scholarly journals Analysis of the correlation between dental arch and articular eminence morphology: a cone beam computed tomography study

2017 ◽  
Vol 124 (4) ◽  
pp. 420-431 ◽  
Author(s):  
Francielle Silvestre Verner ◽  
Gina Delia Roque-Torres ◽  
Laura Ricardina Ramírez-Sotello ◽  
Karina Lopes Devito ◽  
Solange Maria Almeida
Keyword(s):  
Computed Tomography ◽  
Cone Beam Computed Tomography ◽  
Cone Beam ◽  
Dental Arch ◽  
Articular Eminence

scholarly journals Impacts of Thresholds of Gray Value for Cone-Beam Computed Tomography 3D Reconstruction on the Accuracy of Image Matching with Optical Scan

2020 ◽  
Vol 17 (17) ◽  
pp. 6375 ◽  
Author(s):  
Se-Won Park ◽  
Ra Gyoung Yoon ◽  
Hyunwoo Lee ◽  
Heon-Jin Lee ◽  
Yong-Do Choi ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Image Registration ◽  
3D Reconstruction ◽  
Cone Beam Computed Tomography ◽  
Cone Beam ◽  
Dental Arch ◽  
Arch Model ◽  
3D Mesh ◽  
Optical Scan ◽  
Reconstruction Model

In cone-beam computed tomography (CBCT), the minimum threshold of the gray value of segmentation is set to convert the CBCT images to the 3D mesh reconstruction model. This study aimed to assess the accuracy of image registration of optical scans to 3D CBCT reconstructions created by different thresholds of grey values of segmentation in partial edentulous jaw conditions. CBCT of a dentate jaw was reconstructed to 3D mesh models using three different thresholds of gray value (−500, 500, and 1500), and three partially edentulous models with different numbers of remaining teeth (4, 8, and 12) were made from each 3D reconstruction model. To merge CBCT and optical scan data, optical scan images were registered to respective 3D reconstruction CBCT images using a point-based best-fit algorithm. The accuracy of image registration was assessed by measuring the positional deviation between the matched 3D images. The Kruskal–Wallis test and a post hoc Mann–Whitney U test with Bonferroni correction were used to compare the results between groups (α = 0.05). The correlations between the experimental factors were calculated using the two-way analysis of variance test. The positional deviations were lowest with the threshold of 500, followed by the threshold of 1500, and then −500. A significant interaction was found between the threshold of gray values and the number of remaining teeth on the registration accuracy. The most significant deviation was observed in the arch model with four teeth reconstructed with a gray-value threshold of −500. The threshold for the gray value of CBCT segmentation affects the accuracy of image registration of optical scans to the 3D reconstruction model of CBCT. The appropriate gray value that can visualize the anatomical structure should be set, especially when few teeth remain in the dental arch.

scholarly journals Articular Eminence Inclination, Height, and Condyle Morphology on Cone Beam Computed Tomography

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Dilhan İlgüy ◽  
Mehmet İlgüy ◽  
Erdoğan Fişekçioğlu ◽  
Semanur Dölekoğlu ◽  
Nilüfer Ersan
Keyword(s):  
Computed Tomography ◽  
Cone Beam Computed Tomography ◽  
Mean Value ◽  
Cone Beam ◽  
Articular Eminence ◽  
Age And Gender ◽  
Mean Values ◽  
The Mean ◽  
And Gender ◽  
The Relationship

Aim. The aim of the present study was to examine the relationship between articular eminence inclination, height, and thickness of the roof of the glenoid fossa (RGF) according to age and gender and to assess condyle morphology including incidental findings of osseous characteristics associated with osteoarthritis (OA) of the temporomandibular joint (TMJ) using cone beam computed tomography (CBCT).Materials and Methods. CBCT images of 105 patients were evaluated retrospectively. For articular eminence inclination and height, axial views on which the condylar processes were seen with their widest mediolateral extent being used as a reference view for secondary reconstruction. Condyle morphology was categorized both in the sagittal and coronal plane.Results. The mean values of eminence inclination and height of males were higher than those of females (P<0.05). There were significant differences in the RGF thickness in relation to sagittal condyle morphology. Among the group of OA, the mean value of the RGF thickness for “OA-osteophyte” group was the highest (1.59 mm), whereas the lowest RGF values were seen in the “OA-flattening.”Conclusion. The sagittal osteoarthritic changes may have an effect on RGF thickness by mechanical stimulation and changed stress distribution. Gender has a significant effect on eminence height (Eh) and inclination.

scholarly journals Cone-beam computed tomography for assessment of palatal displaced canine position: A methodological study

2013 ◽  
Vol 84 (3) ◽  
pp. 459-466 ◽  
Author(s):  
Julia Naoumova ◽  
Heidrun Kjellberg ◽  
Reet Palm
Keyword(s):  
Computed Tomography ◽  
Cone Beam Computed Tomography ◽  
Cone Beam ◽  
Vertical Position ◽  
Dental Arch ◽  
Linear Measurements ◽  
Precise Position ◽  
Angular Measurements ◽  
Mean Differences ◽  
Intraexaminer Reliability

ABSTRACT Objective: To assess the inter- and intraexaminer reliability of a measurement method for evaluation of eruption angles and position of palatal displaced canines (PDCs) with cone-beam computed tomography (CBCT) images and to test the validity of the measured angles on a dry skull. Materials and Methods: Twenty patients (eight boys, 12 girls; age 11.4 ± 1.2 years) were randomly chosen among 67 patients from a study evaluating the interceptive effect of extracting the deciduous canine in children with PDCs. In total, 60 images were analyzed, because each patient had three CBCT examinations (baseline, 6-month control, and endpoint). Two observers assessed the following measurements twice: mesioangular and sagittal angle, vertical position, canine cusp tip, and canine apex to dental arch. The validity of the angular measurements was tested against angular measurements on a dry skull using mathematical formulations. Results: The inter- and intraexaminer mean differences for angular and linear measurements were all low and statistically insignificant (P &gt; .05). The mean differences between the physical and 3D measurements were 0.5 ± 0.39 mm for the sagittal angle and 0.22 ± 0.19 mm for the mesioangular angle. Conclusions: Linear and angular measurements on CBCT images are accurate and precise and can be used to assess the precise position of a PDC.

scholarly journals Volume measurement of mandibular teeth pulp chamber as a prediction tool of gender and ethnicity in a Brazilian population

2020 ◽  
Vol 24 (1) ◽  
Author(s):  
Karolina Aparecida Castilho Fardim ◽  
Eurico Oliveira Junior ◽  
Rafael Rodrigues ◽  
Elaine Araújo ◽  
João Pedro Gomes ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Cone Beam Computed Tomography ◽  
Cone Beam ◽  
Dental Arch ◽  
P Value ◽  
Forensic Dentistry ◽  
Pulp Chamber ◽  
Dental Tissues ◽  
Chamber Volume ◽  
Volumetric Assessment

Objective: Forensic dentistry has used some methods for the human identification process. However, there is a need to study characteristics that are able to perform identification more specifically, increasing accuracy. Considering the role of dental arch assessment in prediction of gender and ethnicity, the purpose of this study was to assess the volume of pulp chamber as a mean to obtain new forensic evidence. Material and methods: For this task, 1.190 cone beam computed tomography (CBCT) images were retrospectively selected and subdivided according to the population number, gender, age and ethnicity. All DICOM files were imported to the open-source software ITK-SNAP® (http://www.itksnap.org/pmwiki/pmwiki.php). The segmentation process was performed in all pulp chamber aiming to obtain pulp tissue´s volume. Results: As a result, the pulp chamber volume of mandibular canine teeth showed to be larger in white population than in non-white (P-value = 0.003) and in male individuals in comparison with female (P-value = 0.038). Conclusion: These results, however, must be confirmed by future studies with a larger sample size and by the assessment of other variables, including texture analysis and density of dental tissues. KEYWORDS Cone beam computed tomography; Ethnicity; Forensic dentistry; Gender; Pulp chamber volume; Volumetric assessment.

A new evaluation method of three-dimensional tooth axis and dental arch using cone-beam computed tomography

2019 ◽  
Vol 2019.56 (0) ◽  
pp. D023
Author(s):  
Yuta SAKAGAMI ◽  
Makoto SAKAMOTO ◽  
Yusuke MORISE ◽  
Koichi KOBAYASHI ◽  
Takashi KAMEDA ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Cone Beam Computed Tomography ◽  
Evaluation Method ◽  
Three Dimensional ◽  
Cone Beam ◽  
Dental Arch ◽  
Tooth Axis

Dental and Skeletal Changes in the Upper and Lower Jaws after Treatment with Schwarz Appliances Using Cone-Beam Computed Tomography

2010 ◽  
Vol 35 (1) ◽  
pp. 111-120 ◽  
Author(s):  
Kiyoshi Tai ◽  
Jae Hyun Park
Keyword(s):  
Computed Tomography ◽  
Nasal Cavity ◽  
Cone Beam Computed Tomography ◽  
Alveolar Bone ◽  
Middle Turbinate ◽  
Root Apex ◽  
Reference Points ◽  
Cone Beam ◽  
Dental Arch ◽  
Skeletal Changes

Objective: The purpose of this research was to use cone-beam computed tomography (CBCT) images to evaluate dental and skeletal changes in upper and lower jaws after treatment with Schwarz appliances.Materials and Methods: 28 patients with Angle Class I molar relationships and crowding were randomly divided into two groups – 14 non-expanded and 14 expanded patients. 3D-Rugle CBCT software was used to measure various reference points before treatment (T0) and during the retention period of approximately 9 months after 6 to 12 month expansion (T1). Cephalometric and cast measurements were used to evaluate treatment in both groups. To test whether there were any significant differences between the control and treatment groups at T0 and T1, the Mann-Whitney U-test was used. Results: The dental arch (including tooth root apices) had expanded in the upper and lower jaws. Alveolar bone expansion of up to 2 mm apical to the cementoenamel junction (CEJ) was detected. The midpalatal sutures were separated in some cases and subsequent expansion was observed at the inner surface of the nasal cavity at the inferior turbinates. However,no significant (P &gt; 0.05) difference was observed in the inter-width of the mandibular bodies, zygomatic bones, nasal cavity in the middle turbinate region, condylar heads, or antegonial notches. In mandibular and maxillary cast measurements, arch crowding and arch perimeter showed statistically significant changes in the expansion group. The mandibular width values demonstrated no significant changes as measured from a point 2 mm apical to the CEJ, whereas the maxillary width values demonstrated significant changes as measured from a point 2 mm apical to the CEJ. Conclusions: This study indicates that the Schwarz appliance primarily affects the dento-alveolar complex, while it has little effect on either the mandibular bodies, any associated structures including the maxillary midpalatal suture and the inter-width of the nasal cavity in the middle turbinate region. In addition, the center of rotation of the mandibular and maxillary first molar was observed apical to the root apex.

scholarly journals Buccolingual Inclination of Canine and First and Second Molar Teeth and The Curve of Wilson in Different Sagittal Skeletal Patterns of Adults Using Cone-Beam Computed Tomography

2020 ◽  
Author(s):  
Amin Golshah ◽  
Navid Rezae ◽  
Sara Heshmati
Keyword(s):  
Computed Tomography ◽  
Cone Beam Computed Tomography ◽  
Class Ii ◽  
Class I ◽  
Cone Beam ◽  
Dental Arch ◽  
Cross Sectional ◽  
Second Molar ◽  
Molar Teeth ◽  
The Mean

Abstract Background: This study aimed to assess the buccolingual inclination of canine and first and second molar teeth and the curve of Wilson in different sagittal skeletal patterns in untreated adults using cone-beam computed tomography (CBCT). Methods: Sixty-six CBCT scans of adults (mean age: 28.74±5.25 years) were evaluated in this cross-sectional study. The images were standardized using the Frankfurt horizontal plane and the interorbital line. The sagittal skeletal pattern was determined using the ANB angle and Wits appraisal. Inclination angles were measured by NNT Viewer and Mimics software. The curve of Wilson was measured by connecting the tips of mesiobuccal and mesiolingual cusps of maxillary first and second molars along the buccal groove and measuring the formed angle. Data were analyzed using ANOVA. Results: The intraobserver agreement was 0.969. The mean inclination of maxillary first and second molars in class I and III patients was significantly higher than that in class II patients (P<0.05). The mean inclination of mandibular first and second molars in class II patients was significantly higher than that in class I and III patients (P<0.05). The difference in inclination of maxillary and mandibular canine teeth was not significant (P>0.05). The mean curve of Wilson in second molars of class II patients was significantly higher than that in class I patients (P<0.05). Conclusion: In different sagittal skeletal patterns, a compensatory relationship exists between the opposing teeth, which along with the standards of crowns, can be used to determine the appropriate position of teeth in dental arch.

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