Study of occlusion in a group of Egyptian children suffering from thalassemia

This work was carried out to study the occlusion in a group of Egyptian thalassemic children. The sample consisted of seventy Egyptian male children ranging in age from nine to forteen years. The sample was divided into two groups. The first group consisted of forty children suffering from thalassemia major, while the other group consisted of thirty normal children. For every subject of the study full study models analysis were done. It was found that all maxillary cast measurements as well as overjet and overbite measurements of thalassemic patients were significantly higher than those of normal children. Where as there was no significant difference in the palatal vault depth as well as in all the mandibular cast measurements between the two groups

Dento-skeletal pattern in a group of thalassemic Egyptian children

This work was done in order to study the dentoskeletal pattern of a group of Egyptian children suffering from thalassemia. The sample studied consisted of seventy Egyptian children ranging in age between nine and forteen years. The sample was divided into two groups; the first group consisted of forty children suffering from thalassemia major and the other group consisted of thirty normal children. For every subject in the study lateral cephalometric analysis was done. It was found that in thalassemic patients there was significant lengthening of the anterior cranial base, downward and backward rotation of the mandible with increase in the lower face height, while there was no significant abnormality in the antero-posterior position of the maxillary. Upper incisors were retroclined in thalassemic patients, whereas there were no significant difference in the remaining dental cephalometric measurements recorded when compared to normal children

Tensile bone strength of orthodontic brackets at a different occluso-gingival levels

The relation between tensile bond strength of orthodontic brackets and the occluso-gingival bracket position was studied in vitro. A total sample of 60 sound freshly extracted human premolars were used. The sample was divided equally into three groups according to the occluso-gingival level of bracket position; gingival, middle and occlusal groups. Edge wise metallic brackets with mesh were bonded with no-mix adhesive. These specimens were stored in distilled water at 37 degree C for 24 hours, then were subjected to tensile loads to produce bond failure of the brackets using universal tensting machine. It was found that the tensile bond strength was significantly smaller at the middle level when compared with the occlusal and gingival groups. Whereas there was no significant statistical difference between the tensile bond strength of bracket bonded at the latter two levels

Ceramic and metal brackets: their bacterial adherence

The aim of the present study was to clarify and compare the degree ofbacterial adherence in association with the surface of ceramic and metalorthodontic brackets. Equal disks of ceramic, stainless steel as well ashydroxyapatite were used in this study, adhesive properties of Streptococcusmutans to the above mentioned materials were tested experimentally. It wasfound that the bacterial adhesion on ceramic material was significantly higherthan both the stainless steel and hydroxyapatite. While, there was nostatistical significant differences between the two later materials

Mesiodistal crown dimension of the permanent dentition in a sample of Yemeni adolescence

The study was carried out to establish normative data of the mesiodistal crowndimension in a sample of Yemeni adolescence. The sample consisted of 70subjects [38 males and 32 females] with accepted normal occlusion. Their ageranged from 12-14 years. The mesiodistal diameter was measured for themaxillary and mandibular twelve anterior permanent teeth. There was no sexualdimorphism in the means of tooth sizes between males and females. Themesiodistal coronal diameter of the maxillary lateral incisor and secondpremolar as well as the mandibular first premolar were significantly smallerthan that of the corresponding Egyptian measurements

Mandibular lip bumper and first permanent molar position

This study was carried out to clarify the possible changes in the mandibular first molar position after six months wearing of mandibular lip bumper. A sample consisted of twenty Egyptian children suffering from class 11 division 1 malocclusion was selected their age ranged from 8 - 10 years representing the mixed dentition stage of development. The sample was divided into two equal groups. One of them received mandibular for six months and the other considered as a control group. It was found that the mandibular first molars in the lip bumper group moved in three plane of space, inward and upward with significant backward tipping as well as mesiolingual rotation. However, no significant changes in the molar position were recorded in the control group