Cone Beam Computed Tomography Research Articles

The influence of different extraction indications on the morphological changes in the maxillary sinus: A retrospective cohort study.

The comprehensive effects of maxillary posterior tooth extraction on the maxillary sinus (MS) morphology remain to be thoroughly elucidated. This retrospective cohort study aimed at evaluating the influence of different extraction indications on the morphological changes in the MS by utilizing cone-beam computed tomography (CBCT). One hundred and seventy-eight of maxillary posterior tooth extractions underwent CBCT scans before and after extraction using 3D Slicer software. Parameters such as maxillary sinus pneumatization (MSP, the primary outcome measure), buccal bone height (BBH), palatal bone height (PBH), mucosal thickness (MT), and other anatomical structures were measured for patients undergoing extraction due to periodontitis, periapical lesions, or tooth fracture. Multiple linear regression analysis was employed to assess the effect of extraction indications on the MS. While the primary outcome, MSP, did not reveal statistically significant differences across various indications for tooth extraction (p > .05), extraction itself resulted in MSP (p < .05). The rate of this pneumatization was influenced by the position of the extraction site (p < .05). Additionally, baseline values of bone height and mucosal thickness showed an inverse correlation with the rate of change in these parameters following tooth extraction (p < .001). Tooth extraction led to increased pneumatization of the maxillary sinus while simultaneously reducing bone height and mucosal thickness. However, these outcomes were not influenced by the reason for tooth extraction.

ETIOPATHOGENIC ASPECTS OF ODONTOGENIC MAXILLARY SINUSITIS OF PERIAPICAL ORIGIN

Anatomically, the roots of the upper premolar and molar teeth are near the maxillary sinuses. Thus, periapical inflammation of the elements close to the sinuses enables the formation of odontogenic sinusitis. This study aimed to analyze the available literature on the etiopathogenic aspects of odontogenic maxillary sinusitis of periapical origin. A literature review was conducted in the following databases: SciELO, MEDLINE/Pubmed, and LILACS, using the keywords "Maxillary Sinusitis", "Dentistry", "Tooth" and "Infection". Articles written in English, Spanish, and Portuguese were included; those that fit the focus of the paper and those that were most relevant in terms of outlining the desired information. Papers reporting odontogenic sinusitis arising from an operative process were excluded. Odontogenic maxillary sinusitis (OMS) occurs due to sinus infection caused by inflammation of one or more dental elements near this cavity. Despite presenting specific features, sinusitis of odontogenic and non-odontogenic origin are quite similar, making the differential diagnosis difficult. Cone-Beam Computed Tomography (CBCT) is considered the reference standard for diagnosis, and the best treatment is to eliminate the causal factor. It was also found that apical periodontitis is the main non-iatrogenic cause and premolars and molars are the most affected teeth due to their anatomical location near the maxillary sinuses. The anatomical location of the maxillary sinus and the roots of the molars and premolars will allow, through the proximity between them, the OMS. In cases where periodontitis has proven to be the most frequent non-iatrogenic cause of this condition, also due to a great symptomatological similarity with non-odontogenic sinusitis, complementary examinations such as CBCT are necessary. Moreover, the treatment can be performed in a case-specific manner, through accurate diagnosis and etiopathogenesis.

Maxillary Giant Radicular Cyst: A Case Presentation and Management

Objectives: Radicular cysts are the most frequent odontogenic cystic lesions, they are inflammatory cysts that involve the apex of affected tooth and appear as well-defined radiolucencies. Most radicular cysts are small, but they can grow quite large due to their capacity for significant expansion, invasion of adjacent tissues, and rapid growth. They also have a high recurrence rate. We present here a rare case of a giant maxillary radicular cyst in a 60-year-old patient, aiming to highlight the clinical and radiological aspects, as well as the importance of enucleation with extraction of the offending tooth/teeth in the surgical management of these cysts. Methods: a 60-year-old male patient presented with an extensive involving the left anterior area of the maxilla. The cone-beam computed tomography (CBCT) image suggested the presence of an odontogenic cyst at the size of 50 mm × 30 mm in the affected side. For treatment, an enucleation of the cyst, along with the extraction of the association tooth, was performed. Results: The diagnosis of radicular cyst was established on the resected specimen. There were no signs of recurrence two years following the surgery. Conclusions: Imaging plays a crucial role in accurately diagnosing and assessing the extent of the cyst. Surgical treatment primarily relies on enucleation with extraction of the offending tooth which is essential for effective management and to minimize recurrence.

Image Quality Comparison of Three 3D Mobile X-Ray Imaging Guidance Devices Used in Spine Surgery: A Phantom Study

An image-quality CT phantom was scanned with three different 3D X-ray imaging guidance devices in the operating theatre: O-Arm, Loop-X, and Airo TruCT. Default acquisition and reconstruction parameters for lumbar spine procedures were used on each device. The tube current was set to a dose level of around 27 mGy. A task-based image quality assessment was performed by calculating the noise power spectrum (NPS) and task transfer function (TTF). A detectability index (d’) was calculated for three simulated bone lesions. The noise magnitude of the O-Arm was higher than the Airo TruCT, and the Loop-X had higher noise than the Airo TruCT. The highest average NPS frequency was for the O-Arm images, and the lowest was for the Loop-X. The TTFs at 50% values were similar for the Airo TruCT and Loop-X devices. Compared to Airo TruCT, the TTF at 50% value increased with the O-Arm by 53.12% and 41.20% for the Teflon and Delrin inserts, respectively. Compared to Airo TruCT, the d’ value was lower with Loop-X by −26.73%, −27.02%, and −23.95% for lytic lesions, sclerotic lesions, and high-density bone, respectively. Each 3D-imaging spine surgery guidance device has its own strengths and weaknesses in terms of image quality. Cone-beam CT systems apparently offer the best compromise between noise and spatial resolution for spine surgery.

Secondary Reconstruction of Panfacial Fractures With Virtual Reality Surgical Planning Using Both Pre and Postreconstruction Scans.

Late secondary reconstruction is sometimes required in patients with suboptimal primary panfacial fracture repair. At this stage, it can be difficult to discern original facial architecture due to malunion and bony remodeling. By utilizing the original postinjury CT scan to complete fracture reduction in the virtual reality (VR) planning environment, the surgeon may attempt to recreate an "ideal" facial bony anatomy for patients. This technique was completed in 2 patients presenting with facial deformity secondary to malunited panfacial fracture. Each had a cone-beam CT (CBCT) scan taken at presentation and the initial postinjury CT scans were obtained. Fracture reductions were completed in VR to recreate the preinjury anatomy. The resulting model was overlaid with current anatomy to create surgical aids. The first patient, a 23-year-old man, presented with malunion of all bones of the midface. Cutting guides were designed for the Lefort 1 segment, left zygomaticomaxillary complex (ZMC), and naso-orbito-ethmoid (NOE) osteotomies. The second patient, a 30-year-old woman, had bilateral ZMC and subcondylar fractures, midface retrusion, and malunion of parasymphyseal fracture. A 2-stage procedure was planned, including an initial Lefort I and bilateral sagittal split osteotomy with midline wedge excision. To address malar projection, a second surgery was planned using custom MEDPOR midface implants for the NOE and zygomatic regions. Both patients were discharged home, and all surgical goals and esthetic objectives were achieved.

PO0324: Brachytherapy Seed Placement by Robotic Bronchoscopy with Cone-Beam CT Guidance for Early-Stage Lung Cancer Treatments: Evaluation of Implant Quality in Human Cadavers

PO0324: Brachytherapy Seed Placement by Robotic Bronchoscopy with Cone-Beam CT Guidance for Early-Stage Lung Cancer Treatments: Evaluation of Implant Quality in Human Cadavers

Tooth segmentation by low-dose CBCT for orthodontic treatment planning : Explorative ex vivo validation.

Three-dimensional imaging has become an increasingly important component of orthodontics. Associated with this, however, is ahigher radiation exposure for patients. New cone-beam computed tomography (CBCT) devices have been developed that can provide low-dose CBCT(LD-CBCT). We hypothesized that LD-CBCT is as precise and reproducible as standard high-dose CBCT (HD-CBCT) in segmenting roots and crowns as well as measuring tooth length. HD-CBCT and LD-CBCT scans were taken of four human cadaveric heads. Thirty single-rooted teeth were segmented twice by one investigator. The length of each tooth was also measured. Lin's concordance correlation coefficient (CCC) was calculated to assess the agreement of HD-CBCT and LD-CBCT measurements and the intraclass correlation coefficient (ICC) was calculated to assess intrarater reliability. Analyses were supported by Bland-Altman plots. Volume measurements obtained using HD-CBCT were significantly higher than those obtained using LD-CBCT (p < 0.001). CCC was 0.975 (95% confidence interval [CI] = 0.956-0.986) indicating excellent agreement between the two modalities. Intrarater reliability between the two sets of LD-CBCT and HD-CBCT volume measurements was excellent (ICC = 0.998, 95%CI = 0.995-0.999 [HD-CBCT], ICC = 0.997, 95%CI = 0.992-0.998 [LD-CBCT]). CCC for tooth length measurements was 0.991 (95% CI = 0.983-0.995), indicating excellent agreement between HD-CBCT and LD-CBCT. Intrarater reliabilities between the two sets of tooth length measurements were also excellent for both methods (ICC = 0.998, 95%CI = 0.995-0.999 [HD-CBCT], ICC = 0.997, 95%CI = 0.992-0.998 [LD-CBCT]). Within the limitations of this experimental setting, LD-CBCT is as valid as HD-CBCT for measuring tooth length. Regarding the volume differences, in vivo studies are required to determine their clinical relevance.

Computer-guided implant surgery and tooth-mirroring digital workflow to treat an esthetically compromised clinical case

Background: In multidisciplinary dentistry, it is common to observe clinical cases that present multiple complications at the end of orthodontic therapy, such as differences in gingival height, alterations in size and shape of the teeth, and reduced residual spaces for implant therapies. Aim: The aim of the study was to solve an esthetic case with the help of digitally assisted prosthetic and surgical design. Methods: A young patient had been treated orthodontically for the agenesis of tooth 12 and the conoid shape of tooth 22. Previous therapy consisted of opening the space for tooth 12 by positioning a Maryland-type composite bridge, followed by reconstruction with a composite of tooth 22. Various composite reconstructions on teeth 11 and 21 were no longer adequate. Furthermore, both elements had discordant coronal axes, the diastema was observed at the incisal level, and tooth 21 was approximately 1 mm longer than tooth 11. Radiographic analysis revealed that the roots of teeth 11 and 13 converge, providing sufficient space for the insertion of a small-diameter implant. An intraoral scan and cone-beam computed tomography (CBCT) were performed; both data files were merged using surgical design software. A surgical guide was developed for the insertion of an implant in site 12. After insertion, the composite bridge, which was no longer suitable, was removed and a new temporary metal-composite Maryland bridge was positioned. Using an artificial intelligence tool of the design software, tooth 22 was isolated, mirrored, inserted in site 12 to reproduce the gingival profile, and subtracted from the digital impression. A technician then copied this emergence profile to build a zirconia prosthetic crown to be screwed on the implant. Teeth 22, 11, and 21 were restored with a lithium disilicate crown and two veneers, respectively. Results: The initial digital design and the use of a guided surgery procedure allowed for the insertion of a small diameter implant without damaging the roots of the adjacent teeth. The prosthetic design procedure, using the digital tools of the design program, made it possible to standardize and create symmetrical gingival profiles of teeth 12 and 22. The overall composition was completed by the use of minimally invasive adhesive prosthetic techniques on teeth 11, 21, and 22. Conclusion: Digital resources have become essential tools for dental professionals. The knowledge and use of technologies like intraoral scanning and CBCT, combined with various innovations such as artificial intelligence in prosthetic and implant design software, enable dentists to manage even the most complex interdisciplinary clinical cases with greater confidence. Relevance for Patients: Digital techniques are now widely used across all fields of dentistry. This has led to the need for operators of all ages to adjust their decision-making process compared to traditional techniques. These new techniques have also improved communication with patients, allowing the dental team to have a clearer understanding of the clinical path to follow and consequently offer their patients precise dentistry solutions.

Influence of the Vertek aiming device on the surgical accuracy of computer-assisted drilling of the equine distal sesamoid bone-An experimental cadaveric study.

To determine the effect of the Vertek aiming device (VAD) on the surgical accuracy of navigated drilling of the distal sesamoid bone (DSB). Experimental cadaveric study. A total of 30 paired equine cadaveric limbs from 15 horses. Each specimen was placed in a purpose-built frame (PBF). Preoperative cone beam computed tomography (CBCT) images were acquired with an imaging unit coupled with a surgical navigation system. In the DSB of each specimen, a 4.5 mm glide hole and a 3.2 mm thread hole were drilled under navigation guidance, to simulate drilling for the repair of a mid-sagittal DSB fracture. In the VAD group navigated drilling was assisted by using the VAD. In the free-hand drilling group navigated drilling was performed without the VAD. Pre-and postoperative CBCT scans were merged and surgical accuracy aberrations (SAA) between the planned drill corridor and the created bone tunnel were measured. Descriptive statistics and repeated-measures analyses of variance (rep.-meas. ANOVA) were performed to compare SAA measurements between the study groups. The SAA measurements ranged from 0 to 2.9 mm in the free-hand group and from 0 to 2.8 mm in the VAD group. The median overall SAA was lower in the VAD group than in the free-hand navigated group (0.6 mm ± [0.5-0.7] vs. 0.8 mm ± [0.7-1], rep.-meas. ANOVA p = .007). The additional use of the VAD in the described set-up for navigated drilling significantly improved surgical accuracy. The combined use of the VAD and PBF may help improve surgical accuracy in navigated lag screw repair of DSB fractures.

Comprehensive Treatment of Impacted Teeth with Comprehensive Oral Clinical Diagnosis and Treatment Thinking

Impacted teeth are a common disease in oral surgery, which can be caused by systemic factors and local factors, and the incidence of different genders, races and tooth positions is different. The clinical manifestation of impacted teeth is the absence of permanent teeth in normal position. Cone beam CT can accurately diagnose and locate impacted teeth. At present, surgical fenestration or direct extraction are often used to treat impacted teeth, but the treatment effect and prognosis are not ideal enough. In the process of oral clinical diagnosis and treatment, doctors began to adopt comprehensive diagnosis and treatment thinking to solve problems, and the key to improve the success rate of oral disease treatment is to make a clear diagnosis, reasonably evaluate the difficulty of treatment and adopt appropriate correction methods. This paper summarizes the research status of impacted teeth in recent years, focusing on the multidisciplinary comprehensive treatment of impacted teeth, in order to improve the clinical comprehensive diagnosis and treatment thinking of dentists and provide reference for accurate treatment of impacted teeth and reduction of complications in the treatment process.

Initial Clinical and Cone-Beam Computed Tomography (CBCT) Outcomes of Enamel Matrix Derivative-Based Regenerative Therapy in Vertical Bone Defects

Initial Clinical and Cone-Beam Computed Tomography (CBCT) Outcomes of Enamel Matrix Derivative-Based Regenerative Therapy in Vertical Bone Defects

Low-Field MRI for Dental Imaging in Pediatric Patients With Supernumerary and Ectopic Teeth: A Comparative Study of 0.55 T and Ultra-Low-Dose CT.

This study sought to elucidate the diagnostic performance of 0.55 T magnetic resonance imaging (MRI) for pediatric dental imaging, specifically in terms of the image quality (IQ) for detecting ectopic and/or supernumerary teeth, compared with routine ultra-low-dose computed tomography (ULD-CT) of the jaw. A total of 16 pediatric patients (mean age: 12.4 ± 2.6 years, range: 9-17 years) with ectopic and/or supernumerary teeth screened from January 2023 to January 2024 were enrolled in this prospective, single-center study. All patients underwent ULD-CT as the clinical reference standard and 0.55 T MRI as the study scan on the same day. A 0.6-mm isotropic 3-dimensional T1w FLASH sequence was developed with a dedicated field of view of the upper and lower jaws. ULD-CT was performed using a new single-source computed tomography (CT) scanner equipped with a tin filter (Sn100, slice thickness: 1 mm, quality reference mAs: 24). The IQ for the tooth axis, the tooth length, the tooth root, root resorptions, cysts, the periodontal ligament space, and the mandibular canal was evaluated twice by 3 senior readers using a 5-point Likert scale (LS) (LS score of 1: insufficient, 3: reduced IQ but sufficient for clinical use, and 5: perfect) and compared between both methods. Subsequently, the results were dichotomized into nonvalid (LS score of ≤2) and valid (LS score of ≥3) for clinical use. A total of 49 ectopic and/or supernumerary teeth in 16 pediatric patients were investigated using ULD-CT (CTDI: 0.43 ± 0.09 mGy) and 0.55 T MRI. The mean MRI acquisition time was 9:45 minutes. Motion artifacts were nonsignificantly different between 0.55 T MRI and ULD-CT (P = 0.126). The IQ for the tooth axis, the tooth root, root resorptions, and cysts was similar between the methods. The IQ for the periodontal ligament space and tooth length favored ULD-CT by 14% (confidence interval [CI]: 4.3%-24%) and 7.5% (CI: 1.8%-13%), respectively, whereas that for the mandibular canal favored 0.55 T MRI by -35% (CI: -54%-16%). Sufficient IQ was found especially for cystic lesions (CT: 100% sufficient, MRI: 95% sufficient), the tooth root (CT: 100%, MRI: 98%), root resorptions (CT: 94%; MRI: 85%), the tooth axis (CT: 100%; MRI: 98%), and the tooth length (CT: 99%; MRI: 91%). The findings indicate that 0.55 T MRI is a feasible, radiation-free technique for delineating ectopic and/or supernumerary teeth in pediatric patients. Nevertheless, to date, 0.55 T MRI has not yet been able to provide an optimal IQ for all anatomical tooth and jaw structures. In cases of advanced clinical indications that require optimal spatial resolution, high-resolution CT or cone-beam CT may still be necessary.

Accuracy of robotic-assisted surgery for immediate implant placement in posterior teeth: a retrospective case series

BackgroundRobotic computer-assisted implant surgery (r-CAIS) is a revolutionary innovation in oral implantation; however, the clinical feasibility of r-CAIS for immediate implant placement (IIP) in posterior teeth has not been verified. Thus, this study aimed to evaluate the accuracy of r-CAIS for IIP in posterior tooth regions.MethodsPatients with posterior teeth to be extracted and indicated to undergo r-CAIS were evaluated. The patients had positioning markers installed in the oral cavity and underwent cone-beam computed tomography (CBCT). Subsequently, minimally invasive tooth extractions were performed, and an individualised surgical plan was generated in the robotic software. After marker registration, implantation surgery was performed by the robotic arm under the supervision and assistance of the surgeons. Finally, the deviations between the planned and placed implants were evaluated based on preoperative and postoperative CBCT data.ResultsA total of 12 patients were evaluated. No adverse events occurred during the surgery. The mean global coronal, global apical, and angular deviations were 0.46 ± 0.15 mm (95%CI:0.36 to 0.56 mm), 0.46 ± 0.14 mm (95%CI:0.37 to 0.54 mm), and 1.05 ± 0.55° (0.69 to 1.40°), respectively.ConclusionsUnder the limited conditions of this study, the r-CAIS exhibited high accuracy in posterior teeth IIP surgery. Further multicentre randomised controlled studies are required to confirm the feasibility of this technology.

Comparison of Retreatability of AH Plus Sealer and Bioceramic Sealer with Solvent, Retreatment Files and Diode Laser: A CBCT and SEM Analysis

ABSTRACT Aim: The present study evaluated the retreatability of canals obturated using AH Plus sealer and Bioceramic (BC) sealers, employing Cone beam computed tomography (CBCT) and Scanning Electron Microscope (SEM). Methodology: A group of 90 extracted premolars was classified into two main categories based on whether they were sealed with AH Plus or BC Sealer. Each of these categories was then divided into two subcategories according to the retreatment technique applied. CBCT and SEM were used to assess the residual filling material within the canals. Results: The findings showed that there was no marked statistical variation in the retreatment success of canals sealed with BC and AH Plus sealers. Conclusion: The diode laser was the most effective modality for eliminating root canal filling materials in the least amount of time. None of the retreatment modalities used removed the obturating material completely.

Diagnostic Utility of the "Air Sign" as a Radiological Indicator for Mandibular Body and Angle Fractures.

Background: To plan optimal treatment, obtain satisfactory outcomes, and avoid undesirable clinical errors, surgeons need to have efficient tools for providing a complete and prompt diagnosis. The aim of this study was to establish the sensitivity, specificity, positive and negative predictive values, false positive rate, and false negative rate of the "air sign" (AS) within soft tissues as an indirect radiological indicator of mandibular body and angle fractures. Methods: A retrospective analysis of preoperative computed tomography (CT) and cone beam computed tomography (CBCT) scans was performed on patients with mandibular fractures within a three-year period. Two fracture types were analyzed: open and closed fractures. Results: Forty-three patients with a total of 71 mandibular fractures were included in the study. The mean age of the patients was 35 years, and the majority were male (83.7%). The sensitivity of the AS was 92.2%, specificity = 90.0%, positive predictive value = 95.9%, negative predictive value = 81.8%, false positive rate = 10.0%, and false negative rate = 7.8%. Higher values were observed for open fractures compared to closed fractures. Conclusions: The sensitivity and specificity of AS are lower than those of OPG, CT, and CBCT. However, AS offers an important additional radiological indicator that can effectively reduce the risk of misdiagnosing mandibular body and angle fractures.

Relationship of incidence of radix entomolaris and C-shaped canal in mandibular molars using CBCT: A multi-centre study.

This study aimed to evaluate the relationship of incidence between radix entomolaris (RE) in permanent mandibular first molars (FM) with C-shaped canal (CSC) in permanent mandibular second molars (SM). A total of 1015 cone-beam computed tomography (CBCT) images of permanent mandibular molars from Malaysian patients were collected retrospectively and analysed by researchers from seven dental schools in Malaysia trained in CBCT technology. The presence and absence of RE and CSC were scored as 'yes' or 'no'. The prevalence of FM with RE was 21.2% and SM with CSC was 37.9%. The co-occurrence of RE and CSC in the same quadrant was 6.5% (OR = 1.497, p = 0.014). Female, Chinese and samples from Eastern Peninsular Malaysia were associated with CSC in SM (p < 0.05). The increased appearance of CSC in SM when RE is present in FM makes it imperative for clinicians to be vigilant during examination and diagnosis to prevent potential endodontic mishaps.

Measurement and analysis of condylar morphology and thickness of the roof of the glenoid fossa in patients with unilateral second molar scissor bite

Objective The objective of this study was to measure and analyze the joint space, condylar morphology, and thickness of the roof of the glenoid fossa (RGF) in patients with unilateral second molar scissor bite using cone beam CT (CBCT). Methods A total of 80 patients were included in this study. Forty patients with a normal posterior occlusal relationship, who attended the Department of Orthodontics at the First Hospital of Shanxi Medical University from December 2021 to August 2023, were selected as the control group. The experimental group consisted of 40 patients with unilateral second molar scissor bite during the same period. All patients underwent CBCT scanning, and the resulting images were analyzed using the NNT viewer software in multiplanar reconstruction (MPR). Axial, coronal, and sagittal adjustments were made for each patient. Results In the control group, the right and left joint spaces (PS, SS, AS), the height of the upper part of the condyle, and the depth of the glenoid fossa did not show statistically significant differences (P > 0.05). When comparing bilateral condylar morphology and joint space in the experimental group, it was found that the posterior joint space on the scissor bite side was greater than that on the normal occlusion side, while the anterior joint space on the scissor bite side was smaller than that on the normal occlusal side. Additionally, the height of the upper condyle and the depth of the glenoid fossa on the scissor bite side were greater than that on the normal occlusal side, with statistically significant differences (P < 0.05). However, there were no statistically significant differences in SS, internal and external joint diameter, as well as anterior and posterior diameters (P > 0.05). The comparison of the minimum thickness of the roof of the glenoid fossa in both the sagittal and coronal directions between the patients in the experimental group and the control group showed no statistically significant difference (P > 0.05). Furthermore, the asymmetry index of the supracondylar height in the control group was significantly smaller than that in the experimental group, displaying a statistically significant difference (P < 0.05). The differences in the asymmetry indices of the anterior and posterior diameters of the condyle, as well as the inner and outer diameters, were not statistically significant (P > 0.05). When analyzing the position of the condyle in the sagittal direction of the glenoid fossa in the patients of the control group, it was observed that the majority were in the anterior and medial positions, with only 10% and 5% being in the posterior position. However, the analysis of the condyle position in the sagittal direction of the glenoid fossa in the experimental group revealed statistically significant differences (P < 0.05), with the condyle position on the scissor bite side being more anterior. Conclusion Unilateral second molar scissor bite can result in anterior displacement of the condyle, greater height of the condyle superiorly as well as the depth of the glenoid fossa.

Dosimetric benefit and clinical feasibility of deep inspiration breath-hold and volumetric modulated arc therapy-based postmastectomy radiotherapy for left-sided breast cancer

To evaluate the dosimetric benefits and clinical feasibility of deep inspiratory breath-hold (DIBH) combined with volumetric modulated arc therapy (VMAT) in left-sided postmastectomy radiotherapy (PMRT). Eligible patients with left-sided breast cancer undergoing DIBH-based PMRT were prospectively included. Chest wall, supra/infraclavicular fossa, and/or internal mammary node irradiation (IMNI) were planned with a prescription dose of 43.5 Gy in 15 fractions. VMAT plans were designed on free breathing (FB)—and DIBH-CT to compare dosimetric parameters in heart, left anterior descending artery (LAD) and lung. Cone-beam computed tomography (CBCT) was performed before and after treatment to evaluate inter- and intra-fractional setup errors. Heart position and dose variations during treatment were estimated by fusing CBCT with DIBH-CT scans.Twenty patients were included with 10 receiving IMNI. In total, 193 pre-treatment and 39 pairs pre- and post-treatment CBCT scans were analyzed. The Dmean, Dmax, and V5−40 of the heart, LAD, and left lung were significantly lower in DIBH than FB (p < 0.05 for all), except for V5 of LAD (p = 0.167). The cardiopulmonary dosimetric benefits were maintained regardless of IMNI. The inter- and intra-fractional setup errors were < 0.3 cm; and the overall estimated PTV margins were < 1.0 cm. During treatment, the mean dice similarity coefficient of heart position and the mean ratio of heart Dmean between CBCT and DIBH-CT plans was 0.95 (0.88–1.00) and 100% (70.6–119.5%), respectively. DIBH-VMAT could effectively reduce the cardiopulmonary doses with acceptable reproducibility and stability in left-sided PMRT regardless of IMNI.

Impacted mandibular third molars: a comparison of orthopantomography and cone-beam computed tomography imaging in predicting surgical difficulty.

This study investigated the predictive value of orthopantomography (OPG) for the difficulty of extracting impacted mandibular third molars, in comparison with cone-beam computed tomography (CBCT). In this descriptive quantitative investigation, two oral and maxillofacial radiologists evaluated OPG and three-dimensional CBCT images according to the Pell-Gregory and Winter classifications. The results for the classification were compared using the chi-square test, and the prediction of difficulty was assessed using the Pederson scale, with a significance level of p< 0.05. The study included 30 patients (14 men and 16 women), providing a total of 53 samples of impacted mandibular third molars. Of these, 30 (56.6%) were from the right side and 23 (43.4%) from the left. There was a statistically significant difference between the OPG and CBCT images concerning their relation to the mandibular ramus (p< 0.05). However, evaluations based on occlusal lines and angulation showed no significant differences (p> 0.05). According to the Pederson scale, significant differences were observed between OPG and CBCT in predicting extraction difficulty (p< 0.05). CBCT offered a more accurate assessment of the surgical difficulty associated with mandibular third molars than OPG. OPG views frequently failed to adequately visualize the region of the mandibular ramus, influencing the perceived difficulty of mandibular third molar surgery. In certain cases, the use of CBCT imaging is crucial.

Assessment of Condylar Changes in Patients with Degenerative Joint Disease of the TMJ After Stabilizing Splint Therapy: A Retrospective CBCT Study.

Degenerative joint disease (DJD) of the TMJ can impact patients' quality of life and complicate orthodontic treatment. Stabilizing splints are a common conservative treatment in managing TMDs symptoms, although their long-term effects on condylar morphology are poorly studied. This study aimed to assess the impact of stabilizing splints on condyle morphology using cone-beam computed tomography (CBCT) in patients with various stages of DJD. Forty-two condyles with pre- (T1) and post- (T2) splint therapy scans were analyzed. CBCT scans were sectioned into sagittal and coronal slices for condyle classification and measurement. T1 and T2 CBCTs were superimposed before linear and area measurements at different poles. Our results indicate that condyles in the normal group remain unchanged after splint therapy. The majority of subjects in the degenerative groups remained in the same classification group: six out of fourteen degenerative-active patients became degenerative-repair, while three out of twenty-two degenerative-repair patients progressed to degenerative-active. There is no significant remodeling of condylar width pre- and post-splint therapy. On average, there is more bone deposition than reduction in condylar height after splint therapy, although individual variation exists. Stabilizing splints offer a low-risk intervention for managing DJD and may contribute to favorable adaptive changes in the condyles.