Computed Tomography Studies Research Articles

Assessment of the Anterior Clinoid Process and Optic Strut in Chiari Malformation Type I: A Computed Tomography Study.

Objective This study aimed to evaluate morphological features of the anterior clinoid process (ACP) and the optic strut (OS) in Chiari malformation Type I (CM-I). Methods The study universe consisted of computed tomography images of 41 CM-I patients and 45 normal subjects. Comparison of the parameters for CM-I and the control group was performed with the Student's t -test. A " p < 0.05" was accepted as the significance level. Results ACP length was smaller in CM-I than the control group ( p < 0.001). In contrast to ACP length, ACP angle ( p < 0.001), OS length ( p = 0.022), and the distance between ACP and OS ( p = 0.020) were found greater in CM-I in comparison to the control group ( p < 0.05). ACP width ( p = 0.233) and OS width ( p = 0.376) were similar in both groups. ACP pneumatization in CM-I group was found as 12.20%, whereas in the control group as 8.90%. Two different types about the pneumatization were identified in CM-I group (Type 1: 4.9% and Type 2: 7.3%), whereas three different types in the control group (Type 1: 3.3%, Type 2: 4.4%, and Type 3: 1.1%). Relative to ACP, three different types about OS position were identified in CM-I group (Type C: 31.70%, Type D: 64.60%, and Type E: 3.70%) and the control group (Type C: 7.80%, Type D: 64.40%, and Type E: 27.80%). Conclusion Shorter ACP, wide-angled ACP, longer OS, and more anteriorly located OS were found in CM-I group compared with the normal group. Our findings showed that the pneumatization of ACP was not affected by CM-I.

Evaluation of a correlation between the severity of root resorption of adjacent teeth and level of difficulty of impacted canine – A cone-beam computed tomography study

Objectives: An interrelation between the level of difficulty of canine impaction based on its three-dimensional position and the degree of root resorption of the adjacent teeth improves the quality of orthodontic treatment planning. It would be advantageous for clinicians to know the predilection of resorption in varying canine positions. The aim of the study is to evaluate and correlate the severity of root resorption of adjacent teeth and the level of difficulty of impacted canine classified by KPG Index and sector analysis using cone-beam computed tomography. Material and Methods: The study sample comprised 48 impacted canines in orthodontic patients (17 boys and 27 girls) with a mean age of 24 years. The cone-beam computed tomographs were evaluated using Dolphin Imaging Software and primarily, three observations were recorded: KPG index, sector analysis, and root resorption. The samples were equally divided into four groups based on the KPG index, with 12 samples in each group. Additionally, the inclination of the canine in the frontal plane and their degree of vertical eruption were recorded. Results: The number and severity of resorptive lesions increased as the KPG score escalated. The mean KPG score was 13.67 ± 6.336 and the average KPG index was 2.5 ± 1.13. A statistically significant positive correlation was found between all the parameters and root resorption. Conclusion: A positive correlation exists between the level of difficulty of canine impaction and root resorption of the adjacent teeth. A KPG score higher than 13.67 can be a resourceful predictor of resorptive lesions. An increased tendency of root resorption of the neighboring teeth was observed when angle α and angle β exceed 43.71° and 43.26°, respectively.

Detailed analysis of the association between urate deposition and bone erosion in gout: a dual-energy computed tomography study.

This study aimed to analyze the effect of urate deposition (UD) on bone erosion and examine the association between the volume of monosodium urate (MSU) crystals and an improved bone erosion score method, as measured in the metatarsophalangeal (MTP) joints of patients with gout. Fifty-six patients diagnosed with gout using the 2015 European League Against Rheumatism and American College of Rheumatology criteria were enrolled. MSU crystals volume at each MTP joint was measured using dual-energy computed tomography (DECT) images. The degree of bone erosion was evaluated with the modified Sharp/van der Heijde (SvdH) erosion scoring system based on CT images. Differences in clinical features between patients with (UD group) and without (non-UD group) UD were assessed, and the correlation between erosion scores and urate crystal volume was analyzed. The UD and non-UD groups comprised 30 and 26 patients, respectively. Among the 560 MTP joints assessed, 80 showed MSU crystal deposition, and 108 showed bone erosion. Bone erosion occurred in both groups but was significantly less severe in the non-UD group (p <0.001). Both groups had equivalent levels of serum uric acid (p=0.200). Symptom duration was significantly longer in the UD group (p=0.009). The UD group also had a higher rate of kidney stones (p=0.023). The volume of MSU crystals was strongly and positively associated with the degree of bone erosion (r=0.714, p <0.001). This study found that patients with UD show significant increased bone erosion than those without UD. The volume of MSU crystals is associated with the improved SvdH erosion score based on CT images, regardless of serum uric acid level, demonstrating the potential of combining DECT and serum uric acid measurements in helping optimize the management of patients with gout.

Root and canal morphology of mandibular second molars in an Egyptian subpopulation: a cone-beam computed tomography study

BackgroundThis study was using Cone beam computed tomography (CBCT) to examine the anatomical variations in mandibular second molars in an Egyptian sub-population.MethodsA total of 350 CBCT images (215 females and 135 males, aged 15–65 years) of mandibular second molars were evaluated. Samples were evaluated in terms of: number of roots, number of root canals, roots’ cross section as well as prevalence and configurations of C-shaped canals. Statistical analysis was done to highlight differences between different categories and their prevalence among genders (significance level was set at p < 0.05). Data were presented as frequency and percentage values and were analyzed using chi square test followed by pairwise comparisons utilizing multiple Fisher’s exact tests with Bonferroni correction. The significance level was set at p < 0.05 within all tests.ResultsOf the 350 mandibular second molars evaluated, 87.2% were non-C-shaped while 12.8% were C-shaped with no gender-based statistically significant differences (χ2 = 0.19, p = 0.656). Most samples had three root canals (80%) followed by two (16%), then one (3.2%), and finally four (0.8%) root canals. Among the non-C-shaped molars, presence of two roots was most common (83.4%) followed by presence of a single root (16.2%), and only one sample (0.2%) had three roots, and this had no correlation with gender (χ2 = 1.86, p = 0.431). In the mesial roots Type IV Vertucci was the most common configuration found (68.8%), while Type I was the most prevalent in the distal roots (91.8%). The long oval configuration was the most commonly found cross section in mesial roots while “oval” was the most prevalent in distal roots.ConclusionEgyptian sub-population shows highly variable morphological features in mandibular second molars, hence, CBCT is highly recommended on case-to-case conditions.

CT doses based on clinical indications. New national DRL’s in Iceland

A diagnostic reference level (DRL) is an investigation level to use in the optimization of a medical exposure using ionizing radiation. The aim of this project was to gather dose data from computed tomography (CT) studies in Iceland with the purpose of updating existing national DRL and proposing DRLs based on clinical indications.Dose data (total dose length product (DLP) and CT dose index) were retrospectively collected from all CT scanners in Iceland for 50 patients for all common CT studies.After cleaning the data, the data set contained total DLP for 8129 patients. Considering dose-relevant parameters such as the number of phases and scan length, each CT study was assigned to one of 42 study types and (at least) one clinical indication.Data were received from seven or more scanners for 13 clinical indications and from all scanners providing coronary angiography. There was considerable variation in the median total DLP from different scanners, e.g., from 13 to 139 mGycm for Sinusitis, and, the range of individual total DLPs varied between scanners. This underscores the importance of monitoring patients’ exposure. The study shows that there is room for optimization.New Icelandic NDRLs were proposed for the total DLP of CT examinations based on ten different indications, including: Brain ischemia (1060 mGycm), Interstitial lung disease (310 mGycm) and Appendicitis (690 mGycm). The proposed NDRLs were the first clinical indication based NDRLs in Iceland. The Icelandic Radiation Safety Authority has decided to update the NDRLs based on the results of this study.

Influence of Manufacturing Defects on Mechanical Behavior of the Laser Powder Bed Fused Invar 36 Alloy: In-Situ X-ray Computed Tomography Studies.

The mechanical properties of laser powder bed fused (LPBFed) Invar 36 alloy have been limited by the presence of manufacturing defects. It is imperative to investigate the influence of these defects on the mechanical behavior of LPBFed Invar 36 alloy. In this study, in-situ X-ray computed tomography (XCT) tests were conducted on LPBFed Invar 36 alloy fabricated at different scanning speeds to examine the relationship between manufacturing defects and mechanical behavior. For LPBFed Invar 36 alloy fabricated at a scanning speed of 400 mm/s, the manufacturing defects were randomly distributed and tended to be elliptical in shape. Plastic deformation behavior was observed, and failure initiated from defects inside the material resulting in ductile failure. Conversely, for LPBFed Invar 36 alloy fabricated at a scanning speed of 1000 mm/s, numerous lamellar defects were observed mainly located between deposition layers, and their quantity was significantly increased. Little plastic deformation behavior was observed, and failure initiated from defects on the shallow surface of the material resulting in brittle failure. The differences in manufacturing defects and mechanical behavior are attributed to changes in input energy during the laser powder bed fusion process.

Fragmented medial coronoid process in a cat

AbstractFragmented medial coronoid process is common in dogs, but has only been described in the cat once historically. This case describes a case of presumed traumatic fragmented medial coronoid process in a cat, which presented for right thoracic limb lameness of 3‐month duration, which did not respond to medical management. A computed tomography study demonstrated the fragmented medial coronoid process, and surgical removal of the fragment was performed via arthrotomy without complication. Histological examination of the fragment did not show microdamage of the bone or osteocyte loss, which is evident in developmental cases of fragmented medial coronoid process, and was suggestive of a historical fracture that resulted in non‐union. The patient improved postoperatively, but still experiences intermittent lameness after periods of exertion.

Maxillary cortical bone remodeling characteristics in extraction patients: A cone-beam computed tomography study

This study aimed to evaluate labial and palatal cortical bone remodeling (BR) characteristics and related aspects of maxillary incisors after retraction, as these aspects are still controversial among orthodontists. Cortical BR and incisor movement of 44 patients (aged 26.18 ± 4.71 years) who underwent maxillary first premolar extraction and incisor retraction were analyzed using superimposed cone-beam computed tomography images. Labial BR/tooth movement (BT) ratios at the crestal, midroot (S2), and apical (S3) levels were compared using the Friedman test and pairwise comparisons. Multivariate linear regressions were used to explore the relationships between the labial BT ratio and several factors, including age, ANB angle, mandibular plane angle, and incisor movement patterns. According to the type of palatal cortical BR observed, the patients were divided into 3 groups: type I (no BR without root penetration of the original palatal border [RPB]), type II (BR with RPB), and type III (no BR with RPB). Student's t test was used to compare the type II and III groups. The mean labial BT ratios at all levels were<1.00 (0.68-0.89). This value at the S3 level was significantly smaller than that at the crestal and S2 levels (P<0.01). Multivariate linear regression indicated that the tooth movement pattern negatively correlates with the BT ratio at S2 and S3 levels (P<0.01). Type I was noted in 40.9% of the patients, and similar proportions exhibited type II (29.5%, 25.0%) or type III remodeling (29.5%, 34.1%). The retraction distance of the incisors in type III patients was significantly larger than in type II patients (P<0.05). The amount of cortical BR secondary to maxillary incisor retraction is less than the tooth movement. Bodily retraction may lead to lower labial BT ratios at the S3 and S2 levels. Roots penetrating the original border of the cortical plate are necessary for palatal cortical BR initiation.

Time-distance vision transformers in lung cancer diagnosis from longitudinal computed tomography.

Features learned from single radiologic images are unable to provide information about whether and how much a lesion may be changing over time. Time-dependent features computed from repeated images can capture those changes and help identify malignant lesions by their temporal behavior. However, longitudinal medical imaging presents the unique challenge of sparse, irregular time intervals in data acquisition. While self-attention has been shown to be a versatile and efficient learning mechanism for time series and natural images, its potential for interpreting temporal distance between sparse, irregularly sampled spatial features has not been explored. In this work, we propose two interpretations of a time-distance vision transformer (ViT) by using (1) vector embeddings of continuous time and (2) a temporal emphasis model to scale self-attention weights. The two algorithms are evaluated based on benign versus malignant lung cancer discrimination of synthetic pulmonary nodules and lung screening computed tomography studies from the National Lung Screening Trial (NLST). Experiments evaluating the time-distance ViTs on synthetic nodules show a fundamental improvement in classifying irregularly sampled longitudinal images when compared to standard ViTs. In cross-validation on screening chest CTs from the NLST, our methods (0.785 and 0.786 AUC respectively) significantly outperform a cross-sectional approach (0.734 AUC) and match the discriminative performance of the leading longitudinal medical imaging algorithm (0.779 AUC) on benign versus malignant classification. This work represents the first self-attention-based framework for classifying longitudinal medical images. Our code is available at https://github.com/tom1193/time-distance-transformer.

Variations of the Nasal Septum in Adult Nigerians: Computed Tomography Study

Introduction The morphological variants of the nasal septum have been implicated in sinus pathology and pose a challenge during endoscopic surgeries. Objective The present study aimed at evaluating the prevalence of nasal septum variants in adult Nigerians. Methods The present study was performed at the Radiology Department of Delta State University Teaching Hospital, Nigeria, following ethical approval. Brain computed tomography (CT) scan images of 336 adults were evaluated for nasal septum variants. The angle of the deviated nasal septum was measured, and the severity was classified. Data were analyzed using IBM SPSS Statistics for Windows, version 23.0 (IBM Corp., Armonk, NY, USA). The angle of deviation was presented in means and standard deviation. Frequencies of the variants were presented in percentages. The Student t -test was used to compare the angle of deviation, while the chi-squared test was used to compare the frequencies in the different groups. A p-value < 0.05 was considered statistically significant. Results The prevalence of straight and deviated nasal septum was 59.5% and 40.5%, respectively. Deviation was predominant in females (46%) and, more frequently, of moderate severity (75%). The angle of deviation was significantly larger in males (12.55 ± 2.99°) than in females (11.13 ± 2.41°; p = 0.003). Nasal spur had a prevalence of 11.9%, and its coexistence with deviated nasal septum was observed in 5.06%. Septal pneumatization was seen in 10 patients (3%). Conclusion Deviation of the nasal septum occurred more in females and toward the left; however, the angle of deviation was significantly higher in males. Nasal septal spur and pneumatization were the least prevalent variants.

Localization of mental foramen in relation to primary molars in children. A cone-beam computed tomography study.

Localization of mental foramen in relation to primary molars in children. A cone-beam computed tomography study.

The findings of impacted and transmigrated maxillary and mandibular canines: a retrospective cone beam computed tomography study

The aim of this study was to examine and evaluate the maxillary and mandibular impacted and transmigrant canines, their relationship with neighboring tissues and pathology with cone beam computed tomography (CBCT). CBCT data of 217 patients, between January 2018 and December 2019, with a total of 293 impacted canines were retrospectively reviewed. Clinical records were also evaluated. Maxillary or mandibular localization, angulations, transmigration, lateral and premolar tooth resorption, apical dilacerations, pathological formations, presence of persistent deciduous canines and treatment methods were investigated. For 293 impacted canines, 237 were in the maxilla and 56 in the mandible, with this difference being statistically significant (P<0.05). Among the 293 impacted canines, 14 (4.8%) transmigrated canines were detected. From the 14 transmigrant canines, 13 were in the mandible and 1 was in the maxilla. This difference was found statistically significant (P<0.05). Eighteen dentigerous cysts (10 maxilla, 8 mandible) and 4 odontomas (3 maxilla, 1 mandible) were found in impacted canines. For a total of 293 impacted canines, 57 were extracted, 13 were referred to orthodontics and a follow-up decision was made for 223 teeth. Transmigration incidence is statistically significant, on a higher area of the lower jaw, compared to the upper jaw (P<0.05). In patients with impacted canines, taking CBCT together with a detailed clinical examination is effective in correct treatment planning and in minimizing complications that may occur during surgical extraction.

(842) Imaging Attributes of Right Ventricular Systolic and Diastolic Function in Patients with Continuous-Flow LVADs: A Contrast Computed Tomography Study

(842) Imaging Attributes of Right Ventricular Systolic and Diastolic Function in Patients with Continuous-Flow LVADs: A Contrast Computed Tomography Study

Biportal Endoscopic Transforaminal Lumbar Interbody Fusion Using Double Cages: Surgical Techniques and Treatment Outcomes.

To describe the surgical techniques and the treatment outcomes of biportal endoscopic transforaminal lumbar interbody fusion (BETLIF) using double cages. This study included 89 patients with 114 fusion segments between July 2019 and May 2021. One pure polyetheretherketone (PEEK) cage and 1 composite titanium-PEEK cage were used for interbody fusion. Clinical outcomes measures included visual analogue scale (VAS) scores for lower back pain and leg pain, Oswestry Disability Index (ODI), and Japanese Orthopedic Association (JOA) scores. Computed tomography (CT) of the lumbar spine 1 year postoperatively was used to evaluate the Bridwell interbody fusion grades. There were significant improvement in VAS for lower back pain from 5.2 ± 3.1 to 1.7 ± 2.1, VAS for leg pain from 6.3 ± 2.5 to 1.7 ± 2.0, ODI from 46.7 ± 17.0 to 12.7 ± 16.1, and JOA score from 15.6 ± 6.3 to 26.4 ± 3.2. The p-values were all < 0.001. The average hospital stay was 5.7 ± 1.1 days. The CT studies available for 60 fusion segments showed successful fusion (Bridwell grade I or grade II) in 56 segments (93.3%). Significant cage subsidence of more than 2 mm was only noted in 3 segments (5.0%). Complications included 1 dural tear, 2 pedicle screws malposition, and 2 epidural hematomas, in which 2 patients required reoperations. BETLIF with double cages provided good neural decompression and a sound environment for interbody fusion with a big cage footprint, a large amount of bone graft, endplate preservation, and segmental stability.

Supra-renal aortic atheroma extent and composition predict acute kidney injury after transcatheter aortic valve replacement: A three-dimensional computed tomography study

ObjectiveAcute kidney injury (AKI) may complicate transcatheter aortic valve replacement (TAVR) and could be linked to atheroembolization associated with catheter manipulation in the supra-renal (SR) aorta.We sought to determine the impact of SR aortic atheroma burden (SR-AAB) and composition, as well as of the aortic valve calcium score (AV-CS), measured at pre-operative multislice computed tomography (PO-MSCT), on AKI-TAVR. MethodsAll TAVR-patients 3 January-2018 to December-2020 were included. A three-dimensional analysis of PO-MSCT was performed, calculating percentage SR-AAB (%SR-AAB) as [(absolute SR-AAB volume)*100/vessel volume]. Types of plaque were defined according to Hounsfield unit (HU) intensity ranges. Calcified plaque was subcategorized into 3 strata: low- (351–700 HU), mid- (701–1000 HU), and high‑calcium (>1000 HU, termed 1 K-plaque). ResultsThe study population included 222 patients [mean age 83.3 ± 5.7 years, 95 (42.8%) males], AKI-TAVR occurred in 67/222 (30.2%). Absolute SR-AAB (41.3 ± 16.4 cm3 vs. 32.5 ± 10.7 cm3,p < 0.001) and %SR-AAB (17.6 ± 5.1% vs. 13.9 ± 4.3%,p < 0.001) were significantly higher in patients developing AKI-TAVR.Patients who developed AKI-TAVR had higher mid‑calcium (6.9 ± 3.8% vs. 4.2 ± 3.5%,p < 0.001) and 1 K-plaque (5.4 ± 3.7% vs. 2.4 ± 2.4%,p < 0.001) with no difference in AV-CS (p = 0.691).Adjusted multivariable logistic regression analysis showed that %SR-AAB [OR (x%increase): 1.12, 95%CI: 1.04–1.22,p = 0.006] and %SR-calcified plaque [OR (x%increase): 5.60, 95%CI: 2.50–13.36,p < 0.001] were associated with AKI-TAVR. Finally, 3-knots spline analyses identified %SR-AAB >15.0% and %SR-calcified plaque >7.0% as optimal thresholds to predict an increased risk of AKI-TAVR. ConclusionsSuprarenal aortic atheroma, when highly calcified, is associated with AKI-TAVR. Perioperative-MSCT assessment of aortic atherosclerosis may help in identification of patients at high-risk for AKI-TAVR, who could benefit from higher peri-operative surveillance.

What Do Radiology Residents Think of CT Abdomen and Pelvis Structured Reporting System?

Background: &#x0D; Radiology reports play a critical role in communicating information to clinicians in a timely and accurate manner. In recent years, there has been a growing shift towards the use of structured reporting systems (SRS) as an alternative to traditional free-text reports.&#x0D; Objective: The objective of our study is to assess the knowledge, attitude of radiology resident towards structured reporting and whether they practice report writing with SRS.&#x0D; Materials and Methods: This is a cross-sectional study. A cross-sectional study was conducted among 168 residents from radiology residency programs in the Western region of Saudi Arabia. Participants were surveyed using an English questionnaire. The questionnaire included demographic data, and questions concerning residents’ knowledge of SRS, attitude towards SRS and utilization of SRS in abdominopelvic computed tomography (CT) reports. Ethics approval was obtained from the Institutional Review Board of the Faculty of Medicine. &#x0D; Results: 78 residents participated in the survey. 10% of the residents were not familiar with SRS. 71% of the residents who did hear about it, did from a radiology consultant. 30% of the residents denied receiving training in reporting skills. 63.5% of residents preferred using SRS in abdomen and pelvis CT studies. Compared to conventional reporting, residents agreed that SRS helped them spot findings, took less time and decreased errors. On the other hand, residents thought that SRS limits their freedom of speech, and is harder to use in complex cases.&#x0D; Conclusion: Most radiology residents have a positive attitude towards SRS and believe that they increase the efficiency and accuracy of their reports. The overall level of knowledge and positive attitude of residents will, hopefully, help institutions implement structured reporting systems in the future.&#x0D; &#x0D; Key words: structured reports, radiology reports, free-text reports, attitude, practice, knowledge.

How low can we go? CT dose reduction in the assessment of the medial clavicular epiphysis in forensic age estimation: a prospective postmortem CT study.

Projection radiography and, more recently, computed tomography (CT) play an important role in forensic age estimation. Both in terms of general criminal responsibility and government regulations concerning refugee care, it is important to differentiate correctly between youths and adults. A disadvantage of age estimation in CT is the ionizing radiation exposure. To investigate how far the CT dose can be reduced without losing diagnostic confidence in assessing the different stages of ossification of the medial clavicle. We prospectively scanned 25 postmortem cases with a fixed parameters protocol (FPP) and a care dose modulation protocol (CDMP) for different scan parameters. Two radiologists assessed the diagnostic image quality using a 5-point Likert scale. Inter-reader agreement was evaluated with Cohen's kappa. Differences in doses between FPP and CDMP were assessed with the one-tailed t-test. The best combination of diagnostic image quality and lowest radiation dose was obtained using a CDMP with 100 kV and 40 mAs and an FPP with 100 kV and 30 mAs. Doses for 120 kV were significantly higher (one-tailed P < 0.001). The diagnostic image quality for 80 kV was insufficient overall. Our results confirm that CT imaging at 100 kV allows a sufficient image quality that is diagnostic for age estimation in the ossification of the medial clavicle.

Quantitative assessment of ramal bone width and the proximity of the inferior canal for the predictable insertion of ramal implants: Cone-beam computed tomography study

Objectives: The study aimed to investigate the optimum level for the placement of ramal implants as a source of anchorage for disimpacting mandibular molars. The criteria in relation to the maximum transverse width of the ramal bone and proximity of the implant to the inferior alveolar canal (IAC) were evaluated using a three-dimensional cone-beam computed tomography scan for predictable placement of ramal implants. Material and Methods: The cone-beam computed tomographic scans of 53 untreated patients (aged between 18 and 48 years) were utilized in this study. The maximum transverse width of the ramus and the proximity to the IAC from the site of insertion were measured at six different levels above the central groove of the mandibular first molar. To measure the proximity to the IAC, the mid-point of the maximum transverse width of the ramus was selected as the site of insertion of the implant. Results: The maximum and minimum transverse ramal width was 12.48 ± 1.76 mm at 3 mm and 10.42 ± 2.08 mm at 8 mm above the central groove of the permanent mandibular first molar. An average clearance of 9.62 ± 2.59 mm was measured from the site of insertion to the IAC at the different levels evaluated. Conclusion: The ramus of the mandible can be a predictable site for implant placement provided the variations in the anatomical structures have been carefully analyzed. It can be concluded that the ramal implants can be safely placed at a level 3–8 mm above the permanent mandibular first molar in relation to the occlusal plane.

Root and root canal morphology of permanent mandibular first and second molars in a Kuwaiti population: A retrospective cone-beam computed tomography study

AimEndodontic diseases typically affect the mandibular molars. Understanding the complex morphology of the root canal system and its variations is necessary for successful endodontic treatment. The aim of this study was to evaluate the morphology of roots and root canals of mandibular first and second permanent molar teeth in a Kuwaiti population using cone-beam computed tomography (CBCT). Materials and methodsCBCT images of 651 mandibular first and second molar teeth were obtained from specialist government dental centers. The age, sex, root canal configuration, and number and type of roots were recorded. The data were statistically analyzed. ResultsThe most common canal configuration in the mandibular first and second molars was type II (65.6% and 54.4%, respectively), with no significant difference seen between the sexes (p = 0.234). The canal configuration was significantly different between the mandibular first and second molars (p < 0.001). Most teeth had two roots (94.5%); split roots were common (92.6%) and the number thereof varied significantly. Radicular grooves were most common on the lingual side (4.9%). C-shaped canals were present in 43 (6.60%) teeth. Additionally, one tooth had a confluent middle mesial canal and nine (1.4%) had radix entomolaris. ConclusionMandibular molars in our Kuwaiti population typically had two split roots with type II and IV canal configurations. The prevalence rates of C-shaped canals, middle mesial canals, and radix entomolaris were remarkably low.

Cone-beam computed tomography study of mandibular morphology and tooth compensation in asymmetrical patients

This study evaluated mandibular morphology and transverse dental compensation between symmetrical and asymmetrical subjects, allocated according to sagittal skeletal patterns. In addition, the hypothesis that mandibular morphology and dental compensations differed between symmetrical/asymmetrical groups and also among the different types of sagittal skeletal patterns was tested. Cone-beam computed tomography images of 96 patients were included in this study and were divided into 2 groups according to the degree of menton deviation: a symmetrical group with deviation up to 2.0 mm (n= 48; mean age, 15 ± 6 years), and an asymmetrical group with deviation from 3.5 mm (n= 48; mean age, 16 ± 8 years). The 2 groups were divided in accordance with the ANB angle: Class I, II, and III. Skeletal and dental measurements were performed. Intergroup and intragroup analyses were carried out, using a 2-way analysis of variance to assess the interaction of factors: symmetry and sagittal skeletal pattern; and the Student t test for differences between deviated (Dv) and nondeviated (NDv) sides. Symmetrical/asymmetrical groups and Class I, II, and III groups were similar in relation to demographic aspects (P= 0.412 and P= 0.357 for sex and age, respectively). Asymmetrical patients had higher values for body length and mandibular ramus and condyle height on the NDv side (P= 0.011, P= 0.024, and P= 0.001, respectively). When comparing the different skeletal patterns, patients with a Class III relationship demonstrated higher values for mandibular ramus height. Intergroup analysis showed no differences in dental parameters. In the comparison between the sides, the asymmetrical group showed a significant difference in canine inclination (P= 0.008), mandibular ramus height (P= 0.004), condyle height (P= 0.010) and gonion to midsagittal plane distance (P= 0.018). Asymmetrical subjects showed higher values for canine inclination and mandibular body, ramus and condylar height on the NDv side. The hypothesis was partially confirmed that mandibular morphology and dental compensations are different between symmetrical/asymmetrical groups and among different sagittal skeletal patterns.