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

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.

2019 ◽  
Vol 13 (Supl 1) ◽  
pp. 76S
Author(s):  
Alexandre Leme Godoy-Santos ◽  
Cesar Cesar Netto ◽  
Lauren Roberts ◽  
Francois Lintz ◽  
Lew C Schon ◽  
...  

Introduction: Clinical assessment of hindfoot alignment (HA) in adult acquired flatfoot deformity (AAFD) can be challenging, and the weightbearing (WB) cone beam CT (CBCT) may potentially better demonstrate this three-dimensional (3D) deformity. Objective: To compare clinical and WB CBCT assessments of HA in patients with AAFD. Methods: In this prospective study, we included 12 men and 8 women (mean age: 52.2 years, range: 20-88) with flexible AAFD. All subjects also underwent WB CBCT and clinical assessment of hindfoot alignment. Three fellowship-trained foot and ankle surgeons performed six hindfoot alignment measurements on the CT images. Intra- and Inter-observer reliabilities were calculated using Intraclass correlation (ICC). Measurements were compared by paired T-tests, and p-values less than .05 were considered significant. Results: The mean of clinically measured hindfoot valgus was 15.2 (95% confidence interval [CI]: 11.5 - 18.8) degrees. It was significantly different from the mean values of all WB CBCT measurements: Clinical Hindfoot Alignment Angle, 9.9 (CI: 8.9 - 11.1) degrees; Achilles tendon/Calcaneal Tuberosity Angle, 3.2 (CI: 1.3 - 5.0) degrees); Tibial axis/Calcaneal Tuberosity Angle, 6.1 (CI: 4.3 - 7.8) degrees; Tibial axis/Subtalar Joint Angle, 7.0 (CI: 5.3 - 8.8) degrees, and Hindfoot Alignment Angle, 22.8 (CI: 20.4 - 25.3) degrees. We found overall substantial to almost perfect intra- (ICC range: 0.87-0.97) and interobserver agreement (ICC range: 0.51-0.88) for all WB CBCT measurements. Conclusion: Using 3D WB CBCT can help characterize the valgus hindfoot alignment in patients with AAFD. The different CT measurements were reliable and repeatable, significantly differing from the clinical evaluation of hindfoot valgus alignment.


Author(s):  
H. Bertin ◽  
R. Bonnet ◽  
M. Anquetil ◽  
A.S. Delemazure ◽  
E. Mourrain-Langlois ◽  
...  

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
P. López-Jarana ◽  
C. M. Díaz-Castro ◽  
A. Falcão ◽  
C. Falcão ◽  
J. V. Ríos-Santos ◽  
...  

Abstract Background The objective of this study was to measure two parameters involved in tri-dimensional implant planning: the position of the buccal and palatal bone wall and the palatal thickness. Methods Cone beam computed tomography (CBCT) images (Planmeca ProMax 3D) of 403 teeth (208 upper teeth and 195 lower teeth) were obtained from 49 patients referred to the Dental School of Seville from January to December 2014. The height difference between the palatal and buccal walls was measured on the most coronal point of both walls. The thickness of the palatal wall was measured 2 mm from the most coronal point of the palatal wall. Results The mean values in the maxilla were 1.7 ± 0.9 mm for central and lateral incisors, 2.2 ± 1.7 mm for canines, 1.6 ± 0.9 mm for premolars and 1.9 ± 1.5 mm for molars. In the lower jaw, the mean values were 1.3 ± 0.8 mm for incisors, 1.7 ± 1.2 mm for canines, 2.3 ± 1.3 mm for premolars, and 2.6 ± 1.7 mm for molars. In the upper jaw, more than 55% of maxillary teeth (excluding second premolars and molars) presented mean height differences greater than 1 mm. In the mandible, more than 60% of incisors showed a buccal bone thickness of 1 mm from the apical to lingual aspect. All teeth except the second premolar presented a buccal wall located more than 1 mm more apically than the lingual bone wall. Conclusions The buccal bone wall is located more apically (greater than 1 mm) than the palatal or lingual table in most of the cases assessed. The thickness of the palatal or lingual table is also less than 2 mm in the maxilla and mandible, except in the upper canines and premolars and the lower molars.


2017 ◽  
Vol 16 (3) ◽  
pp. 258-264
Author(s):  
Upendra Kumar Giri ◽  
Anirudh Pradhan

AbstractObjectiveThis study was conducted for establishing inherent uncertainty in the shift determination by X-ray volumetric imaging (XVI) and calculating margins due to this inherent uncertainty using van Herk formula.Material and methodsThe study was performed on the XVI which was cone-beam computed tomography integrated with the Elekta AxesseTM linear accelerator machine having six degree of freedom enabled HexaPOD couch. Penta-Guide phantom was used for inherent translational and rotational shift determination by repeated imaging. The process was repeated 20 times a day without moving the phantom for 30 consecutive working days. The measured shifts were used for margins calculation using van Herk formula.ResultsThe mean standard deviations were calculated as 0·05, 0·05, 0·06 mm in the three translational (x, y and z) and 0·05°, 0·05°, 0·05° in the three rotational axes (about x, y, z). Paired sample t-test was performed between the mean values of translational shifts (x, y, z) and rotational shifts. The systematic errors were found to be 0·03, 0·04 and 0·03 mm while the random errors were 0·05, 0·06 and 0·06 mm in the lateral, cranio-caudal and anterio-posterior directions, respectively. For the rotational shifts, the systematic errors were 0·02, 0·03 and 0·03 and the random errors were 0·06, 0·05 and 0·05 in the pitch, roll and yaw directions, respectively.ConclusionOur study concluded that there was an inherent uncertainty associated with the XVI tools, on the basis of these six-dimensional shifts, margins were calculated and recorded as a baseline for the quality assurance (QA) programme for XVI imaging tools by checking its reproducibility once in a year or after any major maintenance in hardware or upgradation in software. Although the shift determined was of the order of submillimetre order, still that shift had great significance for the image quality control of the XVI tools. Every departments practicing quality radiotherapy with such imaging tools should establish their own baseline value of inherent shifts and margins during the commissioning and must use an important QA protocol for the tools.


2018 ◽  
Vol 21 (1) ◽  
pp. 64
Author(s):  
Marcos Marques Rodrigues ◽  
Lucas Borin Moura ◽  
Ariane De Souza Oliveira ◽  
Marisa Aparecida Cabrini Gabrielli ◽  
Valfrido Antonio Pereira Filho ◽  
...  

<p><strong>Objective</strong>: Obstructive Sleep Apnea (OSA) occurs by recurrent collapse of the upper airway during sleep. It results in complete (apnea) or partial (hypopnea) reduction of airflow and has intimate relation with the upper airway anatomy. Cephalometric analysis has been used to quantify airway dimensions. The aim of this study is evaluate the correlation between the anteroposterior dimension of the upper airway and the severity of obstructive sleep apnea. <strong>Material and Methods</strong>: A retrospective analysis was performed reviewing polysomnographic data (AHI) and anteroposterior cephalometric measurements of pharynx subregions: nasopharynx, oropharynx, hypopharynx. <strong>Results</strong>: The sample consisted of 30 patients. The mean body mass index was 29.60 kg/m<sup>2</sup> and the average age was 46.8 years. Nine patients presented severe OSA, seven had moderate OSA , seven had mild OSA, and seven were healthy.  The Pearson's correlation index between the anteroposterior dimension of the nasopharynx, oropharynx and hypopharynx and AHI was respectively -0.128 (p=0.517), -0.272 (p=0.162) and -0.129 (p=0.513).<strong> Conclusion: </strong>The correlation between anteroposterior linear dimension of the airway and OSA severity, assessed by AHI, was not positive. As an isolated parameter it did not correlate to the severity of the obstrucive sleep apnea syndrome and should be evaluated in conjunction with other factors.</p><p><strong> </strong></p><p><strong>Keywords</strong></p><p>Upper Airway; Obstructive sleep apnea; Cone beam CT.</p>


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

2008 ◽  
Vol 78 (5) ◽  
pp. 832-837 ◽  
Author(s):  
Hiroyuki Nawa ◽  
Snehlata Oberoi ◽  
Karin Vargervik

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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