ABSTRACT
This study was aimed to investigate the use of panoramic radiography in patients with low bone mineral density [BMD] in order to diagnose and prevent osteoporotic fractures. Panoramic radiographs of 60 patients [20 men and 40 women] aged from 40 to 70 years with cortical thicknesses of less than 3 mm in the mandibular angle were selected from patients referred to a dentomaxillofacial radiology clinic and were then examined for mandibular cortical angles. These were measured using Computed Radiography [CR] software. The bone densitometry was carried out using Dual Energy X-ray Absorptiometry [DEXA]. Cortical thicknesses at the lower border of the mandibles were also measured by panoramic radiographs. Statistics analyses were then undertaken using Fisher's exact test, Chi-square, t-test, ANOVA and receiver operating characteristic [ROC] curve. In most cases, no significant difference in mandibular angle cortical thickness was found between those patients with a normal BMD and those patients with a lowered BMD [P=0.621]. There was a relationship between the cortical thicknesses of the mandibular lower border, and vertebral and femoral BMD [P<0.0001], and there was a significant difference between the thickness of the mandibular lower border and BMD. The results of this study also revealed a new marker of osteoporosis on the mandibular lower border under the third molar. A thickness of 2.80 mm of the mandibular lower border was detected as a threshold for the measurement of bone densitometry in the chosen Iranian population. Panoramic radiography is effective for screening patients who are at risk of having decreased bone mineral density. Patients with a threshold of 2.80 mm thickness of the mandibular lower border should be considered as individuals likely to have osteoporosis associated low bone density
ABSTRACT
Elongation and calcification of the stylohyoid apparatus is probably related to Eagle's syndrome and may cause such symptoms as facial pain and dysphagia in patients. In the present study, the relationship between serum calcium level and stylohyoid apparatus length was studied in adults referring to the dental college of Yazd. This was a cross-sectional descriptive study on 50 adult patients above 20 years old [28 men, and 22 women] referring to the radiology ward of the dental college. The stylohyoid ligaments were measured from the base of the skull to the bony tip of each appendix by panoramic radiograph. Mineralization of the ligaments more than 30 mm on the panoramic radiographs was considered abnormal. The serum calcium level of all patients was then measured. Data were analyzed by t-test and Pearson's correlation analysis. Mean length of the stylohyoid apparatus was 27.36 +/- 9.10 mm and was not related to age and sex. An elongation rate of 26% was obtained. The mean serum calcium level was 9.39 +/- 0.57 mg/dl and there was not a statistically significant difference in serum calcium level between various age groups and genders. There was no relationship between the length of the stylohyoid apparatus of each side and serum calcium concentrations in different age groups. It appears that the length of the stylohyoid apparatus is not related to serum calcium level within our patient population
Subject(s)
Humans , Male , Female , Hyoid Bone , Adult , Cross-Sectional Studies , Ligaments , Radiography, PanoramicABSTRACT
The aim of the present study was to determine the effect of different restorative materials on fracture resistance of mandibular teeth with class V restorations. One hundred intact mandibular incisors were selected and divided into ten groups with 10 samples in each. Three types of restorative materials; Tetric flow composite [Vivadent Ets, Schaan/Liechtenstein], Compoglass [Vivadent Ets,Schaan/Liechtenstein] and light curing glass ionomer [GC Corporation Tokyo JAPAN] were used in our study. Each of these materials were applied in cavities with 2, 3 and 4 mm widths. Group 10 was considered as the control group in which no restorations was done. All teeth were mounted in cold cure acrylic resin [Tray Resin II, Shofu Inc, Kyoto, Japan] and the samples were tested by applying shear force with cross head speed of 5mm/min in a universal testing machine [Instron corp., Canton, MA,USA]. Data were analyzed with two way ANOVA and Dunnet multiple comparisons test using SPSS 10 software package. Regardless of the types of materials, cavities with 4mm width had less bond strength than those with 2 and 3 mm widths [P-value=0.555]. In the Compoglass and glass ionomer L.C. groups, cavities with 2 and 3mm widths had significant greater strength than cavities with 4mm width [P-value=0.0002]. In groups with Tetric flow restorative material no significant difference in shear force among different widths of cavities were detected [P-value=0.4948]. The mean shear force in this group was comparable with the control group [P-value=0.0001]. In cavities 2 and 3 mm widths, there was not any significant difference in shear force between Tetric flow and compoglass restorative materials. Glass ionomer and Tetric flow had the least and the highest shear bond strength ,respectively. The results showed that although all the restorations need an average load more than masticatory forces in the mouth to fail, but Tetric flow composite with combination of chemical adhesion properties and optimum elastic characteristics was proven to be the restorative material of choice for cervical Defects with different widths