Three-Dimensional Tooth Segmentation by Integrating Multiple Ray-Sum Images From CBCT Data

2015 ◽  
Author(s):  
Sandro Barone ◽  
Alessandro Paoli ◽  
Armando V. Razionale
Keyword(s):  
3D Imaging ◽  
Cone Beam Ct ◽  
Three Dimensional ◽  
Cone Beam ◽  
Data Sets ◽  
Anterior Teeth ◽  
Scan Data ◽  
Cubic Spline Curve ◽  
Transverse Slice ◽  
Selection Of

The reconstruction of tooth anatomies is of utmost importance when dental implant surgeries and/or orthodontic corrections must be planned. In the last few years, cone beam CT (CBCT) has gained popularity in dentistry for 3D imaging of jawbones and teeth. However, within CBCT data sets, each tooth is defined by a region, which cannot be easily separated from surrounding tissues (i.e., bone tissue) by only considering pixel’s grey-intensity values. For this reason, some enhancement is usually necessary in order to properly segment tooth geometries. In this paper, a semi-automatic approach to reconstruct individual 3D tooth anatomies by processing CBCT-scan data is presented. The methodology is based on the creation of a minimal number of 2D “local ray-sum” images by adding the absorption values of adjacent voxels along the most significant views for each tooth. The knowledge of the specific anatomical patient morphology drives the selection of these significant projection directions. The reconstructed “ray-sum” images greatly enhance the clearness of the root contours, which can then be interactively traced by dentists. A set of meaningful 2D tooth contours is consequently obtained and used to automatically extract a cubic spline curve for each transverse slice, thus approximating the overall 3D tooth profile. The effectiveness of the methodology has been evaluated by comparing the results obtained for the reconstruction of anterior teeth with those obtained by using classical segmentation tools provided within commercial software.

The Effects of Mini Implant and Anterior Arch Hook Heights on En Masse Retraction: A Finite Element Analysis

2013 ◽  
Vol 461 ◽  
pp. 993-1001
Author(s):  
Wen Wen Deng ◽  
Fang Wang ◽  
Ferdinand M. Machibya ◽  
Shang Gao ◽  
Xiao Long Wang ◽  
...  
Keyword(s):  
Finite Element ◽  
Cone Beam Ct ◽  
Three Dimensional ◽  
Cone Beam ◽  
Finite Element Models ◽  
Treatment Results ◽  
Element Analysis ◽  
Anterior Teeth ◽  
Orofacial Region ◽  
En Masse Retraction

Introduction: An en-masse retraction with mini implant (MI) anchorage may be associated with unwanted intrusion/extrusion and uncontrolled tipping of anterior teeth. An optimum combination of MIs and hooks heights is required for proper treatment results. Materials and Methods: Maxillary finite element models were constructed from a cone beam CT scan of a patient’s orofacial region. The initial tooth displacement at 200g force with 0.019 × 0.025-in stainless steel working archwires engaged in 0.022 brackets slot was assessed. The three-dimensional displacement was examined at various MI and AAH heights. Results: The lower MI position caused extrusion of the central incisors, but the teeth were intruded at higher (6- and 8-mm) MI heights. While the shorter (2- and 4-mm) hooks extruded the central incisors, the higher (6- and 8-mm) intruded the teeth. The higher MI and hooks reduced the palatal tipping of central incisors. The distobucal cusp of the first molar was intruded, while the mesiobucal cusp was extruded in all models: Nonetheless, the shorter hooks and low MI had small molar tipping effects. Conclusions: The higher MIs caused intrusion and less palatal tipping of the central incisors crowns. The increase in hook height resulted into extrusion and reduction in palatal tipping of the central incisors crowns.

Cone-Beam CT Fast Reconstruction Method Based on the Minimum Three Dimensional Convex Hull for Actual Scan Data

2012 ◽  
Vol 229-231 ◽  
pp. 1819-1822 ◽  
Author(s):  
Kui Dong Huang ◽  
Ding Hua Zhang ◽  
Ming Jun Li ◽  
Hua Zhang
Keyword(s):  
Convex Hull ◽  
Cone Beam Ct ◽  
Three Dimensional ◽  
Cone Beam ◽  
Reconstruction Method ◽  
Ct Reconstruction ◽  
Dimensional Reconstruction ◽  
Fast Reconstruction ◽  
Scan Data ◽  
Definition Of

In the three dimensional reconstruction of cone-beam CT, a fast reconstruction method based on the smallest three dimensional convex hull was proposed for actual scan data. First, according to the definition of the minimum three dimensional convex hull, the minimum three dimensional convex hull of the detected object was obtained in the actual scan using a segmentation algorithm based on the projected images, and then with the Z-line data first algorithm, the image reconstruction area was limited to the minimum three dimensional convex hull to enhance the cone-beam CT reconstruction speed by reducing the redundant computing. The experimental results show that this method can effectively reduce the memory consumption, and significantly improve the reconstruction speed and reduce the noise surrounding the object imaging area.

Three dimensional cone-beam CT sialography in non tumour salivary pathologies: procedure and results

2019 ◽  
Vol 48 ◽  
pp. 226
Author(s):  
H. Bertin ◽  
R. Bonnet ◽  
M. Anquetil ◽  
A.S. Delemazure ◽  
E. Mourrain-Langlois ◽  
...  
Keyword(s):  
Cone Beam Ct ◽  
Three Dimensional ◽  
Cone Beam ◽  
Dimensional Cone

scholarly journals The correlation between the three-dimensional radiolucency area around the crown of impacted maxillary canines and dentigerous cysts

2020 ◽  
Vol 49 (4) ◽  
pp. 20190402
Author(s):  
Junliang Chen ◽  
Dongmei Lv ◽  
MingXia Li ◽  
Wei Zhao ◽  
Yun He
Keyword(s):  
Cone Beam Ct ◽  
Dentigerous Cyst ◽  
Three Dimensional ◽  
Cone Beam ◽  
Hard Tissue ◽  
Mean Values ◽  
Dentigerous Cysts ◽  
Impacted Canine ◽  
The Mean ◽  
Surgical Operations

This study aimed to reveal the correlation between the radiolucency area around the crown of impacted maxillary canines and dentigerous cysts using cone beam CT (CBCT). CBCT data were obtained from patients with impacted maxillary canines. Three points of five areas (tooth cusp area and buccal, lingual, mesial and distal areas of the crown) were randomly selected, and the distance between the point and the surrounding hard tissue was measured respectively. The mean values were recorded as the radiolucency area. These results were compared with the occurrence of dentigerous cysts during surgery. 58 patients with 76 impacted maxillary canines were included. 14 of the 76 impacted canines were accompanied by cysts (18.42%). With the increase in the thickness of the radiolucency area, the incidence of cysts was significantly increased (p < 0.05). No cysts were found in the compacted canines with 0–1 mm thickness of the radiolucency area. The highest incidence (71.43%) was observed in canines with 3–4 mm thickness of the radiolucency area. This study found that the thickness of the radiolucency area around the crown of the maxillary impacted canine was closely related to the occurrence of dentigerous cysts. CBCT can be used to estimate the occurrence possibility of dentigerous cyst and guide surgical operations.

Three-dimensional C-arm Cone-beam CT: Applications in the Interventional Suite

2009 ◽  
Vol 20 (7) ◽  
pp. S523-S537 ◽  
Author(s):  
Michael J. Wallace ◽  
Michael D. Kuo ◽  
Craig Glaiberman ◽  
Christoph A. Binkert ◽  
Robert C. Orth ◽  
...  
Keyword(s):  
Cone Beam Ct ◽  
Three Dimensional ◽  
Cone Beam

scholarly journals Taurodontism and Van der Woude Syndrome

2008 ◽  
Vol 78 (5) ◽  
pp. 832-837 ◽  
Author(s):  
Hiroyuki Nawa ◽  
Snehlata Oberoi ◽  
Karin Vargervik
Keyword(s):  
Clinical Sample ◽  
Cone Beam Ct ◽  
Three Dimensional ◽  
Panoramic Radiograph ◽  
Cross Sectional Study ◽  
Cone Beam ◽  
Linear Measurements ◽  
Van Der Woude Syndrome ◽  
Cross Sectional ◽  
Mandibular First Molar

Abstract Objective: To report the occurrence of taurodontism in a clinical sample of Van der Woude syndrome (VWS) and describe its association with hypodontia and cleft type. Materials and Methods: This retrospective, cross-sectional study was carried out on chart reviews and radiographs of 13 persons with VWS. Mean age was 10 years 11 months ± 1 year 5 months. Panoramic radiographs were used to confirm the presence or absence of teeth and to measure crown body and root lengths of mandibular first molars. Three-dimensional cone beam computed tomography (CT) scans were available on two persons with VWS. Both volumetric and linear measurements were obtained. Results: The occurrence of taurodontism of the mandibular first molar was 35%: 27% hypodont and 8% mesodont. Of the 13 subjects with VWS, 6 (4 males and 2 females) had at least one tooth identified with taurodontism. Half of the cases were unilateral and half were bilateral, and all of the unilateral cases were on the left side. Five of the six subjects with taurodontism had missing incisors and premolars. Taurodontism was two times more frequent in those who were missing their second premolars than in those who had their second premolars. There was no correlation between cleft type and presence of taurodontism. The cone beam CT pilot study on two persons showed very abnormal morphology of both crown and roots, which was not apparent on the standard panoramic radiograph. Both the volumetric and linear measurements of the ratio of crown body to root were highly indicative of taurodontism. Further genetic studies are needed. Conclusion: There is a likely association between VWS and taurodontism.

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