cranial base dimensions then a correlation have been down between the maxillary sinus height and depth with the related dimensions of the craniofacial complex. Results: The correlation between the MSH and the related craniofacial dimensions in the three age groups showed a significantly positive correlations in nearly all of the measurement specially at adolescences and adults with just two significant positive correlations for MRL and TPFH in preadolescence, on the other hand correlating the MSH with the related measurement in general in single group showed a positive significant correlation for all measurement. While correlating the MSD with the related craniofacial dimensions showed a significantly positive correlation with MBL, TML and Nba in adult. For MBL and TML in preadolescence, but no significant correlation showed in adolescence, with a significant correlation for MSD with nearly all the related craniofacial dimensions in all age group in general. In all measurement the percentage of increase from preadolescence to adolescence more than that from adolescence to adult. Conclusions: we could concluded that in the three age groups the growth of the maxillary sinus probably may influence the related craniofacial structures as a functional matrix role in the growth mechanism.
Aims: To compare the mean shear bonding force and mode of bond failure of metallic brackets bonded and rebounded (using new and pre-used brackets) to sandblasted and acid-etched enamel is described. Materials and methods: The buccal surfaces of 40 extracted human premolars were sandblasted for 5 seconds with 50 µ alumina at 4mm distance and the buccal surfaces of a further 40 human premolars were acid etched with 37% phosphoric acid for 20 seconds. Following storage for 24 hours at 37°C in distilled water, then each group was divided into four subgroups of ten teeth, shear bonding force and the bond failure were measured for bonded and rebounded new and pre-used brackets using a Universal Testing Machine with a cross-head speed of 10 mm/minute. Results: The mean shear debonding force was significantly lower for brackets bonded to sandblasted enamel compared to acid etched enamel (P < 0.000), the same thing for the rebounded brackets, with the lowest shear bonding forces for brackets bonded to sandblasted enamel in the first and second step while the shear bond strength was higher for brackets bonded to acid etched enamel what ever the first treatment of enamel weither conventional acid etching or microetching. Statistical analysis showed that at a given stress the probability of failure was significantly greater for brackets bonded to sandblasted enamel. This is in the first step, the same thing in the second step was greater probability of bond failure for enamel treated in the first and second step with Microetcing and still greater in teeth treated with Microetching opposite to that is for teeth treated in second step with acid etching and the significantly lower probability of bond failure for brackets bonded to acid etched enamel in first and second step. Brackets bonded to acid etched enamel showed a mixed mode of bond failure (adhesive and cohesive failure) , whereas following sandblasting, failure was adhesive at the enamel/composite interface (p < 0.000). Conclusions: Whatever the first step of treatment, higher shear bond in the second step could be obtained using acid etching with new and old brackets, but in cases treated with acid etching in first step and microetching in second step a suitable shear bond strength could be obtained insist with new brackets.
Aims: In an effort to improve the shear bond strength of resin modified glass ionomer cement on orthodontic brackets, various enamel conditioning have been evaluated for use with this cement. Materials and methods: A total of 100 freshly extracted human premolars were subjected to two steps of treatment. The first step of treatment involve dividing the teeth into 5 groups each of 20 teeth: (I) treated with 20 second acid etching with 37% phosphoric acid; (II), treated with micro-etching using 50 µ aluminum oxide; (III), treated with air polisher using 45 µ sodium bicarbonate; (IV), treated with coarse finishing disk for 10 second; (V), left the enamel clean without treatment. In the second step each group then subdivided into two subgroups, ten teeth subjected to wetting with tab water and ten left dry. Following, storage for 24 hours at 37°C in distilled water, shear debonding force was measured using a Universal Testing Machine with a cross-head speed of 10 mm/minute. Results: The result indicated that the highest shear bond strength was for acid etched enamel under wet condition with lowest mean for normal dry enamel. the Mann-Whitney analysis estimated a significant difference between wet and dry condition in general with high probability of bond failure for the dry than that of wet conditions. Conclusions: The suitable enamel conditions regarding the shear bond with the mode of bond failure had been shown to be the wet and dry situation of group III and wet situation of group IV. But, it could be concluded that the most suitable enamel condition may be that treated with a coarse finishing disk under wet condition.
Aims:To evaluate the amount of rotation, tipping and extrusion using different wires and to Estimate the difference in the amount of tipping, rotation and extrusion between Stainless steel and Teflon ligature in different wires. Materials and Methods: The standardizing criteria were all Typodont teeth situated in well-aligned, covered and immobilized by the acrylic bite except canine; The available space for canine sliding was (14 mm) measured by digital vernia. Elastic chain exerting 180 gm of force on canine measured carefully by tension gauge. In both vertical and horizontal direction a photographs that were taken for Typodont using digital camera. The angle between bite plane extension bar and Canine extension bar were (90 o ) measured by protractor directly on the photograph. Preformed band with its attachments, ready made stainless steel, composite coated and TMA arch wires all were (0.018×0.025) with the use of stainless steel and Teflon ligature, Standard titanium spring 11 mm length, Typodont components, within six types of connection the two types of ligation material had been applied to the three different wires then the 1 st premolar space tend to be closed by distal canine displacement then the resultant rotation, tipping and extrusion were measured. Statistical Descriptive analysis: One-way and, Two-ways Analysis of Variance were done to detect the variability between methods and which is the best. Results: Three important results showed in the study: First, canine sliding over the composite coated arch wire with the use of stainless steel ligature gave rise to significant decrease in rotation, tipping and extrusion when compared with other methods. Second, stainless steel ligature when compared with Teflon ligature of the same corresponding method gave rise to a significant decrease in the degree of rotation tipping and extrusion. Third, Composite coated arch wires showed lowest degree of rotation then followed by TMA arch wires ordinarily this is due to their rough surface. The largest rotation seen in the stainless steel arch wire this is due to its smooth surface texture, and the same thing for the tipping of the composite coated wires that gave rise to the lowest degree of tipping followed by the stainless steel wires, these result possibly due to their stiffness then higher tipping seen at TMA wires ordinarily a result of their flexibility this sequence were the same for both types of ligations. Conclusions: Best method of space closure is the use of either composite coated arch wire or stainless steel arch wire with stainless steel ligature that give us highest resistance to tipping, lowest extrusion and relatively little rotation when compared with other methods.
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