Quantitative evaluation of cortical bone thickness with computed tomographic scanning for orthodontic implants

2006 ◽  
Vol 129 (6) ◽  
pp. 721.e7-721.e12 ◽  
Author(s):  
Toru Deguchi ◽  
Miho Nasu ◽  
Kaoru Murakami ◽  
Toshinori Yabuuchi ◽  
Hiroshi Kamioka ◽  
...  
Keyword(s):  
Cortical Bone ◽  
Quantitative Evaluation ◽  
Bone Thickness ◽  
Cortical Bone Thickness ◽  
Computed Tomographic ◽  
Orthodontic Implants

scholarly journals Inferior Level of Maxillary Sinus and Cortical Bone Thickness at Maxillary Posterior Quadrant, in Three Different Growth Patterns: 3D-Computed Tomographic Study

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Pavankumar Janardan Vibhute ◽  
Pushkar A. Patil
Keyword(s):  
Maxillary Sinus ◽  
Cortical Bone ◽  
Growth Pattern ◽  
Growth Patterns ◽  
Bone Thickness ◽  
Cortical Bone Thickness ◽  
Computed Tomographic ◽  
Posterior Quadrant ◽  
Maxillary Sinus Floor ◽  
Sinus Floor

Objective of this retrospective study was to measure cortical bone thickness and lowest level of maxillary sinus at maxillary posterior quadrant in different growth pattern (hypodivergent, average, and hyperdivergent) at prospective microimplant placement sites in order to understand both safety and stability aspects of microimplant placement by using cone-beam 3-dimensional computed tomographic images. In posterior quadrant, vertical distance from cementoenamel junction to lowest level of maxillary sinus at interradicular region was measured. Buccal cortical bone thickness was measured at 3 different vertical levels at interradicular space. The cortical bone thickness was found more at sinus floor level and above it than below the sinus floor. In perspective of miniscrew placement, study shows that maxillary sinus floor is safer with average and hyperdivergent growth pattern than hypodivergent growth pattern. In the proximity of maxillary sinus floor, 1 mm or more cortical bone can be expected in maxillary posterior region in average and hyperdivergent growth patterns. However, it was thicker in hypodivergent than hyperdivergent growth patterns. Hypodivergent patients require either more horizontal insertion (more parallel to occlusal plane) or shorter length of miniscrew to avoid damage to maxillary sinus.

scholarly journals POS1092 SUBCHONDRAL BONE NORMALIZATION AFTER KNEE JOINT DISTRACTION TREATMENT AS MEASURED WITH CT

2021 ◽  
Vol 80 (Suppl 1) ◽  
pp. 825.2-826
Author(s):  
M. Jansen ◽  
A. Ooms ◽  
T. D. Turmezei ◽  
J. W. Mackay ◽  
S. Mastbergen ◽  
...  
Keyword(s):  
Bone Density ◽  
Trabecular Bone ◽  
Cortical Bone ◽  
Subchondral Bone ◽  
Trabecular Bone Density ◽  
Bone Thickness ◽  
Cortical Bone Thickness ◽  
Bone Changes ◽  
One Year ◽  
Shape Changes

Background:In addition to cartilage degeneration, knee osteoarthritis (OA) causes bone changes, including cortical bone thickening, subchondral bone density decrease, and bone shape changes as a result of widening and flattening condyles and osteophyte formation. Knee joint distraction (KJD) is a joint-preserving treatment for younger (<65 years) knee OA patients that has been shown to reverse OA cartilage degradation. On radiographs, KJD showed a decrease in subchondral bone density and an increase in osteophyte formation. However, these bone changes have never been evaluated with a 3D imaging technique.Objectives:To evaluate cortical bone thickness, subchondral trabecular bone density, and bone shape on CT scans before and one year after KJD treatment.Methods:19 KJD patients were included in an extended imaging protocol, undergoing a CT scan before and one year after treatment. Stradview v6.0 was used for semi-automatic tibia and femur segmentation from axial thin-slice (0.45mm) CT scans. Cortical bone thickness (mm) and trabecular bone density (Hounsfield units, HU) were measured with an automated algorithm. Osteophytes were excluded. Afterwards, wxRegSurf v18 was used for surface registration. Registration data was used for bone shape measurements. MATLAB R2020a and the SurfStat MATLAB package were used for data analysis and visualization. Two-tailed F-tests were used to calculate changes over time. Two separate linear regression models were used to show the influence of baseline Kellgren-Lawrence grade and sex on the changes over time. Statistical significance was calculated with statistical parametric mapping; a p-value <0.05 was considered statistically significant. Bone shape changes were explored visually using vertex by vertex displacements between baseline and follow-up. Patients were separated into two groups based on whether their most affected compartment (MAC) was medial or lateral. Only patients with axial CT scans at both time points available for analysis were included for evaluation.Results:3 Patients did not have complete CTs and in 1 patient the imaged femur was too short, leaving 16 patients for tibial analyses and 15 patients for femoral analyses. The MAC was predominantly the medial side (medial MAC n=14; lateral n=2). Before treatment, the MAC cortical bone was compared to the rest of the joint (Figure 1). One year after treatment, MAC cortical thickness decreased, although this decrease of up to approximately 0.25 mm was not statistically significant. The trabecular bone density was also higher before treatment in the MAC, and a decrease was seen throughout the entire joint, although statistically significant only for small areas on mostly the MAC where this decrease was up to approximately 80 HU (Figure 1). Female patients and patients with a higher Kellgren-Lawrence grade showed a somewhat larger decrease in cortical bone thickness. Trabecular density decreased less for patients with a higher Kellgren-Lawrence grade, and female patients showed a higher density decrease interiorly while male patients showed a higher decrease exteriorly. None of this was statistically significant. The central areas of both compartments showed an outward shape change, while the outer ring showed inward changes.Conclusion:MAC cortical bone thickness shows a partial decrease after KJD. Trabecular bone density decreased on both sides of the joint, likely as a direct result of the bicompartmental unloading. For both subchondral bone parameters, MAC values became more similar to the LAC, indicating (partial) subchondral bone normalization in the most affected parts of the joint. The bone shape changes may indicate a reversal of typical OA changes, although the inward difference that was seen on the outer edges may be a result of osteophyte-related changes that might have affected the bone segmentation. In conclusion, KJD treatment shows subchondral bone normalization in the first year after treatment, and longer follow-up might show whether these changes are a temporary result of joint unloading or indicate more prolonged bone changes.Disclosure of Interests:None declared.

scholarly journals Effect of Cortical Bone Thickness on Detection of Intraosseous Lesions by Ultrasonography

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Sadaf Adibi ◽  
Alireza Shakibafard ◽  
Zohreh Karimi Sarvestani ◽  
Najmeh Saadat ◽  
Leila Khojastepour
Keyword(s):  
Cortical Bone ◽  
Imaging Technique ◽  
In Vitro Study ◽  
Bone Thickness ◽  
Cortical Bone Thickness ◽  
Bony Lesion ◽  
Ultrasonic Assessment ◽  
Central Lesions ◽  
Made In

Background. Usefulness of ultrasound (US) in detection of intrabony lesions has been showed. A cortical bone perforation or a very thin and intact cortical bone is prerequisite for this purpose.Objective. The current in vitro study was aimed at measuring the cut-off thickness of the overlying cortical bone which allows ultrasonic assessment of bony defects.Materials and Methods. 20 bovine scapula blocks were obtained. Samples were numbered from 1 to 20. In each sample, 5 artificial lesions were made. The lesions were made in order to increase the overlying bone thickness, from 0.1 mm in the first sample to 2 mm in the last one (with 0.1 mm interval). After that, the samples underwent ultrasound examinations by two practicing radiologists.Results. All five lesions in samples numbered 1 to 11 were detected as hypoechoic area. Cortical bone thickness more than 1.1 mm resulted in a failure in the detection of central lesions.Conclusion. We can conclude that neither bony perforation nor very thin cortical bones are needed to consider US to be an effective imaging technique in the evaluation of bony lesion.

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