JOURNAL OF DENTISTRY (SHIRAZ UNIVERSITY OF MEDICAL SCIENCES)
Year:2002 | Volume:3 | Issue:1-2 (4)|Papers Count:9

The purpose of this study was to evaluate and compare the craniofacial morphology of thalassemic patients with normal class I skeletal individuals. Cephalometric analysis, based on Mc. Namara's method, of 102 thalassemic patients between 9-17 years old (mean age, 13) and 78 control cases with the same age range (Mean, 13.5) were carried out. Results showed that thalassemia major has significant effects on components of the craniofacial complex including: Existence of a moderate class II skeletal discrepancy due to mandibular protrusion, pronounced vertical mandibular growth tendency, decreased anterior-posterior dimension of face, increased tooth show, decreased nasolabial angle and prominent mandibular incisors.

Successful root canal treatment depends upon the accurate determination of canal length to achieve adequate biomechanical preparation of canal .The generally accepted method for working length determination, is radiographic method .Use of electronic devices for working length determination has recently gained considerable popularity among both general dentists and endodontists The aim of this study was to compare the accuracy of two apex locators (made in Iran) which were from first generation. A set of 28 single root teeth with one canal was gathered for study. At first, the actual root canal length was determined with placing a file into the canal so that the file tip was seen at the apical foramen. Then, the teeth were placed in the experimental model containing buffered phosphate saline with 1% agar to the cervical area and fixed in that position. The root canal length of these teeth was determined using the DMG and Foramatron V Apex locators in dry and wet conditions and the data were registered. The results of this study showed that Foramatron V accuracy in length determination in dry condition was 75% (21samples) and 71.4% (20 samples) in wet condition. DMG accuracy in dry condition was 64.2% (18 samples) and 53.6% (15 samples) in wet condition. There were no significant statistical differences between actual length mean and length mean evaluated by DMG and Foramatron V apex locators in dry and wet conditions. We concluded that electronic apex locators could be a useful adjacent for determining the working length of root canal.

Associate Professor of Radiology Department, School of Dentistry Shiraz Medical University of Sciences Lateral oblique and true lateral view of mandible is usually used for sialography of major salivary glands. Panoramic view has been recently introduced as a replacement procedure. Among these techniques, true lateral view of mandible with 900 horizontal and vertical angles of projection has the least distortion in images of salivary glands and duct patterns. But this technique because of super imposition of shadow of mandible of the opposite side has lower diagnostic capability compared with the other two techniques. In the present study, probability of removing overlapping shadows and improving of diagnostic power of true lateral views with in vitro digital subtraction procedure has been evaluated. In this research a dry skull and 12 angio-catheter tube sets with 29 artificial filling defects measuring about 2 to 5 mm prepared in them was used. A total of seven radiologists and residents of medical and maxillo facial radiology evaluated digitized para-sialographic images before and after digital subtraction procedure. The results were analyzed with “Chi-square” and “Distribution-sensitivity frequency” tests. Data from analysis showed apparent improved diagnostic capability in true lateral view of mandible by using digital subtraction technique (P<0.05) while there was no statistically significant difference in lateral-oblique view of mandible (P>0.05). In conclusion, the present study showed if we replace lateral oblique view by true lateral of mandible to decrease distortion of sialography images, it is possible to improve image accuracy by digital subtraction technique.

Failure to find and to fill a canal has been demonstrated to be a causative factor in the breakdown of an endodontic treatment. It is almost importance that all canals to be located and treated during the course of root canal therapy. Knowledge of normal pulp anatomy and their variation are critical. A retrospective study was conducted to evaluate frequency, anatomy and morphology of endodontically treated teeth at Endodontic Department of Shiraz Dental School (1999). For this study, the radiographic films of endodontically treated teeth were used. The samples would have been selected, if radiographic films, including initial diagnostics, working length determination, tug back evaluation and final obturation were, and also, for the teeth with additional canals, a radiographic film with different horizontal angle (Shift techniques) was taken. With these criteria, 408 teeth were selected. Percentage of treated teeth, number of roots, types and number of root canals for each tooth were studied. The result was revealed, that 48 percent of treated teeth were in the mandibular arch and 52 percent were in the maxillary arch. The most frequent treated teeth were mandibular first molars (21 percent) and the least frequent treated teeth were mandibular canines (2.9 percent). Our findings have simillarity to those from reported of previously studies. (In Vitro and in Vivo) The difference between studies is the result of ratial differences, methods of study (Invivo or Invitro) and methods of evaluation (Radiography-sectioning-resin casting-dye injection/clearing & scanning electron microscopy).

According to the health program of WHO, oral health is one of the factors that has to be consider for health index of different societies. Dental schools, general dentists and specialized dentists, play an important role in this regard. Also awareness of the people from postdoctoral program of dental School and knowing the duties of each specialized dentist will increase the efficacy of dental treatments. In this study we try to evaluate the awareness of students of different schools except dental school of Universities, in the city of Shiraz toward this subject. The result that is the degree of awareness is not enough and more effort is needed to introduce different dental specialties.

The present clinical trial was designed to evaluate the regeneration potential of the periodontal tissues in degree II mandibular molar furcation defects, using rubber dam as the barrier membrane to achieve guided tissue regeneration. 22 pairs of degree II mandibular furcation involvements at buccal or lingual side from 10 healthy adult periodontitis patients having the age range at 27-58 years were studied. Each patient had symmetrical degree II furcation invasion located of right & left side of mandibular jaw. Two months after completion of phase I, base line clinical measurements were taken and the two symmetrical class II furcation lesions in each subject were randomly assigned either to test or to control treatment procedure. The same sequence of surgical procedures was used for test & control side except placement of rubber dam at the test area. After completion of surgery, interdentally suturing and post operative care were given. Doxycyclin 100 mg two times daily for two weeks & chlorhexidin 0.2% for 6 weeks were prescribed. Sutures were removed after two weeks & rubber dam were removed after 6 weeks. Six months post surgery, clinical measurements were retaken and surgical reentry performed and hard tissue measurements repeated. Comparing the results of the test and control sites with the exception of recessions which were more pronounced at the test sites, all other parameters showed more improvements on the test sites indicating the potential of rubber dam as a barrier membrane to cause guided tissue regeneration and promote healing of furcation lesions.

Tooth movement can be considered as one of the most important fields of research in orthodontics. A basic question in tooth movement has been evaluated. Does "CRes" move the same distance in different types of tooth movement while the force is kept constant? According to biomechnics, the applied force is the main determinant of ''CRes" translation. FEM was employed to evaluate the problem. A 3D model was designed and built in ANSYS Ver 5.40. The same amount of root displacement at the level of "CRes" along the force vector was shown while the force was kept constant. There were different M/F ratios with a constant force. In this way, the efficiency of FEM was proved again and a simple mechanical law was also shown clearly.

The present research was carried out on 506 school children, which were selected according to clustering random sampling. Duncan test, Chi-Square test and Analysis of Variance were applied. The results included: 1.The percentage of fluorosis was 85% and the flourosis prevalence was more in male than female, however, the differences were not statistically significant. 2. There was statistically significant relation between flourosis and DMFT score. 3. Using Dean’s criteria, a large number of cases (p=0.001) had dental fluorosis (grades 1 to 2). 4. The highest degree of dental caries was found in the grade 4 of fluorosis. In the meantime, the lowest degree of decayed teeth had been observed among less fluorosed teeth (grade 2). 5. No statistically significant relation was found between fluorosis and sex. 6. The mean DMFT score was 1.8 and the mean of DMFT components were: D=1.62, M=0.04 and F=0.13.