The Application of Mask Region-Based Convolutional Neural Networks in the Detection of Nasal Septal Deviation Using Cone Beam Computed Tomography Images: Proof-of-Concept Study.

BACKGROUND: Artificial intelligence (AI) models are being increasingly studied for the detection of variations and pathologies in different imaging modalities. Nasal septal deviation (NSD) is an important anatomical structure with clinical implications. However, AI-based radiographic detection of NSD has not yet been studied. OBJECTIVE: This research aimed to develop and evaluate a real-time model that can detect probable NSD using cone beam computed tomography (CBCT) images. METHODS: Coronal section images were obtained from 204 full-volume CBCT scans. The scans were classified as normal and deviated by 2 maxillofacial radiologists. The images were then used to train and test the AI model. Mask region-based convolutional neural networks (Mask R-CNNs) comprising 3 different backbones-ResNet50, ResNet101, and MobileNet-were used to detect deviated nasal septum in 204 CBCT images. To further improve the detection, an image preprocessing technique (contrast enhancement [CEH]) was added. RESULTS: The best-performing model-CEH-ResNet101-achieved a mean average precision of 0.911, with an area under the curve of 0.921. CONCLUSIONS: The performance of the model shows that the model is capable of detecting nasal septal deviation. Future research in this field should focus on additional preprocessing of images and detection of NSD based on multiple planes using 3D images.

ANALYSIS OF THE USE OF COMPLEX DIGITAL TECHNOLOGIES IN THE DIAGNOSIS AND TREATMENT OF OCCLUSAL ANOMALIES.

BACKGROUND: Digital technologies have expanded in the field of dentistry, especially in the clinical and diagnostic aspects of occlusal abnormalities. Consequently, the purpose of this narrative review is to identify and synthesize data concerning the effects of these sophisticated digital technologies on improved diagnostic performance, treatment interventions, and patient outcomes. METHODS: Cochrane, Scopus, Web of Science, and PubMed were searched and, therefore, performed to find the pertinent digital technologies in dentistry from the published literature. The search was conducted in the period between 2000 and 2024. The criteria for inclusion of the studies targeted technologies that were Cone-Beam Computed Tomography (CBCT), intraoral scanners, 3D imaging, and Computer-Aided Design and Manufacturing (CAD/CAM). Some of the comparing between conventional and modern approaches were raised. RESULTS: Digital technologies have enhanced the diagnostic process due to extended visualization and precise evaluation of occlusal disturbances Conclusion: It has been seen that the application of information technologies in dentistry significantly improved the diagnostics and therapy of occlusion disturbances. While there are some invincible challenges posed by these advancements, the prospects are noteworthy when it comes to accuracy, efficiency, and patient benefits.

Evaluation of nasal septal deviation and maxillary bone and nasal airway dimensions and volumes using cone-beam computed tomography in patients with unilateral palatal canine displacement: a retrospective study.

OBJECTIVES: To detect any association between palatally displaced canine (PDC) and nasal septal deviation (NSD), palatal bone thickness and volume, and nasal airway dimensions and volume. MATERIALS AND METHODS: A total of 92 patients were included and subdivided into two groups: group 1, unilateral PDCs (44 patients), and group 2, normally erupted canines (NDCs) (48 subjects). The following variables were measured using cone-beam computed tomography: presence and type of NSD, nasal width, inferior conchae, hard palate and nasal septum thickness, maxillary bone and nasal airway volumes. RESULTS: NSD was detected in 77% and 50% of PDC and NDC subjects, respectively. Within the PDC subjects, significant differences between the displaced and nondisplaced sides were detected. Palate thickness was increased in the canine region and reduced in the molar region. Compared with the control group, PDC subjects had reduced palate thickness and lower nasal airway volume. Two predictors were significant for predicting the odds of PDC occurrence: NSD and maxillary bone volume. CONCLUSIONS: NSD is more frequent in PDC subjects. PDC subjects have reduced palate thickness and decreased nasal airway volume. In the presence of NSD, the odds of developing PDC increase by 3.35 times, and for each one-unit increase in the maxillary bone volume, the odds of developing PDC decrease by 20%.

Comparison of alveolar bone morphology after expansion with hybrid and conventional Hyrax expanders.

OBJECTIVES: To compare the buccal and palatal bone changes of maxillary posterior teeth produced by hybrid hyrax (HH) and conventional hyrax (CH) expanders in growing patients. MATERIAL AND METHODS: A sample of 32 patients with posterior crossbites in the late mixed dentition was recruited and randomly allocated into two groups. Group HH was composed of 18 individuals with a mean age of 10.7 years (six female, 12 male) treated with a hybrid expander with two anterior parasagittal miniscrews. Group CH was composed of 14 individuals with a mean age of 11.4 years (six female, eight male) treated with a conventional Hyrax expander. Cone-beam computed tomography (CBCT) exams were obtained before expansion (T1) and after 11 months when the expander was removed (T2). Buccal and palatal bone plate thickness and height of maxillary posterior teeth were measured. Intergroup comparisons were performed using t or Mann-Whitney tests (P < .05). RESULTS: The CH group showed greater decreases of the buccal bone plate height (mean change: 1.27 mm) at the maxillary first premolars compared to the HH group (mean change: 0.11 mm, P = .001). No intergroup difference was found for changes in the buccal and palatal bone thickness. CONCLUSIONS: Hybrid expanders showed a tendency to cause less negative impact on the buccal bone plate height of first premolars compared to conventional Hyrax expanders. However, the difference was not clinically significant. Both hybrid and conventional Hyrax expanders are safe for the alveolar bone morphology in the late mixed dentition.

Correlation between oral cavity volume and upper airway changes in skeletal Class III patients undergoing bimaxillary orthognathic surgery: a pilot cone-beam computed tomography study.

OBJECTIVES: To evaluate changes of the upper airway and oral cavity volumes in patients with skeletal Class III malocclusion undergoing bimaxillary orthognathic surgery, and to analyze the correlation between postoperative upper airway decrease and the amount of jaw movement and oral cavity volume reduction. MATERIALS AND METHODS: Thirty patients (16 males and 14 females) undergoing bimaxillary surgery were included. Three-dimensional reconstruction of the upper airway and oral cavity were performed using preoperative (T0) and postoperative (T1) (6 months) cone-beam computed tomography scans. RESULTS: The volume, sagittal area and minimum cross-sectional area of the upper airway were diminished (P < .001). The decrease in volume and minimum cross-sectional area in the oropharyngeal region of the upper airway were weakly correlated with B-point posterior movement (P < .05). Total oral cavity volume was decreased, with maxillary oral volume increasing and mandibular oral volume decreasing (P < .001). Upper airway decrease was highly correlated with total oral volume reduction and mandibular oral volume reduction, with the most significant correlation being with total oral volume reduction (P < .001). CONCLUSIONS: Class III bimaxillary surgery reduced the volume, sagittal area, and minimum cross-sectional area of the upper airway as well as oral cavity volume. Upper airway changes were weakly correlated with anterior-posterior mandibular movement but significantly correlated with oral cavity volume changes. Thus, oral cavity volume reduction is a crucial factor of upper airway decrease in patients with skeletal Class III malocclusion undergoing bimaxillary orthognathic surgery.

Changes in the upper airway and its surrounding structures after bimaxillary surgery in patients with cleft-related Class III deformity.

OBJECTIVES: To compare upper airway changes following bimaxillary surgery for correction of Class III deformity between patients with unilateral cleft lip and palate (UCLP) and bilateral cleft lip and palate (BCLP) and to compare the preoperative and postoperative upper airway among patients with UCLP and BCLP to healthy controls. MATERIALS AND METHODS: Sixty adults with CLP-related skeletal Class III deformity (30 UCLP and 30 BCLP) who consecutively underwent bimaxillary surgery were studied retrospectively. Cone-beam computed tomography (CBCT) was performed before and after surgery to measure upper airway and movements of facial skeletal and surrounding structures. CBCT images from 30 noncleft skeletal Class I adults, matched by age, gender, and body mass index and without surgical intervention, served as controls. RESULTS: After surgery, the volume of the nasopharynx increased in patients with CLP (both P < .001). Patients with CLP did not differ from controls in postoperative volume of the nasopharynx or oropharynx. However, the nasal cavity differed significantly between patients with CLP and controls (P < .001). CONCLUSIONS: After bimaxillary surgery, the nasal cavity of patients with CLP differed significantly compared with the controls. Volumes of the nasopharynx and oropharynx did not differ between patients with CLP after surgery and controls.

Do erupting maxillary canines resorb adjacent teeth? A study focusing both on the ipsilateral and contralateral sides among individuals with unilaterally impacted canines.

OBJECTIVES: To determine the prevalence of root resorption of teeth adjacent to permanent maxillary canines on both sides, by cone-beam computed tomography (CBCT), in pretreatment adolescent subjects with unilaterally impacted maxillary canines, and to define predictive factors for the root resorption. MATERIALS AND METHODS: This retrospective sample included 76 adolescents (38 boys, 38 girls, mean age 12.3 ± 2.1 years; range 8-17 years) who had CBCT after detection of a unilateral impacted maxillary canine before any active orthodontic treatment. Both ipsilateral and contralateral sides were examined, and 14 qualitative and quantitative variables were collected. Descriptive statistics were calculated, and multiple logistic regression was used to predict root resorption. RESULTS: On the impaction side, 57.9% of canines resorbed at least one adjacent tooth compared with 13.2% on the contralateral side (P < .001). On the impaction side, resorption was slight in 59.6%, moderate in 5.8%, and severe in 34.6% of the cases. On the contralateral side, resorption was slight in 91.7%, moderate in 0%, and severe in 8.3% of the cases. On both sides, upper lateral incisors were the teeth most frequently resorbed, followed by the upper first premolars and upper central incisors. The presence of contact between the canine and the adjacent roots was the only statistically significant risk factor for resorption for both ipsilateral and contralateral sides. CONCLUSIONS: Orthodontists should look for root resorption on both sides in cases of unilaterally impacted maxillary canines.

Evaluation of dentoalveolar changes following maxillary incisor intrusion with one vs two anterior miniscrews in subjects with gummy smile: a randomized clinical trial.

OBJECTIVES: To examine dentoalveolar changes following intrusion of maxillary incisors with one or two anterior miniscrews in subjects with gummy smile and deep bite. MATERIALS AND METHODS: Forty-three subjects were selected and divided into two groups: group I (22 subjects: 15 women, 7 men; mean age 30 ± 10 years) received one miniscrew between the upper central incisors, and group II (21 subjects: 16 women, 5 men; mean age 30 ± 10 years) received two miniscrews between the canines and lateral incisors. Dentoalveolar parameters, including amount of intrusion, root resorption, incisor inclination, alveolar bone thickness, and buccal alveolar crest height (cementoenamel junction to labial alveolar crest), were evaluated using cone-beam computed tomography scans obtained before and after intrusion. The intergroup comparison was analyzed using a paired t-test and unpaired t-test to determine significant changes within and between groups. RESULTS: The amount of intrusion was significantly greater in group II than in group I (P < .05). No statistically significant differences were found between groups I and II for changes in incisor inclination, labial bone thickness, and buccal alveolar crest height (P > .05). CONCLUSIONS: Maxillary central and lateral incisor intrusion was significantly greater in subjects treated with two miniscrews. Root resorption of the maxillary central incisors was notably greater in subjects with one miniscrew, while maxillary lateral incisor resorption was greater in subjects treated with two miniscrews.

Evaluation of anchorage loss after en masse retraction in orthodontic patients with maxillary protrusion using friction vs frictionless mechanics: randomized clinical trial.

OBJECTIVES: To evaluate anchorage loss after en masse retraction in bimaxillary dentoalveolar protrusion patients using friction vs frictionless mechanics. MATERIALS AND METHODS: Thirty patients with bimaxillary dentoalveolar protrusion needing extraction of upper first premolars and en masse retraction with maximum anchorage were included in this two-arm, parallel, single-center, single-blinded randomized clinical trial with a 1:1 allocation ratio using fully sealed opaque envelopes. Friction group retraction utilized elastomeric power chain between miniscrews and hooks crimped mesial to upper canines on 17 × 25 stainless steel archwire. Frictionless group used customized T-loop springs loading upper first molars indirectly anchored to miniscrews. Activation was every 4 weeks until full retraction. The primary outcome assessed was anchorage loss evaluated at cusp tip and root apex of the first molar. First molar rotation, incisor tip and torque, and root resorption of anterior teeth were evaluated on digital models and cone beam computed tomography taken before and after space closure. RESULTS: Anchorage loss at crown of first molar was significantly more in frictionless group by 2.1 mm (95% CI = -0.4 to 3.5), (P = .014), while there was no significant difference in anchorage loss at root apex between groups. Significant mesial in molar rotation of 6.672° (95% CI = 12.2-21.2), (P = 0.02) was greater in the frictionless group. Both groups showed comparable tip, torque, and root resorption values. No severe harms were reported. There was mild gingival overgrowth and inflammation in the frictionless group due to T-loop irritation. CONCLUSIONS: Extra anchorage considerations are needed during en masse retraction when frictionless mechanics is implemented as higher anchorage loss and molar rotation were detected. No difference in tip, torque, and root resorption was observed.

Influence of Invisalign precision bite ramp utilization on deep bite correction and root length in adults.

OBJECTIVES: To assess the influence of Invisalign precision bite ramp use on skeletal deep overbite correction and root length and volume of maxillary anterior teeth. MATERIALS AND METHODS: This was a retrospective study of 60 adults with skeletal deep overbite. Patients were divided into three groups: Invisalign (Align Technology, San Jose, Calif) with precision bite ramps (Invisalign with Bite Ramps [IBR] = 12), Invisalign with no bite ramps (INBR = 22), and full-fixed appliances (FFA = 26). Cone beam computed tomography records at T1 (pretreatment) and T2 (posttreatment) were used to measure eight skeletal, nine dental, and three soft-tissue cephalometric variables. Maxillary anterior teeth root length (mm), root volume (mm3), and percent root volume loss between T1 and T2 (%) were also recorded. RESULTS: Significant changes from T1 to T2 among the three groups were seen in ANB(o), lower face height (%), ODI (overbite depth indicator) (o), and U1-SN (o). Reduction in root length was significantly less (P < .001) in the INBR and IBR groups compared to the FFA group. Reduction in root volume and percent volume loss were significantly higher in the INBR group compared to the IBR group (P < .001), but the difference between the two Invisalign groups and the FFA group was not significant. CONCLUSIONS: Skeletal deep overbite correction using Invisalign with or without bite ramps is comparable to FFA. Reduction in root length was significantly less with Invisalign compared to FFA. Bite ramps influenced root volume and volume loss but not root length.

Ultrasound and x-ray imageable poloxamer-based hydrogel for loco-regional therapy delivery in the liver.

Intratumoral injections have the potential for enhanced cancer treatment efficacy while reducing costs and systemic exposure. However, intratumoral drug injections can result in substantial off-target leakage and are invisible under standard imaging modalities like ultrasound (US) and x-ray. A thermosensitive poloxamer-based gel for drug delivery was developed that is visible using x-ray imaging (computed tomography (CT), cone beam CT, fluoroscopy), as well as using US by means of integrating perfluorobutane-filled microbubbles (MBs). MBs content was optimized using tissue mimicking phantoms and ex vivo bovine livers. Gel formulations less than 1% MBs provided gel depositions that were clearly identifiable on US and distinguishable from tissue background and with minimal acoustic artifacts. The cross-sectional areas of gel depositions obtained with US and CT imaging were similar in studies using ex vivo bovine liver and postmortem in situ swine liver. The gel formulation enhanced multimodal image-guided navigation, enabling fusion of ultrasound and x-ray/CT imaging, which may enhance targeting, definition of spatial delivery, and overlap of tumor and gel. Although speculative, such a paradigm for intratumoral drug delivery might streamline clinical workflows, reduce radiation exposure by reliance on US, and boost the precision and accuracy of drug delivery targeting during procedures. Imageable gels may also provide enhanced temporal and spatial control of intratumoral conformal drug delivery.

Automated condylar seating assessment using a deep learning-based three-step approach.

OBJECTIVES: In orthognatic surgery, one of the primary determinants for reliable three-dimensional virtual surgery planning (3D VSP) and an accurate transfer of 3D VSP to the patient in the operation room is the condylar seating. Incorrectly seated condyles would primarily affect the accuracy of maxillary-first bimaxillary osteotomies as the maxillary repositioning is dependent on the positioning of the mandible in the cone-beam computed tomography (CBCT) scan. This study aimed to develop and validate a novel tool by utilizing a deep learning algorithm that automatically evaluates the condylar seating based on CBCT images as a proof of concept. MATERIALS AND METHODS: As a reference, 60 CBCT scans (120 condyles) were labeled. The automatic assessment of condylar seating included three main parts: segmentation module, ray-casting, and feed-forward neural network (FFNN). The AI-based algorithm was trained and tested using fivefold cross validation. The method's performance was evaluated by comparing the labeled ground truth with the model predictions on the validation dataset. RESULTS: The model achieved an accuracy of 0.80, positive predictive value of 0.61, negative predictive value of 0.9 and F1-score of 0.71. The sensitivity and specificity of the model was 0.86 and 0.78, respectively. The mean AUC over all folds was 0.87. CONCLUSION: The innovative integration of multi-step segmentation, ray-casting and a FFNN demonstrated to be a viable approach for automating condylar seating assessment and have obtained encouraging results. CLINICAL RELEVANCE: Automated condylar seating assessment using deep learning may improve orthognathic surgery, preventing errors and enhancing patient outcomes in maxillary-first bimaxillary osteotomies.

Evaluation of Foramen Magnum for Sex Determination among the Population of Dakshina Kannada District: A Retrospective CBCT Study.

Background: This study aims to evaluate the accuracy rate of foramen magnum dimensions in determining sex among the South Indian population using discriminant functional analysis. Methods: An observational study in which CBCT images from 200 full field of view (FOV) scans were analysed. The dimensions of the foramen magnum were measured. Intra- and interobserver reliability were calculated. Independent t-tests were used to compare the various parameters between sexes. Stepwise discriminant function analysis was used to determine sex. Results: A total of 200 CBCT scans were included in the study. The mean age (±SD) was 25.66 (±7.11) years among males and 24.64 (±5.12) years among females. The measurements and the circumference of the foramen magnum were significantly (p < 0.001) greater in males than in females. The univariate analysis of foramen magnum measurements reached an accuracy rate of 73.5% in sex determination. The discriminant function analysis combining the foramen magnum measurements and circumference yielded an overall predictability rate of 66.5% for determining sex. Conclusion: Taking into account the predictability rate of sex based on foramen measurement in the present population, it can be concluded that its applicability should be limited to cases associated with fragmentary skull bases.

Incidence of straight and angulated screw channel following immediate implant placement in esthetic zone: A simulated cone-beam computed tomography study.

STATEMENT OF PROBLEM: The demand for immediate implant placement (IIP) in the esthetic zone is rapidly increasing. Despite the treatment's benefits, the sagittal root position often dictates implant angulation, commonly necessitating the use of cement-retained restorations. This study investigates the impact of angulated screw channel on IIP in the esthetic zone. PURPOSE: The purpose of this cone-beam computed tomography (CBCT) study was to determine the probability of IIP in the esthetic zone, using four different implant angulations. MATERIALS AND METHODS: A retrospective review of CBCT images was conducted and accessed on 9 June 2021. The midsagittal images of maxillary anterior teeth were input into an implant planning software (Implant Studio®). Bone Level X Straumann® implant (BLX 3.5, 3.75, 4.0, 4.5, 5.0 mm) and Bone Level Tapered implant (BLT 2.9, 3.3 mm) were selected for 3D implant planning of IIP in the esthetic zone. The frequency distribution and probability of IIP were recorded and compared among all maxillary anterior teeth. RESULTS: CBCT images from 720 teeth (120 patient) were evaluated, revealing an overall probability of IIP in the esthetic zone is 76.11% (548/720). Different implant restoration type was evaluated in this study, with the following results; straight screw-retained prosthesis at 3.47% (19/548), cement-retained prosthesis at 14.59% (80/548) and angle screw-retained prosthesis at 85.40% (468/548). CONCLUSION: IIP with traditional straight screw-retained prosthesis demonstrated the lowest probability. Nevertheless, the use of angulated screw channels enhances the probability of achieving straight screw-retained prostheses. CLINICAL IMPLICATIONS: The angulated screw channel is essential for increasing the probability of screw-retained prosthesis in IIP in the esthetic zone. However, limitation in screw angle correction still necessitate the use of cement-retained prostheses for numbers of patients undergoing IIP.

[Study on fatigue resistance of mechanical nickel-titanium files by phase-locked infrared flaw detection method].

PURPOSE: The movement trend of the posterior teeth and the distribution of the periodontal membrane stress were studied by using three-dimensional digital technology. METHODS: CBCT data of 88 patients admitted to our hospital from June 2017 to June 2022 were selected, and input into Mimics20.0 software for preliminary extraction of all parts and stored with STL files; then the data were repaired and optimized through Geomagic Studio 2014 software. With the help of normal phase extension, the invisible appliance and periodontal membrane were constructed. Finally, the six FEM models were simulated and observed by the current teeth in different groups. Statistical analysis was performed with SPSS 21.0 software package. RESULTS: The effect force of the largest periodontal membrane was distributed in the neck of the tooth, followed by the apical area, with the maximum effect force value in the NA group. In all accessory groups, the periodontal membrane maximum paradigm isoeffect force values of all patients in the accessory vertical rectangular group were significantly smaller than the values obtained in the horizontal rectangular group. CONCLUSIONS: The design of orthodontic tooth accessories has a strong inhibition effect on the position movement of anterior teeth during recovery, which improves the accuracy of tooth three-dimensional movement to a certain extent. Meanwhile, the normal equivalent stress of the periodontal membrane of patients in the initial application of the invisible appliance without brackets is large.

[Evaluation of efficacy of denture occlusal plate combined with comprehensive physical therapy for temporomandibular joint disc displacement without reduction].

PURPOSE: To explore the efficacy of denture occlusal plate combined with comprehensive physical therapy for temporomandibular joint disc displacement without reduction(ADDwoR). METHODS: Sixty patients of ADDwoR and dentition defect or severely worn teeth who visited the Department of Orthodontics and Prosthodontics of Hengshui People's Hospital from January 2019 to December 2020 were selected and randomly divided into denture occlusal plate group (group A) and denture occlusal plate + comprehensive physical therapy group (group B) according to the treatment methods. Maximum mouth opening (MMO) and visual analog pain score(VAS) among all patients were recorded before treatment and every three weeks during three months of treatment. Cone-beam CT(CBCT) was taken before and 3 months after treatment. The changes in clinical efficacy indicators before and after treatment and CBCT data between the two groups were analyzed. Statistical analysis was performed with SPSS 26.0 software package. RESULTS: The differences of VAS of group A and B were statistically significant from before treatment to three weeks after treatment(P＜0.05), and group B decreases more. From 3 weeks after treatment, there was a significant difference of group B for MMO and VAS before treatment (P＜0.05). From 9 weeks after treatment, there was a significant difference of group A for MMO before treatment (P＜0.05), but there was no significant difference in MMO and VAS between group A and B(P＞0.05). CBCT showed narrowed anterior joint space, widened posterior joint space, enlarged superior joint space, decreased horizontal angle of the condyle and increased slope of joint nodules (P＜0.05). The difference between joint depth, anteroposterior diameter of the condyle, internal and external diameter was not significant (P＞0.05). There was significant differences in anterior, superior, and posterior joint space, condylar level angle, and slope of joint nodules of group B compared with group A(P＜0.05). CONCLUSIONS: Denture occlusal plate can effectively improve symptoms of ADDwoR, and denture occlusal plate combined with comprehensive physical therapy can quickly improve mouth opening and reduce pain in the joint area.

[Impact of GuttaFlow Bioseal sealer on the vertical fracture resistance of oval-shaped canals].

PURPOSE: To investigate the effect of GuttaFlow Bioseal root canal sealer on the vertical root fracture resistance of oval-shaped root canals. METHODS: Sixty orthodontically subtracted maxillary and mandibular single-rooted premolar teeth were scanned with CBCT. Oval canals were eligible when the buccolingual diameter of the canal was greater than or equal to two times the mesiodistal diameter at a distance of 5 mm from the root apex. Thirty single-rooted premolars with oval-shaped root canals were prepared to F2 using the Protaper system and then randomly divided into the GuttaFlow Bioseal filling group and iRoot SP filling group. Each group was further divided for root canal filling using warm vertical compression, cold lateral condensation and single cone techniques. Five single-rooted premolars was chosen as a negative control group. After 30 days of storage in a constant thermotank at 37 ℃ and 100% humidity, the filled roots were vertically placed into a cylindrical model of self-polymerizing acrylic resin. Subsequently, the samples were fixed on the lower plate of a universal testing machine, and a ball of 4 mm in diameter was applied vertically with a downward pressure at a speed of 1 mm/min until fracture occurred. The load values were recorded in Newtons. The data were analyzed using SPSS 29.0 software package. Fracture patterns were examined under microscope. RESULTS: T test results showed no significant difference between the GuttaFlow Bioseal-filled and iRoot SP-filled groups (P=0.321). One-way ANOVA showed a significant difference in vertical fracture resistance between the groups(P＜0.05), and LSD analysis showed that the GuttaFlow Bioseal-filled sample teeth were significantly more resistant to vertical fracture than the iRoot SP when using the thermal vertical compression filling method and the single-tip method(P＜0.05). In contrast, the GuttaFlow BIoseal-filled group was significantly less resistant to vertical fracture than the iRoot SP group when using the cold lateral compression filling method(P＜0.05). CONCLUISIONS: GuttaFlow Bioseal has the potential to improve root resistance to vertical fracture when filling root canals using the thermal vertical pressurization method and the single-tip method, but more clinical trials are needed to validate this result and its long-term prognosis.

[Transverse characteristics of normodivergent patients in different sagittal skeletal patterns].

PURPOSE: This study aimed to measure and analyze the transverse indicators of normodivergent patients with different sagittal skeletal malocclusions, to explore the transverse characteristics of different sagittal skeletal malocclusions. METHODS: Lateral cephalograms and CBCT of 90 normodivergent patients with skeletal Class Ⅰ, Ⅱ and Ⅲ in their permanent dentition were collected. Dolphin software was applied to measure the widths of the basal bone, alveolar bone, dental arch and buccolingual inclination angle of the corresponding teeth in the maxillary and mandibular canine, premolar and molar areas. SPSS 22.0 software package was applied for statistical analysis of the data. RESULTS: The widths of the mandibular basal bone in canine, premolar and molar areas of skeletal Class Ⅲ were (27.15±2.74), (39.30±2.82) and (59.97±2.93) mm, respectively. The widths of the mandibular alveolar bone of skeletal Class Ⅲ were (25.38±1.78), (34.51±2.28) and (47.72±2.73) mm, respectively. The dental arch widths of the maxillary premolar and mandibular canine areas of skeletal Class Ⅲ were (48.70±2.35) and (30.69±2.31)mm, respectively. The above data of skeletal Class Ⅲ were significantly larger than those of skeletal Class Ⅰ and Ⅱ(P＜0.01). The dental arch widths of the maxillary canine, maxillary molar and mandibular molar areas of skeletal Class Ⅲ were (38.88±1.90), (59.51±3.40) and (56.01±2.86)mm, respectively, which were significantly larger than those of skeletal Class Ⅱ(P＜0.05). The maxillomandibular width difference of basal bone in the canine, premolar and molar areas of skeletal Class Ⅲ were (4.69±2.84), (2.31±2.39) and (3.27±2.05) mm, respectively, which were significantly less than that of skeletal Class Ⅰ and Ⅱ(P＜0.01). Compared with skeletal Class Ⅰ, the maxillary canines and first molars of skeletal Class Ⅱ had larger lingual inclination level, while the maxillary first premolars and first molars of skeletal Class Ⅲ had larger buccal inclination level, the mandibular canines and the mandibular first premolars of skeletal Class Ⅲ had larger lingual inclination level(P＜0.01). CONCLUSIONS: For normodivergent patients, the width of the mandibular base bone, alveolar bone, and maxillary and mandibular dental arch in skeletal Class Ⅲ is the widest, which is more likely to have width discrepancy in basal bone. In skeletal Class Ⅲ, the maxillary teeth are buccally inclined, and the mandibular teeth are ingually inclined. In skeletal Class Ⅱ, the maxillary teeth are lingually inclined, and the mandibular teeth are compensatory upright.

[A correlation study between the occlusal cant and temporomandibular joint space in patients with mandibular lateral deviation].

PURPOSE: To investigate the correlation between the occlusal canting and the bilateral temporomandibular joint (TMJ) space in adult and juvenile mandibular deviation patients and study the mutual influence between the occlusal canting and mandibular position, in order to provide references for clinical treatment. METHODS: CBCT data of mandibular deviation patients（20 adults，20 juveniles）were selected. Inivo5 Dental Anatomage software was used to reconstruct the structures. The occlusal cant and vertical height of the bilateral maxillary from canines to first molars were measured, and the vertical heights difference between the same teeth on both sides was calculated. The anterior, superior and posterior space of temporomandibular joint were measured respectively in both groups. Pearson correlation analysis between the occlusal canting and bilateral condylar space was carried out by using SPSS 17.0 software package. RESULTS: In the juvenile group, negative correlations were found between the occlusal cant and the superior TMJ space on the deviated side (P＜0.05). Negative correlation was found between the vertical height difference of bilateral canines and the anterior TMJ space on the deviated side in the juvenile group(P＜0.05). In the adult group, no significant correlation was observed among those correlated examination (P＞0.05). CONCLUSONS: The occlusal canting is moderately correlated with mandibular position in the early stage of mandibular deviation patients. Early treatment of mandibular deviation is of great importance in preventing its progression into severe skeletal malocclusion, and more attention should be paid on the correction of the canted frontal occlusion plane.

Enhancing procedural decision making with cone beam CT in renal artery embolization.

Cone-beam computed tomography (CBCT) has proven to be a safe and effective adjunctive imaging tool for interventional radiology. Nevertheless, limited studies have examined the application of CBCT in renal artery embolization (RAE). The objective of this study is to evaluate the role of CBCT in intra-procedural decision-making for RAE. This multicenter retrospective study included 40 consecutive patients (age: 55.9 ± 16.5 years; male, 55%) who underwent CBCT during RAE from January 2019 to January 2023. The additional information provided by CBCT was classified into Category 1 (no additional information), Category 2 (more information without changing the treatment plan), and Category 3 (valuable information that led to a change in the treatment plan). CBCT did not add unique information for four patients (10%) classified as Category 1. CBCT clarified ambiguous angiographic findings and confirmed the existing treatment plan for 19 patients (47.5%) graded as Category 2; complex vascular anatomy was explained (n = 13), and a correlation between vascular territory and target lesion was established (n = 6). CBCT offered valuable information that was not visible on digital subtraction angiography and changed the treatment plan for 17 patients categorized as Category 3; a mismatch between the vascular territory and the target lesion led to the identification of alternative (n = 3) and additional feeders (n = 8); and the extent of embolization was reduced by using automatic feeder detection software (n = 6). CBCT is an efficient tool that aids in the decision-making process during the embolization procedure by providing supplementary imaging information. This additional information enables the confident identification of target vessels, facilitates superselective embolization, prevents non-target embolization, and helps locate missing feeders.