scholarly journals The effect of corticision on root resorption with heavy and light forces

2015 ◽  
Vol 86 (1) ◽  
pp. 17-23 ◽  
Author(s):  
Christopher Murphy ◽  
Zana Kalajzic ◽  
Taranpreet Chandhoke ◽  
Achint Utreja ◽  
Ravindra Nanda ◽  
...  

ABSTRACT Objective:  To investigate the association between corticision and different force magnitudes with the amount of root resorption. Methods:  Forty-four male Wistar rats (7 week old) were evaluated after an orthodontic spring delivering either 10 or 100 g was placed on the left maxillary first molars to move molars mesially. Experimental rats were divided into four groups, with 11 animals in each group: (1) LF, no corticision and 10 g of orthodontic force; (2) LFC, corticision and 10 g of force; (3) HF, no corticision and 100 g of force; and (4) HFC, corticision and 100 g of force. Contralateral sides were used as unloaded controls. The total duration of the experimental period was 14 days. Two-dimensional (histomorphometric) and three-dimensional (volumetric, micro-focus X-ray computed tomography [microCT]) analysis of root craters were performed on maxillary first molars. Results:  Histomorphometric and microCT analysis revealed a significant amount of resorptive areas in the experimental groups when compared to unloaded controls. However, no significant difference was detected in the amount of resorption among the four experimental groups. Conclusions:  At day 14, neither the amount of force nor the cortical incision caused significant effect on root resorption that was registered by histomorphometric or microCT analysis.

2021 ◽  
Author(s):  
Katherine A. Wolcott ◽  
Guillaume Chomicki ◽  
Yannick M. Staedler ◽  
Krystyna Wasylikowa ◽  
Mark Nesbitt ◽  
...  

Author(s):  
Theodore J. Heindel ◽  
Terrence C. Jensen ◽  
Joseph N. Gray

There are several methods available to visualize fluid flows when one has optical access. However, when optical access is limited to near the boundaries or not available at all, alternative visualization methods are required. This paper will describe flow visualization using an X-ray system that is capable of digital X-ray radiography, digital X-ray stereography, and digital X-ray computed tomography (CT). The unique X-ray flow visualization facility will be briefly described, and then flow visualization of various systems will be shown. Radiographs provide a two-dimensional density map of a three dimensional process or object. Radiographic images of various multiphase flows will be presented. When two X-ray sources and detectors simultaneously acquire images of the same process or object from different orientations, stereographic imaging can be completed; this type of imaging will be demonstrated by trickling water through packed columns and by absorbing water in a porous medium. Finally, local time-averaged phase distributions can be determined from X-ray computed tomography (CT) imaging, and this will be shown by comparing CT images from two different gas-liquid sparged columns.


2003 ◽  
Vol 8 (1) ◽  
pp. 2-6 ◽  
Author(s):  
Wolfgang H Stuppy ◽  
Jessica A Maisano ◽  
Matthew W Colbert ◽  
Paula J Rudall ◽  
Timothy B Rowe

2018 ◽  
Vol 139 ◽  
pp. 75-82 ◽  
Author(s):  
A.H. Galmed ◽  
A. du Plessis ◽  
S.G. le Roux ◽  
E. Hartnick ◽  
H. Von Bergmann ◽  
...  

Author(s):  
P Potamianos ◽  
A A Amis ◽  
A J Forester ◽  
M McGurk ◽  
M Bircher

The revision of an orthopaedic procedure can present surgeons with the challenge of a complex reconstructive process. Orthopaedic surgery can also face considerable challenges in cases presenting extensive primary injuries with multiple bone fragmentation, as well as in cases presenting bone deformities. Radiographs are used routinely for orthopaedic surgical planning, yet they provide inadequate information on the precise three-dimensional extent of bone defects. Three-dimensional reconstructions from X-ray computed tomography offer superior visualization but are not portable for consultation or readily available in the operating theatre for guidance during a procedure. A physical model manufactured from X-ray computed tomography data can offer surgeons a clear understanding of complex anatomical detail, by providing an intuitive physical relationship between patient and model. Rapid prototyping was used for the construction of an anatomical model in a case presenting with a complex shoulder injury. The model provided a definitive interpretation of joint pathology and enabled a full assessment of the degree of injury.


Author(s):  
A H A Baazil ◽  
J G G Dobbe ◽  
E van Spronsen ◽  
F A Ebbens ◽  
F G Dikkers ◽  
...  

Abstract Objective This study aimed to compare the necessary scutum defect for transmeatal visualisation of middle-ear landmarks between an endoscopic and microscopic approach. Method Human cadaveric heads were used. In group 1, middle-ear landmarks were visualised by endoscope (group 1 endoscopic approach) and subsequently by microscope (group 1 microscopic approach following endoscopy). In group 2, landmarks were visualised solely microscopically (group 2 microscopic approach). The amount of resected bone was evaluated via computed tomography scans. Results In the group 1 endoscopic approach, a median of 6.84 mm3 bone was resected. No statistically significant difference (Mann–Whitney U test, p = 0.163, U = 49.000) was found between the group 1 microscopic approach following endoscopy (median 17.84 mm3) and the group 2 microscopic approach (median 20.08 mm3), so these were combined. The difference between the group 1 endoscopic approach and the group 1 microscopic approach following endoscopy plus group 2 microscopic approach (median 18.16 mm3) was statistically significant (Mann–Whitney U test, p < 0.001, U = 18.000). Conclusion This study showed that endoscopic transmeatal visualisation of middle-ear landmarks preserves more of the bony scutum than a microscopic transmeatal approach.


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