The authors investigated the accuracy and reliability of three-dimensional and reformatted computed tomographic images by comparing direct measurements on the dry mandible and the measurements on three-dimensional and reformatted computed tomographic images of the dry mandible. 29 Korean dry mandibles were imaged and 16 items of measurements were measured. The results were as follows; 1. The correlation coefficients between the two methods were between 0.95 and 0.99, except for the measurement of Go-Pg. 2. The mean differences of the measurements between the two methods ranged from -0.52 to 0.42 mm and the range of standard deviations for these mean differences was 0.28 to 2.70 mm. 3. Of the difference scores in total measurements, 75.9% were within 1 mm and 95.9% were within 2mm. In conclusion, the agreement between the two methods was excellent and the measurements of the threedimensional and reformatted computed tomographic images were reliable. The three-dimensional and reformatted computed tomographic images can be an useful method in anthropologic study.
Mandible*

No abstract available.
Mandible*

PURPOSE: To evaluate the precision of measurements of distances and angle in the cross-sectional views of linear tomogram of panorama and to assess the technique for visualizing the mandibular canal. METHODS: Ten dry mandibles were radiographically examined with 3 continuous cross-sectional views of linear tomogram of panorama and 4 continuous computed tomograms. The distance between the superior border of canal and alveolar crest and the bucco-lingual width of alveolar bone at the level of the superior border of canal and the angle between the two lines above were measured. Measurements were performed by radiologist and implantologist group and compared with measurements on computed radiograms of the same areas. RESULTS: The measurements differences for the distance of alveolar bone height between in panorama and in CT showed 0.9mm+/-0.6mm by radiologists and 1.3mm+/-0.8mm by implantologists. There was no statistically significant difference between two groups' measurements. The differences in measurements for the distance of alveolar bone width between in panorama and in CT showed 0.5mm+/-0.8mm by radiologists and 2.5mm+/-1.4 mm by implantologists. There was significant difference (p<0.05) between two groups' measurements. The average bucco-lingual inclination of alveolar bone above mandibular canal was average 95.8degrees in CT. The difference of measurements between two groups was average 1+/-0.9degrees. Three cross-sectional views of panorama could show that the mandibular canal crosses antero-lingually and slopes inferiorly from the posterior segment of the mandible. Conclusions : The measurements in the linear tomogram of panorama by radiologists gave the accurate values of the distances and the angle compared with the values in computed tomograms.
Mandible*

PURPOSE: To evaluate the precision of measurements of distances and angle in the cross-sectional views of linear tomogram of panorama and to assess the technique for visualizing the mandibular canal. METHODS: Ten dry mandibles were radiographically examined with 3 continuous cross-sectional views of linear tomogram of panorama and 4 continuous computed tomograms. The distance between the superior border of canal and alveolar crest and the bucco-lingual width of alveolar bone at the level of the superior border of canal and the angle between the two lines above were measured. Measurements were performed by radiologist and implantologist group and compared with measurements on computed radiograms of the same areas. RESULTS: The measurements differences for the distance of alveolar bone height between in panorama and in CT showed 0.9mm+/-0.6mm by radiologists and 1.3mm+/-0.8mm by implantologists. There was no statistically significant difference between two groups' measurements. The differences in measurements for the distance of alveolar bone width between in panorama and in CT showed 0.5mm+/-0.8mm by radiologists and 2.5mm+/-1.4 mm by implantologists. There was significant difference (p<0.05) between two groups' measurements. The average bucco-lingual inclination of alveolar bone above mandibular canal was average 95.8degrees in CT. The difference of measurements between two groups was average 1+/-0.9degrees. Three cross-sectional views of panorama could show that the mandibular canal crosses antero-lingually and slopes inferiorly from the posterior segment of the mandible. Conclusions : The measurements in the linear tomogram of panorama by radiologists gave the accurate values of the distances and the angle compared with the values in computed tomograms.
Mandible*

No abstract available.
Mandible*

No abstract available.
Mandible*

No abstract available.
Mandible*

STATEMENT OF PROBLEM: Resonance frequency analysis (RFA) has been increasingly served as a non-invasive and objective method for clinical monitoring of implant stability. Many clinical studies must be required for standardized baseline data using RFA. PURPOSE: This study was performed to evaluate RFA value changes in two stage surgery group and one stage surgery group in patients. MATERIAL AND METHOD: Forty-seven mandibles in consecutively implant installed patients were selected for this study and 141 fixtures were installed. Ninety-three fixtures were double threaded, machined surface design (Bra.nemark. MK III, Nobel Biocare AB, Go teborg, Sweden) and 48 fixtures were root form, threaded, HA-coated surface one (Replace(TM), Steri-Oss/Nobel Biocare AB, USA). Among those, each 10 fixture was installed in one stage group patients. ISQ values were measured using Osstell(TM) (Integration Diagnostics Ltd. Sweden) during fixture installation, at healing abutment connection and in the loading period for two stage surgery group patients and during at each 4, 6, 8, 10, 12 week and in the loading phase for one stage surgery group patients and evaluated the changes according to the time and fixture type. RESULTS: In two stage surgery group, mean and SD of ISQ values of machined surface implants were 76.85 +/- 3.74, 75.76 +/- 5.04, 75.73 +/- 4.41 and those of HA-coated surface implant were 75.05 +/- 6.23, 77.58 +/- 5.23, 78.32 +/- 4.29 during fixtures installation, at healing abutment connection and in the loading period, respectively. In one-stage surgery group, the ISQ values of machined surface and HA-coated surface implants decreased until 4 or 6 week and maintained at plateau for 1-3 week and increased to the loading period. CONCLUSIONS: Machined and HA-coated surface implants showed minimal ISQ changes with time if they were installed at the sites showing at least intact cortical plate and good bone qualities. And HA-coated implants had a tendency to show somewhat increased ISQ values with time.
Humans ; Mandible

No abstract available.
Mandible* ; Spine*

No abstract available.
Mandible* ; Osteoblastoma*