scholarly journals Reproducibility of landmark identification in the jaw and teeth on 3-dimensional cone-beam computed tomography images

2011 ◽  
Vol 81 (5) ◽  
pp. 843-849 ◽  
Author(s):  
Mariko Fuyamada ◽  
Hiroyuki Nawa ◽  
Momoko Shibata ◽  
Kazuhito Yoshida ◽  
Yoshitaka Kise ◽  
...  

Abstract Objective: To compare the reproducibility of landmark identification on three-dimensional (3D) cone-beam computed tomography (CBCT) images between procedures based on traditional cephalometric definitions (procedure 1) and those tentatively proposed for 3D images (procedure 2). Materials and Methods: A phantom with embedded dried human skull was scanned using CBCT. The acquired volume data were transferred to a personal computer, and 3D images were reconstructed. Eighteen dentists plotted nine landmarks related to the jaws and teeth four times: menton (Me), pogonion (Po), upper-1 (U1), lower-1 (L1), left upper-6 (U6), left lower-6 (L6), gonion (Go), condyle (Cd), and coronoid process (Cp). The plotting reliabilities of the two procedures were compared by calculating standard deviations (SDs) in three components (x, y, and z) of coordinates and volumes of 95% confidence ellipsoid. Results: All 27 SDs for procedure 2 were less than 1 mm, and only five of them exceeded 0.5 mm. The variations were significantly different between the two procedures, and the SDs of procedure 2 were smaller than those of procedure 1 in 21 components of coordinates. The ellipsoid volumes were also smaller for procedure 2 than procedure 1, although a significant difference was not found. Conclusions: Definitions determined strictly on each three sectional images, such as for procedure 2, were required for sufficient reliability in identifying the landmark related to the jaws and teeth.

2017 ◽  
Vol 5 (1) ◽  
pp. 5-15
Author(s):  
Rishikesh Pratap Sah ◽  
Fusheng Dong ◽  
Rahul Gupta

 Background and Objectives: The aim of this paper is to describe the application of a newly developed three-dimensional imaging system, Cone-Beam Computed Tomography in the diagnosis and evaluation of supernumerary teeth.Material and Methods: One hundred and eighty-five patients with supernumerary teeth (134 males and 51 females) were included in this study. Patients ranged in age from 6 to 38 years. Supernumerary teeth were detected by clinical examination and conventional radiographs. Moreover, careful investigation for more details was made with the cone beam computed tomography. Supernumerary teeth which were detected with the examinations of the cone beam computed tomography images were analyzed according to the number, location, shape and position.Results: Males were affected more than females in a ratio of 2.6:1. 95 % supernumerary teeth were located in maxilla and 5 % in the mandible. 71.6% of supernumerary teeth were conical in shape. 93.6% supernumerary teeth were impacted and 6.4% were erupted. A total of 198 supernumerary teeth were found to be present in palatal/lingual side and 24 were found on the buccal side. 80.5 % of the patients had one, 18.9 % had two, and 0.5 % had three supernumeraries.Conclusion: Detailed examinations and evaluations of these teeth with Cone-Beam Computed tomography (CBCT) yields accurate 3-dimensional pictures of supernumerary teeth, local dental and bony structures which are very beneficial in terms of proper diagnosis and treatment planning and preventing complications which may occur. Janaki Medical College Journal of Medical Sciences (2017) Vol. 5(1): 5-15


2020 ◽  
Vol 12 (3) ◽  
pp. 93-96
Author(s):  
Nasim Shams ◽  
Bahareh Shams ◽  
Zahra Sajadi

Background: The ostiomeatal complex (OMC) is not a separate anatomical structure although it is a functional unit of structures, including the middle meatus, uncinate process, infundibulum, maxillary sinus ostium, ethmoidal bulla, anterior ethmoid sinus ostium, and frontal recess. Concha bullosa is the pneumatization of the concha, which is one of the most common anatomical variations in the middle turbinate. Methods: This study was conducted using the cone-beam computed tomography (CBCT) images of 172 patients in the archives of the Department of Oral and Maxillofacial Radiology, Dentistry School, Ahvaz Jundishapur. Patient information including age and gender, presence or absence of concha bullosa, the involved side (left or right), and its type (i.e., extensive, lamellar, and bulbous) were collected in the information form. Finally, the chi-square test (with SPSS, version 22) was used to analyze the data, and P value less than 0.05 was considered statistically significant. Results: Patients with and without concha bullosa were 39.1 and 41.7 years, respectively, but it was no significant difference in terms of age (P = 0.321). Out of 52 patients with concha bullosa, 19 (36.5%) cases were males and 33 (63.5%) of them were females. The prevalence of concha bullosa was higher for the bilateral side (20 patients, 38.5%, P = 0.000). The prevalence of bulbulsand lamellar-shape was nearly the same (32.7% and 30.8%, respectively). Eventually, the extensive shape with 36.5% was more frequent for the shape of concha bullosa (P = 0.000). Conclusions: The prevalence of concha bullosa was high. There was no significant difference in terms of age (P = 0.321) and gender (P = 0.058) of patients with concha bullosa. The extensive type and the bilateral appearance of concha bullosa were more significant (P = 0.000).


2016 ◽  
Vol 86 (6) ◽  
pp. 949-954 ◽  
Author(s):  
Takatoshi Nakawaki ◽  
Tetsutaro Yamaguchi ◽  
Daisuke Tomita ◽  
Yu Hikita ◽  
Mohamed Adel ◽  
...  

ABSTRACT Objective: To investigate the relationship between anteroposterior and vertical differences in maxillofacial morphology and mandibular volume. Materials and Methods: Subjects comprised 213 Japanese adults (84 males and 129 females) who were divided into three groups based on mandibular basal arch (ANB) and Wits, measured in a cephalometric analysis: Class I (−1° ≤ ANB < 4°,−1 mm ≤ Wits < 0 mm), Class II (ANB ≥ 4°, Wits ≥ 0), and Class III (ANB <−1°, Wits <−1 mm). Subjects were also divided into three groups based on the mandibular plane angle (Mp), as follows: hypodivergent (Mp < 23°), normodivergent (Mp  =  23–30°), and hyperdivergent (Mp > 30°) groups. Mandibular volume was measured from cone-beam computed tomographic images that were analyzed using Analyze™ image processing software and compared among the three groups in each classification. Results: No significant differences were noted in mandibular volume among Classes I, II, and III. An inverse relationship was found between mandibular volume and Mp, and a significant difference was noted in mandibular volume between the hypodivergent and hyperdivergent groups. Conclusions: In addition to two-dimensional analysis, such as lateral cephalometry, three-dimensional information such as volume, provided by cone-beam computed tomography, contributes to a more detailed assessment of maxillofacial morphology.


2019 ◽  
Vol 10 (1) ◽  
pp. 22-25
Author(s):  
Moiza Ijaz ◽  
Saira Ibrahim ◽  
Ayesha Aslam ◽  
Abdul Rehman ◽  
Sameena Younis ◽  
...  

Objective: To evaluate the type and depth of lingual concavity in posterior mandible using pre-treatment CBCT (Cone Beam Computed Tomography) images for dental implants. Study Design and Setting: A cross-sectional study was designed and conducted on pre-treatment CBCT scans of 75 patients at Armed Forces Institute of Dentistry, Rawalpindi, Pakistan from February 2018 to November 2018. Methodology: Pre-treatment CBCT scans of 75 patients were selected and following parameters were measured: type of ridge (undercut, parallel, convex), ridge width, ridge height, depth of lingual concavity, concavity angle, and location of the undercut. Data was analyzed using SPSS version .24. Post-stratification Mann-Whitney U test was used for effect modifiers, while Kruskal-Wallis test was used to compare study parameters between groups. P value <0.05 was taken as significant. Results: A mean concavity depth of 1.17±1.40 mm was observed while majority (46.7%) of the CBCT images presented with undercut type ridge. No significant difference was observed between males and females for any study parameter. Conclusion: Undercut ridges were frequently observed, posing a threat of lingual perforation during implant placement. Pre-operative assessment of implant site using CBCT can serve as a reliable method to avoid such complications


2015 ◽  
Vol 86 (4) ◽  
pp. 617-624 ◽  
Author(s):  
Carolina Morsani Mordente ◽  
Juan Martin Palomo ◽  
Martinho Campolina Rebello Horta ◽  
Bernardo Quiroga Souki ◽  
Dauro Douglas Oliveira ◽  
...  

ABSTRACTObjective: To evaluate the anterior and posterior maxillary width, the nasal passage volume, the oropharyngeal minimum axial area, and volume changes in unilateral cleft lip and palate patients treated with one of the following four expanders: Hyrax, Fan-Type, inverted mini-hyrax supported on the first permanent molars (iMini-M), or inverted mini-hyrax supported on the first premolars (iMini-B).Materials and Methods: A total of 40 patients with transverse maxillary deficiency who were submitted for rapid maxillary expansion were divided in four groups according to type of expander used. Cone-beam computed tomography images were taken before and 3 months after expansion. One-way analysis of variance was used to analyze the differences among the groups, and paired t-tests were used to evaluate the changes in each group.Results: All groups showed a significant increase in the anterior maxillary width, with no intergroup differences. The iMini-B was the only group that did not show a significant increase in the posterior maxillary width. The intergroup comparison demonstrated differences among all groups except between Hyrax and iMini-M, which showed the greatest posterior expansions. The intragroup analysis showed a significant increase in the nasal passage volume in hyrax and inverted mini-hyrax on the molar groups, but the intergroup comparison revealed a significant difference only between Fan-Type and inverted mini-hyrax on the molars. None of the expanders caused significant changes in the oropharyngeal measurements.Conclusions: Only the Hyrax and inverted mini-hyrax on the molar expanders effectively increased the nasal passage volume, and none of the expanders evaluated in this study modified the oropharyngeal airway.


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