scholarly journals A volumetric study of mandibular condyles in orthognathic patients by semiautomatic segmentation

Author(s):  
Max-Philipp Lentzen ◽  
Maximilian Riekert ◽  
Johannes Buller ◽  
Andrea Grandoch ◽  
Matthias Zirk ◽  
...  

Abstract Purpose This study was conducted to elucidate volumetric data of mandibular condyles of orthognathic patients by analyzing cone beam computed tomography images based upon semiautomatic segmentation. Methods Cone beam computed tomography images of 87 patients with malocclusions were analyzed in this retrospective study. Patients were between 17 and 53 years old and diagnosed with Angle class I, II, or III malocclusion. By using the validated open-source software “ITK-SNAP,” the volumetric measurements of 174 mandibular condyles were performed. Volumetric analysis was performed according to intra-subject side differences by paired Student t test. In accordance to inter-subject side, gender, age and type of malocclusion differences bivariate analysis and ANOVA were applied. Results The mean volume for the right condyle was 1.378 ± 0.447 cm3, with a maximum of 2.379 cm3 and a minimum of 0.121 cm3. The mean volume for the left side was 1.435 ± 0.474 cm3, with a maximum of 3.264 cm3 and a minimum of 0.109 cm3. Bivariate analysis indicated a highly significant inter-subject difference between the volume of the left and right mandibular condyles (p < 0.01). Females had a significantly smaller condyle volume than males (p < 0.05 left condyle; p < 0.01 right condyle). Conclusion The fact that shape and volume of mandibular condyles show a high susceptibility to pathological alterations and particularly malocclusions makes a precise knowledge about volumetric changes indispensable. Our results show that significant inter-subject differences in condyle volume could be found with respect to the side and gender. Larger volumes could be assessed for the left condyle and for male patients.

2020 ◽  
Vol Publish Ahead of Print ◽  
Author(s):  
Max-Philipp Lentzen ◽  
Ali-Farid Safi ◽  
Maximilian Riekert ◽  
Veerle Visser-Vandewalle ◽  
Andrea Grandoch ◽  
...  

2019 ◽  
Vol 2019 ◽  
pp. 1-7
Author(s):  
Andre Luiz Ferreira Costa ◽  
Aline Kataki Paixão ◽  
Bianca Costa Gonçalves ◽  
Celso Massahiro Ogawa ◽  
Thiago Martinelli ◽  
...  

This study aimed to investigate the olfactory fossa according to the Keros classification using cone beam computed tomography. This cross-sectional study analysed cone beam computed tomography images selected from a database belonging to a radiology centre. The scans of 174 healthy patients were analysed by using the Xoran software. Gender, age, and side were correlated with the Keros classification. The mean age of the 174 patients was 45.3 years. The most prevalent Keros classification was type II (65.52%), followed by type III (20.69%) and type I (13.79%). No significant differences were found between Keros classification and the variables age, right side (pvalue = 0.4620), and left side (pvalue = 0.5709). There were also no significant differences between gender and the variables right side (pvalue = 0.1421) and left side (pvalue = 0.2136). Based on these results, we suggest that cone beam computed tomography can be recommended for analysis of the anterior skull base. Keros type II was the most prevalent type in our sample.


2020 ◽  
Vol Publish Ahead of Print ◽  
Author(s):  
Max-Philipp Lentzen ◽  
Matthias Zirk ◽  
Maximilian Riekert ◽  
Johannes Buller ◽  
Matthias Kreppel

2018 ◽  
Vol 22 (3) ◽  
pp. 150-156
Author(s):  
Melih Özdede ◽  
Elif Yıldızer Keriş ◽  
Bülent Altunkaynak ◽  
İlkay Peker

SummaryBackground/Aim: The morphology of the greater palatine canal (GPC) should be determined preoperatively to prevent possible complications in surgical procedures required maxillary nerve block anesthesia and reduction of descending palatine artery bleeding. The purpose of this investigation was to evaluate the GPC morphology.Material and Methods: In this retrospective cross-sectional study, cone-beam computed tomography images obtained for various causes of 200 patients (females, 55%; males, 45%) age ranged between 18 and 86 (mean age±standard deviation=47±13.6) were examined. The mean length, mean angles of the GPC and anatomic routes of the GPC were evaluated.Results: The mean length of the GPC was found to be 31.07 mm and 32.01 mm in sagittal and coronal sections, respectively. The mean angle of the GPC was measured as 156.16° and 169.23° in sagittal and coronal sections. The mean angle of the GPC with horizontal plane was measured as 113.76° in the sagittal sections and 92.94° in the coronal sections. The mean GPC length was longer in males than in females.Conclusions: The results of this study showed that the most common pathway of the GPC was “first inferior, and then anterior-inferior direction” in sagittal plane and “first medial-inferior, then inferior direction” in coronal plane.


2020 ◽  
pp. 20200400
Author(s):  
Alaettin Koç ◽  
Sema Kaya

Objectives: The purpose of this study was to evaluate the effect of section thickness on volume estimations of bone defects scanned using cone beam computed tomography (CBCT). Methods: 25 bone defects were prepared on sheep mandibles and scanned using a KaVo 3D eXam (KaVo Dental, Biberach, Germany) CBCT device. Section thickness of images were reconstructed at 0.25, 0.5, and 0.75 mm to estimate the volume of these defects using the semiautomatic segmentation method. The volume averages obtained using microcomputed tomography and Archimedes’ method served as reference values. The estimated volumes at each section thickness were compared with the actual volumes using the Friedman test. The accuracy of volume estimation was determined by the percentage error with respect to the reference values, and the mean absolute error (MAE) was calculated. Results: Volumetric values of bone defects obtained with CBCT at section thicknesses up to 0.5 mm were compatible with the actual volumes (p > 0.05). The percentage errors at section thicknesses of 0.25, 0.5, and 0.75 mm were −5.4%, −7.3%, and −13.1%, respectively. The mean absolute errors were 13.6 mm3, 15.7 mm3, and 18.2 mm3, respectively. Conclusions: The section thickness values of CBCT images can be increased to a reasonable level to obtain accurate volume estimation results and save time. The semiautomatic segmentation method can be used reliably for volume estimations of bone defects.


2020 ◽  
Vol 47 (4) ◽  
pp. 303-310
Author(s):  
Prasanna Arvind TR ◽  
SP Saravana Dinesh

Objective: To interpret a correlation between buccolingual inclination of molars and palatal depth in hyperdivergent patients and to identify importance of determining inclination of molars in assessing transverse discrepancies (as skeletal or dental) Design: This was a retrospective cone beam computed tomography (CBCT) study. Setting: The study was conducted in the Department of Orthodontics, Saveetha Dental College and Hospital, Tamil Nadu, India. Methods: This was a retrospective CBCT study of 79 patients who underwent diagnostic CBCT for treatment purposes. The CBCT scans were evaluated systematically and the required parameters were accessed with suitable reference planes. Student’s t-test (95% confidence interval) was performed to determine buccolingual inclination of first molars between the right and left sides. Only patients with a vertical growth pattern and skeletal class I relation were included and they were classified into three groups based on their palate depth. Results: In patients with palatal depth > 22 mm, the mean inclination of molars was 7.4°; with palatal depth in the range of 19–22 mm, the mean inclination of molars was 5.23°; and with palatal depth < 19 mm, the mean inclination of molars was 2.9°. Results showed that there was a significant correlation between the buccolingual inclination of molars and the palate depth in vertical growers ( P < 0.05). Conclusion: The buccolingual inclination of first molars is increased in patients with greater palatal depth. This parameter is helpful in classifying crossbites as skeletal or dental. The amount of compensation required to correct the cross bite can be adjusted using Korkhaus Index.


2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Mahnaz Sheikhi ◽  
Mitra Karbasi Kheir ◽  
Ehsan Hekmatian

Background. Mental foramen is important in surgical operations of premolars because it transfers the mental nerves and vessels. This study evaluated the variations of mental foramen by cone-beam computed tomography among a selected Iranian population.Materials and Methods. A total number of 180 cone-beam computed tomography projections were analyzed in terms of shape, size, direction, and horizontal and vertical positions of mental foramen in the right and left sides.Results. The most common shape was oval, opening direction was posterior-superior, horizontal position was in line with second premolar, and vertical position was apical to the adjacent dental root. The mean of foremen diameter was 3.59 mm.Conclusion. In addition to the most common types of mental foramen, other variations exist, too. Hence, it reflects the significance of preoperative radiographic examinations, especially 3-dimensional images to prevent nerve damage.


Urolithiasis ◽  
2021 ◽  
Author(s):  
R. A. Kingma ◽  
M. J. H. Voskamp ◽  
B. H. J. Doornweerd ◽  
I. J. de Jong ◽  
S. Roemeling

AbstractCone beam computed tomography (CBCT) provides multiplanar cross-sectional imaging and three-dimensional reconstructions and can be used intraoperatively in a hybrid operating room. In this study, we investigated the feasibility of using a CBCT-scanner for detecting residual stones during percutaneous nephrolithotomy (PCNL). Intraoperative CBCT-scans were made during PCNL procedures from November 2018 until March 2019 in a university hospital. At the point where the urologist would have otherwise ended the procedure, a CBCT-scan was made to image any residual fragments that could not be detected by either nephroscopy or conventional C-arm fluoroscopy. Residual fragments that were visualized on the CBCT-scan were attempted to be extracted additionally. To evaluate the effect of this additional extraction, each CBCT-scan was compared with a regular follow-up CT-scan that was made 4 weeks postoperatively. A total of 19 procedures were analyzed in this study. The mean duration of performing the CBCT-scan, including preparation and interpretation, was 8 min. Additional stone extraction, if applicable, had a mean duration of 11 min. The mean effective dose per CBCT-scan was 7.25 mSv. Additional extraction of residual fragments as imaged on the CBCT-scan occurred in nine procedures (47%). Of the follow-up CT-scans, 63% showed a stone-free status as compared to 47% of the intraoperative CBCT-scans. We conclude that the use of CBCT for the detection of residual stones in PCNL is meaningful, safe, and feasible.


Author(s):  
Esraa Ahmed Eid ◽  
Fatma Mostafa El-Badawy ◽  
Walaa Mohamed Hamed

Abstract Background The proximity of the maxillary sinus floor to the maxillary molar roots increases the probability of oroantral communication on conducting any surgical or endodontic procedure in the involved area. The aim of this study is to evaluate the relationship between each maxillary molar root and maxillary sinus floor using cone beam computed tomography. Predicting the probability of protrusion of each root into the sinus will consequently predict the probability of occurrence of the oroantral fistula in a sample of the Egyptian population. Results The total number of roots located outside the sinus was 121 (35.3%), while those contacting the sinus floor were 80 (23.3%) and those intruded the sinus were 141 (41.2%). The percentage of root intrusion into the sinus in males (56.9%) was significantly (p = 0.01) higher than females (42.9%). The probability of root intrusion in the left molars (54.2%) was non-significantly (p = 0.067) higher than that of the right side (44.3%). As for the type of tooth, the second molar showed the highest probability of root intrusion into the sinus (55.3%) followed by the third molars (52.6%) then the first molars (40.9). According to the type of root, the mesiobuccal root showed the highest probability of intrusion into the sinus (50.9%) followed by the palatal root (49.1%) then the distobuccal root (47.4%). However, the difference in both type of tooth and type of root was statistically non-significant (p = 0.051 and 0.869 respectively). As for the individual root with the highest probability of intrusion, the mesio-buccal root of the right third molar is the most frequent root to intrude the sinus (71.4%) and the mesio-buccal root of the right first molar is the least frequent (22.7%). Conclusions In a sample of the Egyptian population, males exhibit higher probability of root protrusion into the sinus than females. The side and type of tooth are of higher impact on the probability of its intrusion into the sinus compared to the type of root. Left second molars are at a higher risk of oroantral communications on surgical or endodontic procedures compared to other molars due to its highest probability of intrusion into the sinus.


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